Commit 275f3033 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Greg Kroah-Hartman

KVM: x86: block guest protection keys unless the host has them enabled

commit c469268c upstream.

If the host has protection keys disabled, we cannot read and write the
guest PKRU---RDPKRU and WRPKRU fail with #GP(0) if CR4.PKE=0.  Block
the PKU cpuid bit in that case.

This ensures that guest_CR4.PKE=1 implies host_CR4.PKE=1.

Fixes: 1be0e61cReviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cfb917a1
......@@ -456,7 +456,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
entry->ecx &= kvm_cpuid_7_0_ecx_x86_features;
cpuid_mask(&entry->ecx, CPUID_7_ECX);
/* PKU is not yet implemented for shadow paging. */
if (!tdp_enabled)
if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
entry->ecx &= ~F(PKU);
} else {
entry->ebx = 0;
......
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