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 05a9e065059e566f218f8778c4d17ee75db56c55 Mon Sep 17 00:00:00 2001
From: Like Xu <likexu@xxxxxxxxxxx>
Date: Wed, 26 Jan 2022 17:22:26 +0000
Subject: [PATCH] KVM: x86: Sync the states size with the XCR0/IA32_XSS at, any
time
XCR0 is reset to 1 by RESET but not INIT and IA32_XSS is zeroed by
both RESET and INIT. The kvm_set_msr_common()'s handling of MSR_IA32_XSS
also needs to update kvm_update_cpuid_runtime(). In the above cases, the
size in bytes of the XSAVE area containing all states enabled by XCR0 or
(XCRO | IA32_XSS) needs to be updated.
For simplicity and consistency, existing helpers are used to write values
and call kvm_update_cpuid_runtime(), and it's not exactly a fast path.
Fixes: a554d207dc46 ("KVM: X86: Processor States following Reset or INIT")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Like Xu <likexu@xxxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Message-Id: <20220126172226.2298529-4-seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9c984eeed30c..5481d2259f02 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11266,8 +11266,8 @@ 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;
+ __kvm_set_xcr(vcpu, 0, XFEATURE_MASK_FP);
+ __kvm_set_msr(vcpu, MSR_IA32_XSS, 0, true);
}
/* All GPRs except RDX (handled below) are zeroed on RESET/INIT. */
