[PATCH 17/26] KVM: x86: Handle MPX CPUID adjustment in vendor code

Sean Christopherson
2020-01-29T23:47:30Z

Move the MPX CPUID adjustments into vendor code to eliminate an instance
of the undesirable "unsigned f_* = *_supported ? F(*) : 0" pattern in
the common CPUID handling code.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/cpuid.c | 3 +--
arch/x86/kvm/svm.c | 3 +++
arch/x86/kvm/vmx/vmx.c | 14 ++++++++++++--
3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 2d75410092e6..aa03dc665a44 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -322,7 +322,6 @@ static int __do_cpuid_func_emulated(struct kvm_cpuid_entry2 *entry,
static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry, int index)
{
unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
- unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0;
unsigned f_umip = kvm_x86_ops->umip_emulated() ? F(UMIP) : 0;
unsigned f_intel_pt = kvm_x86_ops->pt_supported() ? F(INTEL_PT) : 0;
unsigned f_la57;
@@ -331,7 +330,7 @@ static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry, int index)
/* cpuid 7.0.ebx */
const u32 kvm_cpuid_7_0_ebx_x86_features =
F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
- F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
+ F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | F(MPX) | F(RDSEED) |
F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) |
F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) |
F(SHA_NI) | F(AVX512BW) | F(AVX512VL) | f_intel_pt;
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index fee2af01ba21..f64c2c1f9d1f 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6059,6 +6059,9 @@ static void svm_set_supported_cpuid(struct kvm_cpuid_entry2 *entry)
if (avic)
cpuid_entry_clear(entry, X86_FEATURE_X2APIC);
break;
+ case 0x7:
+ cpuid_entry_clear(entry, X86_FEATURE_MPX);
+ break;
case 0x80000001:
if (nested)
cpuid_entry_set(entry, X86_FEATURE_SVM);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d21b2eccf3fe..f33bf519690e 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7136,8 +7136,18 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)

static void vmx_set_supported_cpuid(struct kvm_cpuid_entry2 *entry)
{
- if (entry->function == 1 && nested)
- entry->ecx |= feature_bit(VMX);
+ switch (entry->function) {
+ case 0x1:
+ if (nested)
+ cpuid_entry_set(entry, X86_FEATURE_VMX);
+ break;
+ case 0x7:
+ if (!kvm_mpx_supported())
+ cpuid_entry_clear(entry, X86_FEATURE_MPX);
+ break;
+ default:
+ break;
+ }
}

static void vmx_request_immediate_exit(struct kvm_vcpu *vcpu)
--
2.24.1