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From: Sean Christopherson <seanjc@google.com>
To: Sean Christopherson <seanjc@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	 Naveen N Rao <naveen@kernel.org>,
	Kim Phillips <kim.phillips@amd.com>,
	 Tom Lendacky <thomas.lendacky@amd.com>,
	Alexey Kardashevskiy <aik@amd.com>,
	 Pankaj Gupta <pankaj.gupta@amd.com>
Subject: [PATCH v2 10/10] KVM: SVM: Invalidate "next" SNP VMSA GPA even on failure
Date: Wed, 26 Feb 2025 17:25:41 -0800	[thread overview]
Message-ID: <20250227012541.3234589-11-seanjc@google.com> (raw)
In-Reply-To: <20250227012541.3234589-1-seanjc@google.com>

When processing an SNP AP Creation event, invalidate the "next" VMSA GPA
even if acquiring the page/pfn for the new VMSA fails.  In practice, the
next GPA will never be used regardless of whether or not its invalidated,
as the entire flow is guarded by snp_ap_waiting_for_reset, and said guard
and snp_vmsa_gpa are always written as a pair.  But that's really hard to
see in the code.

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/svm/sev.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 3f85bd1cac37..de153a19fa6c 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3875,6 +3875,7 @@ void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu)
 		return;
 
 	gfn = gpa_to_gfn(svm->sev_es.snp_vmsa_gpa);
+	svm->sev_es.snp_vmsa_gpa = INVALID_PAGE;
 
 	slot = gfn_to_memslot(vcpu->kvm, gfn);
 	if (!slot)
@@ -3904,8 +3905,6 @@ void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu)
 	/* Mark the vCPU as runnable */
 	kvm_set_mp_state(vcpu, KVM_MP_STATE_RUNNABLE);
 
-	svm->sev_es.snp_vmsa_gpa = INVALID_PAGE;
-
 	/*
 	 * gmem pages aren't currently migratable, but if this ever changes
 	 * then care should be taken to ensure svm->sev_es.vmsa is pinned
-- 
2.48.1.711.g2feabab25a-goog


  parent reply	other threads:[~2025-02-27  1:26 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-02-27  1:25 [PATCH v2 00/10] KVM: SVM: Attempt to cleanup SEV_FEATURES Sean Christopherson
2025-02-27  1:25 ` [PATCH v2 01/10] KVM: SVM: Save host DR masks on CPUs with DebugSwap Sean Christopherson
2025-02-27  1:25 ` [PATCH v2 02/10] KVM: SVM: Don't rely on DebugSwap to restore host DR0..DR3 Sean Christopherson
2025-02-27  1:25 ` [PATCH v2 03/10] KVM: SVM: Refuse to attempt VRMUN if an SEV-ES+ guest has an invalid VMSA Sean Christopherson
2025-02-27 16:03   ` Tom Lendacky
2025-02-27 16:56   ` Gupta, Pankaj
2025-02-27  1:25 ` [PATCH v2 04/10] KVM: SVM: Don't change target vCPU state on AP Creation VMGEXIT error Sean Christopherson
2025-02-27 10:25   ` Gupta, Pankaj
2025-02-27  1:25 ` [PATCH v2 05/10] KVM: SVM: Require AP's "requested" SEV_FEATURES to match KVM's view Sean Christopherson
2025-02-27  7:12   ` Gupta, Pankaj
2025-02-27 14:33     ` Sean Christopherson
2025-02-27 15:18       ` Gupta, Pankaj
2025-02-27 15:42         ` Sean Christopherson
2025-02-27  1:25 ` [PATCH v2 06/10] KVM: SVM: Simplify request+kick logic in SNP AP Creation handling Sean Christopherson
2025-02-27  1:25 ` [PATCH v2 07/10] KVM: SVM: Use guard(mutex) to simplify SNP AP Creation error handling Sean Christopherson
2025-02-27 16:51   ` Gupta, Pankaj
2025-02-27  1:25 ` [PATCH v2 08/10] KVM: SVM: Mark VMCB dirty before processing incoming snp_vmsa_gpa Sean Christopherson
2025-02-27  1:25 ` [PATCH v2 09/10] KVM: SVM: Use guard(mutex) to simplify SNP vCPU state updates Sean Christopherson
2025-02-27  1:25 ` Sean Christopherson [this message]
2025-03-05  1:05 ` [PATCH v2 00/10] KVM: SVM: Attempt to cleanup SEV_FEATURES Sean Christopherson

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