On 3/7/25 08:49, Philippe Mathieu-Daudé wrote:
@@ -170,13 +171,16 @@ static bool virtio_mem_has_shared_zeropage(RAMBlock *rb)
* necessary (as the section size can change). But it's more likely that the
* section size will rather get smaller and not bigger over time.
*/
-#if defined(TARGET_X86_64) || defined(TARGET_I386) || defined(TARGET_S390X)
-#define VIRTIO_MEM_USABLE_EXTENT (2 * (128 * MiB))
-#elif defined(TARGET_ARM)
-#define VIRTIO_MEM_USABLE_EXTENT (2 * (512 * MiB))
-#else
-#error VIRTIO_MEM_USABLE_EXTENT not defined
-#endif
+static uint64_t virtio_mem_usable_extent_size(void)
+{
+ if (qemu_arch_available(QEMU_ARCH_I386 | QEMU_ARCH_S390X)) {
+ return 2 * 128 * MiB;
+ } else if (qemu_arch_available(QEMU_ARCH_ARM)) {
+ return 2 * 512 * MiB;
+ } else {
+ g_assert_not_reached();
+ }
+}
What happens if/when we have multiple arches available? Won't we want to
know which CPU the virtio-mem device is attached to or do we take the
minimal value over the whole system?
"per attached vcpu" is how I was previously considering this problem,
but IIUC from the discussions with Pierrick, we should consider single
binary as a first step before heterogeneous emulation.
If you think the minimal value is good enough, then that'd be my
preferred choice, as the simplest to implement.
Indeed, you have already done so; see above.
Reviewed-by: Richard Henderson <richard.hender...@linaro.org>
r~
