Panic if Xen provides a memory map with 0 entries. Although this is
unlikely, it is better to catch the error at the point of seeing the map
than later on as a symptom of some other crash.
Signed-off-by: Martin Kelly <martkell@amazon.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Instead of ballooning up and down dom0 memory this remaps the existing mfns
that were replaced by the identity map. The reason for this is that the
existing implementation ballooned memory up and and down which caused dom0
to have discontiguous pages. In some cases this resulted in the use of bounce
buffers which reduced network I/O performance significantly. This change will
honor the existing order of the pages with the exception of some boundary
conditions.
To do this we need to update both the Linux p2m table and the Xen m2p table.
Particular care must be taken when updating the p2m table since it's important
to limit table memory consumption and reuse the existing leaf pages which get
freed when an entire leaf page is set to the identity map. To implement this,
mapping updates are grouped into blocks with table entries getting cached
temporarily and then released.
On my test system before:
Total pages: 2105014
Total contiguous: 1640635
After:
Total pages: 2105014
Total contiguous: 2098904
Signed-off-by: Matthew Rushton <mrushton@amazon.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Remove xen_enable_nmi() to fix a 64-bit guest crash when registering
the NMI callback on Xen 3.1 and earlier.
It's not needed since the NMI callback is set by a set_trap_table
hypercall (in xen_load_idt() or xen_write_idt_entry()).
It's also broken since it only set the current VCPU's callback.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Pull x86 cdso updates from Peter Anvin:
"Vdso cleanups and improvements largely from Andy Lutomirski. This
makes the vdso a lot less ''special''"
* 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/vdso, build: Make LE access macros clearer, host-safe
x86/vdso, build: Fix cross-compilation from big-endian architectures
x86/vdso, build: When vdso2c fails, unlink the output
x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET
x86, mm: Replace arch_vma_name with vm_ops->name for vsyscalls
x86, mm: Improve _install_special_mapping and fix x86 vdso naming
mm, fs: Add vm_ops->name as an alternative to arch_vma_name
x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET
x86, vdso: Remove vestiges of VDSO_PRELINK and some outdated comments
x86, vdso: Move the vvar and hpet mappings next to the 64-bit vDSO
x86, vdso: Move the 32-bit vdso special pages after the text
x86, vdso: Reimplement vdso.so preparation in build-time C
x86, vdso: Move syscall and sysenter setup into kernel/cpu/common.c
x86, vdso: Clean up 32-bit vs 64-bit vdso params
x86, mm: Ensure correct alignment of the fixmap
This reverts commit 9103bb0f82.
Now than xen_memory_setup() is not called for auto-translated guests,
we can remove this commit.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Tested-by: Roger Pau Monné <roger.pau@citrix.com>
Since af06d66ee32b (x86: fix setup of PVH Dom0 memory map) in Xen, PVH
dom0 need only use the memory memory provided by Xen which has already
setup all the correct holes.
xen_memory_setup() then ends up being trivial for a PVH guest so
introduce a new function (xen_auto_xlated_memory_setup()).
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Tested-by: Roger Pau Monné <roger.pau@citrix.com>
PCI devices may have BARs located above the end of RAM so mark such
frames as identity frames in the p2m (instead of the default of
missing).
PFNs outside the p2m (above MAX_P2M_PFN) are also considered to be
identity frames for the same reason.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
In xen_add_extra_mem(), if the WARN() checks for bad MFNs trigger it is
likely that they will trigger at lot, spamming the log.
Use WARN_ONCE() instead.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Currently, vdso.so files are prepared and analyzed by a combination
of objcopy, nm, some linker script tricks, and some simple ELF
parsers in the kernel. Replace all of that with plain C code that
runs at build time.
All five vdso images now generate .c files that are compiled and
linked in to the kernel image.
This should cause only one userspace-visible change: the loaded vDSO
images are stripped more heavily than they used to be. Everything
outside the loadable segment is dropped. In particular, this causes
the section table and section name strings to be missing. This
should be fine: real dynamic loaders don't load or inspect these
tables anyway. The result is roughly equivalent to eu-strip's
--strip-sections option.
The purpose of this change is to enable the vvar and hpet mappings
to be moved to the page following the vDSO load segment. Currently,
it is possible for the section table to extend into the page after
the load segment, so, if we map it, it risks overlapping the vvar or
hpet page. This happens whenever the load segment is just under a
multiple of PAGE_SIZE.
The only real subtlety here is that the old code had a C file with
inline assembler that did 'call VDSO32_vsyscall' and a linker script
that defined 'VDSO32_vsyscall = __kernel_vsyscall'. This most
likely worked by accident: the linker script entry defines a symbol
associated with an address as opposed to an alias for the real
dynamic symbol __kernel_vsyscall. That caused ld to relocate the
reference at link time instead of leaving an interposable dynamic
relocation. Since the VDSO32_vsyscall hack is no longer needed, I
now use 'call __kernel_vsyscall', and I added -Bsymbolic to make it
work. vdso2c will generate an error and abort the build if the
resulting image contains any dynamic relocations, so we won't
silently generate bad vdso images.
(Dynamic relocations are a problem because nothing will even attempt
to relocate the vdso.)
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/2c4fcf45524162a34d87fdda1eb046b2a5cecee7.1399317206.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull x86 asmlinkage (LTO) changes from Peter Anvin:
"This patchset adds more infrastructure for link time optimization
(LTO).
This patchset was pulled into my tree late because of a
miscommunication (part of the patchset was picked up by other
maintainers). However, the patchset is strictly build-related and
seems to be okay in testing"
* 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, asmlinkage, xen: Fix type of NMI
x86, asmlinkage, xen, kvm: Make {xen,kvm}_lock_spinning global and visible
x86: Use inline assembler instead of global register variable to get sp
x86, asmlinkage, paravirt: Make paravirt thunks global
x86, asmlinkage, paravirt: Don't rely on local assembler labels
x86, asmlinkage, lguest: Fix C functions used by inline assembler
LTO requires consistent types of symbols over all files.
