Commit Graph

11591 Commits

Author SHA1 Message Date
Joao Martins
73e69a8634 KVM: x86/xen: register vcpu info
The vcpu info supersedes the per vcpu area of the shared info page and
the guest vcpus will use this instead.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
2021-02-04 14:19:39 +00:00
David Woodhouse
42387042ba xen: add wc_sec_hi to struct shared_info
Xen added this in 2015 (Xen 4.6). On x86_64 and Arm it fills what was
previously a 32-bit hole in the generic shared_info structure; on
i386 it had to go at the end of struct arch_shared_info.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
2021-02-04 14:19:38 +00:00
Joao Martins
13ffb97a3b KVM: x86/xen: register shared_info page
Add KVM_XEN_ATTR_TYPE_SHARED_INFO to allow hypervisor to know where the
guest's shared info page is.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
2021-02-04 14:19:38 +00:00
David Woodhouse
a3833b81b0 KVM: x86/xen: latch long_mode when hypercall page is set up
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
2021-02-04 14:19:38 +00:00
Joao Martins
23200b7a30 KVM: x86/xen: intercept xen hypercalls if enabled
Add a new exit reason for emulator to handle Xen hypercalls.

Since this means KVM owns the ABI, dispense with the facility for the
VMM to provide its own copy of the hypercall pages; just fill them in
directly using VMCALL/VMMCALL as we do for the Hyper-V hypercall page.

This behaviour is enabled by a new INTERCEPT_HCALL flag in the
KVM_XEN_HVM_CONFIG ioctl structure, and advertised by the same flag
being returned from the KVM_CAP_XEN_HVM check.

Rename xen_hvm_config() to kvm_xen_write_hypercall_page() and move it
to the nascent xen.c while we're at it, and add a test case.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
2021-02-04 14:18:45 +00:00
Ben Gardon
9a77daacc8 KVM: x86/mmu: Use atomic ops to set SPTEs in TDP MMU map
To prepare for handling page faults in parallel, change the TDP MMU
page fault handler to use atomic operations to set SPTEs so that changes
are not lost if multiple threads attempt to modify the same SPTE.

Reviewed-by: Peter Feiner <pfeiner@google.com>
Signed-off-by: Ben Gardon <bgardon@google.com>

Message-Id: <20210202185734.1680553-21-bgardon@google.com>
[Document new locking rules. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04 05:27:44 -05:00
Ben Gardon
531810caa9 KVM: x86/mmu: Use an rwlock for the x86 MMU
Add a read / write lock to be used in place of the MMU spinlock on x86.
The rwlock will enable the TDP MMU to handle page faults, and other
operations in parallel in future commits.

Reviewed-by: Peter Feiner <pfeiner@google.com>
Signed-off-by: Ben Gardon <bgardon@google.com>

Message-Id: <20210202185734.1680553-19-bgardon@google.com>
[Introduce virt/kvm/mmu_lock.h - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04 05:27:43 -05:00
Sean Christopherson
6a28913947 KVM: VMX: Use the kernel's version of VMXOFF
Drop kvm_cpu_vmxoff() in favor of the kernel's cpu_vmxoff().  Modify the
latter to return -EIO on fault so that KVM can invoke
kvm_spurious_fault() when appropriate.  In addition to the obvious code
reuse, dropping kvm_cpu_vmxoff() also eliminates VMX's last usage of the
__ex()/__kvm_handle_fault_on_reboot() macros, thus helping pave the way
toward dropping them entirely.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20201231002702.2223707-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04 05:27:33 -05:00
David P. Reed
53666664a3 x86/virt: Mark flags and memory as clobbered by VMXOFF
Explicitly tell the compiler that VMXOFF modifies flags (like all VMX
instructions), and mark memory as clobbered since VMXOFF must not be
reordered and also may have memory side effects (though the kernel
really shouldn't be accessing the root VMCS anyways).

Practically speaking, adding the clobbers is most likely a nop; the
primary motivation is to properly document VMXOFF's behavior.

For the flags clobber, both Clang and GCC automatically mark flags as
clobbered; this is noted in commit 4b1e54786e ("KVM/x86: Use assembly
instruction mnemonics instead of .byte streams"), which intentionally
removed the previous clobber.  But, neither Clang nor GCC documents
this behavior, and there's no downside to including the clobber.

For the memory clobber, the RFLAGS.IF and CR4.VMXE manipulations that
immediately follow VMXOFF have compiler barriers of their own, i.e.
VMXOFF can't get reordered after clearing CR4.VMXE, which is really
what's of interest.

Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David P. Reed <dpreed@deepplum.com>
[sean: rewrote changelog, dropped comment adjustments]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20201231002702.2223707-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04 05:27:32 -05:00
Sean Christopherson
aec511ad15 x86/virt: Eat faults on VMXOFF in reboot flows
Silently ignore all faults on VMXOFF in the reboot flows as such faults
are all but guaranteed to be due to the CPU not being in VMX root.
Because (a) VMXOFF may be executed in NMI context, e.g. after VMXOFF but
before CR4.VMXE is cleared, (b) there's no way to query the CPU's VMX
state without faulting, and (c) the whole point is to get out of VMX
root, eating faults is the simplest way to achieve the desired behaior.

Technically, VMXOFF can fault (or fail) for other reasons, but all other
fault and failure scenarios are mode related, i.e. the kernel would have
to magically end up in RM, V86, compat mode, at CPL>0, or running with
the SMI Transfer Monitor active.  The kernel is beyond hosed if any of
those scenarios are encountered; trying to do something fancy in the
error path to handle them cleanly is pointless.

Fixes: 1e9931146c ("x86: asm/virtext.h: add cpu_vmxoff() inline function")
Reported-by: David P. Reed <dpreed@deepplum.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20201231002702.2223707-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04 05:27:31 -05:00
Jason Baron
b3646477d4 KVM: x86: use static calls to reduce kvm_x86_ops overhead
Convert kvm_x86_ops to use static calls. Note that all kvm_x86_ops are
covered here except for 'pmu_ops and 'nested ops'.

Here are some numbers running cpuid in a loop of 1 million calls averaged
over 5 runs, measured in the vm (lower is better).

Intel Xeon 3000MHz:

           |default    |mitigations=off
-------------------------------------
vanilla    |.671s      |.486s
static call|.573s(-15%)|.458s(-6%)

AMD EPYC 2500MHz:

           |default    |mitigations=off
-------------------------------------
vanilla    |.710s      |.609s
static call|.664s(-6%) |.609s(0%)

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jason Baron <jbaron@akamai.com>
Message-Id: <e057bf1b8a7ad15652df6eeba3f907ae758d3399.1610680941.git.jbaron@akamai.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04 05:27:30 -05:00
Jason Baron
9af5471bdb KVM: x86: introduce definitions to support static calls for kvm_x86_ops
Use static calls to improve kvm_x86_ops performance. Introduce the
definitions that will be used by a subsequent patch to actualize the
savings. Add a new kvm-x86-ops.h header that can be used for the
definition of static calls. This header is also intended to be
used to simplify the defition of svm_kvm_ops and vmx_x86_ops.

Note that all functions in kvm_x86_ops are covered here except for
'pmu_ops' and 'nested ops'. I think they can be covered by static
calls in a simlilar manner, but were omitted from this series to
reduce scope and because I don't think they have as large of a
performance impact.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Jason Baron <jbaron@akamai.com>
Message-Id: <e5cc82ead7ab37b2dceb0837a514f3f8bea4f8d1.1610680941.git.jbaron@akamai.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04 05:27:29 -05:00
Wei Huang
3b9c723ed7 KVM: SVM: Add support for SVM instruction address check change
New AMD CPUs have a change that checks #VMEXIT intercept on special SVM
instructions before checking their EAX against reserved memory region.
This change is indicated by CPUID_0x8000000A_EDX[28]. If it is 1, #VMEXIT
is triggered before #GP. KVM doesn't need to intercept and emulate #GP
faults as #GP is supposed to be triggered.

Co-developed-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Wei Huang <wei.huang2@amd.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210126081831.570253-4-wei.huang2@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04 05:27:28 -05:00
Chenyi Qiang
9a3ecd5e2a KVM: X86: Rename DR6_INIT to DR6_ACTIVE_LOW
DR6_INIT contains the 1-reserved bits as well as the bit that is cleared
to 0 when the condition (e.g. RTM) happens. The value can be used to
initialize dr6 and also be the XOR mask between the #DB exit
qualification (or payload) and DR6.

Concerning that DR6_INIT is used as initial value only once, rename it
to DR6_ACTIVE_LOW and apply it in other places, which would make the
incoming changes for bus lock debug exception more simple.

Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Message-Id: <20210202090433.13441-2-chenyi.qiang@intel.com>
[Define DR6_FIXED_1 from DR6_ACTIVE_LOW and DR6_VOLATILE. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04 05:27:27 -05:00
Chenyi Qiang
fe6b6bc802 KVM: VMX: Enable bus lock VM exit
Virtual Machine can exploit bus locks to degrade the performance of
system. Bus lock can be caused by split locked access to writeback(WB)
memory or by using locks on uncacheable(UC) memory. The bus lock is
typically >1000 cycles slower than an atomic operation within a cache
line. It also disrupts performance on other cores (which must wait for
the bus lock to be released before their memory operations can
complete).

