86c00b2c36
5243 Commits
Author | SHA1 | Message | Date | |
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40c93d7fff |
Two X86 fixes:
- Move the command line preparation and the early command line parsing earlier so that the command line parameters which affect early_reserve_memory(), e.g. efi=nosftreserve, are taken into account. This was broken when the invocation of early_reserve_memory() was moved recently. - Use an atomic type for the SGX page accounting, which is read and written lockless, to plug various race conditions related to it. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmGaYPoTHHRnbHhAbGlu dXRyb25peC5kZQAKCRCmGPVMDXSYoTM7D/9bivpPDiNzfjUV7kNKx6aTUwPjdFer G0RuuDZqkpJm9j7+51VnQNFssIfAFtzKMJn/DuGVoXF0ERxXMEhJVHiSTeOlCjJU u1760qFYlAQ1mwvKVNLk2SenWuNZwwgUneY3VvvS4qYsSq7PsbYlekuddPeX0Nws AJ1llOoCoBkm5vNZ5c3/CmhY6iPSRQQkDmbA11cZZUyWl2uouSk21+ax24IDCvW3 E8Aq9QqB6ND2uukB32kQ7Wp7/UZ4inJHTUXF9UF/8P+N1ftDWeKDjQz6y9U19Tsd ivuMr6NqqAos/Fpo9PhlGns07C8HeKGf4ronnt9cUMqjzYWfdS+pRT+0pQR+vIPa M8+jyHQplzeOX9/nKOkpV+u0tYP2zgx8e7yeu5Sion8TqsKqiNOy9+D0D2utUDmw 1x3DzuzGx/mK2OX5gjGSx4ZbS4u0DIAWnF8vB9YfgEfcnqpxr6KdbrY0bLatIbKv ip9mh0rRYeTkTZ4FGmvy3hFgAmadCODWxva/7AhzbWVZoM+AShwnTDsipkRaaj3V nMdgcVix8qVDg9YIAn9ziZbxkXKQUXFJn7lZj3KBeWjKcV2svA89S/9YL6JTaSeW TJ4X6wK8EoApKhEasZhufXBNAl9EmQlBS1k9pHiIjKVuRgBGlzMuEhzvrqZM2+rA KaUQSwBN6Ij6Dg== =CJUK -----END PGP SIGNATURE----- Merge tag 'x86-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: - Move the command line preparation and the early command line parsing earlier so that the command line parameters which affect early_reserve_memory(), e.g. efi=nosftreserve, are taken into account. This was broken when the invocation of early_reserve_memory() was moved recently. - Use an atomic type for the SGX page accounting, which is read and written locklessly, to plug various race conditions related to it. * tag 'x86-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sgx: Fix free page accounting x86/boot: Pull up cmdline preparation and early param parsing |
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ac5d272a0a |
x86/sgx: Fix free page accounting
The SGX driver maintains a single global free page counter,
sgx_nr_free_pages, that reflects the number of free pages available
across all NUMA nodes. Correspondingly, a list of free pages is
associated with each NUMA node and sgx_nr_free_pages is updated
every time a page is added or removed from any of the free page
lists. The main usage of sgx_nr_free_pages is by the reclaimer
that runs when it (sgx_nr_free_pages) goes below a watermark
to ensure that there are always some free pages available to, for
example, support efficient page faults.
With sgx_nr_free_pages accessed and modified from a few places
it is essential to ensure that these accesses are done safely but
this is not the case. sgx_nr_free_pages is read without any
protection and updated with inconsistent protection by any one
of the spin locks associated with the individual NUMA nodes.
For example:
CPU_A CPU_B
----- -----
spin_lock(&nodeA->lock); spin_lock(&nodeB->lock);
... ...
sgx_nr_free_pages--; /* NOT SAFE */ sgx_nr_free_pages--;
spin_unlock(&nodeA->lock); spin_unlock(&nodeB->lock);
Since sgx_nr_free_pages may be protected by different spin locks
while being modified from different CPUs, the following scenario
is possible:
CPU_A CPU_B
----- -----
{sgx_nr_free_pages = 100}
spin_lock(&nodeA->lock); spin_lock(&nodeB->lock);
sgx_nr_free_pages--; sgx_nr_free_pages--;
/* LOAD sgx_nr_free_pages = 100 */ /* LOAD sgx_nr_free_pages = 100 */
/* sgx_nr_free_pages-- */ /* sgx_nr_free_pages-- */
/* STORE sgx_nr_free_pages = 99 */ /* STORE sgx_nr_free_pages = 99 */
spin_unlock(&nodeA->lock); spin_unlock(&nodeB->lock);
In the above scenario, sgx_nr_free_pages is decremented from two CPUs
but instead of sgx_nr_free_pages ending with a value that is two less
than it started with, it was only decremented by one while the number
of free pages were actually reduced by two. The consequence of
sgx_nr_free_pages not being protected is that its value may not
accurately reflect the actual number of free pages on the system,
impacting the availability of free pages in support of many flows.
The problematic scenario is when the reclaimer does not run because it
believes there to be sufficient free pages while any attempt to allocate
a page fails because there are no free pages available. In the SGX driver
the reclaimer's watermark is only 32 pages so after encountering the
above example scenario 32 times a user space hang is possible when there
are no more free pages because of repeated page faults caused by no
free pages made available.
The following flow was encountered:
asm_exc_page_fault
...
sgx_vma_fault()
sgx_encl_load_page()
sgx_encl_eldu() // Encrypted page needs to be loaded from backing
// storage into newly allocated SGX memory page
sgx_alloc_epc_page() // Allocate a page of SGX memory
__sgx_alloc_epc_page() // Fails, no free SGX memory
...
if (sgx_should_reclaim(SGX_NR_LOW_PAGES)) // Wake reclaimer
wake_up(&ksgxd_waitq);
return -EBUSY; // Return -EBUSY giving reclaimer time to run
return -EBUSY;
return -EBUSY;
return VM_FAULT_NOPAGE;
The reclaimer is triggered in above flow with the following code:
static bool sgx_should_reclaim(unsigned long watermark)
{
return sgx_nr_free_pages < watermark &&
!list_empty(&sgx_active_page_list);
}
In the problematic scenario there were no free pages available yet the
value of sgx_nr_free_pages was above the watermark. The allocation of
SGX memory thus always failed because of a lack of free pages while no
free pages were made available because the reclaimer is never started
because of sgx_nr_free_pages' incorrect value. The consequence was that
user space kept encountering VM_FAULT_NOPAGE that caused the same
address to be accessed repeatedly with the same result.
Change the global free page counter to an atomic type that
ensures simultaneous updates are done safely. While doing so, move
the updating of the variable outside of the spin lock critical
section to which it does not belong.
Cc: stable@vger.kernel.org
Fixes:
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f3e613e72f |
x86/hyperv: Move required MSRs check to initial platform probing
Explicitly check for MSR_HYPERCALL and MSR_VP_INDEX support when probing for running as a Hyper-V guest instead of waiting until hyperv_init() to detect the bogus configuration. Add messages to give the admin a heads up that they are likely running on a broken virtual machine setup. At best, silently disabling Hyper-V is confusing and difficult to debug, e.g. the kernel _says_ it's using all these fancy Hyper-V features, but always falls back to the native versions. At worst, the half baked setup will crash/hang the kernel. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20211104182239.1302956-3-seanjc@google.com Signed-off-by: Wei Liu <wei.liu@kernel.org> |
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1654e95ee3 |
- Add the model number of a new, Raptor Lake CPU, to intel-family.h
- Do not log spurious corrected MCEs on SKL too, due to an erratum - Clarify the path of paravirt ops patches upstream - Add an optimization to avoid writing out AMX components to sigframes when former are in init state -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmGQ3CgACgkQEsHwGGHe VUoLAA/+NXRvcBHYkLaByT9f4OI6B79HzyguIBSfipYiw8ir0H7uEdV5FUCCUgCz egBRVFpOsXWt1teeuu6ViO+WBHncUxG/ryZ0ka35lri/3kuVYnugZExWDs4MrGR5 vehRXehOxYNRaYc3oLYjubSbxqF1nWz3WWfGfhiBKk0jT/S1T9tX6lsRXlKsJCgj M4x5aqBWP8HTbFQfqjdHwagNitmSKzgjZvMcC4UWcql33ZCycbjvRdrAzBtw7WRI UBvgxWVmeMoagu5fqEOoph1oSoFxWuFrweFUjnxJmT6uZrTsfF7BVgXkxdG6eYUy 2Xogcd4bPDBiRgbs0vPEog1tyyrKHOQ6p1pvksySKMPq6ULcSZ6hBpEZRpgr6Y9u 0jB3P6weQgCckx5Hd+iwvX1a+GvEuHSEqAE+j160wFyrsBS5Cir3P1WqthWaPd5I 3nH3h955PokUHPUioUhdf+8cfuP6h6K0nz1gdYI8GR8+fJHhEceT+pLLeyIxj/VM yr+bq+V7D6Cg62w3z3s9Dzg2XKpxStu1R9L1N/K8MtIGf6Uc7paL6xR27XxhmBp5 Y6bGZw0mxxFhp6AEsFWo3rwLL9Dl5DmFcfgUHHpPK5VP0pVWp48Uapx2Hi2/JzAo c1o4UkPQa/EZJBPTklmGkS1JNp/2TsEL4Fw7sew+j7DWtsJpCfk= =Ge2T -----END PGP SIGNATURE----- Merge tag 'x86_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Borislav Petkov: - Add the model number of a new, Raptor Lake CPU, to intel-family.h - Do not log spurious corrected MCEs on SKL too, due to an erratum - Clarify the path of paravirt ops patches upstream - Add an optimization to avoid writing out AMX components to sigframes when former are in init state * tag 'x86_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Add Raptor Lake to Intel family x86/mce: Add errata workaround for Skylake SKX37 MAINTAINERS: Add some information to PARAVIRT_OPS entry x86/fpu: Optimize out sigframe xfeatures when in init state |
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e629fc1407 |
x86/mce: Add errata workaround for Skylake SKX37
Errata SKX37 is word-for-word identical to the other errata listed in
this workaround. I happened to notice this after investigating a CMCI
storm on a Skylake host. While I can't confirm this was the root cause,
spurious corrected errors does sound like a likely suspect.
