linux-kernel - [PATCH 33/61] KVM: x86: Handle PKU CPUID adjustment in VMX code

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Date:   Sat,  1 Feb 2020 10:51:50 -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 33/61] KVM: x86: Handle PKU CPUID adjustment in VMX code

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.

Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.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 9baff70ad419..ba828569cda5 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1166,7 +1166,6 @@ 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 202a6c0f1db8..a1f46b3ca16e 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 c0f8c09f3b04..630520f8adfa 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6094,11 +6094,6 @@ 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), \
@@ -7457,7 +7452,6 @@ 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 9d2e36a5ecb9..a9728cc0c343 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7113,6 +7113,11 @@ 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;
@@ -7868,7 +7873,6 @@ 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