linux-kernel - [PATCH RFC v7 53/64] KVM: SVM: Use a VMSA physical address variable for populating VMCB

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Date:   Wed, 14 Dec 2022 13:40:45 -0600
From:   Michael Roth <michael.roth@....com>
To:     <kvm@...r.kernel.org>
CC:     <linux-coco@...ts.linux.dev>, <linux-mm@...ck.org>,
        <linux-crypto@...r.kernel.org>, <x86@...nel.org>,
        <linux-kernel@...r.kernel.org>, <tglx@...utronix.de>,
        <mingo@...hat.com>, <jroedel@...e.de>, <thomas.lendacky@....com>,
        <hpa@...or.com>, <ardb@...nel.org>, <pbonzini@...hat.com>,
        <seanjc@...gle.com>, <vkuznets@...hat.com>,
        <wanpengli@...cent.com>, <jmattson@...gle.com>, <luto@...nel.org>,
        <dave.hansen@...ux.intel.com>, <slp@...hat.com>,
        <pgonda@...gle.com>, <peterz@...radead.org>,
        <srinivas.pandruvada@...ux.intel.com>, <rientjes@...gle.com>,
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        <sathyanarayanan.kuppuswamy@...ux.intel.com>,
        <alpergun@...gle.com>, <dgilbert@...hat.com>, <jarkko@...nel.org>,
        <ashish.kalra@....com>, <harald@...fian.com>
Subject: [PATCH RFC v7 53/64] KVM: SVM: 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>
---
 arch/x86/kvm/svm/sev.c | 5 ++---
 arch/x86/kvm/svm/svm.c | 9 ++++++++-
 arch/x86/kvm/svm/svm.h | 1 +
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 18efa70553c2..36c312143d12 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3845,10 +3845,9 @@ static void sev_es_init_vmcb(struct vcpu_svm *svm)
 
 	/*
 	 * An SEV-ES guest requires a VMSA area that is a separate from the
-	 * VMCB page. Do not include the encryption mask on the VMSA physical
-	 * address since hardware will access it using the guest key.
+	 * VMCB page.
 	 */
-	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 43f04fc95a0a..e9317d27a01d 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1398,9 +1398,16 @@ 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 7c0f9d00950f..284902e22dce 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -204,6 +204,7 @@ struct svm_nested_state {
 struct vcpu_sev_es_state {
 	/* SEV-ES support */
 	struct sev_es_save_area *vmsa;
+	hpa_t vmsa_pa;
 	bool ghcb_in_use;
 	bool received_first_sipi;
 	unsigned int ap_reset_hold_type;
-- 
2.25.1