FAILED: patch "[PATCH] KVM: VMX: enable X86_FEATURE_WAITPKG in KVM capabilities" failed to apply to 5.6-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.6-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 0abcc8f65cc23b65bc8d1614cc64b02b1641ed7c Mon Sep 17 00:00:00 2001
From: Maxim Levitsky <mlevitsk@redhat.com>
Date: Sat, 23 May 2020 19:14:54 +0300
Subject: [PATCH] KVM: VMX: enable X86_FEATURE_WAITPKG in KVM capabilities

Even though we might not allow the guest to use WAITPKG's new
instructions, we should tell KVM that the feature is supported by the
host CPU.

Note that vmx_waitpkg_supported checks that WAITPKG _can_ be set in
secondary execution controls as specified by VMX capability MSR, rather
that we actually enable it for a guest.

Cc: stable@vger.kernel.org
Fixes: e69e72faa3a0 ("KVM: x86: Add support for user wait instructions")
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200523161455.3940-2-mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 89c766fad889..9b63ac8d97ee 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7138,6 +7138,9 @@ static __init void vmx_set_cpu_caps(void)
 	/* CPUID 0x80000001 */
 	if (!cpu_has_vmx_rdtscp())
 		kvm_cpu_cap_clear(X86_FEATURE_RDTSCP);
+
+	if (vmx_waitpkg_supported())
+		kvm_cpu_cap_check_and_set(X86_FEATURE_WAITPKG);
 }
 
 static void vmx_request_immediate_exit(struct kvm_vcpu *vcpu)