diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2019-11-18 20:58:26 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-12-21 12:41:39 +0300 |
| commit | 0bc72dbb9dbc2dfa0f975f4b519ae91fa338aec8 (patch) | |
| tree | ce9cd9ffd3349395e98b09aed292e14319c9f02b | |
| parent | 3d079704b654ba728322d7e915bfa68a4b42201f (diff) | |
| download | linux-0bc72dbb9dbc2dfa0f975f4b519ae91fa338aec8.tar.xz | |
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 0af34f26b501..c9c533370e88 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1075,10 +1075,15 @@ 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; } |