Fixes:
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95faf6ba65 |
Driver core changes for 5.16-rc1
Here is the big set of driver core changes for 5.16-rc1. All of these have been in linux-next for a while now with no reported problems. Included in here are: - big update and cleanup of the sysfs abi documentation files and scripts from Mauro. We are almost at the place where we can properly check that the running kernel's sysfs abi is documented fully. - firmware loader updates - dyndbg updates - kernfs cleanups and fixes from Christoph - device property updates - component fix - other minor driver core cleanups and fixes Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -----BEGIN PGP SIGNATURE----- iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCYYPbjQ8cZ3JlZ0Brcm9h aC5jb20ACgkQMUfUDdst+ync9gCfXKMUI1GAnCfJWAwTdTcd18q5akoAoMw32/AH 0yh5TjAWFyFd7xz5d7qs =itsC -----END PGP SIGNATURE----- Merge tag 'driver-core-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the big set of driver core changes for 5.16-rc1. All of these have been in linux-next for a while now with no reported problems. Included in here are: - big update and cleanup of the sysfs abi documentation files and scripts from Mauro. We are almost at the place where we can properly check that the running kernel's sysfs abi is documented fully. - firmware loader updates - dyndbg updates - kernfs cleanups and fixes from Christoph - device property updates - component fix - other minor driver core cleanups and fixes" * tag 'driver-core-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (122 commits) device property: Drop redundant NULL checks x86/build: Tuck away built-in firmware under FW_LOADER vmlinux.lds.h: wrap built-in firmware support under FW_LOADER firmware_loader: move struct builtin_fw to the only place used x86/microcode: Use the firmware_loader built-in API firmware_loader: remove old DECLARE_BUILTIN_FIRMWARE() firmware_loader: formalize built-in firmware API component: do not leave master devres group open after bind dyndbg: refine verbosity 1-4 summary-detail gpiolib: acpi: Replace custom code with device_match_acpi_handle() i2c: acpi: Replace custom function with device_match_acpi_handle() driver core: Provide device_match_acpi_handle() helper dyndbg: fix spurious vNpr_info change dyndbg: no vpr-info on empty queries dyndbg: vpr-info on remove-module complete, not starting device property: Add missed header in fwnode.h Documentation: dyndbg: Improve cli param examples dyndbg: Remove support for ddebug_query param dyndbg: make dyndbg a known cli param dyndbg: show module in vpr-info in dd-exec-queries ... |
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30d02551ba |
x86/fpu: Optimize out sigframe xfeatures when in init state
tl;dr: AMX state is ~8k. Signal frames can have space for this
~8k and each signal entry writes out all 8k even if it is zeros.
Skip writing zeros for AMX to speed up signal delivery by about
4% overall when AMX is in its init state.
This is a user-visible change to the sigframe ABI.
== Hardware XSAVE Background ==
XSAVE state components may be tracked by the processor as being
in their initial configuration. Software can detect which
features are in this configuration by looking at the XSTATE_BV
field in an XSAVE buffer or with the XGETBV(1) instruction.
Both the XSAVE and XSAVEOPT instructions enumerate features s
being in the initial configuration via the XSTATE_BV field in the
XSAVE header, However, XSAVEOPT declines to actually write
features in their initial configuration to the buffer. XSAVE
writes the feature unconditionally, regardless of whether it is
in the initial configuration or not.
Basically, XSAVE users never need to inspect XSTATE_BV to
determine if the feature has been written to the buffer.
XSAVEOPT users *do* need to inspect XSTATE_BV. They might also
need to clear out the buffer if they want to make an isolated
change to the state, like modifying one register.
== Software Signal / XSAVE Background ==
Signal frames have historically been written with XSAVE itself.
Each state is written in its entirety, regardless of being in its
initial configuration.
In other words, the signal frame ABI uses the XSAVE behavior, not
the XSAVEOPT behavior.
== Problem ==
This means that any application which has acquired permission to
use AMX via ARCH_REQ_XCOMP_PERM will write 8k of state to the
signal frame. This 8k write will occur even when AMX was in its
initial configuration and software *knows* this because of
XSTATE_BV.
This problem also exists to a lesser degree with AVX-512 and its
2k of state. However, AVX-512 use does not require
ARCH_REQ_XCOMP_PERM and is more likely to have existing users
which would be impacted by any change in behavior.
== Solution ==
Stop writing out AMX xfeatures which are in their initial state
to the signal frame. This effectively makes the signal frame
XSAVE buffer look as if it were written with a combination of
XSAVEOPT and XSAVE behavior. Userspace which handles XSAVEOPT-
style buffers should be able to handle this naturally.
For now, include only the AMX xfeatures: XTILE and XTILEDATA in
this new behavior. These require new ABI to use anyway, which
makes their users very unlikely to be broken. This XSAVEOPT-like
behavior should be expected for all future dynamic xfeatures. It
may also be extended to legacy features like AVX-512 in the
future.
Only attempt this optimization on systems with dynamic features.
Disable dynamic feature support (XFD) if XGETBV1 is unavailable
by adding a CPUID dependency.
This has been measured to reduce the *overall* cycle cost of
signal delivery by about 4%.
Fixes:
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56d3375448 |
drm for 5.16-rc1
core: - improve dma_fence, lease and resv documentation - shmem-helpers: allocate WC pages on x86, use vmf_insert_pin - sched fixes/improvements - allow empty drm leases - add dma resv iterator - add more DP 2.0 headers - DP MST helper improvements for DP2.0 dma-buf: - avoid warnings, remove fence trace macros bridge: - new helper to get rid of panels - probe improvements for it66121 - enable DSI EOTP for anx7625 fbdev: - efifb: release runtime PM on destroy ttm: - kerneldoc switch - helper to clear all DMA mappings - pool shrinker optimizaton - remove ttm_tt_destroy_common - update ttm_move_memcpy for async use panel: - add new panel-edp driver amdgpu: - Initial DP 2.0 support - Initial USB4 DP tunnelling support - Aldebaran MCE support - Modifier support for DCC image stores for GFX 10.3 - Display rework for better FP code handling - Yellow Carp/Cyan Skillfish updates - Cyan Skillfish display support - convert vega/navi to IP discovery asic enumeration - validate IP discovery table - RAS improvements - Lots of fixes i915: - DG1 PCI IDs + LMEM discovery/placement - DG1 GuC submission by default - ADL-S PCI IDs updated + enabled by default - ADL-P (XE_LPD) fixed and updates - DG2 display fixes - PXP protected object support for Gen12 integrated - expose multi-LRC submission interface for GuC - export logical engine instance to user - Disable engine bonding on Gen12+ - PSR cleanup - PSR2 selective fetch by default - DP 2.0 prep work - VESA vendor block + MSO use of it - FBC refactor - try again to fix fast-narrow vs slow-wide eDP training - use THP when IOMMU enabled - LMEM backup/restore for suspend/resume - locking simplification - GuC major reworking - async flip VT-D workaround changes - DP link training improvements - misc display refactorings bochs: - new PCI ID rcar-du: - Non-contiguious buffer import support for rcar-du - r8a779a0 support prep omapdrm: - COMPILE_TEST fixes sti: - COMPILE_TEST fixes msm: - fence ordering improvements - eDP support in DP sub-driver - dpu irq handling cleanup - CRC support for making igt happy - NO_CONNECTOR bridge support - dsi: 14nm phy support for msm8953 - mdp5: msm8x53, sdm450, sdm632 support stm: - layer alpha + zpo support v3d: - fix Vulkan CTS failure - support multiple sync objects gud: - add R8/RGB332/RGB888 pixel formats vc4: - convert to new bridge helpers vgem: - use shmem helpers virtio: - support mapping exported vram zte: - remove obsolete driver rockchip: - use bridge attach no connector for LVDS/RGB -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEEKbZHaGwW9KfbeusDHTzWXnEhr4FAmGByPYACgkQDHTzWXnE hr6fxA//cXUvTHlEtF7UJDBRAYv+9lXH39NbGYU4aLJuBNlZztCuUi5JOSyDFDH1 N9VI5biVseev2PEnCzJUubWxTqbUO7FBQTw0TyvZ4Eqn+UZMuFeo0dvdKZRAkvjV VHSUc0fm0+WSYanKUK7XK0fwG8aE6JVyYngzgKPSjifhszTdiiRsbU21iTinFhkS rgh3HEVELp+LqfoG4qzAYqFUjYqUjvCjd/hX/UkzCII8ZXKr38/4127e95443WOk +jes0gWGJe9TvSDrqo9TMx4qukcOniINFUvnzoD2RhOS+Jzr/i5rBh51Xy92g3NO Q7hy6byZdk/ZO/MXCDQ2giUOkBiqn5fQjlRGQp4iAZYw9pb3HU+/xrTq0BWVWd8o /vmzZYEKKU/sCGpxVDMZxsHV3mXIuVBvuZq6bjmSGcybgOBCiDx5F/Rum4nY2yHp lr3cuc0HP3m3f4b/HVvACO4tGd1nDDpVcon7CuhBB7HB7t6Zl9u18qc/qFw0tCTh 3sgAhno6XFXtPFcSX2KAeeg0mhKDKKrsOnq5y3bDRr05Z0jLocJk95aXEKs6em4j gbyHwNaX3CHtiCnFn2/5169+n1K7zqHBtVSGmQlmFDv55rcdx7L3Spk7tCahQeSQ ur24r+sEggm8d5Wjl+MYq6wW3oP31s04JFaeV6oCkaSp1wS+alg= =jdhH -----END PGP SIGNATURE----- Merge tag 'drm-next-2021-11-03' of git://anongit.freedesktop.org/drm/drm Pull drm updates from Dave Airlie: "Summary below. i915 starts to add support for DG2 GPUs, enables DG1 and ADL-S support by default, lots of work to enable DisplayPort 2.0 across drivers. Lots of documentation updates and fixes across the board. core: - improve dma_fence, lease and resv documentation - shmem-helpers: allocate WC pages on x86, use vmf_insert_pin - sched fixes/improvements - allow empty drm leases - add dma resv iterator - add more DP 2.0 headers - DP MST helper improvements for DP2.0 dma-buf: - avoid warnings, remove fence trace macros bridge: - new helper to get rid of panels - probe improvements for it66121 - enable DSI EOTP for anx7625 fbdev: - efifb: release runtime PM on destroy ttm: - kerneldoc switch - helper to clear all DMA mappings - pool shrinker optimizaton - remove ttm_tt_destroy_common - update ttm_move_memcpy for async use panel: - add new panel-edp driver amdgpu: - Initial DP 2.0 support - Initial USB4 DP tunnelling support - Aldebaran MCE support - Modifier support for DCC image stores for GFX 10.3 - Display rework for better FP code handling - Yellow Carp/Cyan Skillfish updates - Cyan Skillfish display support - convert vega/navi to IP discovery asic enumeration - validate IP discovery table - RAS improvements - Lots of fixes i915: - DG1 PCI IDs + LMEM discovery/placement - DG1 GuC submission by default - ADL-S PCI IDs updated + enabled by default - ADL-P (XE_LPD) fixed and updates - DG2 display fixes - PXP protected object support for Gen12 integrated - expose multi-LRC submission interface for GuC - export logical engine instance to user - Disable engine bonding on Gen12+ - PSR cleanup - PSR2 selective fetch by default - DP 2.0 prep work - VESA vendor block + MSO use of it - FBC refactor - try again to fix fast-narrow vs slow-wide eDP training - use THP when IOMMU enabled - LMEM backup/restore for suspend/resume - locking simplification - GuC major reworking - async flip VT-D workaround changes - DP link training improvements - misc display refactorings bochs: - new PCI ID rcar-du: - Non-contiguious buffer import support for rcar-du - r8a779a0 support prep omapdrm: - COMPILE_TEST fixes sti: - COMPILE_TEST fixes msm: - fence ordering improvements - eDP support in DP sub-driver - dpu irq handling cleanup - CRC support for making igt happy - NO_CONNECTOR bridge support - dsi: 14nm phy support for msm8953 - mdp5: msm8x53, sdm450, sdm632 support stm: - layer alpha + zpo support v3d: - fix Vulkan CTS failure - support multiple sync objects gud: - add R8/RGB332/RGB888 pixel formats vc4: - convert to new bridge helpers vgem: - use shmem helpers virtio: - support mapping exported vram zte: - remove obsolete driver rockchip: - use bridge attach no connector for LVDS/RGB" * tag 'drm-next-2021-11-03' of git://anongit.freedesktop.org/drm/drm: (1259 commits) drm/amdgpu/gmc6: fix DMA mask from 44 to 40 bits drm/amd/display: MST support for DPIA drm/amdgpu: Fix even more out of bound writes from debugfs drm/amdgpu/discovery: add SDMA IP instance info for soc15 parts drm/amdgpu/discovery: add UVD/VCN IP instance info for soc15 parts drm/amdgpu/UAPI: rearrange header to better align related items drm/amd/display: Enable dpia in dmub only for DCN31 B0 drm/amd/display: Fix USB4 hot plug crash issue drm/amd/display: Fix deadlock when falling back to v2 from v3 drm/amd/display: Fallback to clocks which meet requested voltage on DCN31 drm/amd/display: move FPU associated DCN301 code to DML folder drm/amd/display: fix link training regression for 1 or 2 lane drm/amd/display: add two lane settings training options drm/amd/display: decouple hw_lane_settings from dpcd_lane_settings drm/amd/display: implement decide lane settings drm/amd/display: adopt DP2.0 LT SCR revision 8 drm/amd/display: FEC configuration for dpia links in MST mode drm/amd/display: FEC configuration for dpia links drm/amd/display: Add workaround flag for EDID read on certain docks drm/amd/display: Set phy_mux_sel bit in dmub scratch register ... |
