[PATCH 20/26] KVM: x86: Handle PKU CPUID adjustment in SVM code

Sean Christopherson
2020-01-29T23:46:59Z

Move the clearing of the PKU CPUID bit into SVM, which does not yet
support virtualizing PKU, to eliminate an instance of the undesirable
"unsigned f_* = *_supported ? F(*) : 0" pattern in the common CPUID
handling code. Drop ->pku_supported() since CPUID adjustment was the
only user.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/kvm/cpuid.c | 4 +---
arch/x86/kvm/svm.c | 7 +------
arch/x86/kvm/vmx/capabilities.h | 5 -----
arch/x86/kvm/vmx/vmx.c | 1 -
5 files changed, 2 insertions(+), 16 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index b9c871c03bf5..8a685509c218 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1167,7 +1167,6 @@ struct kvm_x86_ops {
bool (*xsaves_supported)(void);
bool (*umip_emulated)(void);
bool (*pt_supported)(void);
- bool (*pku_supported)(void);

int (*check_nested_events)(struct kvm_vcpu *vcpu, bool external_intr);
void (*request_immediate_exit)(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index d835f4662fba..e376d648f94d 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -323,7 +323,6 @@ static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry, int index)
{
unsigned f_intel_pt = kvm_x86_ops->pt_supported() ? F(INTEL_PT) : 0;
unsigned f_la57;
- unsigned f_pku = kvm_x86_ops->pku_supported() ? F(PKU) : 0;

/* cpuid 7.0.ebx */
const u32 kvm_cpuid_7_0_ebx_x86_features =
@@ -335,7 +334,7 @@ static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry, int index)

/* cpuid 7.0.ecx*/
const u32 kvm_cpuid_7_0_ecx_x86_features =
- F(AVX512VBMI) | F(LA57) | 0 /*PKU*/ | 0 /*OSPKE*/ | F(RDPID) |
+ F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ | F(RDPID) |
F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) |
F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG) |
F(CLDEMOTE) | F(MOVDIRI) | F(MOVDIR64B) | 0 /*WAITPKG*/;
@@ -363,7 +362,6 @@ static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry, int index)
cpuid_mask(&entry->ecx, CPUID_7_ECX);
/* Set LA57 based on hardware capability. */
entry->ecx |= f_la57;
- entry->ecx |= f_pku;
/* PKU is not yet implemented for shadow paging. */
if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
cpuid_entry_clear(entry, X86_FEATURE_PKU);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 4ea530ff6a0c..1092d5e6c683 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6060,6 +6060,7 @@ static void svm_set_supported_cpuid(struct kvm_cpuid_entry2 *entry)
cpuid_entry_clear(entry, X86_FEATURE_X2APIC);
break;
case 0x7:
+ cpuid_entry_clear(entry, X86_FEATURE_PKU);
cpuid_entry_clear(entry, X86_FEATURE_MPX);
cpuid_entry_clear(entry, X86_FEATURE_INVPCID);
break;
@@ -6120,11 +6121,6 @@ static bool svm_has_wbinvd_exit(void)
return true;
}

-static bool svm_pku_supported(void)
-{
- return false;
-}
-
#define PRE_EX(exit) { .exit_code = (exit), \
.stage = X86_ICPT_PRE_EXCEPT, }
#define POST_EX(exit) { .exit_code = (exit), \
@@ -7484,7 +7480,6 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
.xsaves_supported = svm_xsaves_supported,
.umip_emulated = svm_umip_emulated,
.pt_supported = svm_pt_supported,
- .pku_supported = svm_pku_supported,

.set_supported_cpuid = svm_set_supported_cpuid,

diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index 0a0b1494a934..7cae355e3490 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -145,11 +145,6 @@ static inline bool vmx_umip_emulated(void)
SECONDARY_EXEC_DESC;
}

-static inline bool vmx_pku_supported(void)
-{
- return boot_cpu_has(X86_FEATURE_PKU);
-}
-
static inline bool cpu_has_vmx_rdtscp(void)
{
return vmcs_config.cpu_based_2nd_exec_ctrl &
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 6bcdfb8744d3..3845ca7da6e0 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7900,7 +7900,6 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
.xsaves_supported = vmx_xsaves_supported,
.umip_emulated = vmx_umip_emulated,
.pt_supported = vmx_pt_supported,
- .pku_supported = vmx_pku_supported,

.request_immediate_exit = vmx_request_immediate_exit,

--
2.24.1