tree 3448c4e65aecd71260c9bbe4e99c70533c6055e9
parent 94b3ffcd41a90d2cb0b32ca23aa58a01111d5dc0
author Paolo Bonzini <pbonzini@redhat.com> 1393240516 +0100
committer Paolo Bonzini <pbonzini@redhat.com> 1395055298 +0100

KVM: x86: introduce kvm_supported_xcr0()

XSAVE support for KVM is already using host_xcr0 & KVM_SUPPORTED_XCR0 as
a "dynamic" version of KVM_SUPPORTED_XCR0.

However, this is not enough because the MPX bits should not be presented
to the guest unless kvm_x86_ops confirms the support.  So, replace all
instances of host_xcr0 & KVM_SUPPORTED_XCR0 with a new function
kvm_supported_xcr0() that also has this check.

Note that here:

		if (xstate_bv & ~KVM_SUPPORTED_XCR0)
			return -EINVAL;
		if (xstate_bv & ~host_cr0)
			return -EINVAL;

the code is equivalent to

		if ((xstate_bv & ~KVM_SUPPORTED_XCR0) ||
		    (xstate_bv & ~host_cr0)
			return -EINVAL;

i.e. "xstate_bv & (~KVM_SUPPORTED_XCR0 | ~host_cr0)" which is in turn
equal to "xstate_bv & ~(KVM_SUPPORTED_XCR0 & host_cr0)".  So we should
also use the new function there.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>