[PATCH 5.11 301/329] KVM: VMX: Do not advertise RDPID if ENABLE_RDTSCP control is unsupported

From: Greg Kroah-Hartman
Date: Mon May 17 2021 - 11:59:21 EST

From: Sean Christopherson <seanjc@xxxxxxxxxx>

commit 8aec21c04caa2000f91cf8822ae0811e4b0c3971 upstream.

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@xxxxxxxxxxxxxxx
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Message-Id: <20210504171734.1434054-2-seanjc@xxxxxxxxxx>
Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>
Reviewed-by: Reiji Watanabe <reijiw@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
arch/x86/kvm/vmx/vmx.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7288,9 +7288,11 @@ static __init void vmx_set_cpu_caps(void
if (!cpu_has_vmx_xsaves())

- /* CPUID 0x80000001 */
- if (!cpu_has_vmx_rdtscp())
+ /* CPUID 0x80000001 and 0x7 (RDPID) */
+ if (!cpu_has_vmx_rdtscp()) {
+ kvm_cpu_cap_clear(X86_FEATURE_RDPID);
+ }

if (cpu_has_vmx_waitpkg())