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

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Message-Id: <20200129234640.8147-21-sean.j.christopherson@intel.com>
Date:   Wed, 29 Jan 2020 15:46:34 -0800
From:   Sean Christopherson <sean.j.christopherson@...el.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <sean.j.christopherson@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 20/26] KVM: x86: Handle PKU CPUID adjustment in SVM code

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@...el.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