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44261f8e28 |
hyperv-next for 5.16
-----BEGIN PGP SIGNATURE----- iQFHBAABCAAxFiEEIbPD0id6easf0xsudhRwX5BBoF4FAmGBMQUTHHdlaS5saXVA a2VybmVsLm9yZwAKCRB2FHBfkEGgXmE5B/9MK3Ju+tc6C8eyR3Ic4XBYHJ3voEKO M+R90gggBriDOgkz4B8vF+k0aD8wevXAUtmCSXonDzCh5H7GoyfrVZmJEVkwlioH ZMSMlFHcjGhCPIXhLbNtfo/NsAYEtT/lRM2lLGCSbdGuKabylXKujVdhuSIcRPdj Rj5innUgcAywOoxG6WzFt3JBzM33UQErCGfUF2b7Rvp9E+Zii4vIMxkMzUpnkEHH F8WMEdL0DqH5ThOs0MslNgy03pUC9wk1d5DNd9ytYHqiSQtcQZhFHw/P6dxzUFlW OptWv31PXUIsiJf4Zi9hmfjgUl+KZHeacZ2hXtidAo86VPcIjVs25OQW =40fn -----END PGP SIGNATURE----- Merge tag 'hyperv-next-signed-20211102' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - Initial patch set for Hyper-V isolation VM support (Tianyu Lan) - Fix a warning on preemption (Vitaly Kuznetsov) - A bunch of misc cleanup patches * tag 'hyperv-next-signed-20211102' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Protect set_hv_tscchange_cb() against getting preempted Drivers: hv : vmbus: Adding NULL pointer check x86/hyperv: Remove duplicate include x86/hyperv: Remove duplicated include in hv_init Drivers: hv: vmbus: Remove unused code to check for subchannels Drivers: hv: vmbus: Initialize VMbus ring buffer for Isolation VM Drivers: hv: vmbus: Add SNP support for VMbus channel initiate message x86/hyperv: Add ghcb hvcall support for SNP VM x86/hyperv: Add Write/Read MSR registers via ghcb page Drivers: hv: vmbus: Mark vmbus ring buffer visible to host in Isolation VM x86/hyperv: Add new hvcall guest address host visibility support x86/hyperv: Initialize shared memory boundary in the Isolation VM. x86/hyperv: Initialize GHCB page in Isolation VM |
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a5a9e00605 |
seccomp updates for v5.16-rc1
- set spec_store_bypass_disable & spectre_v2_user to prctl (Andrea Arcangeli) -----BEGIN PGP SIGNATURE----- iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmGAGAkWHGtlZXNjb29r QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJqOWD/4mMFp84IMa/VdCmD6PS+BhisyI i7+Hyfisg8AWpjgW4+JihU/6hfsDgs/hNNKbiIopcwc/12KV4M0QIQyF7vmceSwB uMsAX7pkobNUUisnrQVbw6boK4hrBvrV3STlVdRHvNlLeQLQIu4UN3+9UMj/qsmh 46ltdxR489oDDLXFgMkKq9auVP2t5t4fbyRmgBPLSKIXaOxIhWck3kUQwt/Rbr44 M87/Xr4iQ0w4ddiBFJz9GOHQ5Iz08ms4dBfO+e5FSl6I69Nt6q836el35c/6j4y8 r7C21WU088MSkjk75RCa3v2sq8db2CjLe+wBugq+yYC29qGgxtTiUZaoiNQCN5bL DIRfl1iU5Ge1wEKorpr3DR6DksmfJO4MNPdMo4CcVZT3Gkdi7udLHfrEI82xgdDl lh1UiJlRx4YNEcDbGBnxCzKGwauqHa2TgPNWulUPdH7OGhUL86FAV49L84uz9lCD C/+PKxDqc2XKjbgqMsbuyQ7hzB2KQK/ieEXzduoHxTxIr5vO/viENrbkUiSL8bsO 6msCVbCIjtFDvW4Ac16IOwGoflJ7vLAIuXIdAYCeN+JXqOVV+FG/MN447Y674FeH R84G6JCT82ULEXrKlwuoSSVJEwA5lzP4IwoWm/ujeUbzi1s+7m+7WRpuJe2jZm6c zPsCVkNPUrvp82L/wA== =NAsc -----END PGP SIGNATURE----- Merge tag 'seccomp-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull seccomp updates from Kees Cook: "These are x86-specific, but I carried these since they're also seccomp-specific. This flips the defaults for spec_store_bypass_disable and spectre_v2_user from "seccomp" to "prctl", as enough time has passed to allow system owners to have updated the defensive stances of their various workloads, and it's long overdue to unpessimize seccomp threads. Extensive rationale and details are in Andrea's main patch. Summary: - set spec_store_bypass_disable & spectre_v2_user to prctl (Andrea Arcangeli)" * tag 'seccomp-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: x86: deduplicate the spectre_v2_user documentation x86: change default to spec_store_bypass_disable=prctl spectre_v2_user=prctl |
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879dbe9ffe |
Add a SGX_IOC_VEPC_REMOVE ioctl to the /dev/sgx_vepc virt interface with
which EPC pages can be put back into their uninitialized state without having to reopen /dev/sgx_vepc, which could not be possible anymore after startup due to security policies. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmF/x7AACgkQEsHwGGHe VUqHXA//YWrukmJ5PQZwWqkXGo6h42JWhIdNfSC2c1SVdz1cioGUCCswALTX4g8l MYYf3eN12GJ296jPh7m9bz8JvlYjdavSm3Y1yzHIjuQ3q6qywHIuYTbsrMD7waUD PkcY1TTYgNJ2+f0AgsC4GZhlcpf9g5DqiftW6wvExx5tLUNsVu3Y3gZy/+fajP4f s/TMjcdr2QmPsjun00KfoIY4/z0u8LkyRMSwyoxSV6wYdL6rRtfYFWsbEUS+W6Nw /VJ0IKl+aBQ1ztsDc4M5h1uy9II2M/Row5k6JjyrdG4X8D6ACSG7cho6qcMjXgcP Gac7Im5IyjPEorxqXAgJiMoAl9lU9a2JMVZqPtihYsQW/ygMTdpzP9sBpcZPMevc gxQD4gyixwzUa3cyVDzTPBdk/DEuGc2nwn2k9nPvmNxKMonX1oLEiP7hu265mvet 56DtwKJF9ddtpepO2zFCg1qX+eZnTuhuZNCPsm/pmdGgzI8cyLznho33OgUSZEQY c1UisT7HXNRVC/1Q8VBDTU/D9LtIk+2+Q5lQkcNeftI5PYKTXIVddkOkqJ4GhGWJ 9EasA4UtnhvsLzJ76gxxuUf677ns+1TCo65e7Hu1+X0eTmBJK3boe3aMHvJeHEWH Asd+SMkYWfxAlW/arAYhR2JgT9wgEH3pSx4eXnpGwpeValxBPRs= =1UYy -----END PGP SIGNATURE----- Merge tag 'x86_sgx_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 SGX updates from Borislav Petkov: "Add a SGX_IOC_VEPC_REMOVE ioctl to the /dev/sgx_vepc virt interface with which EPC pages can be put back into their uninitialized state without having to reopen /dev/sgx_vepc, which could not be possible anymore after startup due to security policies" * tag 'x86_sgx_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sgx/virt: implement SGX_IOC_VEPC_REMOVE ioctl x86/sgx/virt: extract sgx_vepc_remove_page |
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e0f4c59dc4 |
- Start checking a CPUID bit on AMD Zen3 which states that the CPU
clears the segment base when a null selector is written. Do the explicit detection on older CPUs, zen2 and hygon specifically, which have the functionality but do not advertize the CPUID bit. Factor in the presence of a hypervisor underneath the kernel and avoid doing the explicit check there which the HV might've decided to not advertize for migration safety reasons, a.o. - Add support for a new X86 CPU vendor: VORTEX. Needed for whitelisting those CPUs in the hardware vulnerabilities detection - Force the compiler to use rIP-relative addressing in the fallback path of static_cpu_has(), in order to avoid unnecessary register pressure -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmF/wRgACgkQEsHwGGHe VUoGQBAAk9V9//FMoENuGFGul/IK8+VBibTfztYgaPvm7vjMDYaYuRBCQiZg5Y8U D14pwkg7CuRa6iwZmrk/X/y6FVjo5BJA//ROk/n/9JNvV5QUp3/o00uLiziv80K3 H6Wm3PUyGgkpBuJg+/K8SLE9UQ6uSh4nsykS+70Dcd45DtkC/vH8pkDs5Q1fVQwb 7AuOuWTCWKUYOMFYWFI3a9D8tZYhg99ABREbXBaJGiGdIlZKNVe/7W8qQw5s6cVA cD5Q2ILY2RCGP55ZQiWoFy3XNP3/ygvZ7Zm1ARYUvUMR2Y5X2XJWN/B6oMbc0oEu OZsDDA/ILYcah9eBV/zk4ON/1djksp1iWNXNxjct0cNBPAKxi6T/HhHuIHBtzvW+ zDyBWUMLlv1m2i1oW4J4NuNJJi9Gaz+7PesmI7C0OQPgywR8UqqfMD+TzlEHWya1 YqYqI0f3aiyC/sLjUp3GSA7a9sWSd3BZfyAlLBJZCxyXAxX92tXX5BRPh/KYbnJn c/NaYA6X4m4Rdvr0gKKtCklaC6w4GLzVak6wIvftzHlUYsWX21BhnTkQrciKbqc+ AKWed41AO+4pDHROePxc409x3UZolti+1RandikrztIVAolVJ6W/OkHWxXfy28Fg iSrtl4M3omv8fCHDaJ26STrXqxH8pIK8noVolwQoXKyAFVyvXTk= =rlVy -----END PGP SIGNATURE----- Merge tag 'x86_cpu_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cpu updates from Borislav Petkov: - Start checking a CPUID bit on AMD Zen3 which states that the CPU clears the segment base when a null selector is written. Do the explicit detection on older CPUs, zen2 and hygon specifically, which have the functionality but do not advertize the CPUID bit. Factor in the presence of a hypervisor underneath the kernel and avoid doing the explicit check there which the HV might've decided to not advertize for migration safety reasons, or similar. - Add support for a new X86 CPU vendor: VORTEX. Needed for whitelisting those CPUs in the hardware vulnerabilities detection - Force the compiler to use rIP-relative addressing in the fallback path of static_cpu_has(), in order to avoid unnecessary register pressure * tag 'x86_cpu_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Fix migration safety with X86_BUG_NULL_SEL x86/CPU: Add support for Vortex CPUs x86/umip: Downgrade warning messages to debug loglevel x86/asm: Avoid adding register pressure for the init case in static_cpu_has() x86/asm: Add _ASM_RIP() macro for x86-64 (%rip) suffix |
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158405e888 |
- Get rid of a bunch of function pointers used in MCA land in favor
of normal functions. This is in preparation of making the MCA code noinstr-aware - When the kernel copies data from user addresses and it encounters a machine check, a SIGBUS is sent to that process. Change this action to either an -EFAULT which is returned to the user or a short write, making the recovery action a lot more user-friendly -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmF/s8sACgkQEsHwGGHe VUqnaQ/8DIHkIOF6vy2w56snJwCj0XQYNLO+Clf6sHJ7ukWpWDoAi6HzvjqrBmaa bQEdOLeO92wGtVutCQ5ndzq2SJ6UFcZtOulpHyzCpwNinhY2QMsPG6pkSzeaAy/e aR4gpTY6pyCJyWl5DXXr7FMzBZVaWYdtZ2szPKmW1d1mLeDIdv5d3hInDbZ48XJF o+fZx0uuK0CIuDjDujRNvkPbHXLbBSqSLCTRf66o+sCY5ZXHlAipabxa3UmhHKvd dBxMrlObAaDBmDjqpc/YpS4IfWZb7+rHQfVmiq5O85ExXx6cyF6vlM7GI/5VBxSA 2dVcZX/3TsSqGbFdVygbcF6e/Yl1xhP5AE+pBb5jpzbzEaf4oiM8MDhoMAai3lEL 7CFsXL2oyAzho7QQsUSkv/hffHHrph2/aUZbGJlz6SdeRF9aoIjZANpcwm44TZrk c11Fh1MLTDxx8uhCGrYFXqR8QgeTi4B+8d/CEXNJnkLXZMfSUtoL1iIzhBpsGkv3 r0JOIG2o5dGX2lLhQOiHZ+us33O1e8mvOli9P1jLoDttoKvNqSqLUuwpBCz4sc0E ugfarf7v/R07NN+7SIT+O83ZG8dXxIRPzHm/g7wjZYgyOfEBgFSMBKVWXRotPo/f aY88sDVyvF5sbYnUcA6zZANBCKAVfilqdMgCyaoGegoNGzDOCYE= =bIZq -----END PGP SIGNATURE----- Merge tag 'ras_core_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RAS updates from Borislav Petkov: - Get rid of a bunch of function pointers used in MCA land in favor of normal functions. This is in preparation of making the MCA code noinstr-aware - When the kernel copies data from user addresses and it encounters a machine check, a SIGBUS is sent to that process. Change this action to either an -EFAULT which is returned to the user or a short write, making the recovery action a lot more user-friendly * tag 'ras_core_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce: Sort mca_config members to get rid of unnecessary padding x86/mce: Get rid of the ->quirk_no_way_out() indirect call x86/mce: Get rid of msr_ops x86/mce: Get rid of machine_check_vector x86/mce: Get rid of the mce_severity function pointer x86/mce: Drop copyin special case for #MC x86/mce: Change to not send SIGBUS error during copy from user |