To address the threat, bus lock VM exit is introduced to notify the VMM
when a bus lock was acquired, allowing it to enforce throttling or other
policy based mitigations.

A VMM can enable VM exit due to bus locks by setting a new "Bus Lock
Detection" VM-execution control(bit 30 of Secondary Processor-based VM
execution controls). If delivery of this VM exit was preempted by a
higher priority VM exit (e.g. EPT misconfiguration, EPT violation, APIC
access VM exit, APIC write VM exit, exception bitmap exiting), bit 26 of
exit reason in vmcs field is set to 1.

In current implementation, the KVM exposes this capability through
KVM_CAP_X86_BUS_LOCK_EXIT. The user can get the supported mode bitmap
(i.e. off and exit) and enable it explicitly (disabled by default). If
bus locks in guest are detected by KVM, exit to user space even when
current exit reason is handled by KVM internally. Set a new field
KVM_RUN_BUS_LOCK in vcpu->run->flags to inform the user space that there
is a bus lock detected in guest.

Document for Bus Lock VM exit is now available at the latest "Intel
Architecture Instruction Set Extensions Programming Reference".

Document Link:
https://software.intel.com/content/www/us/en/develop/download/intel-architecture-instruction-set-extensions-programming-reference.html

Co-developed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Message-Id: <20201106090315.18606-4-chenyi.qiang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04 05:27:21 -05:00
Sean Christopherson
c5e2184d15 KVM: x86/mmu: Remove the defunct update_pte() paging hook
Remove the update_pte() shadow paging logic, which was obsoleted by
commit 4731d4c7a0 ("KVM: MMU: out of sync shadow core"), but never
removed.  As pointed out by Yu, KVM never write protects leaf page
tables for the purposes of shadow paging, and instead marks their
associated shadow page as unsync so that the guest can write PTEs at
will.

The update_pte() path, which predates the unsync logic, optimizes COW
scenarios by refreshing leaf SPTEs when they are written, as opposed to
zapping the SPTE, restarting the guest, and installing the new SPTE on
the subsequent fault.  Since KVM no longer write-protects leaf page
tables, update_pte() is unreachable and can be dropped.

Reported-by: Yu Zhang <yu.c.zhang@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210115004051.4099250-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04 05:27:17 -05:00
Kyung Min Park
b85a0425d8 Enumerate AVX Vector Neural Network instructions
Add AVX version of the Vector Neural Network (VNNI) Instructions.

A processor supports AVX VNNI instructions if CPUID.0x07.0x1:EAX[4] is
present. The following instructions are available when this feature is
present.
  1. VPDPBUS: Multiply and Add Unsigned and Signed Bytes
  2. VPDPBUSDS: Multiply and Add Unsigned and Signed Bytes with Saturation
  3. VPDPWSSD: Multiply and Add Signed Word Integers
  4. VPDPWSSDS: Multiply and Add Signed Integers with Saturation

The only in-kernel usage of this is kvm passthrough. The CPU feature
flag is shown as "avx_vnni" in /proc/cpuinfo.

This instruction is currently documented in the latest "extensions"
manual (ISE). It will appear in the "main" manual (SDM) in the future.

Signed-off-by: Kyung Min Park <kyung.min.park@intel.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Message-Id: <20210105004909.42000-2-yang.zhong@intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04 05:27:16 -05:00
Kan Liang
61b985e3e7 perf/x86/intel: Add perf core PMU support for Sapphire Rapids
Add perf core PMU support for the Intel Sapphire Rapids server, which is
the successor of the Intel Ice Lake server. The enabling code is based
on Ice Lake, but there are several new features introduced.

The event encoding is changed and simplified, e.g., the event codes
which are below 0x90 are restricted to counters 0-3. The event codes
which above 0x90 are likely to have no restrictions. The event
constraints, extra_regs(), and hardware cache events table are changed
accordingly.

A new Precise Distribution (PDist) facility is introduced, which
further minimizes the skid when a precise event is programmed on the GP
counter 0. Enable the Precise Distribution (PDist) facility with :ppp
event. For this facility to work, the period must be initialized with a
value larger than 127. Add spr_limit_period() to apply the limit for
:ppp event.

Two new data source fields, data block & address block, are added in the
PEBS Memory Info Record for the load latency event. To enable the
feature,
- An auxiliary event has to be enabled together with the load latency
  event on Sapphire Rapids. A new flag PMU_FL_MEM_LOADS_AUX is
  introduced to indicate the case. A new event, mem-loads-aux, is
  exposed to sysfs for the user tool.
  Add a check in hw_config(). If the auxiliary event is not detected,
  return an unique error -ENODATA.
- The union perf_mem_data_src is extended to support the new fields.
- Ice Lake and earlier models do not support block information, but the
  fields may be set by HW on some machines. Add pebs_no_block to
  explicitly indicate the previous platforms which don't support the new
  block fields. Accessing the new block fields are ignored on those
  platforms.