So "nmi" cannot be declared as a char [] here, need to use the
correct function type.
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1382458079-24450-8-git-send-email-andi@firstfloor.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
In xen_add_extra_mem() we can skip updating P2M as it's managed
by Xen. PVH maps the entire IO space, but only RAM pages need
to be repopulated.
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
We don't use the filtering that 'xen_cpuid' is doing
because the hypervisor treats 'XEN_EMULATE_PREFIX' as
an invalid instruction. This means that all of the filtering
will have to be done in the hypervisor/toolstack.
Without the filtering we expose to the guest the:
- cpu topology (sockets, cores, etc);
- the APERF (which the generic scheduler likes to
use), see 5e62625420
"xen/setup: filter APERFMPERF cpuid feature out"
- and the inability to figure out whether MWAIT_LEAF
should be exposed or not. See
df88b2d96e
"xen/enlighten: Disable MWAIT_LEAF so that acpi-pad won't be loaded."
- x2apic, see 4ea9b9aca9
"xen: mask x2APIC feature in PV"
We also check for vector callback early on, as it is a required
feature. PVH also runs at default kernel IOPL.
Finally, pure PV settings are moved to a separate function that are
only called for pure PV, ie, pv with pvmmu. They are also #ifdef
with CONFIG_XEN_PVMMU.
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
commit 6efa20e49b
("xen: Support 64-bit PV guest receiving NMIs") and
commit cd9151e26d
( "xen/balloon: set a mapping for ballooned out pages")
added new instances of __cpuinit usage.
We removed this a couple versions ago; we now want to remove
the compat no-op stubs. Introducing new users is not what
we want to see at this point in time, as it will break once
the stubs are gone.
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
- Xen Trusted Platform Module (TPM) frontend driver - with the backend in MiniOS.
- Scalability improvements in event channel.
- Two extra Xen co-maintainers (David, Boris) and one going away (Jeremy)
Bug-fixes:
- Make the 1:1 mapping work during early bootup on selective regions.
- Add scratch page to balloon driver to deal with unexpected code still holding
on stale pages.
- Allow NMIs on PV guests (64-bit only)
- Remove unnecessary TLB flush in M2P code.
- Fixes duplicate callbacks in Xen granttable code.
- Fixes in PRIVCMD_MMAPBATCH ioctls to allow retries
- Fix for events being lost due to rescheduling on different VCPUs.
- More documentation.
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Merge tag 'stable/for-linus-3.12-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen updates from Konrad Rzeszutek Wilk:
"A couple of features and a ton of bug-fixes. There is also some
maintership changes. Jeremy is enjoying the full-time work at the
startup and as much as he would love to help - he can't find the time.
I have a bunch of other things that I promised to work on - paravirt
diet, get SWIOTLB working everywhere, etc, but haven't been able to
find the time.
As such both David Vrabel and Boris Ostrovsky have graciously
volunteered to help with the maintership role. They will keep the lid
on regressions, bug-fixes, etc. I will be in the background to help -
but eventually there will be less of me doing the Xen GIT pulls and
more of them. Stefano is still doing the ARM/ARM64 and will continue
on doing so.
Features:
- Xen Trusted Platform Module (TPM) frontend driver - with the
backend in MiniOS.
- Scalability improvements in event channel.
- Two extra Xen co-maintainers (David, Boris) and one going away (Jeremy)
Bug-fixes:
- Make the 1:1 mapping work during early bootup on selective regions.
- Add scratch page to balloon driver to deal with unexpected code
still holding on stale pages.
- Allow NMIs on PV guests (64-bit only)
- Remove unnecessary TLB flush in M2P code.
- Fixes duplicate callbacks in Xen granttable code.
- Fixes in PRIVCMD_MMAPBATCH ioctls to allow retries
- Fix for events being lost due to rescheduling on different VCPUs.
- More documentation"
* tag 'stable/for-linus-3.12-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (23 commits)
hvc_xen: Remove unnecessary __GFP_ZERO from kzalloc
drivers/xen-tpmfront: Fix compile issue with missing option.
xen/balloon: don't set P2M entry for auto translated guest
xen/evtchn: double free on error
Xen: Fix retry calls into PRIVCMD_MMAPBATCH*.
xen/pvhvm: Initialize xen panic handler for PVHVM guests
xen/m2p: use GNTTABOP_unmap_and_replace to reinstate the original mapping
xen: fix ARM build after 6efa20e4
MAINTAINERS: Remove Jeremy from the Xen subsystem.
xen/events: document behaviour when scanning the start word for events
x86/xen: during early setup, only 1:1 map the ISA region
x86/xen: disable premption when enabling local irqs
swiotlb-xen: replace dma_length with sg_dma_len() macro
swiotlb: replace dma_length with sg_dma_len() macro
xen/balloon: set a mapping for ballooned out pages
xen/evtchn: improve scalability by using per-user locks
xen/p2m: avoid unneccesary TLB flush in m2p_remove_override()
MAINTAINERS: Add in two extra co-maintainers of the Xen tree.
MAINTAINERS: Update the Xen subsystem's with proper mailing list.
xen: replace strict_strtoul() with kstrtoul()
...
- On ARM did not have balanced calls to get/put_cpu.
- Fix to make tboot + Xen + Linux correctly.
- Fix events VCPU binding issues.
- Fix a vCPU online race where IPIs are sent to not-yet-online vCPU.
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Merge tag 'stable/for-linus-3.11-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen bug-fixes from Konrad Rzeszutek Wilk:
- On ARM did not have balanced calls to get/put_cpu.
