| Message ID | 20210921171121.2148982-3-oupton@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | selftests: KVM: Address some bugs caught by clang | expand |
On Tue, Sep 21, 2021 at 05:11:21PM +0000, Oliver Upton wrote: > 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> > --- > 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 ecec30865a74..aafaa8e38b7c 100644 > --- a/tools/testing/selftests/kvm/steal_time.c > +++ b/tools/testing/selftests/kvm/steal_time.c > @@ -118,12 +118,12 @@ 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" > -- > 2.33.0.464.g1972c5931b-goog > Reviewed-by: Andrew Jones <drjones@redhat.com>
diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c index ecec30865a74..aafaa8e38b7c 100644 --- a/tools/testing/selftests/kvm/steal_time.c +++ b/tools/testing/selftests/kvm/steal_time.c @@ -118,12 +118,12 @@ 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"
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> --- tools/testing/selftests/kvm/steal_time.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)