linux-kernel - [PATCH 39/61] KVM: SVM: Convert feature updates from CPUID to KVM cpu caps

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Message-Id: <20200201185218.24473-40-sean.j.christopherson@intel.com>
Date:   Sat,  1 Feb 2020 10:51:56 -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 39/61] KVM: SVM: Convert feature updates from CPUID to KVM cpu caps

Use the recently introduced KVM CPU caps to propagate SVM-only (kernel)
settings to supported CPUID flags.

Note, setting a flag based on a *different* feature is effectively
emulation, and so must be done at runtime via ->set_supported_cpuid().

Opportunistically add a technically unnecessary break and fix an
indentation issue in svm_set_supported_cpuid().

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
---
 arch/x86/kvm/svm.c | 40 +++++++++++++++++++++++-----------------
 1 file changed, 23 insertions(+), 17 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 630520f8adfa..f98a192459f7 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1350,6 +1350,25 @@ static __init void svm_adjust_mmio_mask(void)
 	kvm_mmu_set_mmio_spte_mask(mask, mask, PT_WRITABLE_MASK | PT_USER_MASK);
 }
 
+static __init void svm_set_cpu_caps(void)
+{
+	/* CPUID 0x1 */
+	if (avic)
+		kvm_cpu_cap_clear(X86_FEATURE_X2APIC);
+
+	/* CPUID 0x80000001 */
+	if (nested)
+		kvm_cpu_cap_set(X86_FEATURE_SVM);
+
+	/* CPUID 0x8000000A */
+	/* Support next_rip if host supports it */
+	if (boot_cpu_has(X86_FEATURE_NRIPS))
+		kvm_cpu_cap_set(X86_FEATURE_NRIPS);
+
+	if (npt_enabled)
+		kvm_cpu_cap_set(X86_FEATURE_NPT);
+}
+
 static __init int svm_hardware_setup(void)
 {
 	int cpu;
@@ -1462,6 +1481,8 @@ static __init int svm_hardware_setup(void)
 			pr_info("Virtual GIF supported\n");
 	}
 
+	svm_set_cpu_caps();
+
 	return 0;
 
 err:
@@ -6033,17 +6054,9 @@ static void svm_cpuid_update(struct kvm_vcpu *vcpu)
 static void svm_set_supported_cpuid(struct kvm_cpuid_entry2 *entry)
 {
 	switch (entry->function) {
-	case 0x1:
-		if (avic)
-			cpuid_entry_clear(entry, X86_FEATURE_X2APIC);
-		break;
-	case 0x80000001:
-		if (nested)
-			cpuid_entry_set(entry, X86_FEATURE_SVM);
-		break;
 	case 0x80000008:
 		if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) ||
-		     boot_cpu_has(X86_FEATURE_AMD_SSBD))
+		    boot_cpu_has(X86_FEATURE_AMD_SSBD))
 			cpuid_entry_set(entry, X86_FEATURE_VIRT_SSBD);
 		break;
 	case 0x8000000A:
@@ -6053,14 +6066,7 @@ static void svm_set_supported_cpuid(struct kvm_cpuid_entry2 *entry)
 		entry->ecx = 0; /* Reserved */
 		entry->edx = 0; /* Per default do not support any
 				   additional features */
-
-		/* Support next_rip if host supports it */
-		if (boot_cpu_has(X86_FEATURE_NRIPS))
-			cpuid_entry_set(entry, X86_FEATURE_NRIPS);
-
-		/* Support NPT for the guest if enabled */
-		if (npt_enabled)
-			cpuid_entry_set(entry, X86_FEATURE_NPT);
+		break;
 	}
 }
 
-- 
2.24.1