A new store Latency facility is introduced, which leverages the PEBS
facility where it can provide additional information about sampled
stores. The additional information includes the data address, memory
auxiliary info (e.g. Data Source, STLB miss) and the latency of the
store access. To enable the facility, the new event (0x02cd) has to be
programed on the GP counter 0. A new flag PERF_X86_EVENT_PEBS_STLAT is
introduced to indicate the event. The store_latency_data() is introduced
to parse the memory auxiliary info.

The layout of access latency field of PEBS Memory Info Record has been
changed. Two latency, instruction latency (bit 15:0) and cache access
latency (bit 47:32) are recorded.
- The cache access latency is similar to previous memory access latency.
  For loads, the latency starts by the actual cache access until the
  data is returned by the memory subsystem.
  For stores, the latency starts when the demand write accesses the L1
  data cache and lasts until the cacheline write is completed in the
  memory subsystem.
  The cache access latency is stored in low 32bits of the sample type
  PERF_SAMPLE_WEIGHT_STRUCT.
- The instruction latency starts by the dispatch of the load operation
  for execution and lasts until completion of the instruction it belongs
  to.
  Add a new flag PMU_FL_INSTR_LATENCY to indicate the instruction
  latency support. The instruction latency is stored in the bit 47:32
  of the sample type PERF_SAMPLE_WEIGHT_STRUCT.

Extends the PERF_METRICS MSR to feature TMA method level 2 metrics. The
lower half of the register is the TMA level 1 metrics (legacy). The
upper half is also divided into four 8-bit fields for the new level 2
metrics. Expose all eight Topdown metrics events to user space.

The full description for the SPR features can be found at Intel
Architecture Instruction Set Extensions and Future Features
Programming Reference, 319433-041.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1611873611-156687-5-git-send-email-kan.liang@linux.intel.com
2021-02-01 15:31:37 +01:00
Kan Liang
1ab5f235c1 perf/x86/intel: Filter unsupported Topdown metrics event
Intel Sapphire Rapids server will introduce 8 metrics events. Intel
Ice Lake only supports 4 metrics events. A perf tool user may mistakenly
use the unsupported events via RAW format on Ice Lake. The user can
still get a value from the unsupported Topdown metrics event once the
following Sapphire Rapids enabling patch is applied.

To enable the 8 metrics events on Intel Sapphire Rapids, the
INTEL_TD_METRIC_MAX has to be updated, which impacts the
is_metric_event(). The is_metric_event() is a generic function.
On Ice Lake, the newly added SPR metrics events will be mistakenly
accepted as metric events on creation. At runtime, the unsupported
Topdown metrics events will be updated.

Add a variable num_topdown_events in x86_pmu to indicate the available
number of the Topdown metrics event on the platform. Apply the number
into is_metric_event(). Only the supported Topdown metrics events
should be created as metrics events.

Apply the num_topdown_events in icl_update_topdown_event() as well. The
function can be reused by the following patch.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1611873611-156687-4-git-send-email-kan.liang@linux.intel.com
2021-02-01 15:31:36 +01:00
Will Deacon
c7bd8010a3 tlb: arch: Remove empty __tlb_remove_tlb_entry() stubs
If __tlb_remove_tlb_entry() is not defined by the architecture then
we provide an empty definition in asm-generic/tlb.h.

Remove the redundant empty definitions for sparc64 and x86.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Yu Zhao <yuzhao@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lkml.kernel.org/r/20210127235347.1402-6-will@kernel.org
2021-01-29 20:02:29 +01:00
Andy Lutomirski
49200d17d2 x86/fpu/64: Don't FNINIT in kernel_fpu_begin()
The remaining callers of kernel_fpu_begin() in 64-bit kernels don't use 387
instructions, so there's no need to sanitize the FPU state.  Skip it to get
most of the performance we lost back.

Reported-by: Krzysztof Olędzki <ole@ans.pl>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/57f8841ccbf9f3c25a23196c888f5f6ec5887577.1611205691.git.luto@kernel.org
2021-01-29 12:27:47 +01:00
Andy Lutomirski
b0dc553cfc x86/fpu: Make the EFI FPU calling convention explicit
EFI uses kernel_fpu_begin() to conform to the UEFI calling convention.
This specifically requires initializing FCW (FPU Control Word), whereas
no sane 64-bit kernel code should use legacy 387 operations that
reference FCW.