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8cb1ae19bf |
x86/fpu updates:
- Cleanup of extable fixup handling to be more robust, which in turn allows to make the FPU exception fixups more robust as well. - Change the return code for signal frame related failures from explicit error codes to a boolean fail/success as that's all what the calling code evaluates. - A large refactoring of the FPU code to prepare for adding AMX support: - Distangle the public header maze and remove especially the misnomed kitchen sink internal.h which is despite it's name included all over the place. - Add a proper abstraction for the register buffer storage (struct fpstate) which allows to dynamically size the buffer at runtime by flipping the pointer to the buffer container from the default container which is embedded in task_struct::tread::fpu to a dynamically allocated container with a larger register buffer. - Convert the code over to the new fpstate mechanism. - Consolidate the KVM FPU handling by moving the FPU related code into the FPU core which removes the number of exports and avoids adding even more export when AMX has to be supported in KVM. This also removes duplicated code which was of course unnecessary different and incomplete in the KVM copy. - Simplify the KVM FPU buffer handling by utilizing the new fpstate container and just switching the buffer pointer from the user space buffer to the KVM guest buffer when entering vcpu_run() and flipping it back when leaving the function. This cuts the memory requirements of a vCPU for FPU buffers in half and avoids pointless memory copy operations. This also solves the so far unresolved problem of adding AMX support because the current FPU buffer handling of KVM inflicted a circular dependency between adding AMX support to the core and to KVM. With the new scheme of switching fpstate AMX support can be added to the core code without affecting KVM. - Replace various variables with proper data structures so the extra information required for adding dynamically enabled FPU features (AMX) can be added in one place - Add AMX (Advanved Matrix eXtensions) support (finally): AMX is a large XSTATE component which is going to be available with Saphire Rapids XEON CPUs. The feature comes with an extra MSR (MSR_XFD) which allows to trap the (first) use of an AMX related instruction, which has two benefits: 1) It allows the kernel to control access to the feature 2) It allows the kernel to dynamically allocate the large register state buffer instead of burdening every task with the the extra 8K or larger state storage. It would have been great to gain this kind of control already with AVX512. The support comes with the following infrastructure components: 1) arch_prctl() to - read the supported features (equivalent to XGETBV(0)) - read the permitted features for a task - request permission for a dynamically enabled feature Permission is granted per process, inherited on fork() and cleared on exec(). The permission policy of the kernel is restricted to sigaltstack size validation, but the syscall obviously allows further restrictions via seccomp etc. 2) A stronger sigaltstack size validation for sys_sigaltstack(2) which takes granted permissions and the potentially resulting larger signal frame into account. This mechanism can also be used to enforce factual sigaltstack validation independent of dynamic features to help with finding potential victims of the 2K sigaltstack size constant which is broken since AVX512 support was added. 3) Exception handling for #NM traps to catch first use of a extended feature via a new cause MSR. If the exception was caused by the use of such a feature, the handler checks permission for that feature. If permission has not been granted, the handler sends a SIGILL like the #UD handler would do if the feature would have been disabled in XCR0. If permission has been granted, then a new fpstate which fits the larger buffer requirement is allocated. In the unlikely case that this allocation fails, the handler sends SIGSEGV to the task. That's not elegant, but unavoidable as the other discussed options of preallocation or full per task permissions come with their own set of horrors for kernel and/or userspace. So this is the lesser of the evils and SIGSEGV caused by unexpected memory allocation failures is not a fundamentally new concept either. When allocation succeeds, the fpstate properties are filled in to reflect the extended feature set and the resulting sizes, the fpu::fpstate pointer is updated accordingly and the trap is disarmed for this task permanently. 4) Enumeration and size calculations 5) Trap switching via MSR_XFD The XFD (eXtended Feature Disable) MSR is context switched with the same life time rules as the FPU register state itself. The mechanism is keyed off with a static key which is default disabled so !AMX equipped CPUs have zero overhead. On AMX enabled CPUs the overhead is limited by comparing the tasks XFD value with a per CPU shadow variable to avoid redundant MSR writes. In case of switching from a AMX using task to a non AMX using task or vice versa, the extra MSR write is obviously inevitable. All other places which need to be aware of the variable feature sets and resulting variable sizes are not affected at all because they retrieve the information (feature set, sizes) unconditonally from the fpstate properties. 6) Enable the new AMX states Note, this is relatively new code despite the fact that AMX support is in the works for more than a year now. The big refactoring of the FPU code, which allowed to do a proper integration has been started exactly 3 weeks ago. Refactoring of the existing FPU code and of the original AMX patches took a week and has been subject to extensive review and testing. The only fallout which has not been caught in review and testing right away was restricted to AMX enabled systems, which is completely irrelevant for anyone outside Intel and their early access program. There might be dragons lurking as usual, but so far the fine grained refactoring has held up and eventual yet undetected fallout is bisectable and should be easily addressable before the 5.16 release. Famous last words... Many thanks to Chang Bae and Dave Hansen for working hard on this and also to the various test teams at Intel who reserved extra capacity to follow the rapid development of this closely which provides the confidence level required to offer this rather large update for inclusion into 5.16-rc1. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmF/NkITHHRnbHhAbGlu dXRyb25peC5kZQAKCRCmGPVMDXSYodDkEADH4+/nN/QoSUHIuuha5Zptj3g2b16a /3TxT9fhwPen/kzMGsUk70s3iWJMA+I5dCfkSZexJ2hfhcRe9cBzZIa1HCawKwf3 YCISTsO/M+LpeORuZ+TpfFLJKnxNr1SEOl+EYffGhq0AkCjifb9Cnr0JZuoMUzGU jpfJZ2bj28ri5lG812DtzSMBM9E3SAwgJv+GNjmZbxZKb9mAfhbAMdBUXHirX7Ej jmx6koQjYOKwYIW8w1BrdC270lUKQUyJTbQgdRkN9Mh/HnKyFixQ18JqGlgaV2cT EtYePUfTEdaHdAhUINLIlEug1MfOslHU+HyGsdywnoChNB4GHPQuePC5Tz60VeFN RbQ9aKcBUu8r95rjlnKtAtBijNMA4bjGwllVxNwJ/ZoA9RPv1SbDZ07RX3qTaLVY YhVQl8+shD33/W24jUTJv1kMMexpHXIlv0gyfMryzpwI7uzzmGHRPAokJdbYKctC dyMPfdE90rxTiMUdL/1IQGhnh3awjbyfArzUhHyQ++HyUyzCFh0slsO0CD18vUy8 FofhCugGBhjuKw3XwLNQ+KsWURz5qHctSzBc3qMOSyqFHbAJCVRANkhsFvWJo2qL 75+Z7OTRebtsyOUZIdq26r4roSxHrps3dupWTtN70HWx2NhQG1nLEw986QYiQu1T hcKvDmehQLrUvg== =x3WL -----END PGP SIGNATURE----- Merge tag 'x86-fpu-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fpu updates from Thomas Gleixner: - Cleanup of extable fixup handling to be more robust, which in turn allows to make the FPU exception fixups more robust as well. - Change the return code for signal frame related failures from explicit error codes to a boolean fail/success as that's all what the calling code evaluates. - A large refactoring of the FPU code to prepare for adding AMX support: - Distangle the public header maze and remove especially the misnomed kitchen sink internal.h which is despite it's name included all over the place. - Add a proper abstraction for the register buffer storage (struct fpstate) which allows to dynamically size the buffer at runtime by flipping the pointer to the buffer container from the default container which is embedded in task_struct::tread::fpu to a dynamically allocated container with a larger register buffer. - Convert the code over to the new fpstate mechanism. - Consolidate the KVM FPU handling by moving the FPU related code into the FPU core which removes the number of exports and avoids adding even more export when AMX has to be supported in KVM. This also removes duplicated code which was of course unnecessary different and incomplete in the KVM copy. - Simplify the KVM FPU buffer handling by utilizing the new fpstate container and just switching the buffer pointer from the user space buffer to the KVM guest buffer when entering vcpu_run() and flipping it back when leaving the function. This cuts the memory requirements of a vCPU for FPU buffers in half and avoids pointless memory copy operations. This also solves the so far unresolved problem of adding AMX support because the current FPU buffer handling of KVM inflicted a circular dependency between adding AMX support to the core and to KVM. With the new scheme of switching fpstate AMX support can be added to the core code without affecting KVM. - Replace various variables with proper data structures so the extra information required for adding dynamically enabled FPU features (AMX) can be added in one place - Add AMX (Advanced Matrix eXtensions) support (finally): AMX is a large XSTATE component which is going to be available with Saphire Rapids XEON CPUs. The feature comes with an extra MSR (MSR_XFD) which allows to trap the (first) use of an AMX related instruction, which has two benefits: 1) It allows the kernel to control access to the feature 2) It allows the kernel to dynamically allocate the large register state buffer instead of burdening every task with the the extra 8K or larger state storage. It would have been great to gain this kind of control already with AVX512. The support comes with the following infrastructure components: 1) arch_prctl() to - read the supported features (equivalent to XGETBV(0)) - read the permitted features for a task - request permission for a dynamically enabled feature Permission is granted per process, inherited on fork() and cleared on exec(). The permission policy of the kernel is restricted to sigaltstack size validation, but the syscall obviously allows further restrictions via seccomp etc. 2) A stronger sigaltstack size validation for sys_sigaltstack(2) which takes granted permissions and the potentially resulting larger signal frame into account. This mechanism can also be used to enforce factual sigaltstack validation independent of dynamic features to help with finding potential victims of the 2K sigaltstack size constant which is broken since AVX512 support was added. 3) Exception handling for #NM traps to catch first use of a extended feature via a new cause MSR. If the exception was caused by the use of such a feature, the handler checks permission for that feature. If permission has not been granted, the handler sends a SIGILL like the #UD handler would do if the feature would have been disabled in XCR0. If permission has been granted, then a new fpstate which fits the larger buffer requirement is allocated. In the unlikely case that this allocation fails, the handler sends SIGSEGV to the task. That's not elegant, but unavoidable as the other discussed options of preallocation or full per task permissions come with their own set of horrors for kernel and/or userspace. So this is the lesser of the evils and SIGSEGV caused by unexpected memory allocation failures is not a fundamentally new concept either. When allocation succeeds, the fpstate properties are filled in to reflect the extended feature set and the resulting sizes, the fpu::fpstate pointer is updated accordingly and the trap is disarmed for this task permanently. 