diff mbox series

[2/8] accel/kvm: Use target_needs_bswap()

Message ID 20250417131004.47205-3-philmd@linaro.org
State New
Headers show
Series misc: Prefer evaluating TARGET_BIG_ENDIAN in C | expand

Commit Message

Philippe Mathieu-Daudé April 17, 2025, 1:09 p.m. UTC 
Check whether we need to swap at runtime using
target_needs_bswap().

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 accel/kvm/kvm-all.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

Comments

Richard Henderson April 18, 2025, 5:47 p.m. UTC | #1 
On 4/17/25 06:09, Philippe Mathieu-Daudé wrote:
> Check whether we need to swap at runtime using
> target_needs_bswap().
> 
> Signed-off-by: Philippe Mathieu-Daudé<philmd@linaro.org>
> ---
>   accel/kvm/kvm-all.c | 29 +++++++++++++++--------------
>   1 file changed, 15 insertions(+), 14 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~
diff mbox series

Patch

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 7c5d1a98bc4..28a32afb209 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -33,6 +33,7 @@ 
 #include "system/cpus.h"
 #include "system/accel-blocker.h"
 #include "qemu/bswap.h"
+#include "exec/tswap.h"
 #include "system/memory.h"
 #include "system/ram_addr.h"
 #include "qemu/event_notifier.h"
@@ -1319,21 +1320,21 @@  bool kvm_hwpoisoned_mem(void)
 
 static uint32_t adjust_ioeventfd_endianness(uint32_t val, uint32_t size)
 {
-#if HOST_BIG_ENDIAN != TARGET_BIG_ENDIAN
-    /* The kernel expects ioeventfd values in HOST_BIG_ENDIAN
-     * endianness, but the memory core hands them in target endianness.
-     * For example, PPC is always treated as big-endian even if running
-     * on KVM and on PPC64LE.  Correct here.
-     */
-    switch (size) {
-    case 2:
-        val = bswap16(val);
-        break;
-    case 4:
-        val = bswap32(val);
-        break;
+    if (target_needs_bswap()) {
+        /* The kernel expects ioeventfd values in HOST_BIG_ENDIAN
+         * endianness, but the memory core hands them in target endianness.
+         * For example, PPC is always treated as big-endian even if running
+         * on KVM and on PPC64LE.  Correct here, swapping back.
+         */
+        switch (size) {
+        case 2:
+            val = bswap16(val);
+            break;
+        case 4:
+            val = bswap32(val);
+            break;
+        }
     }
-#endif
     return val;
 }