The patch below does not apply to the 5.4-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@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 4c282e51e4450b94680d6ca3b10f830483b1f243 Mon Sep 17 00:00:00 2001 From: Like Xu likexu@tencent.com Date: Wed, 26 Jan 2022 17:22:25 +0000 Subject: [PATCH] KVM: x86: Update vCPU's runtime CPUID on write to MSR_IA32_XSS
Do a runtime CPUID update for a vCPU if MSR_IA32_XSS is written, as the size in bytes of the XSAVE area is affected by the states enabled in XSS.
Fixes: 203000993de5 ("kvm: vmx: add MSR logic for XSAVES") Cc: stable@vger.kernel.org Signed-off-by: Like Xu likexu@tencent.com [sean: split out as a separate patch, adjust Fixes tag] Signed-off-by: Sean Christopherson seanjc@google.com Message-Id: 20220126172226.2298529-3-seanjc@google.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index b6d60c296eda..9c984eeed30c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3535,6 +3535,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if (data & ~supported_xss) return 1; vcpu->arch.ia32_xss = data; + kvm_update_cpuid_runtime(vcpu); break; case MSR_SMI_COUNT: if (!msr_info->host_initiated)