This should allow to safely change the default semantics of
kernel_fpu_begin() to stop initializing FCW on 64-bit kernels.

 [ bp: Massage commit message a little. ]

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/25d392fff64680e0f4bb8cf0b1003314dc29eafe.1611205691.git.luto@kernel.org
2021-01-29 12:22:15 +01:00
Viresh Kumar
a6a0683b71 arch: x86: Remove CONFIG_OPROFILE support
The "oprofile" user-space tools don't use the kernel OPROFILE support
any more, and haven't in a long time. User-space has been converted to
the perf interfaces.

Remove the old oprofile's architecture specific support.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Robert Richter <rric@kernel.org>
Acked-by: William Cohen <wcohen@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
2021-01-29 10:05:51 +05:30
Linus Torvalds
e5ff2cb9cf Merge tag 'for-linus-5.11-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:

 - A fix for a regression introduced in 5.11 resulting in Xen dom0
   having problems to correctly initialize Xenstore.

 - A fix for avoiding WARN splats when booting as Xen dom0 with
   CONFIG_AMD_MEM_ENCRYPT enabled due to a missing trap handler for the
   #VC exception (even if the handler should never be called).

 - A fix for the Xen bklfront driver adapting to the correct but
   unexpected behavior of new qemu.

* tag 'for-linus-5.11-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: avoid warning in Xen pv guest with CONFIG_AMD_MEM_ENCRYPT enabled
  xen: Fix XenStore initialisation for XS_LOCAL
  xen-blkfront: allow discard-* nodes to be optional
2021-01-28 10:08:08 -08:00
Sean Christopherson
fb35d30fe5 x86/cpufeatures: Assign dedicated feature word for CPUID_0x8000001F[EAX]
Collect the scattered SME/SEV related feature flags into a dedicated
word.  There are now five recognized features in CPUID.0x8000001F.EAX,
with at least one more on the horizon (SEV-SNP).  Using a dedicated word
allows KVM to use its automagic CPUID adjustment logic when reporting
the set of supported features to userspace.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Link: https://lkml.kernel.org/r/20210122204047.2860075-2-seanjc@google.com
2021-01-28 17:41:24 +01:00
Like Xu
abd562df94 x86/perf: Use static_call for x86_pmu.guest_get_msrs
Clean up that CONFIG_RETPOLINE crud and replace the
indirect call x86_pmu.guest_get_msrs with static_call().

Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210125121458.181635-1-like.xu@linux.intel.com
2021-01-27 17:26:58 +01:00
Juergen Gross
2e92493637 x86/xen: avoid warning in Xen pv guest with CONFIG_AMD_MEM_ENCRYPT enabled
When booting a kernel which has been built with CONFIG_AMD_MEM_ENCRYPT
enabled as a Xen pv guest a warning is issued for each processor:

[    5.964347] ------------[ cut here ]------------
[    5.968314] WARNING: CPU: 0 PID: 1 at /home/gross/linux/head/arch/x86/xen/enlighten_pv.c:660 get_trap_addr+0x59/0x90
[    5.972321] Modules linked in:
[    5.976313] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W         5.11.0-rc5-default #75
[    5.980313] Hardware name: Dell Inc. OptiPlex 9020/0PC5F7, BIOS A05 12/05/2013
[    5.984313] RIP: e030:get_trap_addr+0x59/0x90
[    5.988313] Code: 42 10 83 f0 01 85 f6 74 04 84 c0 75 1d b8 01 00 00 00 c3 48 3d 00 80 83 82 72 08 48 3d 20 81 83 82 72 0c b8 01 00 00 00 eb db <0f> 0b 31 c0 c3 48 2d 00 80 83 82 48 ba 72 1c c7 71 1c c7 71 1c 48
[    5.992313] RSP: e02b:ffffc90040033d38 EFLAGS: 00010202
[    5.996313] RAX: 0000000000000001 RBX: ffffffff82a141d0 RCX: ffffffff8222ec38
[    6.000312] RDX: ffffffff8222ec38 RSI: 0000000000000005 RDI: ffffc90040033d40
[    6.004313] RBP: ffff8881003984a0 R08: 0000000000000007 R09: ffff888100398000
[    6.008312] R10: 0000000000000007 R11: ffffc90040246000 R12: ffff8884082182a8
[    6.012313] R13: 0000000000000100 R14: 000000000000001d R15: ffff8881003982d0
[    6.016316] FS:  0000000000000000(0000) GS:ffff888408200000(0000) knlGS:0000000000000000
[    6.020313] CS:  e030 DS: 0000 ES: 0000 CR0: 0000000080050033
[    6.024313] CR2: ffffc900020ef000 CR3: 000000000220a000 CR4: 0000000000050660
[    6.028314] Call Trace:
[    6.032313]  cvt_gate_to_trap.part.7+0x3f/0x90
[    6.036313]  ? asm_exc_double_fault+0x30/0x30
[    6.040313]  xen_convert_trap_info+0x87/0xd0
[    6.044313]  xen_pv_cpu_up+0x17a/0x450
[    6.048313]  bringup_cpu+0x2b/0xc0
[    6.052313]  ? cpus_read_trylock+0x50/0x50
[    6.056313]  cpuhp_invoke_callback+0x80/0x4c0
[    6.060313]  _cpu_up+0xa7/0x140
[    6.064313]  cpu_up+0x98/0xd0
[    6.068313]  bringup_nonboot_cpus+0x4f/0x60
[    6.072313]  smp_init+0x26/0x79
[    6.076313]  kernel_init_freeable+0x103/0x258
[    6.080313]  ? rest_init+0xd0/0xd0
[    6.084313]  kernel_init+0xa/0x110
[    6.088313]  ret_from_fork+0x1f/0x30
[    6.092313] ---[ end trace be9ecf17dceeb4f3 ]---

