[PATCH v2 34/66] KVM: x86: Handle RDTSCP CPUID adjustment in VMX code

Sean Christopherson
2020-03-02T23:58:00Z

Move the clearing of the RDTSCP CPUID bit into VMX, which has a separate
VMCS control to enable RDTSCP in non-root, to eliminate an instance of
the undesirable "unsigned f_* = *_supported ? F(*) : 0" pattern in the
common CPUID handling code. Drop ->rdtscp_supported() since CPUID
adjustment was the last remaining user.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/cpuid.c | 3 +--
arch/x86/kvm/vmx/vmx.c | 4 ++++
2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 9c2e20a76ca8..f39efc9d640b 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -424,7 +424,6 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
unsigned f_gbpages = 0;
unsigned f_lm = 0;
#endif
- unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
unsigned f_intel_pt = kvm_x86_ops->pt_supported() ? F(INTEL_PT) : 0;

@@ -446,7 +445,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
F(PAT) | F(PSE36) | 0 /* Reserved */ |
f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
- F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
+ F(FXSR) | F(FXSR_OPT) | f_gbpages | F(RDTSCP) |
0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
/* cpuid 1.ecx */
const u32 kvm_cpuid_1_ecx_x86_features =
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 49a1cac7bf0c..3bcb09b5efac 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7139,6 +7139,10 @@ static void vmx_set_supported_cpuid(struct kvm_cpuid_entry2 *entry)
boot_cpu_has(X86_FEATURE_OSPKE))
cpuid_entry_set(entry, X86_FEATURE_PKU);
break;
+ case 0x80000001:
+ if (!cpu_has_vmx_rdtscp())
+ cpuid_entry_clear(entry, X86_FEATURE_RDTSCP);
+ break;
default:
break;
}
--
2.24.1