KVM: x86: only copy XSAVE state for the supported features

This makes the interface more deterministic for userspace, which can expect
(after configuring only the features it supports) to get exactly the same
state from the kernel, independent of the host CPU and kernel version.

Suggested-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 35d10d1a6b58..52110d0ceb13 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -390,6 +390,7 @@ struct kvm_vcpu_arch {
         struct fpu guest_fpu;
         u64 xcr0;
         u64 guest_supported_xcr0;
+        u32 guest_xstate_size;
 
         struct kvm_pio_request pio;
         void *pio_data;