Reason is that there is no Xen pv trap entry for X86_TRAP_VC.

Fix that by adding a generic trap handler for unknown traps and wire all
unknown bare metal handlers to this generic handler, which will just
crash the system in case such a trap will ever happen.

Fixes: 0786138c78 ("x86/sev-es: Add a Runtime #VC Exception Handler")
Cc: <stable@vger.kernel.org> # v5.10
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
2021-01-27 15:45:29 +01:00
Josh Poimboeuf
b735bd3e68 objtool: Combine UNWIND_HINT_RET_OFFSET and UNWIND_HINT_FUNC
The ORC metadata generated for UNWIND_HINT_FUNC isn't actually very
func-like.  With certain usages it can cause stack state mismatches
because it doesn't set the return address (CFI_RA).

Also, users of UNWIND_HINT_RET_OFFSET no longer need to set a custom
return stack offset.  Instead they just need to specify a func-like
situation, so the current ret_offset code is hacky for no good reason.

Solve both problems by simplifying the RET_OFFSET handling and
converting it into a more useful UNWIND_HINT_FUNC.

If we end up needing the old 'ret_offset' functionality again in the
future, we should be able to support it pretty easily with the addition
of a custom 'sp_offset' in UNWIND_HINT_FUNC.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/db9d1f5d79dddfbb3725ef6d8ec3477ad199948d.1611263462.git.jpoimboe@redhat.com
2021-01-26 11:12:00 -06:00
Linus Torvalds
17b6c49da3 Merge tag 'x86_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:

 - Add a new Intel model number for Alder Lake

 - Differentiate which aspects of the FPU state get saved/restored when
   the FPU is used in-kernel and fix a boot crash on K7 due to early
   MXCSR access before CR4.OSFXSR is even set.

 - A couple of noinstr annotation fixes

 - Correct die ID setting on AMD for users of topology information which
   need the correct die ID

 - A SEV-ES fix to handle string port IO to/from kernel memory properly

* tag 'x86_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Add another Alder Lake CPU to the Intel family
  x86/mmx: Use KFPU_387 for MMX string operations
  x86/fpu: Add kernel_fpu_begin_mask() to selectively initialize state
  x86/topology: Make __max_die_per_package available unconditionally
  x86: __always_inline __{rd,wr}msr()
  x86/mce: Remove explicit/superfluous tracing
  locking/lockdep: Avoid noinstr warning for DEBUG_LOCKDEP
  locking/lockdep: Cure noinstr fail
  x86/sev: Fix nonistr violation
  x86/entry: Fix noinstr fail
  x86/cpu/amd: Set __max_die_per_package on AMD
  x86/sev-es: Handle string port IO to kernel memory properly
2021-01-24 09:46:05 -08:00
Gayatri Kammela
6e1239c139 x86/cpu: Add another Alder Lake CPU to the Intel family
Add Alder Lake mobile CPU model number to Intel family.

Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210121215004.11618-1-tony.luck@intel.com
2021-01-21 23:01:51 +01:00
Andy Lutomirski
8ece53ef7f x86/vm86/32: Remove VM86_SCREEN_BITMAP support
The implementation was rather buggy.  It unconditionally marked PTEs
read-only, even for VM_SHARED mappings.  I'm not sure whether this is
actually a problem, but it certainly seems unwise.  More importantly, it
released the mmap lock before flushing the TLB, which could allow a racing
CoW operation to falsely believe that the underlying memory was not
writable.

