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    SubjectRe: [PATCH 01/15] KVM: VMX: Do not adverise RDPID if ENABLE_RDTSCP control is unsupported
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    On Tue, 2021-05-04 at 10:17 -0700, Sean Christopherson wrote:
    > Clear KVM's RDPID capability if the ENABLE_RDTSCP secondary exec control is
    > unsupported. Despite being enumerated in a separate CPUID flag, RDPID is
    > bundled under the same VMCS control as RDTSCP and will #UD in VMX non-root
    > if ENABLE_RDTSCP is not enabled.
    >
    > Fixes: 41cd02c6f7f6 ("kvm: x86: Expose RDPID in KVM_GET_SUPPORTED_CPUID")
    > Cc: stable@vger.kernel.org
    > Signed-off-by: Sean Christopherson <seanjc@google.com>
    > ---
    > arch/x86/kvm/vmx/vmx.c | 6 ++++--
    > 1 file changed, 4 insertions(+), 2 deletions(-)
    >
    > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
    > index 10b610fc7bbc..82404ee2520e 100644
    > --- a/arch/x86/kvm/vmx/vmx.c
    > +++ b/arch/x86/kvm/vmx/vmx.c
    > @@ -7377,9 +7377,11 @@ static __init void vmx_set_cpu_caps(void)
    > if (!cpu_has_vmx_xsaves())
    > kvm_cpu_cap_clear(X86_FEATURE_XSAVES);
    >
    > - /* CPUID 0x80000001 */
    > - if (!cpu_has_vmx_rdtscp())
    > + /* CPUID 0x80000001 and 0x7 (RDPID) */
    > + if (!cpu_has_vmx_rdtscp()) {
    > kvm_cpu_cap_clear(X86_FEATURE_RDTSCP);
    > + kvm_cpu_cap_clear(X86_FEATURE_RDPID);
    > + }
    >
    > if (cpu_has_vmx_waitpkg())
    > kvm_cpu_cap_check_and_set(X86_FEATURE_WAITPKG);

    Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>

    Best regards,
    Maxim Levitsky

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