diff mbox series

[01/11] KVM: x86: Fix steal time asm constraints in 32-bit mode

Message ID 20211115165030.7422-1-dwmw2@infradead.org (mailing list archive)
State New, archived
Headers show
Series Rework gfn_to_pfn_cache | expand

Commit Message

David Woodhouse Nov. 15, 2021, 4:50 p.m. UTC 
From: David Woodhouse <dwmw@amazon.co.uk>

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".

Fixes: 7e2175ebd695 ("KVM: x86: Fix recording of guest steal time / preempted status")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
 arch/x86/kvm/x86.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index dc7eb5fddfd3..54452269a4ff 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3307,7 +3307,7 @@  static void record_steal_time(struct kvm_vcpu *vcpu)
 			     "xor %1, %1\n"
 			     "2:\n"
 			     _ASM_EXTABLE_UA(1b, 2b)
-			     : "+r" (st_preempted),
+			     : "+q" (st_preempted),
 			       "+&r" (err)
 			     : "m" (st->preempted));
 		if (err)