- Fix to make tboot + Xen + Linux correctly.
- Fix events VCPU binding issues.
- Fix a vCPU online race where IPIs are sent to not-yet-online vCPU.
* tag 'stable/for-linus-3.11-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/smp: initialize IPI vectors before marking CPU online
xen/events: mask events when changing their VCPU binding
xen/events: initialize local per-cpu mask for all possible events
x86/xen: do not identity map UNUSABLE regions in the machine E820
xen/arm: missing put_cpu in xen_percpu_init
During early setup, when the reserved regions and MMIO holes are being
setup as 1:1 in the p2m, clear any mappings instead of making them 1:1
(execept for the ISA region which is expected to be mapped).
This fixes a regression introduced in 3.5 by 83d51ab473 (xen/setup:
update VA mapping when releasing memory during setup) which caused
hosts with tboot to fail to boot.
tboot marks a region in the e820 map as unusable and the dom0 kernel
would attempt to map this region and Xen does not permit unusable
regions to be mapped by guests.
(XEN) 0000000000000000 - 0000000000060000 (usable)
(XEN) 0000000000060000 - 0000000000068000 (reserved)
(XEN) 0000000000068000 - 000000000009e000 (usable)
(XEN) 0000000000100000 - 0000000000800000 (usable)
(XEN) 0000000000800000 - 0000000000972000 (unusable)
tboot marked this region as unusable.
(XEN) 0000000000972000 - 00000000cf200000 (usable)
(XEN) 00000000cf200000 - 00000000cf38f000 (reserved)
(XEN) 00000000cf38f000 - 00000000cf3ce000 (ACPI data)
(XEN) 00000000cf3ce000 - 00000000d0000000 (reserved)
(XEN) 00000000e0000000 - 00000000f0000000 (reserved)
(XEN) 00000000fe000000 - 0000000100000000 (reserved)
(XEN) 0000000100000000 - 0000000630000000 (usable)
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
If there are UNUSABLE regions in the machine memory map, dom0 will
attempt to map them 1:1 which is not permitted by Xen and the kernel
will crash.
There isn't anything interesting in the UNUSABLE region that the dom0
kernel needs access to so we can avoid making the 1:1 mapping and
treat it as RAM.
We only do this for dom0, as that is where tboot case shows up.
A PV domU could have an UNUSABLE region in its pseudo-physical map
and would need to be handled in another patch.
This fixes a boot failure on hosts with tboot.
tboot marks a region in the e820 map as unusable and the dom0 kernel
would attempt to map this region and Xen does not permit unusable
regions to be mapped by guests.
(XEN) 0000000000000000 - 0000000000060000 (usable)
(XEN) 0000000000060000 - 0000000000068000 (reserved)
(XEN) 0000000000068000 - 000000000009e000 (usable)
(XEN) 0000000000100000 - 0000000000800000 (usable)
(XEN) 0000000000800000 - 0000000000972000 (unusable)
tboot marked this region as unusable.
(XEN) 0000000000972000 - 00000000cf200000 (usable)
(XEN) 00000000cf200000 - 00000000cf38f000 (reserved)
(XEN) 00000000cf38f000 - 00000000cf3ce000 (ACPI data)
(XEN) 00000000cf3ce000 - 00000000d0000000 (reserved)
(XEN) 00000000e0000000 - 00000000f0000000 (reserved)
(XEN) 00000000fe000000 - 0000000100000000 (reserved)
(XEN) 0000000100000000 - 0000000630000000 (usable)
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
[v1: Altered the patch and description with domU's with UNUSABLE regions]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This is based on a patch that Zhenzhong Duan had sent - which
was missing some of the remaining pieces. The kernel has the
logic to handle Xen-type-exceptions using the paravirt interface
in the assembler code (see PARAVIRT_ADJUST_EXCEPTION_FRAME -
pv_irq_ops.adjust_exception_frame and and INTERRUPT_RETURN -
pv_cpu_ops.iret).
That means the nmi handler (and other exception handlers) use
the hypervisor iret.
The other changes that would be neccessary for this would
be to translate the NMI_VECTOR to one of the entries on the
ipi_vector and make xen_send_IPI_mask_allbutself use different
events.
Fortunately for us commit 1db01b4903
(xen: Clean up apic ipi interface) implemented this and we piggyback
on the cleanup such that the apic IPI interface will pass the right
vector value for NMI.
With this patch we can trigger NMIs within a PV guest (only tested
x86_64).
For this to work with normal PV guests (not initial domain)
we need the domain to be able to use the APIC ops - they are
already implemented to use the Xen event channels. For that
to be turned on in a PV domU we need to remove the masking
of X86_FEATURE_APIC.
Incidentally that means kgdb will also now work within
a PV guest without using the 'nokgdbroundup' workaround.
Note that the 32-bit version is different and this patch
does not enable that.
CC: Lisa Nguyen <lisa@xenapiadmin.com>
CC: Ben Guthro <benjamin.guthro@citrix.com>
CC: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v1: Fixed up per David Vrabel comments]
Reviewed-by: Ben Guthro <benjamin.guthro@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.
After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.
Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings. In any case, they are temporary and harmless.
This removes all the arch/x86 uses of the __cpuinit macros from
all C files. x86 only had the one __CPUINIT used in assembly files,
and it wasn't paired off with a .previous or a __FINIT, so we can
delete it directly w/o any corresponding additional change there.
[1] https://lkml.org/lkml/2013/5/20/589
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Remove 32-bit x86 a cmdline param "no-hlt",
and the cpuinfo_x86.hlt_works_ok that it sets.
If a user wants to avoid HLT, then "idle=poll"
is much more useful, as it avoids invocation of HLT
in idle, while "no-hlt" failed to do so.
