linux-kernel - [PATCH 10/21] KVM: SEV: Use a VMSA physical address variable for populating VMCB

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Message-Id: <20240227232100.478238-11-pbonzini@redhat.com>
Date: Tue, 27 Feb 2024 18:20:49 -0500
From: Paolo Bonzini <pbonzini@...hat.com>
To: linux-kernel@...r.kernel.org,
	kvm@...r.kernel.org
Cc: seanjc@...gle.com,
	michael.roth@....com,
	isaku.yamahata@...el.com,
	thomas.lendacky@....com,
	Ashish Kalra <ashish.kalra@....com>
Subject: [PATCH 10/21] KVM: SEV: Use a VMSA physical address variable for populating VMCB

From: Tom Lendacky <thomas.lendacky@....com>

In preparation to support SEV-SNP AP Creation, use a variable that holds
the VMSA physical address rather than converting the virtual address.
This will allow SEV-SNP AP Creation to set the new physical address that
will be used should the vCPU reset path be taken.

Signed-off-by: Tom Lendacky <thomas.lendacky@....com>
Signed-off-by: Ashish Kalra <ashish.kalra@....com>
Signed-off-by: Michael Roth <michael.roth@....com>
Message-Id: <20231230172351.574091-26-michael.roth@....com>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 arch/x86/kvm/svm/sev.c | 3 +--
 arch/x86/kvm/svm/svm.c | 9 ++++++++-
 arch/x86/kvm/svm/svm.h | 1 +
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index a9e2fcf494a2..2bde1ad6bcfd 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3094,8 +3094,7 @@ static void sev_es_init_vmcb(struct vcpu_svm *svm)
 	 * the VMSA will be NULL if this vCPU is the destination for intrahost
 	 * migration, and will be copied later.
 	 */
-	if (svm->sev_es.vmsa)
-		svm->vmcb->control.vmsa_pa = __pa(svm->sev_es.vmsa);
+	svm->vmcb->control.vmsa_pa = svm->sev_es.vmsa_pa;
 
 	/* Can't intercept CR register access, HV can't modify CR registers */
 	svm_clr_intercept(svm, INTERCEPT_CR0_READ);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index f4a750426b24..8893975826f1 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1459,9 +1459,16 @@ static int svm_vcpu_create(struct kvm_vcpu *vcpu)
 	svm->vmcb01.pa = __sme_set(page_to_pfn(vmcb01_page) << PAGE_SHIFT);
 	svm_switch_vmcb(svm, &svm->vmcb01);
 
-	if (vmsa_page)
+	if (vmsa_page) {
 		svm->sev_es.vmsa = page_address(vmsa_page);
 
+		/*
+		 * Do not include the encryption mask on the VMSA physical
+		 * address since hardware will access it using the guest key.
+		 */
+		svm->sev_es.vmsa_pa = __pa(svm->sev_es.vmsa);
+	}
+
 	svm->guest_state_loaded = false;
 
 	return 0;
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 7a921acc534f..1812fd61ea56 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -198,6 +198,7 @@ struct vcpu_sev_es_state {
 	struct ghcb *ghcb;
 	u8 valid_bitmap[16];
 	struct kvm_host_map ghcb_map;
+	hpa_t vmsa_pa;
 	bool received_first_sipi;
 
 	/* SEV-ES scratch area support */
-- 
2.39.0