Commit 00c87e9a authored Feb 01, 2017 by Radim Krčmář

KVM: x86: do not save guest-unsupported XSAVE state



Saving unsupported state prevents migration when the new host does not
support a XSAVE feature of the original host, even if the feature is not
exposed to the guest.

We've masked host features with guest-visible features before, with
4344ee98 ("KVM: x86: only copy XSAVE state for the supported
features") and dropped it when implementing XSAVES.  Do it again.

Fixes: df1daba7 ("KVM: x86: support XSAVES usage in the host")
Cc: stable@vger.kernel.org
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

parent 566cf877

arch/x86/kvm/x86.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -3182,6 +3182,7 @@ static void fill_xsave(u8 dest, struct kvm_vcpu vcpu)
		memcpy(dest, xsave, XSAVE_HDR_OFFSET);

		/* Set XSTATE_BV */
		xstate_bv &= vcpu->arch.guest_supported_xcr0 \| XFEATURE_MASK_FPSSE;
		(u64 )(dest + XSAVE_HDR_OFFSET) = xstate_bv;

		/*

Admin message