FAILED: patch "[PATCH] KVM: x86: Update vCPU's runtime CPUID on write to" failed to apply to 4.9-stable tree

FAILED: patch "[PATCH] KVM: x86: Update vCPU's runtime CPUID on write to" failed to apply to 4.9-stable tree

[gregkh]

The patch below does not apply to the 4.9-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)