4) Enumeration and size calculations 5) Trap switching via MSR_XFD The XFD (eXtended Feature Disable) MSR is context switched with the same life time rules as the FPU register state itself. The mechanism is keyed off with a static key which is default disabled so !AMX equipped CPUs have zero overhead. On AMX enabled CPUs the overhead is limited by comparing the tasks XFD value with a per CPU shadow variable to avoid redundant MSR writes. In case of switching from a AMX using task to a non AMX using task or vice versa, the extra MSR write is obviously inevitable. All other places which need to be aware of the variable feature sets and resulting variable sizes are not affected at all because they retrieve the information (feature set, sizes) unconditonally from the fpstate properties. 6) Enable the new AMX states Note, this is relatively new code despite the fact that AMX support is in the works for more than a year now. The big refactoring of the FPU code, which allowed to do a proper integration has been started exactly 3 weeks ago. Refactoring of the existing FPU code and of the original AMX patches took a week and has been subject to extensive review and testing. The only fallout which has not been caught in review and testing right away was restricted to AMX enabled systems, which is completely irrelevant for anyone outside Intel and their early access program. There might be dragons lurking as usual, but so far the fine grained refactoring has held up and eventual yet undetected fallout is bisectable and should be easily addressable before the 5.16 release. Famous last words... Many thanks to Chang Bae and Dave Hansen for working hard on this and also to the various test teams at Intel who reserved extra capacity to follow the rapid development of this closely which provides the confidence level required to offer this rather large update for inclusion into 5.16-rc1 * tag 'x86-fpu-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (110 commits) Documentation/x86: Add documentation for using dynamic XSTATE features x86/fpu: Include vmalloc.h for vzalloc() selftests/x86/amx: Add context switch test selftests/x86/amx: Add test cases for AMX state management x86/fpu/amx: Enable the AMX feature in 64-bit mode x86/fpu: Add XFD handling for dynamic states x86/fpu: Calculate the default sizes independently x86/fpu/amx: Define AMX state components and have it used for boot-time checks x86/fpu/xstate: Prepare XSAVE feature table for gaps in state component numbers x86/fpu/xstate: Add fpstate_realloc()/free() x86/fpu/xstate: Add XFD #NM handler x86/fpu: Update XFD state where required x86/fpu: Add sanity checks for XFD x86/fpu: Add XFD state to fpstate x86/msr-index: Add MSRs for XFD x86/cpufeatures: Add eXtended Feature Disabling (XFD) feature bit x86/fpu: Reset permission and fpstate on exec() x86/fpu: Prepare fpu_clone() for dynamically enabled features x86/fpu/signal: Prepare for variable sigframe length x86/signal: Use fpu::__state_user_size for sigalt stack validation ... |
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9a7e0a90a4 |
Scheduler updates:
- Revert the printk format based wchan() symbol resolution as it can leak the raw value in case that the symbol is not resolvable. - Make wchan() more robust and work with all kind of unwinders by enforcing that the task stays blocked while unwinding is in progress. - Prevent sched_fork() from accessing an invalid sched_task_group - Improve asymmetric packing logic - Extend scheduler statistics to RT and DL scheduling classes and add statistics for bandwith burst to the SCHED_FAIR class. - Properly account SCHED_IDLE entities - Prevent a potential deadlock when initial priority is assigned to a newly created kthread. A recent change to plug a race between cpuset and __sched_setscheduler() introduced a new lock dependency which is now triggered. Break the lock dependency chain by moving the priority assignment to the thread function. - Fix the idle time reporting in /proc/uptime for NOHZ enabled systems. - Improve idle balancing in general and especially for NOHZ enabled systems. - Provide proper interfaces for live patching so it does not have to fiddle with scheduler internals. - Add cluster aware scheduling support. - A small set of tweaks for RT (irqwork, wait_task_inactive(), various scheduler options and delaying mmdrop) - The usual small tweaks and improvements all over the place -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmF/OUkTHHRnbHhAbGlu dXRyb25peC5kZQAKCRCmGPVMDXSYoR/5D/9ikdGNpKg9osNqJ3GjAmxsK6kVkB29 iFe2k8pIpWDToWQf/wQRGih4Yj3Cl49QSnZcPIibh2/12EB1qrrW6iSPJkInz8Ec /1LS5/Vewn2OyoxyXZjdvGC5gTXEodSbIazASvX7nvdMeI4gsAsL5etzrMJirT/t aymqvr7zovvywrwMTQJrGjUMo9l4ewE8tafMNNhRu1BHU1U4ojM9yvThyRAAcmp7 3Xy49A+Yq3IgrvYI4u8FMK5Zh08KaxSFjiLhePGm/bF+wSfYmWop2TP1jY05W2Uo ti8hfbJMUoFRYuMxAiEldkItnc0wV4M9PtWZZ/x+B71bs65Y4Zjt9cW+rxJv2+m1 vzV31EsQwGnOti072dzWN4c/cZqngVXAjaNtErvDwJUr+Tw1ayv9KUvuodMQqZY6 mu68bFUO2kV9EMe1CBOv51Uy1RGHyLj3rlNqrkw+Xp5ISE9Ad2vhUEiRp5bQx5Ci V/XFhGZkGUluh0vccrdFlNYZwhj8cZEzkOPCnPSeZ+bq8SyZE6xuHH/lTP1CJCOy s800rW1huM+kgV+zRN8adDkGXibAk9N3RtVGnQXmuEy8gB9LZmQg+JeM2wsc9B+6 i0gdqZnsjNAfoK+BBAG4holxptSL8/eOJsFH8ZNIoxQ+iqooyPx9tFX7yXnRTBQj d2qWG7UvoseT+g== =fgtS -----END PGP SIGNATURE----- Merge tag 'sched-core-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Thomas Gleixner: - Revert the printk format based wchan() symbol resolution as it can leak the raw value in case that the symbol is not resolvable. - Make wchan() more robust and work with all kind of unwinders by enforcing that the task stays blocked while unwinding is in progress. - Prevent sched_fork() from accessing an invalid sched_task_group - Improve asymmetric packing logic - Extend scheduler statistics to RT and DL scheduling classes and add statistics for bandwith burst to the SCHED_FAIR class. - Properly account SCHED_IDLE entities - Prevent a potential deadlock when initial priority is assigned to a newly created kthread. A recent change to plug a race between cpuset and __sched_setscheduler() introduced a new lock dependency which is now triggered. Break the lock dependency chain by moving the priority assignment to the thread function. - Fix the idle time reporting in /proc/uptime for NOHZ enabled systems. - Improve idle balancing in general and especially for NOHZ enabled systems. - Provide proper interfaces for live patching so it does not have to fiddle with scheduler internals. - Add cluster aware scheduling support. - A small set of tweaks for RT (irqwork, wait_task_inactive(), various scheduler options and delaying mmdrop) - The usual small tweaks and improvements all over the place * tag 'sched-core-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (69 commits) sched/fair: Cleanup newidle_balance sched/fair: Remove sysctl_sched_migration_cost condition sched/fair: Wait before decaying max_newidle_lb_cost sched/fair: Skip update_blocked_averages if we are defering load balance sched/fair: Account update_blocked_averages in newidle_balance cost x86: Fix __get_wchan() for !STACKTRACE sched,x86: Fix L2 cache mask sched/core: Remove rq_relock() sched: Improve wake_up_all_idle_cpus() take #2 irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT irq_work: Handle some irq_work in a per-CPU thread on PREEMPT_RT irq_work: Allow irq_work_sync() to sleep if irq_work() no IRQ support. sched/rt: Annotate the RT balancing logic irqwork as IRQ_WORK_HARD_IRQ sched: Add cluster scheduler level for x86 sched: Add cluster scheduler level in core and related Kconfig for ARM64 topology: Represent clusters of CPUs within a die sched: Disable -Wunused-but-set-variable sched: Add wrapper for get_wchan() to keep task blocked x86: Fix get_wchan() to support the ORC unwinder proc: Use task_is_running() for wchan in /proc/$pid/stat ... |
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43aa0a195f |
objtool updates:
- Improve retpoline code patching by separating it from alternatives which reduces memory footprint and allows to do better optimizations in the actual runtime patching. - Add proper retpoline support for x86/BPF - Address noinstr warnings in x86/kvm, lockdep and paravirtualization code - Add support to handle pv_opsindirect calls in the noinstr analysis - Classify symbols upfront and cache the result to avoid redundant str*cmp() invocations. - Add a CFI hash to reduce memory consumption which also reduces runtime on a allyesconfig by ~50% - Adjust XEN code to make objtool handling more robust and as a side effect to prevent text fragmentation due to placement of the hypercall page. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmF/GFgTHHRnbHhAbGlu dXRyb25peC5kZQAKCRCmGPVMDXSYoc1JD/0Sz6seP2OUMxbMT3gCcFo9sMvYTdsM 7WuGFbBbnCIo7g8JH7k0zRRBigptMp2eUtQXKkgaaIbWN4JbuVKf8KxN5/qXxLi4 fJ12QnNTGH9N2jtzl5wKmpjaKJnnJMD9D10XwoR+T6gn6NHd+AgLEs7GxxuQUlgo eC9oEXhNHC8uNhiZc38EwfwmItI1bRgaLrnZWIL4rYGSMxfCK1/cEOpWrFfX9wmj /diB6oqMyPXZXMCtgpX7TniUr5XOTCcUkeO9mQv5bmyq/YM/8hrTbcVSJlsVYLvP EsBnUSHAcfLFiHXwa1RNiIGdbiPjbN+UYeXGAvqF58f3e5dTIHtN/UmWo7OH93If 9rLMVNcMpsfPx7QRk2IxEPumLCkyfwjzfKrVDM6P6TKEIUzD1og4IK9gTlfykVsh 56G5XiCOC/X2x8IMxKTLGuBiAVLFHXK/rSwoqhvNEWBFKDbP13QWs0LurBcW09Sa /kQI9pIBT1xFA/R+OY5Xy1cqNVVK1Gxmk8/bllCijA9pCFSCFM4hLZE5CevdrBCV h5SdqEK5hIlzFyypXfsCik/4p/+rfvlGfUKtFsPctxx29SPe+T0orx+l61jiWQok rZOflwMawK5lDuASHrvNHGJcWaTwoo3VcXMQDnQY0Wulc43J5IFBaPxkZzgyd+S1 4lktHxatrCMUgw== =pfZi -----END PGP SIGNATURE----- Merge tag 'objtool-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool updates from Thomas Gleixner: - Improve retpoline code patching by separating it from alternatives which reduces memory footprint and allows to do better optimizations in the actual runtime patching. - Add proper retpoline support for x86/BPF - Address noinstr warnings in x86/kvm, lockdep and paravirtualization code - Add support to handle pv_opsindirect calls in the noinstr analysis - Classify symbols upfront and cache the result to avoid redundant str*cmp() invocations. - Add a CFI hash to reduce memory consumption which also reduces runtime on a allyesconfig by ~50% - Adjust XEN code to make objtool handling more robust and as a side effect to prevent text fragmentation due to placement of the hypercall page. * tag 'objtool-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits) bpf,x86: Respect X86_FEATURE_RETPOLINE* bpf,x86: Simplify computing label offsets x86,bugs: Unconditionally allow spectre_v2=retpoline,amd x86/alternative: Add debug prints to apply_retpolines() x86/alternative: Try inline spectre_v2=retpoline,amd x86/alternative: Handle Jcc __x86_indirect_thunk_\reg x86/alternative: Implement .retpoline_sites support x86/retpoline: Create a retpoline thunk array x86/retpoline: Move the retpoline thunk declarations to nospec-branch.h x86/asm: Fixup odd GEN-for-each-reg.h usage x86/asm: Fix register order x86/retpoline: Remove unused replacement symbols objtool,x86: Replace alternatives with .retpoline_sites objtool: Shrink struct instruction objtool: Explicitly avoid self modifying code in .altinstr_replacement objtool: Classify symbols objtool: Support pv_opsindirect calls for noinstr x86/xen: Rework the xen_{cpu,irq,mmu}_opsarrays x86/xen: Mark xen_force_evtchn_callback() noinstr x86/xen: Make irq_disable() noinstr ... |
