Re: [Qemu-devel] [PATCH v2 17/28] s390x/tcg: MVCS/MVCP: Use access_memmove_idx()

[Richard Henderson]

On 9/6/19 3:57 AM, David Hildenbrand wrote:
> As we are moving between address spaces, we can use access_memmove_idx()
> without checking for destructive overlaps (especially of real storage
> locations):
> "Each storage operand is processed left to right. The
> storage-operand-consistency rules are the same as
> for MOVE (MVC), except that when the operands
> overlap in real storage, the use of the common real-
> storage locations is not necessarily recognized."
> 
> Signed-off-by: David Hildenbrand 
> ---
>  target/s390x/mem_helper.c | 20 ++--
>  1 file changed, 6 insertions(+), 14 deletions(-)

Reviewed-by: Richard Henderson 

r~

[Qemu-devel] [PATCH v2 17/28] s390x/tcg: MVCS/MVCP: Use access_memmove_idx()

[David Hildenbrand]

As we are moving between address spaces, we can use access_memmove_idx()
without checking for destructive overlaps (especially of real storage
locations):
"Each storage operand is processed left to right. The
storage-operand-consistency rules are the same as
for MOVE (MVC), except that when the operands
overlap in real storage, the use of the common real-
storage locations is not necessarily recognized."

Signed-off-by: David Hildenbrand 
---
 target/s390x/mem_helper.c | 20 ++--
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c
index db678ddf47..2607dd1677 100644
--- a/target/s390x/mem_helper.c
+++ b/target/s390x/mem_helper.c
@@ -2049,7 +2049,7 @@ uint32_t HELPER(mvcs)(CPUS390XState *env, uint64_t l, 
uint64_t a1, uint64_t a2)
 {
 const uint8_t psw_as = (env->psw.mask & PSW_MASK_ASC) >> PSW_SHIFT_ASC;
 uintptr_t ra = GETPC();
-int cc = 0, i;
+int cc = 0;
 
 HELPER_LOG("%s: %16" PRIx64 " %16" PRIx64 " %16" PRIx64 "\n",
__func__, l, a1, a2);
@@ -2068,12 +2068,8 @@ uint32_t HELPER(mvcs)(CPUS390XState *env, uint64_t l, 
uint64_t a1, uint64_t a2)
 return cc;
 }
 
-/* XXX replace w/ memcpy */
-for (i = 0; i < l; i++) {
-uint8_t x = cpu_ldub_primary_ra(env, a2 + i, ra);
-cpu_stb_secondary_ra(env, a1 + i, x, ra);
-}
-
+/* TODO: Access key handling */
+access_memmove_idx(env, a1, a2, l, MMU_SECONDARY_IDX, MMU_PRIMARY_IDX, ra);
 return cc;
 }
 
@@ -2081,7 +2077,7 @@ uint32_t HELPER(mvcp)(CPUS390XState *env, uint64_t l, 
uint64_t a1, uint64_t a2)
 {
 const uint8_t psw_as = (env->psw.mask & PSW_MASK_ASC) >> PSW_SHIFT_ASC;
 uintptr_t ra = GETPC();
-int cc = 0, i;
+int cc = 0;
 
 HELPER_LOG("%s: %16" PRIx64 " %16" PRIx64 " %16" PRIx64 "\n",
__func__, l, a1, a2);
@@ -2100,12 +2096,8 @@ uint32_t HELPER(mvcp)(CPUS390XState *env, uint64_t l, 
uint64_t a1, uint64_t a2)
 return cc;
 }
 
-/* XXX replace w/ memcpy */
-for (i = 0; i < l; i++) {
-uint8_t x = cpu_ldub_secondary_ra(env, a2 + i, ra);
-cpu_stb_primary_ra(env, a1 + i, x, ra);
-}
-
+/* TODO: Access key handling */
+access_memmove_idx(env, a1, a2, l, MMU_PRIMARY_IDX, MMU_SECONDARY_IDX, ra);
 return cc;
 }
 
-- 
2.21.0