Patch-mainline: v5.17-rc2
Git-commit: be4f3b3f82271c3193ce200a996dc70682c8e622
References: git-fixes
From: Xiaoyao Li <xiaoyao.li@intel.com>
Date: Wed, 26 Jan 2022 17:22:24 +0000
Subject: [PATCH] KVM: x86: Keep MSR_IA32_XSS unchanged for INIT

It has been corrected from SDM version 075 that MSR_IA32_XSS is reset to
zero on Power up and Reset but keeps unchanged on INIT.

Fixes: a554d207dc46 ("KVM: X86: Processor States following Reset or INIT")
Cc: stable@vger.kernel.org
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220126172226.2298529-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
---
 arch/x86/kvm/x86.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a50baf4c5bff..b6d60c296eda 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11266,6 +11266,7 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
 		vcpu->arch.msr_misc_features_enables = 0;
 
 		vcpu->arch.xcr0 = XFEATURE_MASK_FP;
+		vcpu->arch.ia32_xss = 0;
 	}
 
 	/* All GPRs except RDX (handled below) are zeroed on RESET/INIT. */
@@ -11282,8 +11283,6 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
 	memset(vcpu->arch.regs, 0, sizeof(vcpu->arch.regs));
 	kvm_register_mark_dirty(vcpu, VCPU_REGS_RSP);
 
-	vcpu->arch.ia32_xss = 0;
-
 	static_call(kvm_x86_vcpu_reset)(vcpu, init_event);
 
 	vcpu->arch.cr3 = 0;
-- 
2.35.3