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f8a66d608a |
x86,bugs: Unconditionally allow spectre_v2=retpoline,amd
Currently Linux prevents usage of retpoline,amd on !AMD hardware, this is unfriendly and gets in the way of testing. Remove this restriction. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Tested-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/r/20211026120310.487348118@infradead.org |
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af788f355e |
x86/hyperv: Initialize shared memory boundary in the Isolation VM.
Hyper-V exposes shared memory boundary via cpuid HYPERV_CPUID_ISOLATION_CONFIG and store it in the shared_gpa_boundary of ms_hyperv struct. This prepares to share memory with host for SNP guest. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20211025122116.264793-3-ltykernel@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org> |
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0cc4f6d9f0 |
x86/hyperv: Initialize GHCB page in Isolation VM
Hyperv exposes GHCB page via SEV ES GHCB MSR for SNP guest to communicate with hypervisor. Map GHCB page for all cpus to read/write MSR register and submit hvcall request via ghcb page. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20211025122116.264793-2-ltykernel@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org> |
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970eae1560 |
Linux 5.15-rc7
-----BEGIN PGP SIGNATURE----- iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmF298ceHHRvcnZhbGRz QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGIJYH/1rsEFQQ6caeQdy1 z9eFIe48DNM4l7bFk+qEj2UAbzPdahVJ299Mg5fW0n2CDemOc9/n0b9TxQ37YObi mOzu0xwJVupIxkyFMPQSSc2q8aLm67NSpJy08DsmaNses5hSvu8x15RPHLQTybjt SwtKns+jpCq79P1GWbrB5e5UkLb0VNoxNp4L1U4pMrYGcEkJUXbaxNY2V/JcXdM7 Vtn+qN0T/J6V6QVftv0t8Ecj3bjEnmL3kZHaTaNg3dGeKRpCGyHc5lcBQ0cNFG6t vjZ9VbuhBzGI3TN2tHH5hpA1UXo7HPBBCwQqxF1jeGLGHULikYwZ3TAPWqL3QZqC 9cxr9SY= =p75d -----END PGP SIGNATURE----- BackMerge tag 'v5.15-rc7' into drm-next The msm next tree is based on rc3, so let's just backmerge rc7 before pulling it in. Signed-off-by: Dave Airlie <airlied@redhat.com> |
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2308ee57d9 |
x86/fpu/amx: Enable the AMX feature in 64-bit mode
Add the AMX state components in XFEATURE_MASK_USER_SUPPORTED and the TILE_DATA component to the dynamic states and update the permission check table accordingly. This is only effective on 64 bit kernels as for 32bit kernels XFEATURE_MASK_TILE is defined as 0. TILE_DATA is caller-saved state and the only dynamic state. Add build time sanity check to ensure the assumption that every dynamic feature is caller- saved. Make AMX state depend on XFD as it is dynamic feature. Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20211021225527.10184-24-chang.seok.bae@intel.com |
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c351101678 |
x86/cpufeatures: Add eXtended Feature Disabling (XFD) feature bit
Intel's eXtended Feature Disable (XFD) feature is an extension of the XSAVE architecture. XFD allows the kernel to enable a feature state in XCR0 and to receive a #NM trap when a task uses instructions accessing that state. This is going to be used to postpone the allocation of a larger XSTATE buffer for a task to the point where it is actually using a related instruction after the permission to use that facility has been granted. XFD is not used by the kernel, but only applied to userspace. This is a matter of policy as the kernel knows how a fpstate is reallocated and the XFD state. The compacted XSAVE format is adjustable for dynamic features. Make XFD depend on XSAVES. Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20211021225527.10184-13-chang.seok.bae@intel.com |
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ae095b16fc |
x86/sgx/virt: implement SGX_IOC_VEPC_REMOVE ioctl
For bare-metal SGX on real hardware, the hardware provides guarantees SGX state at reboot. For instance, all pages start out uninitialized. The vepc driver provides a similar guarantee today for freshly-opened vepc instances, but guests such as Windows expect all pages to be in uninitialized state on startup, including after every guest reboot. Some userspace implementations of virtual SGX would rather avoid having to close and reopen the /dev/sgx_vepc file descriptor and re-mmap the virtual EPC. For example, they could sandbox themselves after the guest starts and forbid further calls to open(), in order to mitigate exploits from untrusted guests. Therefore, add a ioctl that does this with EREMOVE. Userspace can invoke the ioctl to bring its vEPC pages back to uninitialized state. There is a possibility that some pages fail to be removed if they are SECS pages, and the child and SECS pages could be in separate vEPC regions. Therefore, the ioctl returns the number of EREMOVE failures, telling userspace to try the ioctl again after it's done with all vEPC regions. A more verbose description of the correct usage and the possible error conditions is documented in sgx.rst. Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20211021201155.1523989-3-pbonzini@redhat.com |
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fd5128e622 |
x86/sgx/virt: extract sgx_vepc_remove_page
For bare-metal SGX on real hardware, the hardware provides guarantees SGX state at reboot. For instance, all pages start out uninitialized. The vepc driver provides a similar guarantee today for freshly-opened vepc instances, but guests such as Windows expect all pages to be in uninitialized state on startup, including after every guest reboot. One way to do this is to simply close and reopen the /dev/sgx_vepc file descriptor and re-mmap the virtual EPC. However, this is problematic because it prevents sandboxing the userspace (for example forbidding open() after the guest starts; this is doable with heavy use of SCM_RIGHTS file descriptor passing). In order to implement this, we will need a ioctl that performs EREMOVE on all pages mapped by a /dev/sgx_vepc file descriptor: other possibilities, such as closing and reopening the device, are racy. Start the implementation by creating a separate function with just the __eremove wrapper. Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20211021201155.1523989-2-pbonzini@redhat.com |
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9d48960414 |
x86/microcode: Use the firmware_loader built-in API
The microcode loader has been looping through __start_builtin_fw down to __end_builtin_fw to look for possibly built-in firmware for microcode updates. Now that the firmware loader code has exported an API for looping through the kernel's built-in firmware section, use it and drop the x86 implementation in favor. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20211021155843.1969401-4-mcgrof@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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415de44076 |
x86/cpu: Fix migration safety with X86_BUG_NULL_SEL
Currently, Linux probes for X86_BUG_NULL_SEL unconditionally which makes it unsafe to migrate in a virtualised environment as the properties across the migration pool might differ. To be specific, the case which goes wrong is: 1. Zen1 (or earlier) and Zen2 (or later) in a migration pool 2. Linux boots on Zen2, probes and finds the absence of X86_BUG_NULL_SEL 3. Linux is then migrated to Zen1 Linux is now running on a X86_BUG_NULL_SEL-impacted CPU while believing that the bug is fixed. The only way to address the problem is to fully trust the "no longer affected" CPUID bit when virtualised, because in the above case it would be clear deliberately to indicate the fact "you might migrate to somewhere which has this behaviour". Zen3 adds the NullSelectorClearsBase CPUID bit to indicate that loading a NULL segment selector zeroes the base and limit fields, as well as just attributes. Zen2 also has this behaviour but doesn't have the NSCB bit. [ bp: Minor touchups. ] Signed-off-by: Jane Malalane <jane.malalane@citrix.com> Signed-off-by: Borislav Petkov <bp@suse.de> CC: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20211021104744.24126-1-jane.malalane@citrix.com |
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639475d434 |
x86/CPU: Add support for Vortex CPUs
DM&P devices were not being properly identified, which resulted in unneeded Spectre/Meltdown mitigations being applied. The manufacturer states that these devices execute always in-order and don't support either speculative execution or branch prediction, so they are not vulnerable to this class of attack. [1] This is something I've personally tested by a simple timing analysis on my Vortex86MX CPU, and can confirm it is true. Add identification for some devices that lack the CPUID product name call, so they appear properly on /proc/cpuinfo. ¹https://www.ssv-embedded.de/doks/infos/DMP_Ann_180108_Meltdown.pdf [ bp: Massage commit message. ] Signed-off-by: Marcos Del Sol Vives <marcos@orca.pet> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20211017094408.1512158-1-marcos@orca.pet |
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b56d2795b2 |
x86/fpu: Replace the includes of fpu/internal.h
Now that the file is empty, fixup all references with the proper includes and delete the former kitchen sink. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20211015011540.001197214@linutronix.de |
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082f20b21d |
Merge branch 'x86/urgent' into x86/fpu, to resolve a conflict
Resolve the conflict between these commits: x86/fpu: |
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66558b730f |
sched: Add cluster scheduler level for x86
There are x86 CPU architectures (e.g. Jacobsville) where L2 cahce is shared among a cluster of cores instead of being exclusive to one single core. To prevent oversubscription of L2 cache, load should be balanced between such L2 clusters, especially for tasks with no shared data. On benchmark such as SPECrate mcf test, this change provides a boost to performance especially on medium load system on Jacobsville. on a Jacobsville that has 24 Atom cores, arranged into 6 clusters of 4 cores each, the benchmark number is as follow: Improvement over baseline kernel for mcf_r copies run time base rate 1 -0.1% -0.2% 6 25.1% 25.1% 12 18.8% 19.0% 24 0.3% 0.3% So this looks pretty good. In terms of the system's task distribution, some pretty bad clumping can be seen for the vanilla kernel without the L2 cluster domain for the 6 and 12 copies case. With the extra domain for cluster, the load does get evened out between the clusters. Note this patch isn't an universal win as spreading isn't necessarily a win, particually for those workload who can benefit from packing. Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210924085104.44806-4-21cnbao@gmail.com |
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f38ce910d8 |
x86/MCE/AMD: Export smca_get_bank_type symbol
Export smca_get_bank_type for use in the AMD GPU driver to determine MCA bank while handling correctable and uncorrectable errors in GPU UMC. Signed-off-by: Mukul Joshi <mukul.joshi@amd.com> Acked-by: Borislav Petkov <bp@suse.de> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> |
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3958b9c34c |
x86/entry: Clear X86_FEATURE_SMAP when CONFIG_X86_SMAP=n
Commit |
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d4ebfca26d |
x86/resctrl: Fix kfree() of the wrong type in domain_add_cpu()
Commit in Fixes separated the architecture specific and filesystem parts
of the resctrl domain structures.
