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| author | Sean Christopherson <seanjc@google.com> | 2021-05-04 10:17:21 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-19 10:29:55 +0200 |
| commit | 5fc7a3a1e9d3dbdaec6685a5d89d5f16a9b9cfcc (patch) | |
| tree | e02096593bcb3d8451a9d5575f9a6ae5baefee56 | |
| parent | 323cda5fff437ecc37f353f36c85863253480a83 (diff) | |
| download | linux-stable-5fc7a3a1e9d3dbdaec6685a5d89d5f16a9b9cfcc.tar.gz linux-stable-5fc7a3a1e9d3dbdaec6685a5d89d5f16a9b9cfcc.zip | |
KVM: x86: Emulate RDPID only if RDTSCP is supported
commit 85d0011264da24be08ae907d7f29983a597ca9b1 upstream.
Do not advertise emulation support for RDPID if RDTSCP is unsupported.
RDPID emulation subtly relies on MSR_TSC_AUX to exist in hardware, as
both vmx_get_msr() and svm_get_msr() will return an error if the MSR is
unsupported, i.e. ctxt->ops->get_msr() will fail and the emulator will
inject a #UD.
Note, RDPID emulation also relies on RDTSCP being enabled in the guest,
but this is a KVM bug and will eventually be fixed.
Fixes: fb6d4d340e05 ("KVM: x86: emulate RDPID")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210504171734.1434054-3-seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Reiji Watanabe <reijiw@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/cpuid.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 38172ca627d3..0bd815101ff4 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -573,7 +573,8 @@ static int __do_cpuid_func_emulated(struct kvm_cpuid_array *array, u32 func) case 7: entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; entry->eax = 0; - entry->ecx = F(RDPID); + if (kvm_cpu_cap_has(X86_FEATURE_RDTSCP)) + entry->ecx = F(RDPID); ++array->nent; default: break; |