[PATCH 5.10 24/29] selftests: KVM: Align SMCCC call with the spec in steal_time

Greg Kroah-Hartman
2021-10-08T11:34:18Z

From: Oliver Upton <oupton@google.com>

[ Upstream commit 01f91acb55be7aac3950b89c458bcea9ef6e4f49 ]

The SMC64 calling convention passes a function identifier in w0 and its
parameters in x1-x17. Given this, there are two deviations in the
SMC64 call performed by the steal_time test: the function identifier is
assigned to a 64 bit register and the parameter is only 32 bits wide.

Align the call with the SMCCC by using a 32 bit register to handle the
function identifier and increasing the parameter width to 64 bits.

Suggested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Message-Id: <20210921171121.2148982-3-oupton@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/testing/selftests/kvm/steal_time.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c
index fcc840088c91..7daedee3e7ee 100644
--- a/tools/testing/selftests/kvm/steal_time.c
+++ b/tools/testing/selftests/kvm/steal_time.c
@@ -120,12 +120,12 @@ struct st_time {
uint64_t st_time;
};

-static int64_t smccc(uint32_t func, uint32_t arg)
+static int64_t smccc(uint32_t func, uint64_t arg)
{
unsigned long ret;

asm volatile(
- "mov x0, %1\n"
+ "mov w0, %w1\n"
"mov x1, %2\n"
"hvc #0\n"
"mov %0, x0\n"
--
2.33.0