Indeed, hlt_works_ok was consulted in only 3 places.
First, in /proc/cpuinfo where "hlt_bug yes"
would be printed if and only if the user booted
the system with "no-hlt" -- as there was no other code
to set that flag.
Second, check_hlt() would not invoke halt() if "no-hlt"
were on the cmdline.
Third, it was consulted in stop_this_cpu(), which is invoked
by native_machine_halt()/reboot_interrupt()/smp_stop_nmi_callback() --
all cases where the machine is being shutdown/reset.
The flag was not consulted in the more frequently invoked
play_dead()/hlt_play_dead() used in processor offline and suspend.
Since Linux-3.0 there has been a run-time notice upon "no-hlt" invocations
indicating that it would be removed in 2012.
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: x86@kernel.org
This macro is only invoked by Xen,
so make its definition specific to Xen.
> set_pm_idle_to_default()
< xen_set_default_idle()
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: xen-devel@lists.xensource.com
* When hotplugging PCI devices in a PV guest we can allocate Xen-SWIOTLB later.
* Cleanup Xen SWIOTLB.
* Support pages out grants from HVM domains in the backends.
* Support wild cards in xen-pciback.hide=(BDF) arguments.
* Update grant status updates with upstream hypervisor.
* Boot PV guests with more than 128GB.
* Cleanup Xen MMU code/add comments.
* Obtain XENVERS using a preferred method.
* Lay out generic changes to support Xen ARM.
* Allow privcmd ioctl for HVM (used to do only PV).
* Do v2 of mmap_batch for privcmd ioctls.
* If hypervisor saves the LED keyboard light - we will now instruct the kernel
about its state.
Fixes:
* More fixes to Xen PCI backend for various calls/FLR/etc.
* With more than 4GB in a 64-bit PV guest disable native SWIOTLB.
* Fix up smatch warnings.
* Fix up various return values in privmcmd and mm.
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Merge tag 'stable/for-linus-3.7-x86-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Pull Xen update from Konrad Rzeszutek Wilk:
"Features:
- When hotplugging PCI devices in a PV guest we can allocate
Xen-SWIOTLB later.
- Cleanup Xen SWIOTLB.
- Support pages out grants from HVM domains in the backends.
- Support wild cards in xen-pciback.hide=(BDF) arguments.
- Update grant status updates with upstream hypervisor.
- Boot PV guests with more than 128GB.
- Cleanup Xen MMU code/add comments.
- Obtain XENVERS using a preferred method.
- Lay out generic changes to support Xen ARM.
- Allow privcmd ioctl for HVM (used to do only PV).
- Do v2 of mmap_batch for privcmd ioctls.
- If hypervisor saves the LED keyboard light - we will now instruct
the kernel about its state.
Fixes:
- More fixes to Xen PCI backend for various calls/FLR/etc.
- With more than 4GB in a 64-bit PV guest disable native SWIOTLB.
- Fix up smatch warnings.
- Fix up various return values in privmcmd and mm."
* tag 'stable/for-linus-3.7-x86-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: (48 commits)
xen/pciback: Restore the PCI config space after an FLR.
xen-pciback: properly clean up after calling pcistub_device_find()
xen/vga: add the xen EFI video mode support
xen/x86: retrieve keyboard shift status flags from hypervisor.
xen/gndev: Xen backend support for paged out grant targets V4.
xen-pciback: support wild cards in slot specifications
xen/swiotlb: Fix compile warnings when using plain integer instead of NULL pointer.
xen/swiotlb: Remove functions not needed anymore.
xen/pcifront: Use Xen-SWIOTLB when initting if required.
xen/swiotlb: For early initialization, return zero on success.
xen/swiotlb: Use the swiotlb_late_init_with_tbl to init Xen-SWIOTLB late when PV PCI is used.
xen/swiotlb: Move the error strings to its own function.
xen/swiotlb: Move the nr_tbl determination in its own function.
xen/arm: compile and run xenbus
xen: resynchronise grant table status codes with upstream
xen/privcmd: return -EFAULT on error
xen/privcmd: Fix mmap batch ioctl error status copy back.
xen/privcmd: add PRIVCMD_MMAPBATCH_V2 ioctl
xen/mm: return more precise error from xen_remap_domain_range()
xen/mmu: If the revector fails, don't attempt to revector anything else.
...
The hypervisor is in charge of allocating the proper "NUMA" memory
and dealing with the CPU scheduler to keep them bound to the proper
NUMA node. The PV guests (and PVHVM) have no inkling of where they
run and do not need to know that right now. In the future we will
need to inject NUMA configuration data (if a guest spans two or more
NUMA nodes) so that the kernel can make the right choices. But those
patches are not yet present.
In the meantime, disable the NUMA capability in the PV guest, which
also fixes a bootup issue. Andre says:
"we see Dom0 crashes due to the kernel detecting the NUMA topology not
by ACPI, but directly from the northbridge (CONFIG_AMD_NUMA).
This will detect the actual NUMA config of the physical machine, but
will crash about the mismatch with Dom0's virtual memory. Variation of
the theme: Dom0 sees what it's not supposed to see.
