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From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org
Cc: michael.roth@amd.com,
	isaku.yamahata@intel.com,
	seanjc@google.com
Subject: [PATCH v4 01/15] KVM: SVM: Invert handling of SEV and SEV_ES feature flags
Date: Mon, 18 Mar 2024 19:33:38 -0400
Message-ID: <20240318233352.2728327-2-pbonzini@redhat.com>
In-Reply-To: <20240318233352.2728327-1-pbonzini@redhat.com>
References: <20240318233352.2728327-1-pbonzini@redhat.com>
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From: Sean Christopherson <seanjc@google.com>

Leave SEV and SEV_ES '0' in kvm_cpu_caps by default, and instead set them
in sev_set_cpu_caps() if SEV and SEV-ES support are fully enabled.  Aside
from the fact that sev_set_cpu_caps() is wildly misleading when it *clears*
capabilities, this will allow compiling out sev.c without falsely
advertising SEV/SEV-ES support in KVM_GET_SUPPORTED_CPUID.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/cpuid.c   | 2 +-
 arch/x86/kvm/svm/sev.c | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index adba49afb5fe..bde4df13a7e8 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -761,7 +761,7 @@ void kvm_set_cpu_caps(void)
 	kvm_cpu_cap_mask(CPUID_8000_000A_EDX, 0);
 
 	kvm_cpu_cap_mask(CPUID_8000_001F_EAX,
-		0 /* SME */ | F(SEV) | 0 /* VM_PAGE_FLUSH */ | F(SEV_ES) |
+		0 /* SME */ | 0 /* SEV */ | 0 /* VM_PAGE_FLUSH */ | 0 /* SEV_ES */ |
 		F(SME_COHERENT));
 
 	kvm_cpu_cap_mask(CPUID_8000_0021_EAX,
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index e5a4d9b0e79f..382c745b8ba9 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2186,10 +2186,10 @@ void sev_vm_destroy(struct kvm *kvm)
 
 void __init sev_set_cpu_caps(void)
 {
-	if (!sev_enabled)
-		kvm_cpu_cap_clear(X86_FEATURE_SEV);
-	if (!sev_es_enabled)
-		kvm_cpu_cap_clear(X86_FEATURE_SEV_ES);
+	if (sev_enabled)
+		kvm_cpu_cap_set(X86_FEATURE_SEV);
+	if (sev_es_enabled)
+		kvm_cpu_cap_set(X86_FEATURE_SEV_ES);
 }
 
 void __init sev_hardware_setup(void)
-- 
2.43.0