This left the error paths in domain_add_cpu() kfree()ing the memory with
the wrong type.
This will cause a problem if someone adds a new member to struct
rdt_hw_domain meaning d_resctrl is no longer the first member.
Fixes:
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64e87d4bd3 |
x86/resctrl: Free the ctrlval arrays when domain_setup_mon_state() fails
domain_add_cpu() is called whenever a CPU is brought online. The earlier call to domain_setup_ctrlval() allocates the control value arrays. If domain_setup_mon_state() fails, the control value arrays are not freed. Add the missing kfree() calls. Fixes: |
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2f46993d83 |
x86: change default to spec_store_bypass_disable=prctl spectre_v2_user=prctl
Switch the kernel default of SSBD and STIBP to the ones with CONFIG_SECCOMP=n (i.e. spec_store_bypass_disable=prctl spectre_v2_user=prctl) even if CONFIG_SECCOMP=y. Several motivations listed below: - If SMT is enabled the seccomp jail can still attack the rest of the system even with spectre_v2_user=seccomp by using MDS-HT (except on XEON PHI where MDS can be tamed with SMT left enabled, but that's a special case). Setting STIBP become a very expensive window dressing after MDS-HT was discovered. - The seccomp jail cannot attack the kernel with spectre-v2-HT regardless (even if STIBP is not set), but with MDS-HT the seccomp jail can attack the kernel too. - With spec_store_bypass_disable=prctl the seccomp jail can attack the other userland (guest or host mode) using spectre-v2-HT, but the userland attack is already mitigated by both ASLR and pid namespaces for host userland and through virt isolation with libkrun or kata. (if something if somebody is worried about spectre-v2-HT it's best to mount proc with hidepid=2,gid=proc on workstations where not all apps may run under container runtimes, rather than slowing down all seccomp jails, but the best is to add pid namespaces to the seccomp jail). As opposed MDS-HT is not mitigated and the seccomp jail can still attack all other host and guest userland if SMT is enabled even with spec_store_bypass_disable=seccomp. - If full security is required then MDS-HT must also be mitigated with nosmt and then spectre_v2_user=prctl and spectre_v2_user=seccomp would become identical. - Setting spectre_v2_user=seccomp is overall lower priority than to setting javascript.options.wasm false in about:config to protect against remote wasm MDS-HT, instead of worrying about Spectre-v2-HT and STIBP which again is already statistically well mitigated by other means in userland and it's fully mitigated in kernel with retpolines (unlike the wasm assist call with MDS-HT). - SSBD is needed to prevent reading the JIT memory and the primary user being the OpenJDK. However the primary user of SSBD wouldn't be covered by spec_store_bypass_disable=seccomp because it doesn't use seccomp and the primary user also explicitly declined to set PR_SET_SPECULATION_CTRL+PR_SPEC_STORE_BYPASS despite it easily could. In fact it would need to set it only when the sandboxing mechanism is enabled for javaws applets, but it still declined it by declaring security within the same user address space as an untenable objective for their JIT, even in the sandboxing case where performance would be a lesser concern (for the record: I kind of disagree in not setting PR_SPEC_STORE_BYPASS in the sandbox case and I prefer to run javaws through a wrapper that sets PR_SPEC_STORE_BYPASS if I need). In turn it can be inferred that even if the primary user of SSBD would use seccomp, they would invoke it with SECCOMP_FILTER_FLAG_SPEC_ALLOW by now. - runc/crun already set SECCOMP_FILTER_FLAG_SPEC_ALLOW by default, k8s and podman have a default json seccomp allowlist that cannot be slowed down, so for the #1 seccomp user this change is already a noop. - systemd/sshd or other apps that use seccomp, if they really need STIBP or SSBD, they need to explicitly set the PR_SET_SPECULATION_CTRL by now. The stibp/ssbd seccomp blind catch-all approach was done probably initially with a wishful thinking objective to pretend to have a peace of mind that it could magically fix it all. That was wishful thinking before MDS-HT was discovered, but after MDS-HT has been discovered it become just window dressing. - For qemu "-sandbox" seccomp jail it wouldn't make sense to set STIBP or SSBD. SSBD doesn't help with KVM because there's no JIT (if it's needed with TCG it should be an opt-in with PR_SET_SPECULATION_CTRL+PR_SPEC_STORE_BYPASS and it shouldn't slowdown KVM for nothing). For qemu+KVM STIBP would be even more window dressing than it is for all other apps, because in the qemu+KVM case there's not only the MDS attack to worry about with SMT enabled. Even after disabling SMT, there's still a theoretical spectre-v2 attack possible within the same thread context from guest mode to host ring3 that the host kernel retpoline mitigation has no theoretical chance to mitigate. On some kernels a ibrs-always/ibrs-retpoline opt-in model is provided that will enabled IBRS in the qemu host ring3 userland which fixes this theoretical concern. Only after enabling IBRS in the host userland it would then make sense to proceed and worry about STIBP and an attack on the other host userland, but then again SMT would need to be disabled for full security anyway, so that would render STIBP again a noop. - last but not the least: the lack of "spec_store_bypass_disable=prctl spectre_v2_user=prctl" means the moment a guest boots and sshd/systemd runs, the guest kernel will write to SPEC_CTRL MSR which will make the guest vmexit forever slower, forcing KVM to issue a very slow rdmsr instruction at every vmexit. So the end result is that SPEC_CTRL MSR is only available in GCE. Most other public cloud providers don't expose SPEC_CTRL, which means that not only STIBP/SSBD isn't available, but IBPB isn't available either (which would cause no overhead to the guest or the hypervisor because it's write only and requires no reading during vmexit). So the current default already net loss in security (missing IBPB) which means most public cloud providers cannot achieve a fully secure guest with nosmt (and nosmt is enough to fully mitigate MDS-HT). It also means GCE and is unfairly penalized in performance because it provides the option to enable full security in the guest as an opt-in (i.e. nosmt and IBPB). So this change will allow all cloud providers to expose SPEC_CTRL without incurring into any hypervisor slowdown and at the same time it will remove the unfair penalization of GCE performance for doing the right thing and it'll allow to get full security with nosmt with IBPB being available (and STIBP becoming meaningless). Example to put things in prospective: the STIBP enabled in seccomp has never been about protecting apps using seccomp like sshd from an attack from a malicious userland, but to the contrary it has always been about protecting the system from an attack from sshd, after a successful remote network exploit against sshd. In fact initially it wasn't obvious STIBP would work both ways (STIBP was about preventing the task that runs with STIBP to be attacked with spectre-v2-HT, but accidentally in the STIBP case it also prevents the attack in the other direction). In the hypothetical case that sshd has been remotely exploited the last concern should be STIBP being set, because it'll be still possible to obtain info even from the kernel by using MDS if nosmt wasn't set (and if it was set, STIBP is a noop in the first place). As opposed kernel cannot leak anything with spectre-v2 HT because of retpolines and the userland is mitigated by ASLR already and ideally PID namespaces too. If something it'd be worth checking if sshd run the seccomp thread under pid namespaces too if available in the running kernel. SSBD also would be a noop for sshd, since sshd uses no JIT. If sshd prefers to keep doing the STIBP window dressing exercise, it still can even after this change of defaults by opting-in with PR_SPEC_INDIRECT_BRANCH. Ultimately setting SSBD and STIBP by default for all seccomp jails is a bad sweet spot and bad default with more cons than pros that end up reducing security in the public cloud (by giving an huge incentive to not expose SPEC_CTRL which would be needed to get full security with IBPB after setting nosmt in the guest) and by excessively hurting performance to more secure apps using seccomp that end up having to opt out with SECCOMP_FILTER_FLAG_SPEC_ALLOW. The following is the verified result of the new default with SMT enabled: (gdb) print spectre_v2_user_stibp $1 = SPECTRE_V2_USER_PRCTL (gdb) print spectre_v2_user_ibpb $2 = SPECTRE_V2_USER_PRCTL (gdb) print ssb_mode $3 = SPEC_STORE_BYPASS_PRCTL Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201104235054.5678-1-aarcange@redhat.com Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/lkml/AAA2EF2C-293D-4D5B-BFA6-FF655105CD84@redhat.com Acked-by: Waiman Long <longman@redhat.com> Link: https://lore.kernel.org/lkml/c0722838-06f7-da6b-138f-e0f26362f16a@redhat.com |
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15802468a9 |
x86/mce: Sort mca_config members to get rid of unnecessary padding
$ pahole -C mca_config arch/x86/kernel/cpu/mce/core.o before: /* size: 40, cachelines: 1, members: 16 */ /* sum members: 21, holes: 1, sum holes: 3 */ /* sum bitfield members: 64 bits, bit holes: 2, sum bit holes: 32 bits */ /* padding: 4 */ /* last cacheline: 40 bytes */ after: /* size: 32, cachelines: 1, members: 16 */ /* padding: 3 */ /* last cacheline: 32 bytes */ No functional changes. Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/20210922165101.18951-6-bp@alien8.de |
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cc466666ab |
x86/mce: Get rid of the ->quirk_no_way_out() indirect call
Use a flag setting to call the only quirk function for that. No functional changes. Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/20210922165101.18951-5-bp@alien8.de |
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8121b8f947 |
x86/mce: Get rid of msr_ops
Avoid having indirect calls and use a normal function which returns the proper MSR address based on ->smca setting. No functional changes. Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/20210922165101.18951-4-bp@alien8.de |
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cbe1de162d |
x86/mce: Get rid of machine_check_vector
Get rid of the indirect function pointer and use flags settings instead to steer execution. Now that it is not an indirect call any longer, drop the instrumentation annotation for objtool too. No functional changes. Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/20210922165101.18951-3-bp@alien8.de |
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631adc7b0b |
x86/mce: Get rid of the mce_severity function pointer
Turn it into a normal function which calls an AMD- or Intel-specific variant depending on the CPU it runs on. No functional changes. Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/20210922165101.18951-2-bp@alien8.de |
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a6e3cf70b7 |