This happens with the said config option enabled and on a machine where
this scanning is still enabled (K8 and Fam10h, not Bulldozer class)
We have this dump then:
NUMA: Warning: node ids are out of bound, from=-1 to=-1 distance=10
Scanning NUMA topology in Northbridge 24
Number of physical nodes 4
Node 0 MemBase 0000000000000000 Limit 0000000040000000
Node 1 MemBase 0000000040000000 Limit 0000000138000000
Node 2 MemBase 0000000138000000 Limit 00000001f8000000
Node 3 MemBase 00000001f8000000 Limit 0000000238000000
Initmem setup node 0 0000000000000000-0000000040000000
NODE_DATA [000000003ffd9000 - 000000003fffffff]
Initmem setup node 1 0000000040000000-0000000138000000
NODE_DATA [0000000137fd9000 - 0000000137ffffff]
Initmem setup node 2 0000000138000000-00000001f8000000
NODE_DATA [00000001f095e000 - 00000001f0984fff]
Initmem setup node 3 00000001f8000000-0000000238000000
Cannot find 159744 bytes in node 3
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff81d220e6>] __alloc_bootmem_node+0x43/0x96
Pid: 0, comm: swapper Not tainted 3.3.6 #1 AMD Dinar/Dinar
RIP: e030:[<ffffffff81d220e6>] [<ffffffff81d220e6>] __alloc_bootmem_node+0x43/0x96
.. snip..
[<ffffffff81d23024>] sparse_early_usemaps_alloc_node+0x64/0x178
[<ffffffff81d23348>] sparse_init+0xe4/0x25a
[<ffffffff81d16840>] paging_init+0x13/0x22
[<ffffffff81d07fbb>] setup_arch+0x9c6/0xa9b
[<ffffffff81683954>] ? printk+0x3c/0x3e
[<ffffffff81d01a38>] start_kernel+0xe5/0x468
[<ffffffff81d012cf>] x86_64_start_reservations+0xba/0xc1
[<ffffffff81007153>] ? xen_setup_runstate_info+0x2c/0x36
[<ffffffff81d050ee>] xen_start_kernel+0x565/0x56c
"
so we just disable NUMA scanning by setting numa_off=1.
CC: stable@vger.kernel.org
Reported-and-Tested-by: Andre Przywara <andre.przywara@amd.com>
Acked-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* stable/128gb.v5.1:
xen/mmu: If the revector fails, don't attempt to revector anything else.
xen/p2m: When revectoring deal with holes in the P2M array.
xen/mmu: Release just the MFN list, not MFN list and part of pagetables.
xen/mmu: Remove from __ka space PMD entries for pagetables.
xen/mmu: Copy and revector the P2M tree.
xen/p2m: Add logic to revector a P2M tree to use __va leafs.
xen/mmu: Recycle the Xen provided L4, L3, and L2 pages
xen/mmu: For 64-bit do not call xen_map_identity_early
xen/mmu: use copy_page instead of memcpy.
xen/mmu: Provide comments describing the _ka and _va aliasing issue
xen/mmu: The xen_setup_kernel_pagetable doesn't need to return anything.
Revert "xen/x86: Workaround 64-bit hypervisor and 32-bit initial domain." and "xen/x86: Use memblock_reserve for sensitive areas."
xen/x86: Workaround 64-bit hypervisor and 32-bit initial domain.
xen/x86: Use memblock_reserve for sensitive areas.
xen/p2m: Fix the comment describing the P2M tree.
Conflicts:
arch/x86/xen/mmu.c
The pagetable_init is the old xen_pagetable_setup_done and xen_pagetable_setup_start
rolled in one.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This reverts commit 806c312e50 and
commit 59b294403e.
And also documents setup.c and why we want to do it that way, which
is that we tried to make the the memblock_reserve more selective so
that it would be clear what region is reserved. Sadly we ran
in the problem wherein on a 64-bit hypervisor with a 32-bit
initial domain, the pt_base has the cr3 value which is not
neccessarily where the pagetable starts! As Jan put it: "
Actually, the adjustment turns out to be correct: The page
tables for a 32-on-64 dom0 get allocated in the order "first L1",
"first L2", "first L3", so the offset to the page table base is
indeed 2. When reading xen/include/public/xen.h's comment
very strictly, this is not a violation (since there nothing is said
that the first thing in the page table space is pointed to by
pt_base; I admit that this seems to be implied though, namely
do I think that it is implied that the page table space is the
range [pt_base, pt_base + nt_pt_frames), whereas that
range here indeed is [pt_base - 2, pt_base - 2 + nt_pt_frames),
which - without a priori knowledge - the kernel would have
difficulty to figure out)." - so lets just fall back to the
easy way and reserve the whole region.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
When we are finished with return PFNs to the hypervisor, then
populate it back, and also mark the E820 MMIO and E820 gaps
as IDENTITY_FRAMEs, we then call P2M to set areas that can
be used for ballooning. We were off by one, and ended up
over-writting a P2M entry that most likely was an IDENTITY_FRAME.
For example:
1-1 mapping on 40000->40200
1-1 mapping on bc558->bc5ac
1-1 mapping on bc5b4->bc8c5
1-1 mapping on bc8c6->bcb7c
1-1 mapping on bcd00->100000
Released 614 pages of unused memory
Set 277889 page(s) to 1-1 mapping
Populating 40200-40466 pfn range: 614 pages added
=> here we set from 40466 up to bc559 P2M tree to be
INVALID_P2M_ENTRY. We should have done it up to bc558.
The end result is that if anybody is trying to construct
a PTE for PFN bc558 they end up with ~PAGE_PRESENT.
CC: stable@vger.kernel.org
Reported-by-and-Tested-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
instead of a big memblock_reserve. This way we can be more
selective in freeing regions (and it also makes it easier
to understand where is what).
[v1: Move the auto_translate_physmap to proper line]
[v2: Per Stefano suggestion add more comments]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
We did not take into account that xen_released_pages would be
used outside the initial E820 parsing code. As such we would
did not subtract from xen_released_pages the count of pages
that we had populated back (instead we just did a simple
extra_pages = released - populated).
The balloon driver uses xen_released_pages to set the initial
current_pages count. If this is wrong (too low) then when a new
(higher) target is set, the balloon driver will request too many pages
from Xen."