I can't find any users at all of this mechanism, so just remove it.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Stas Sergeev <stsp2@yandex.ru>
Link: https://lkml.kernel.org/r/f3086de0babcab36f69949b5780bde851f719bc8.1611078018.git.luto@kernel.org
2021-01-21 20:08:53 +01:00
Andy Lutomirski
e45122893a x86/fpu: Add kernel_fpu_begin_mask() to selectively initialize state
Currently, requesting kernel FPU access doesn't distinguish which parts of
the extended ("FPU") state are needed.  This is nice for simplicity, but
there are a few cases in which it's suboptimal:

 - The vast majority of in-kernel FPU users want XMM/YMM/ZMM state but do
   not use legacy 387 state.  These users want MXCSR initialized but don't
   care about the FPU control word.  Skipping FNINIT would save time.
   (Empirically, FNINIT is several times slower than LDMXCSR.)

 - Code that wants MMX doesn't want or need MXCSR initialized.
   _mmx_memcpy(), for example, can run before CR4.OSFXSR gets set, and
   initializing MXCSR will fail because LDMXCSR generates an #UD when the
   aforementioned CR4 bit is not set.

 - Any future in-kernel users of XFD (eXtended Feature Disable)-capable
   dynamic states will need special handling.

Add a more specific API that allows callers to specify exactly what they
want.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Krzysztof Piotr Olędzki <ole@ans.pl>
Link: https://lkml.kernel.org/r/aff1cac8b8fc7ee900cf73e8f2369966621b053f.1611205691.git.luto@kernel.org
2021-01-21 12:07:28 +01:00
Ard Biesheuvel
514b1a8477 efi: x86: clean up previous struct mm switching
EFI on x86_64 keeps track of the process's MM pointer by storing it
in a global struct called 'efi_scratch', which also used to contain
the mixed mode stack pointer. Let's clean this up a little bit, by
getting rid of the struct, and pushing the mm handling into the
callees entirely.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-01-19 17:57:15 +01:00
Ard Biesheuvel
3e1e00c00e efi: x86: move mixed mode stack PA variable out of 'efi_scratch'
As a first step to removing the awkward 'struct efi_scratch' definition
that conveniently combines the storage of the mixed mode stack pointer
with the MM pointer variable that records the task's MM pointer while it
is being replaced with the EFI MM one, move the mixed mode stack pointer
into a separate variable.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-01-19 17:57:16 +01:00
Borislav Petkov
1eb8f690bc x86/topology: Make __max_die_per_package available unconditionally
Move it outside of CONFIG_SMP in order to avoid ifdeffery at the usage
sites.

Fixes: 76e2fc63ca ("x86/cpu/amd: Set __max_die_per_package on AMD")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210114111814.5346-1-bp@alien8.de
2021-01-14 12:18:36 +01:00
Ard Biesheuvel
a04ea6f7ff crypto: x86 - use local headers for x86 specific shared declarations
The Camellia, Serpent and Twofish related header files only contain
declarations that are shared between different implementations of the
respective algorithms residing under arch/x86/crypto, and none of their
contents should be used elsewhere. So move the header files into the
same location, and use local #includes instead.

Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-01-14 17:10:30 +11:00
Ard Biesheuvel
64ca771cd6 crypto: x86 - remove glue helper module
All dependencies on the x86 glue helper module have been replaced by
local instantiations of the new ECB/CBC preprocessor helper macros, so
the glue helper module can be retired.

Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-01-14 17:10:29 +11:00
Ard Biesheuvel
89b7ba5c8b crypto: x86/glue-helper - drop CTR helper routines
The glue helper's CTR routines are no longer used, so drop them.

Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-01-14 17:10:28 +11:00
Ard Biesheuvel
f43dcaf2c9 crypto: x86/twofish - drop CTR mode implementation
Twofish in CTR mode is never used by the kernel directly, and is highly
unlikely to be relied upon by dm-crypt or algif_skcipher. So let's drop
the accelerated CTR mode implementation, and instead, rely on the CTR
template and the bare cipher.

Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-01-14 17:10:28 +11:00
Ard Biesheuvel
a1f91ecf81 crypto: x86/camellia - drop CTR mode implementation
Camellia in CTR mode is never used by the kernel directly, and is highly
unlikely to be relied upon by dm-crypt or algif_skcipher. So let's drop
the accelerated CTR mode implementation, and instead, rely on the CTR
template and the bare cipher.

Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-01-14 17:10:28 +11:00
Ard Biesheuvel
31d49c448a crypto: x86/glue-helper - drop XTS helper routines
The glue helper's XTS routines are no longer used, so drop them.

Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-01-14 17:10:27 +11:00
Ard Biesheuvel
9ec0af8aa6 crypto: x86/serpent- switch to XTS template
Now that the XTS template can wrap accelerated ECB modes, it can be
used to implement Serpent in XTS mode as well, which turns out to
be at least as fast, and sometimes even faster

Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-01-14 17:10:27 +11:00
Ard Biesheuvel
55a7e88f01 crypto: x86/camellia - switch to XTS template
Now that the XTS template can wrap accelerated ECB modes, it can be
used to implement Camellia in XTS mode as well, which turns out to
be at least as fast, and sometimes even faster.

Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-01-14 17:10:27 +11:00
Vasily Gorbik
5ed934e57e x86/insn: Fix vector instruction decoding on big endian cross-compiles
Running instruction decoder posttest on an s390 host with an x86 target
with allyesconfig shows errors. Instructions used in a couple of kernel
objects could not be correctly decoded on big endian system.

  insn_decoder_test: warning: objdump says 6 bytes, but insn_get_length() says 5
  insn_decoder_test: warning: Found an x86 instruction decoder bug, please report this.
  insn_decoder_test: warning: ffffffff831eb4e1:    62 d1 fd 48 7f 04 24    vmovdqa64 %zmm0,(%r12)
  insn_decoder_test: warning: objdump says 7 bytes, but insn_get_length() says 6
  insn_decoder_test: warning: Found an x86 instruction decoder bug, please report this.
  insn_decoder_test: warning: ffffffff831eb4e8:    62 51 fd 48 7f 44 24 01         vmovdqa64 %zmm8,0x40(%r12)
  insn_decoder_test: warning: objdump says 8 bytes, but insn_get_length() says 6

This is because in a few places instruction field bytes are set directly
with further usage of "value". To address that introduce and use a
insn_set_byte() helper, which correctly updates "value" on big endian
systems.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
2021-01-13 18:13:17 -06:00
Vasily Gorbik
8bfe273238 objtool: Fix x86 orc generation on big endian cross-compiles
Correct objtool orc generation endianness problems to enable fully
functional x86 cross-compiles on big endian hardware.

Introduce bswap_if_needed() macro, which does a byte swap if target
endianness doesn't match the host, i.e. cross-compilation for little
endian on big endian and vice versa.  The macro is used for conversion
of multi-byte values which are read from / about to be written to a
target native endianness ELF file.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
2021-01-13 18:13:13 -06:00
Martin Schwidefsky
1d509f2a6e x86/insn: Support big endian cross-compiles
The x86 instruction decoder code is shared across the kernel source and
the tools. Currently objtool seems to be the only tool from build tools
needed which breaks x86 cross-compilation on big endian systems. Make
the x86 instruction decoder build host endianness agnostic to support
x86 cross-compilation and enable objtool to implement endianness
awareness for big endian architectures support.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Co-developed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
2021-01-13 18:13:11 -06:00
Peter Zijlstra
66a425011c x86: __always_inline __{rd,wr}msr()
When the compiler choses to not inline the trivial MSR helpers:

  vmlinux.o: warning: objtool: __sev_es_nmi_complete()+0xce: call to __wrmsr.constprop.14() leaves .noinstr.text section

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Link: https://lore.kernel.org/r/X/bf3gV+BW7kGEsB@hirez.programming.kicks-ass.net
2021-01-12 21:10:59 +01:00
Hao Lee
11aa1415d8 x86/entry: Remove now unused do_IRQ() declaration
do_IRQ() has been replaced by common_interrupt() in

  fa5e5c4092 ("x86/entry: Use idtentry for interrupts")

Remove its now unused declaration.

Signed-off-by: Hao Lee <haolee.swjtu@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210103030834.GA15432@haolee.github.io
2021-01-12 14:37:37 +01:00
Linus Torvalds
f1ee3e150b Merge tag 'hyperv-fixes-signed-20210111' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv fixes from Wei Liu:

  - fix kexec panic/hang (Dexuan Cui)

  - fix occasional crashes when flushing TLB (Wei Liu)

* tag 'hyperv-fixes-signed-20210111' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: check cpu mask after interrupt has been disabled
  x86/hyperv: Fix kexec panic/hang issues
2021-01-11 11:28:58 -08:00
Valentin Schneider
6d3b47ddff x86/resctrl: Apply READ_ONCE/WRITE_ONCE to task_struct.{rmid,closid}
A CPU's current task can have its {closid, rmid} fields read locally
while they are being concurrently written to from another CPU.
This can happen anytime __resctrl_sched_in() races with either
__rdtgroup_move_task() or rdt_move_group_tasks().

Prevent load / store tearing for those accesses by giving them the
READ_ONCE() / WRITE_ONCE() treatment.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/9921fda88ad81afb9885b517fbe864a2bc7c35a9.1608243147.git.reinette.chatre@intel.com
2021-01-11 11:43:23 +01:00