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8 Commits (192a3697600382c5606fc1b2c946e737c5450f88)

Author SHA1 Message Date
Marios Pomonis c2b02d093a KVM: x86: Protect pmu_intel.c from Spectre-v1/L1TF attacks
commit 66061740f1 upstream.

This fixes Spectre-v1/L1TF vulnerabilities in intel_find_fixed_event()
and intel_rdpmc_ecx_to_pmc().
kvm_rdpmc() (ancestor of intel_find_fixed_event()) and
reprogram_fixed_counter() (ancestor of intel_rdpmc_ecx_to_pmc()) are
exported symbols so KVM should treat them conservatively from a security
perspective.

Fixes: 25462f7f52 ("KVM: x86/vPMU: Define kvm_pmu_ops to support vPMU function dispatch")

Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:37 -08:00
Jim Mattson e1fba49cc1 kvm: vmx: Limit guest PMCs to those supported on the host
KVM can only virtualize as many PMCs as the host supports.

Limit the number of generic counters and fixed counters to the number
of corresponding counters supported on the host, rather than to
INTEL_PMC_MAX_GENERIC and INTEL_PMC_MAX_FIXED, respectively.

Note that INTEL_PMC_MAX_GENERIC is currently 32, which exceeds the 18
contiguous MSR indices reserved by Intel for event selectors. Since
the existing code relies on a contiguous range of MSR indices for
event selectors, it can't possibly work for more than 18 general
purpose counters.

Fixes: f5132b0138 ("KVM: Expose a version 2 architectural PMU to a guests")
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Marc Orr <marcorr@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-01 15:15:06 +02:00
Like Xu 4d1a082da9 KVM: x86/vPMU: reset pmc->counter to 0 for pmu fixed_counters
To avoid semantic inconsistency, the fixed_counters in Intel vPMU
need to be reset to 0 in intel_pmu_reset() as gp_counters does.

Signed-off-by: Like Xu <like.xu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-17 12:23:20 +02:00
Thomas Gleixner 20c8ccb197 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499
Based on 1 normalized pattern(s):

  this work is licensed under the terms of the gnu gpl version 2 see
  the copying file in the top level directory

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 35 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.797835076@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:53 +02:00
Paolo Bonzini 2924b52117 KVM: x86/pmu: do not mask the value that is written to fixed PMUs
According to the SDM, for MSR_IA32_PERFCTR0/1 "the lower-order 32 bits of
each MSR may be written with any value, and the high-order 8 bits are
sign-extended according to the value of bit 31", but the fixed counters
in real hardware are limited to the width of the fixed counters ("bits
beyond the width of the fixed-function counter are reserved and must be
written as zeros").  Fix KVM to do the same.

Reported-by: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-05-24 21:27:14 +02:00
Paolo Bonzini 0e6f467ee2 KVM: x86/pmu: mask the result of rdpmc according to the width of the counters
This patch will simplify the changes in the next, by enforcing the
masking of the counters to RDPMC and RDMSR.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-05-24 21:27:13 +02:00
Luwei Kang c715eb9fe9 KVM: x86: Add support of clear Trace_ToPA_PMI status
Let guests clear the Intel PT ToPA PMI status (bit 55 of
MSR_CORE_PERF_GLOBAL_OVF_CTRL).

Signed-off-by: Luwei Kang <luwei.kang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-04-30 21:32:14 +02:00
Sean Christopherson a821bab2d1 KVM: VMX: Move VMX specific files to a "vmx" subdirectory
...to prepare for shattering vmx.c into multiple files without having
to prepend "vmx_" to all new files.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 12:34:24 +01:00