This fixes errors such as:
(XEN) memory.c:133:d0 Could not allocate order=0 extent: id=0 memflags=0 (51 of 512)
during bootup and
free_memory : 0
where the free_memory should be 128.
Acked-by: David Vrabel <david.vrabel@citrix.com>
[v1: Per David's review made the git commit better]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
In xen_memory_setup(), if a page that is being released has a VA
mapping this must also be updated. Otherwise, the page will be not
released completely -- it will still be referenced in Xen and won't be
freed util the mapping is removed and this prevents it from being
reallocated at a different PFN.
This was already being done for the ISA memory region in
xen_ident_map_ISA() but on many systems this was omitting a few pages
as many systems marked a few pages below the ISA memory region as
reserved in the e820 map.
This fixes errors such as:
(XEN) page_alloc.c:1148:d0 Over-allocation for domain 0: 2097153 > 2097152
(XEN) memory.c:133:d0 Could not allocate order=0 extent: id=0 memflags=0 (0 of 17)
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
They use the same set of arguments, so it is just the matter
of using the proper hypercall.
Acked-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
When the Xen hypervisor boots a PV kernel it hands it two pieces
of information: nr_pages and a made up E820 entry.
The nr_pages value defines the range from zero to nr_pages of PFNs
which have a valid Machine Frame Number (MFN) underneath it. The
E820 mirrors that (with the VGA hole):
BIOS-provided physical RAM map:
Xen: 0000000000000000 - 00000000000a0000 (usable)
Xen: 00000000000a0000 - 0000000000100000 (reserved)
Xen: 0000000000100000 - 0000000080800000 (usable)
The fun comes when a PV guest that is run with a machine E820 - that
can either be the initial domain or a PCI PV guest, where the E820
looks like the normal thing:
BIOS-provided physical RAM map:
Xen: 0000000000000000 - 000000000009e000 (usable)
Xen: 000000000009ec00 - 0000000000100000 (reserved)
Xen: 0000000000100000 - 0000000020000000 (usable)
Xen: 0000000020000000 - 0000000020200000 (reserved)
Xen: 0000000020200000 - 0000000040000000 (usable)
Xen: 0000000040000000 - 0000000040200000 (reserved)
Xen: 0000000040200000 - 00000000bad80000 (usable)
Xen: 00000000bad80000 - 00000000badc9000 (ACPI NVS)
..
With that overlaying the nr_pages directly on the E820 does not
work as there are gaps and non-RAM regions that won't be used
by the memory allocator. The 'xen_release_chunk' helps with that
by punching holes in the P2M (PFN to MFN lookup tree) for those
regions and tells us that:
Freeing 20000-20200 pfn range: 512 pages freed
Freeing 40000-40200 pfn range: 512 pages freed
Freeing bad80-badf4 pfn range: 116 pages freed
Freeing badf6-bae7f pfn range: 137 pages freed
Freeing bb000-100000 pfn range: 282624 pages freed
Released 283999 pages of unused memory
Those 283999 pages are subtracted from the nr_pages and are returned
to the hypervisor. The end result is that the initial domain
boots with 1GB less memory as the nr_pages has been subtracted by
the amount of pages residing within the PCI hole. It can balloon up
to that if desired using 'xl mem-set 0 8092', but the balloon driver
is not always compiled in for the initial domain.
This patch, implements the populate hypercall (XENMEM_populate_physmap)
which increases the the domain with the same amount of pages that
were released.
The other solution (that did not work) was to transplant the MFN in
the P2M tree - the ones that were going to be freed were put in
the E820_RAM regions past the nr_pages. But the modifications to the
M2P array (the other side of creating PTEs) were not carried away.
As the hypervisor is the only one capable of modifying that and the
only two hypercalls that would do this are: the update_va_mapping
(which won't work, as during initial bootup only PFNs up to nr_pages
are mapped in the guest) or via the populate hypercall.
The end result is that the kernel can now boot with the
nr_pages without having to subtract the 283999 pages.
On a 8GB machine, with various dom0_mem= parameters this is what we get:
no dom0_mem
-Memory: 6485264k/9435136k available (5817k kernel code, 1136060k absent, 1813812k reserved, 2899k data, 696k init)
+Memory: 7619036k/9435136k available (5817k kernel code, 1136060k absent, 680040k reserved, 2899k data, 696k init)
dom0_mem=3G
-Memory: 2616536k/9435136k available (5817k kernel code, 1136060k absent, 5682540k reserved, 2899k data, 696k init)
+Memory: 2703776k/9435136k available (5817k kernel code, 1136060k absent, 5595300k reserved, 2899k data, 696k init)
dom0_mem=max:3G
-Memory: 2696732k/4281724k available (5817k kernel code, 1136060k absent, 448932k reserved, 2899k data, 696k init)
+Memory: 2702204k/4281724k available (5817k kernel code, 1136060k absent, 443460k reserved, 2899k data, 696k init)
And the 'xm list' or 'xl list' now reflect what the dom0_mem=
argument is.
Acked-by: David Vrabel <david.vrabel@citrix.com>
[v2: Use populate hypercall]
[v3: Remove debug printks]
[v4: Simplify code]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Otherwise we can get these meaningless:
Freeing bad80-badf4 pfn range: 0 pages freed
We also can do this for the summary ones - no point of printing
"Set 0 page(s) to 1-1 mapping"
Acked-by: David Vrabel <david.vrabel@citrix.com>
[v1: Extended to the summary printks]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
By using the functionality provided by "[CPUFREQ]: provide
disable_cpuidle() function to disable the API."
Under the Xen hypervisor we do not want the initial domain to exercise
the cpufreq scaling drivers. This is b/c the Xen hypervisor is
in charge of doing this as well and we can end up with both the
Linux kernel and the hypervisor trying to change the P-states
leading to weird performance issues.
