KVM: VMX: Do not advertise RDPID if ENABLE_RDTSCP control is unsupported

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>
Message-Id: <20210504171734.1434054-2-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>

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index cbe0cda..46573b8 100644 (file)
--- 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);