KVM: x86: Advertise AMD_IBPB_RET to userspace

This is an inherent feature of IA32_PRED_CMD[0], so it is trivially
virtualizable (as long as IA32_PRED_CMD[0] is virtualized).

Suggested-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20241011214353.1625057-4-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 41786b834b16357c3e7408364805d3d0a5a11218..53112669be002172485f78fa8c819152da947ba1 100644 (file)
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -755,7 +755,7 @@ void kvm_set_cpu_caps(void)
                F(CLZERO) | F(XSAVEERPTR) |
                F(WBNOINVD) | F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) |
                F(AMD_SSB_NO) | F(AMD_STIBP) | F(AMD_STIBP_ALWAYS_ON) |
-               F(AMD_PSFD)
+               F(AMD_PSFD) | F(AMD_IBPB_RET)
        );
 
        /*