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FAILED: patch "[PATCH] KVM: VMX: Do not advertise RDPID if ENABLE_RDTSCP control is" failed to apply to 5.4-stable tree

PATCH [email protected] 1 participant 1 message May 17, 2021

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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 <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 8aec21c04caa2000f91cf8822ae0811e4b0c3971 Mon Sep 17 00:00:00 2001
From: Sean Christopherson <[email protected]>
Date: Tue, 4 May 2021 10:17:20 -0700
Subject: [PATCH] KVM: VMX: Do not advertise RDPID if ENABLE_RDTSCP control is
unsupported

Clear KVM's RDPID capability if the ENABLE_RDTSCP secondary exec control is unsupported. Despite being enumerated in a separate CPUID flag, RDPID is bundled under the same VMCS control as RDTSCP and will #UD in VMX non-root if ENABLE_RDTSCP is not enabled.

Fixes 41cd02c6f7f6 ("kvm: x86: Expose RDPID in KVM_GET_SUPPORTED_CPUID")

Message-Id: <[email protected]>

arch/x86/kvm/vmx/vmx.c +4 -2
index cbe0cdade38a..46573b862638 100644
@@ -7377,9 +7377,11 @@ static __init void vmx_set_cpu_caps(void)
 	if (!cpu_has_vmx_xsaves())
 		kvm_cpu_cap_clear(X86_FEATURE_XSAVES);
 
-	/* CPUID 0x80000001 */
-	if (!cpu_has_vmx_rdtscp())
+	/* CPUID 0x80000001 and 0x7 (RDPID) */
+	if (!cpu_has_vmx_rdtscp()) {
 		kvm_cpu_cap_clear(X86_FEATURE_RDTSCP);
+		kvm_cpu_cap_clear(X86_FEATURE_RDPID);
+	}
 
 	if (cpu_has_vmx_waitpkg())
 		kvm_cpu_cap_check_and_set(X86_FEATURE_WAITPKG);