diff options
author | David Woodhouse <dwmw@amazon.co.uk> | 2021-11-14 11:59:02 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-21 15:44:12 +0300 |
commit | 19e32bd1cc37c34683a214242bee7a0b114831bd (patch) | |
tree | 86303f562e0716f89192ce1b9cfaf5d2fa51d72e | |
parent | b06962406eca3d0ca818e2cda96e1b2e1f82bc94 (diff) | |
download | linux-19e32bd1cc37c34683a214242bee7a0b114831bd.tar.xz |
KVM: Fix steal time asm constraints
commit 964b7aa0b040bdc6ec1c543ee620cda3f8b4c68a upstream.
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: 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>
Message-Id: <89bf72db1b859990355f9c40713a34e0d2d86c98.camel@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | arch/x86/kvm/x86.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 3de93d4bf16b..c48e2b5729c5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3242,9 +3242,9 @@ 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; |