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Fix compile error spotted by Benjamin Schweikert <b.schweikert@googlemail.com>]
We needed that call in the past to force the kernel to use
default_idle (which called safe_halt, which called xen_safe_halt).
But set_pm_idle_to_default() does now that, so there is no need
to use this boot option operand.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* 'stable/for-linus-fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/swiotlb: Use page alignment for early buffer allocation.
xen: only limit memory map to maximum reservation for domain 0.
d312ae878b "xen: use maximum reservation to limit amount of usable RAM"
clamped the total amount of RAM to the current maximum reservation. This is
correct for dom0 but is not correct for guest domains. In order to boot a guest
"pre-ballooned" (e.g. with memory=1G but maxmem=2G) in order to allow for
future memory expansion the guest must derive max_pfn from the e820 provided by
the toolstack and not the current maximum reservation (which can reflect only
the current maximum, not the guest lifetime max). The existing algorithm
already behaves this correctly if we do not artificially limit the maximum
number of pages for the guest case.
For a guest booted with maxmem=512, memory=128 this results in:
[ 0.000000] BIOS-provided physical RAM map:
[ 0.000000] Xen: 0000000000000000 - 00000000000a0000 (usable)
[ 0.000000] Xen: 00000000000a0000 - 0000000000100000 (reserved)
-[ 0.000000] Xen: 0000000000100000 - 0000000008100000 (usable)
-[ 0.000000] Xen: 0000000008100000 - 0000000020800000 (unusable)
+[ 0.000000] Xen: 0000000000100000 - 0000000020800000 (usable)
...
[ 0.000000] NX (Execute Disable) protection: active
[ 0.000000] DMI not present or invalid.
[ 0.000000] e820 update range: 0000000000000000 - 0000000000010000 (usable) ==> (reserved)
[ 0.000000] e820 remove range: 00000000000a0000 - 0000000000100000 (usable)
-[ 0.000000] last_pfn = 0x8100 max_arch_pfn = 0x1000000
+[ 0.000000] last_pfn = 0x20800 max_arch_pfn = 0x1000000
[ 0.000000] initial memory mapped : 0 - 027ff000
[ 0.000000] Base memory trampoline at [c009f000] 9f000 size 4096
-[ 0.000000] init_memory_mapping: 0000000000000000-0000000008100000
-[ 0.000000] 0000000000 - 0008100000 page 4k
-[ 0.000000] kernel direct mapping tables up to 8100000 @ 27bb000-27ff000
+[ 0.000000] init_memory_mapping: 0000000000000000-0000000020800000
+[ 0.000000] 0000000000 - 0020800000 page 4k
+[ 0.000000] kernel direct mapping tables up to 20800000 @ 26f8000-27ff000
[ 0.000000] xen: setting RW the range 27e8000 - 27ff000
[ 0.000000] 0MB HIGHMEM available.
-[ 0.000000] 129MB LOWMEM available.
-[ 0.000000] mapped low ram: 0 - 08100000
-[ 0.000000] low ram: 0 - 08100000
+[ 0.000000] 520MB LOWMEM available.
+[ 0.000000] mapped low ram: 0 - 20800000
+[ 0.000000] low ram: 0 - 20800000
With this change "xl mem-set <domain> 512M" will successfully increase the
guest RAM (by reducing the balloon).
There is no change for dom0.
Reported-and-Tested-by: George Shuklin <george.shuklin@gmail.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: stable@kernel.org
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The idea behind commit d91ee5863b ("cpuidle: replace xen access to x86
pm_idle and default_idle") was to have one call - disable_cpuidle()
which would make pm_idle not be molested by other code. It disallows
cpuidle_idle_call to be set to pm_idle (which is excellent).
But in the select_idle_routine() and idle_setup(), the pm_idle can still
be set to either: amd_e400_idle, mwait_idle or default_idle. This
depends on some CPU flags (MWAIT) and in AMD case on the type of CPU.
In case of mwait_idle we can hit some instances where the hypervisor
(Amazon EC2 specifically) sets the MWAIT and we get:
Brought up 2 CPUs
invalid opcode: 0000 [#1] SMP
Pid: 0, comm: swapper Not tainted 3.1.0-0.rc6.git0.3.fc16.x86_64 #1
RIP: e030:[<ffffffff81015d1d>] [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4
...
Call Trace:
[<ffffffff8100e2ed>] cpu_idle+0xae/0xe8
[<ffffffff8149ee78>] cpu_bringup_and_idle+0xe/0x10
RIP [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4
RSP <ffff8801d28ddf10>
In the case of amd_e400_idle we don't get so spectacular crashes, but we
do end up making an MSR which is trapped in the hypervisor, and then
follow it up with a yield hypercall. Meaning we end up going to
hypervisor twice instead of just once.
The previous behavior before v3.0 was that pm_idle was set to
default_idle regardless of select_idle_routine/idle_setup.
We want to do that, but only for one specific case: Xen. This patch
does that.
Fixes RH BZ #739499 and Ubuntu #881076
Reported-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Conflicts & resolutions:
* arch/x86/xen/setup.c
dc91c728fd "xen: allow extra memory to be in multiple regions"
24aa07882b "memblock, x86: Replace memblock_x86_reserve/free..."
conflicted on xen_add_extra_mem() updates. The resolution is
trivial as the latter just want to replace
memblock_x86_reserve_range() with memblock_reserve().
* drivers/pci/intel-iommu.c
166e9278a3 "x86/ia64: intel-iommu: move to drivers/iommu/"
5dfe8660a3 "bootmem: Replace work_with_active_regions() with..."
conflicted as the former moved the file under drivers/iommu/.
Resolved by applying the chnages from the latter on the moved
file.
