The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From be4f3b3f82271c3193ce200a996dc70682c8e622 Mon Sep 17 00:00:00 2001
From: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
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@xxxxxxxxxxxxxxx
Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Message-Id: <20220126172226.2298529-2-seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
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)
cpuid_0x1 = kvm_find_cpuid_entry(vcpu, 1, 0);
kvm_rdx_write(vcpu, cpuid_0x1 ? cpuid_0x1->eax : 0x600);
- vcpu->arch.ia32_xss = 0;
-
static_call(kvm_x86_vcpu_reset)(vcpu, init_event);
kvm_set_rflags(vcpu, X86_EFLAGS_FIXED);
