Commit 964b7aa0 authored by David Woodhouse's avatar David Woodhouse Committed by Paolo Bonzini
Browse files

KVM: Fix steal time asm constraints 



In 64-bit mode, x86 instruction encoding allows us to use the low 8 bits
of any GPR as an 8-bit operand. In 32-bit mode, however, we can only use
the [abcd] registers. For which, GCC has the "q" constraint instead of
the less restrictive "r".

Also fix st->preempted, which is an input/output operand rather than an
input.

Fixes: 7e2175eb ("KVM: x86: Fix recording of guest steal time / preempted status")
Reported-by: default avatarkernel test robot <lkp@intel.com>
Signed-off-by: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
Message-Id: <89bf72db1b859990355f9c40713a34e0d2d86c98.camel@infradead.org>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent dc23a511

arch/x86/kvm/x86.c

+3 −3
Original line number Diff line number Diff line
@@ -3307,9 +3307,9 @@ static void record_steal_time(struct kvm_vcpu *vcpu) 
			     "xor %1, %1\n"

			     "2:\n"

			     _ASM_EXTABLE_UA(1b, 2b)

			     : "+r" (st_preempted),

			       "+&r" (err)

			     : "m" (st->preempted));

			     : "+q" (st_preempted),

			       "+&r" (err),

			       "+m" (st->preempted));

		if (err)

			goto out;