* mm/Kconfig
6661672053 "memblock: add NO_BOOTMEM config symbol"
c378ddd53f "memblock, x86: Make ARCH_DISCARD_MEMBLOCK a config option"
conflicted trivially. Both added config options. Just
letting both add their own options resolves the conflict.
* mm/memblock.c
d1f0ece6cd "mm/memblock.c: small function definition fixes"
ed7b56a799 "memblock: Remove memblock_memory_can_coalesce()"
confliected. The former updates function removed by the
latter. Resolution is trivial.
Signed-off-by: Tejun Heo <tj@kernel.org>
In xen_memory_setup() all reserved regions and gaps are set to an
identity (1-1) p2m mapping. If an available page has a PFN within one
of these 1-1 mappings it will become inaccessible (as it MFN is lost)
so release them before setting up the mapping.
This can make an additional 256 MiB or more of RAM available
(depending on the size of the reserved regions in the memory map) if
the initial pages overlap with reserved regions.
The 1:1 p2m mappings are also extended to cover partial pages. This
fixes an issue with (for example) systems with a BIOS that puts the
DMI tables in a reserved region that begins on a non-page boundary.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Allow the extra memory (used by the balloon driver) to be in multiple
regions (typically two regions, one for low memory and one for high
memory). This allows the balloon driver to increase the number of
available low pages (if the initial number if pages is small).
As a side effect, the algorithm for building the e820 memory map is
simpler and more obviously correct as the map supplied by the
hypervisor is (almost) used as is (in particular, all reserved regions
and gaps are preserved). Only RAM regions are altered and RAM regions
above max_pfn + extra_pages are marked as unused (the region is split
in two if necessary).
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Allow the xen balloon driver to populate its list of extra pages from
more than one region of memory. This will allow platforms to provide
(for example) a region of low memory and a region of high memory.
The maximum possible number of extra regions is 128 (== E820MAX) which
is quite large so xen_extra_mem is placed in __initdata. This is safe
as both xen_memory_setup() and balloon_init() are in __init.
The balloon regions themselves are not altered (i.e., there is still
only the one region).
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
In xen_memory_setup() pages that occur in gaps in the memory map are
released back to Xen. This reduces the domain's current page count in
the hypervisor. The Xen balloon driver does not correctly decrease
its initial current_pages count to reflect this. If 'delta' pages are
released and the target is adjusted the resulting reservation is
always 'delta' less than the requested target.
This affects dom0 if the initial allocation of pages overlaps the PCI
memory region but won't affect most domU guests that have been setup
with pseudo-physical memory maps that don't have gaps.
Fix this by accouting for the released pages when starting the balloon
driver.
If the domain's targets are managed by xapi, the domain may eventually
run out of memory and die because xapi currently gets its target
calculations wrong and whenever it is restarted it always reduces the
target by 'delta'.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* 'stable/bug.fixes' of git://oss.oracle.com/git/kwilk/xen:
xen/i386: follow-up to "replace order-based range checking of M2P table by linear one"
xen/irq: Alter the locking to use a mutex instead of a spinlock.
xen/e820: if there is no dom0_mem=, don't tweak extra_pages.
xen: disable PV spinlocks on HVM
The patch "xen: use maximum reservation to limit amount of usable RAM"
(d312ae878b) breaks machines that
do not use 'dom0_mem=' argument with:
reserve RAM buffer: 000000133f2e2000 - 000000133fffffff
(XEN) mm.c:4976:d0 Global bit is set to kernel page fffff8117e
(XEN) domain_crash_sync called from entry.S
(XEN) Domain 0 (vcpu#0) crashed on cpu#0:
...
The reason being that the last E820 entry is created using the
'extra_pages' (which is based on how many pages have been freed).
The mentioned git commit sets the initial value of 'extra_pages'
using a hypercall which returns the number of pages (if dom0_mem
has been used) or -1 otherwise. If the later we return with
MAX_DOMAIN_PAGES as basis for calculation:
return min(max_pages, MAX_DOMAIN_PAGES);
and use it:
extra_limit = xen_get_max_pages();
if (extra_limit >= max_pfn)
extra_pages = extra_limit - max_pfn;
else
extra_pages = 0;
which means we end up with extra_pages = 128GB in PFNs (33554432)
- 8GB in PFNs (2097152, on this specific box, can be larger or smaller),
and then we add that value to the E820 making it:
Xen: 00000000ff000000 - 0000000100000000 (reserved)
Xen: 0000000100000000 - 000000133f2e2000 (usable)
which is clearly wrong. It should look as so:
Xen: 00000000ff000000 - 0000000100000000 (reserved)
Xen: 0000000100000000 - 000000027fbda000 (usable)
Naturally this problem does not present itself if dom0_mem=max:X
is used.
CC: stable@kernel.org
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* 'stable/bug.fixes' of git://oss.oracle.com/git/kwilk/xen:
xen/smp: Warn user why they keel over - nosmp or noapic and what to use instead.
xen: x86_32: do not enable iterrupts when returning from exception in interrupt context
xen: use maximum reservation to limit amount of usable RAM
Use the domain's maximum reservation to limit the amount of extra RAM
for the memory balloon. This reduces the size of the pages tables and
the amount of reserved low memory (which defaults to about 1/32 of the
total RAM).
On a system with 8 GiB of RAM with the domain limited to 1 GiB the
kernel reports:
Before:
Memory: 627792k/4472000k available
After:
Memory: 549740k/11132224k available
A increase of about 76 MiB (~1.5% of the unused 7 GiB). The reserved
low memory is also reduced from 253 MiB to 32 MiB. The total
additional usable RAM is 329 MiB.
For dom0, this requires at patch to Xen ('x86: use 'dom0_mem' to limit
the number of pages for dom0') (c/s 23790)
CC: stable@kernel.org
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
