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)