[PATCH v2 33/66] KVM: x86: Handle PKU CPUID adjustment in VMX code

Sean Christopherson
2020-03-02T23:58:38Z

Move the setting of the PKU CPUID bit into VMX to eliminate an instance
of the undesirable "unsigned f_* = *_supported ? F(*) : 0" pattern in
the common CPUID handling code. Drop ->pku_supported(), CPUID
adjustment was the only user.

Note, some AMD CPUs now support PKU, but SVM doesn't yet support
exposing it to a guest.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/kvm/cpuid.c | 5 -----
arch/x86/kvm/svm.c | 6 ------
arch/x86/kvm/vmx/capabilities.h | 5 -----
arch/x86/kvm/vmx/vmx.c | 6 +++++-
5 files changed, 5 insertions(+), 18 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 96ea76e0a69f..449695788351 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1172,7 +1172,6 @@ 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 35451ea0a690..9c2e20a76ca8 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -341,7 +341,6 @@ static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry)
{
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 =
@@ -381,10 +380,6 @@ static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry)
cpuid_entry_mask(entry, 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);

entry->edx &= kvm_cpuid_7_0_edx_x86_features;
cpuid_entry_mask(entry, CPUID_7_EDX);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index c0e0dd7acb1f..0725a67e3480 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6091,11 +6091,6 @@ 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), \
@@ -7454,7 +7449,6 @@ 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 c00e26570198..8903475f751e 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -146,11 +146,6 @@ 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 f4efc45810b8..49a1cac7bf0c 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7133,6 +7133,11 @@ static void vmx_set_supported_cpuid(struct kvm_cpuid_entry2 *entry)
cpuid_entry_set(entry, X86_FEATURE_INVPCID);
if (vmx_umip_emulated())
cpuid_entry_set(entry, X86_FEATURE_UMIP);
+
+ /* PKU is not yet implemented for shadow paging. */
+ if (enable_ept && boot_cpu_has(X86_FEATURE_PKU) &&
+ boot_cpu_has(X86_FEATURE_OSPKE))
+ cpuid_entry_set(entry, X86_FEATURE_PKU);
break;
default:
break;
@@ -7933,7 +7938,6 @@ 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