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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
Subject: [PATCH 2/4] KVM: SVM: Use KVM's snapshot of the host's XCR0 for SEV-ES host state
Date: Tue, 23 Apr 2024 15:15:19 -0700	[thread overview]
Message-ID: <20240423221521.2923759-3-seanjc@google.com> (raw)
In-Reply-To: <20240423221521.2923759-1-seanjc@google.com>

Use KVM's snapshot of the host's XCR0 when stuffing SEV-ES host state
instead of reading XCR0 from hardware.  XCR0 is only written during
boot, i.e. won't change while KVM is running (and KVM at large is hosed
if that doesn't hold true).

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/svm/sev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 71f1518f0ca1..c56070991a58 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3249,7 +3249,7 @@ void sev_es_prepare_switch_to_guest(struct vcpu_svm *svm, struct sev_es_save_are
 	 * isn't saved by VMRUN, that isn't already saved by VMSAVE (performed
 	 * by common SVM code).
 	 */
-	hostsa->xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+	hostsa->xcr0 = kvm_host.xcr0;
 	hostsa->pkru = read_pkru();
 	hostsa->xss = kvm_host.xss;
 
-- 
2.44.0.769.g3c40516874-goog


  parent reply	other threads:[~2024-04-23 22:15 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-23 22:15 [PATCH 0/4] KVM: x86: Collect host state snapshots into a struct Sean Christopherson
2024-04-23 22:15 ` [PATCH 1/4] KVM: x86: Add a struct to consolidate host values, e.g. EFER, XCR0, etc Sean Christopherson
2024-04-25 11:29   ` Wang, Wei W
2024-04-25 14:10     ` Sean Christopherson
2024-04-25 14:37       ` Wang, Wei W
2024-04-25 14:47         ` Sean Christopherson
2024-04-23 22:15 ` Sean Christopherson [this message]
2024-04-23 22:15 ` [PATCH 3/4] KVM: x86/mmu: Snapshot shadow_phys_bits when kvm.ko is loaded Sean Christopherson
2024-04-23 22:15 ` [PATCH 4/4] KVM: x86: Move shadow_phys_bits into "kvm_host", as "maxphyaddr" Sean Christopherson
2024-04-25 11:17 ` [PATCH 0/4] KVM: x86: Collect host state snapshots into a struct Wang, Wei W
2024-04-25 14:24   ` Sean Christopherson
2024-06-04 23:29 ` Sean Christopherson

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