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| author | Paolo Bonzini <pbonzini@redhat.com> | 2019-11-18 18:58:26 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-12-13 08:52:45 +0100 |
| commit | 6a10f818a9adbe394eb36d223814e207e5121236 (patch) | |
| tree | 69256a33905fca43fe6745e0eba2da837709c795 | |
| parent | 5efbd9a9d9c5492fb467bfaf55b77085898645c1 (diff) | |
| download | linux-stable-6a10f818a9adbe394eb36d223814e207e5121236.tar.gz linux-stable-6a10f818a9adbe394eb36d223814e207e5121236.tar.bz2 linux-stable-6a10f818a9adbe394eb36d223814e207e5121236.zip | |
KVM: x86: fix presentation of TSX feature in ARCH_CAPABILITIES
commit cbbaa2727aa3ae9e0a844803da7cef7fd3b94f2b upstream.
KVM does not implement MSR_IA32_TSX_CTRL, so it must not be presented
to the guests. It is also confusing to have !ARCH_CAP_TSX_CTRL_MSR &&
!RTM && ARCH_CAP_TAA_NO: lack of MSR_IA32_TSX_CTRL suggests TSX was not
hidden (it actually was), yet the value says that TSX is not vulnerable
to microarchitectural data sampling. Fix both.
Cc: stable@vger.kernel.org
Tested-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kvm/x86.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 9192c2369af6..68dd949bc0eb 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1174,10 +1174,15 @@ u64 kvm_get_arch_capabilities(void) * If TSX is disabled on the system, guests are also mitigated against * TAA and clear CPU buffer mitigation is not required for guests. */ - if (boot_cpu_has_bug(X86_BUG_TAA) && boot_cpu_has(X86_FEATURE_RTM) && - (data & ARCH_CAP_TSX_CTRL_MSR)) + if (!boot_cpu_has(X86_FEATURE_RTM)) + data &= ~ARCH_CAP_TAA_NO; + else if (!boot_cpu_has_bug(X86_BUG_TAA)) + data |= ARCH_CAP_TAA_NO; + else if (data & ARCH_CAP_TSX_CTRL_MSR) data &= ~ARCH_CAP_MDS_NO; + /* KVM does not emulate MSR_IA32_TSX_CTRL. */ + data &= ~ARCH_CAP_TSX_CTRL_MSR; return data; } |