x86/mce: Change to not send SIGBUS error during copy from user
Sending a SIGBUS for a copy from user is not the correct semantic. System calls should return -EFAULT (or a short count for write(2)). Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210818002942.1607544-3-tony.luck@intel.com |
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20621d2f27 |
A set of x86 fixes:
- Prevent a infinite loop in the MCE recovery on return to user space, which was caused by a second MCE queueing work for the same page and thereby creating a circular work list. - Make kern_addr_valid() handle existing PMD entries, which are marked not present in the higher level page table, correctly instead of blindly dereferencing them. - Pass a valid address to sanitize_phys(). This was caused by the mixture of inclusive and exclusive ranges. memtype_reserve() expect 'end' being exclusive, but sanitize_phys() wants it inclusive. This worked so far, but with end being the end of the physical address space the fail is exposed. - Increase the maximum supported GPIO numbers for 64bit. Newer SoCs exceed the previous maximum. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmFHhPIACgkQEsHwGGHe VUqqQA/+MHQ2HxVOPxnJ0i/D1nK8ccNqTEkSN08z23RGnjqKQun/VaNIIceJY25f Abeb2tI+0qRrdWVPVd5YqcTHuBLmnPs6Je3MfOrG47eQNW4/SmkXYuOexK80Bew3 YDgEV73d40rHcolXZCaonVajx+FmjoNvkDt5LpLvLcCxIyv0GClFBcZrFAm70AxI Feax30koh3/MIFxHoXyADN8D+MJu1GxA6QWuoTK40s3G/gTTAwimkDgnNU1JXbcj VvVVZaNnnAxjxrCa81blr9nDpHJCDinG9bdvDT3UDLous52hGMZTsHoHogxwfogT EhIgPvL8hf+wm1WXA4NyvSNKZxsGfdkvIXaUq9XYHpLRD6Ao6x7jQDL039imucqb 9YtaH52GhG0SgJlYjkm/zrKezIjKLDen0ZYr/2iNTDM1p2GqQEFo07wC/ME8TkQ6 /BvtbkIvOuUz3nJeV4/AO+O4kaNvto9O2eHq9oodIN9nrwmlO5fMg8XO9nrhWB11 ChXEz6kPqta1nyZXy0mwOrlXlqzcusiroG4G9F7IBBz+t/gNwlu3uZuIgkQCXyYw DgKz9cnQ3RdgCFknbmEwV5oCjewm7UdcgwaDAaelHIDuWMcshZFvMf1uSjnyg4Z/ 39WI8W7W2aZnIoKWpvu8s7Gr8f1krE7C3xrkvl2WmbKPkxNAin8= =7cq3 -----END PGP SIGNATURE----- Merge tag 'x86_urgent_for_v5.15_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Borislav Petkov: - Prevent a infinite loop in the MCE recovery on return to user space, which was caused by a second MCE queueing work for the same page and thereby creating a circular work list. - Make kern_addr_valid() handle existing PMD entries, which are marked not present in the higher level page table, correctly instead of blindly dereferencing them. - Pass a valid address to sanitize_phys(). This was caused by the mixture of inclusive and exclusive ranges. memtype_reserve() expect 'end' being exclusive, but sanitize_phys() wants it inclusive. This worked so far, but with end being the end of the physical address space the fail is exposed. - Increase the maximum supported GPIO numbers for 64bit. Newer SoCs exceed the previous maximum. * tag 'x86_urgent_for_v5.15_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce: Avoid infinite loop for copy from user recovery x86/mm: Fix kern_addr_valid() to cope with existing but not present entries x86/platform: Increase maximum GPIO number for X86_64 x86/pat: Pass valid address to sanitize_phys() |
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81065b35e2 |
x86/mce: Avoid infinite loop for copy from user recovery
There are two cases for machine check recovery:
1) The machine check was triggered by ring3 (application) code.
This is the simpler case. The machine check handler simply queues
work to be executed on return to user. That code unmaps the page
from all users and arranges to send a SIGBUS to the task that
triggered the poison.
2) The machine check was triggered in kernel code that is covered by
an exception table entry. In this case the machine check handler
still queues a work entry to unmap the page, etc. but this will
not be called right away because the #MC handler returns to the
fix up code address in the exception table entry.
Problems occur if the kernel triggers another machine check before the
return to user processes the first queued work item.
Specifically, the work is queued using the ->mce_kill_me callback
structure in the task struct for the current thread. Attempting to queue
a second work item using this same callback results in a loop in the
linked list of work functions to call. So when the kernel does return to
user, it enters an infinite loop processing the same entry for ever.
There are some legitimate scenarios where the kernel may take a second
machine check before returning to the user.
1) Some code (e.g. futex) first tries a get_user() with page faults
disabled. If this fails, the code retries with page faults enabled
expecting that this will resolve the page fault.
2) Copy from user code retries a copy in byte-at-time mode to check
whether any additional bytes can be copied.
On the other side of the fence are some bad drivers that do not check
the return value from individual get_user() calls and may access
multiple user addresses without noticing that some/all calls have
failed.
Fix by adding a counter (current->mce_count) to keep track of repeated
machine checks before task_work() is called. First machine check saves
the address information and calls task_work_add(). Subsequent machine
checks before that task_work call back is executed check that the address
is in the same page as the first machine check (since the callback will
offline exactly one page).
Expected worst case is four machine checks before moving on (e.g. one
user access with page faults disabled, then a repeat to the same address
with page faults enabled ... repeat in copy tail bytes). Just in case
there is some code that loops forever enforce a limit of 10.
[ bp: Massage commit message, drop noinstr, fix typo, extend panic
messages. ]
Fixes:
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0c2e62ba04 |
x86/extable: Remove EX_TYPE_FAULT from MCE safe fixups
Now that the MC safe copy and FPU have been converted to use the MCE safe fixup types remove EX_TYPE_FAULT from the list of types which MCE considers to be safe to be recovered in kernel. This removes the SGX exception handling of ENCLS from the #MC safe handling, but according to the SGX wizards the current SGX implementations cannot survive #MC on ENCLS: https://lore.kernel.org/r/YS+upEmTfpZub3s9@google.com The code relies on the trap number being stored if ENCLS raised an exception. That's still working, but it does no longer trick the MCE code into assuming that #MC is handled correctly for ENCLS. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210908132525.445255957@linutronix.de |
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2cadf5248b |
x86/extable: Provide EX_TYPE_DEFAULT_MCE_SAFE and EX_TYPE_FAULT_MCE_SAFE
Provide exception fixup types which can be used to identify fixups which allow in kernel #MC recovery and make them invoke the existing handlers. These will be used at places where #MC recovery is handled correctly by the caller. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210908132525.269689153@linutronix.de |
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46d28947d9 |
x86/extable: Rework the exception table mechanics
The exception table entries contain the instruction address, the fixup address and the handler address. All addresses are relative. Storing the handler address has a few downsides: 1) Most handlers need to be exported 2) Handlers can be defined everywhere and there is no overview about the handler types 3) MCE needs to check the handler type to decide whether an in kernel #MC can be recovered. The functionality of the handler itself is not in any way special, but for these checks there need to be separate functions which in the worst case have to be exported. Some of these 'recoverable' exception fixups are pretty obscure and just reuse some other handler to spare code. That obfuscates e.g. the #MC safe copy functions. Cleaning that up would require more handlers and exports Rework the exception fixup mechanics by storing a fixup type number instead of the handler address and invoke the proper handler for each fixup type. Also teach the extable sort to leave the type field alone. This makes most handlers static except for special cases like the MCE MSR fixup and the BPF fixup. This allows to add more types for cleaning up the obscure places without adding more handler code and exports. There is a marginal code size reduction for a production config and it removes _eight_ exported symbols. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Alexei Starovoitov <ast@kernel.org> Link: https://lkml.kernel.org/r/20210908132525.211958725@linutronix.de |
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083b32d6f4 |
x86/mce: Get rid of stray semicolons
and the random number of tabs. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210908132525.154428878@linutronix.de |
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e42404afc4 |
x86/mce: Deduplicate exception handling
Prepare code for further simplification. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210908132525.096452100@linutronix.de |
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c2f4954c2d |
Merge branch 'linus' into smp/urgent
Ensure that all usage sites of get/put_online_cpus() except for the struggler in drivers/thermal are gone. So the last user and the deprecated inlines can be removed. |
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c07f191907 |
hyperv-next for 5.15
-----BEGIN PGP SIGNATURE----- iQFHBAABCAAxFiEEIbPD0id6easf0xsudhRwX5BBoF4FAmEuJwwTHHdlaS5saXVA a2VybmVsLm9yZwAKCRB2FHBfkEGgXp0ICACsx9NtQh1f9xGMClYrbobJfGmiwHVV uKut/44Vg39tSyZB4mQt3A8YcaQj1Nibo6HVmxJtbKbrKwlTGAiQh5fiOmBOd7Re /rII/S+CGtAyChI1adHTSL2xdk6WY0c7XQw+IPaERBikG5rO81Y6NLjFZNOv494k JnG9uGGjAcJWFYylPcLxt4sR/hEfE4KDzsWjWOb5azYgo/RwOan6zYDdkUgocp4A J+zmgCiME8LLmEV19gn7p4gpX7X9m5mcNgn53eICYPhrBqI0PTWocm6DepCEnrQ+ pEobIagWIMx5Dr7euEJwLxFSN7bdzleVOa4FSfM0zUsEjdbiPH47VQFM =Vae6 -----END PGP SIGNATURE----- Merge tag 'hyperv-next-signed-20210831' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - make Hyper-V code arch-agnostic (Michael Kelley) - fix sched_clock behaviour on Hyper-V (Ani Sinha) - fix a fault when Linux runs as the root partition on MSHV (Praveen Kumar) - fix VSS driver (Vitaly Kuznetsov) - cleanup (Sonia Sharma) * tag 'hyperv-next-signed-20210831' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: hv_utils: Set the maximum packet size for VSS driver to the length of the receive buffer Drivers: hv: Enable Hyper-V code to be built on ARM64 arm64: efi: Export screen_info arm64: hyperv: Initialize hypervisor on boot arm64: hyperv: Add panic handler arm64: hyperv: Add Hyper-V hypercall and register access utilities x86/hyperv: fix root partition faults when writing to VP assist page MSR hv: hyperv.h: Remove unused inline functions drivers: hv: Decouple Hyper-V clock/timer code from VMbus drivers x86/hyperv: add comment describing TSC_INVARIANT_CONTROL MSR setting bit 0 Drivers: hv: Move Hyper-V misc functionality to arch-neutral code Drivers: hv: Add arch independent default functions for some Hyper-V handlers Drivers: hv: Make portions of Hyper-V init code be arch neutral x86/hyperv: fix for unwanted manipulation of sched_clock when TSC marked unstable asm-generic/hyperv: Add missing #include of nmi.h |