On 5/10/22 6:08 PM, Vishal Annapurve wrote:
Fix inline assembly for hypercall to explicitly set
eax with hypercall number to allow the implementation
to work even in cases where compiler would inline the
function.
Please explain what happens without this change as well.
Signed-off-by: Vishal Annapurve <vannapurve@xxxxxxxxxx>
---
tools/testing/selftests/kvm/lib/x86_64/processor.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index 9f000dfb5594..4d88e1a553bf 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -1461,7 +1461,7 @@ uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2,
asm volatile("vmcall"
: "=a"(r)
- : "b"(a0), "c"(a1), "d"(a2), "S"(a3));
+ : "a"(nr), "b"(a0), "c"(a1), "d"(a2), "S"(a3));
return r;
}
With the above change to commit log:
Reviewed-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
thanks,
-- Shuah
