On Wed, Dec 24, 2025 at 5:22 PM Philippe Mathieu-Daudé
<philmd@linaro.org> wrote:
>
> Defining DEBUG_SUBPAGE allows to use raw printf() statements to
> print information about some events; convert these to tracepoints.
>
> Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
> system/physmem.c | 29 ++++++-----------------------
> system/trace-events | 6 ++++++
> 2 files changed, 12 insertions(+), 23 deletions(-)
>
> diff --git a/system/physmem.c b/system/physmem.c
> index 1292f49095f..7e914ecf648 100644
> --- a/system/physmem.c
> +++ b/system/physmem.c
> @@ -91,8 +91,6 @@
>
> #include "memory-internal.h"
>
> -//#define DEBUG_SUBPAGE
> -
> /* ram_list is read under rcu_read_lock()/rcu_read_unlock(). Writes
> * are protected by the ramlist lock.
> */
> @@ -2903,10 +2901,7 @@ static MemTxResult subpage_read(void *opaque, hwaddr addr, uint64_t *data,
> uint8_t buf[8];
> MemTxResult res;
>
> -#if defined(DEBUG_SUBPAGE)
> - printf("%s: subpage %p len %u addr " HWADDR_FMT_plx "\n", __func__,
> - subpage, len, addr);
> -#endif
> + trace_subpage_read(subpage, len, addr);
> res = flatview_read(subpage->fv, addr + subpage->base, attrs, buf, len);
> if (res) {
> return res;
> @@ -2921,11 +2916,7 @@ static MemTxResult subpage_write(void *opaque, hwaddr addr,
> subpage_t *subpage = opaque;
> uint8_t buf[8];
>
> -#if defined(DEBUG_SUBPAGE)
> - printf("%s: subpage %p len %u addr " HWADDR_FMT_plx
> - " value %"PRIx64"\n",
> - __func__, subpage, len, addr, value);
> -#endif
> + trace_subpage_write(subpage, len, addr, value);
> stn_p(buf, len, value);
> return flatview_write(subpage->fv, addr + subpage->base, attrs, buf, len);
> }
> @@ -2935,10 +2926,8 @@ static bool subpage_accepts(void *opaque, hwaddr addr,
> MemTxAttrs attrs)
> {
> subpage_t *subpage = opaque;
> -#if defined(DEBUG_SUBPAGE)
> - printf("%s: subpage %p %c len %u addr " HWADDR_FMT_plx "\n",
> - __func__, subpage, is_write ? 'w' : 'r', len, addr);
> -#endif
> +
> + trace_subpage_accepts(subpage, is_write ? 'w' : 'r', len, addr);
>
> return flatview_access_valid(subpage->fv, addr + subpage->base,
> len, is_write, attrs);
> @@ -2964,10 +2953,7 @@ static int subpage_register(subpage_t *mmio, uint32_t start, uint32_t end,
> return -1;
> idx = SUBPAGE_IDX(start);
> eidx = SUBPAGE_IDX(end);
> -#if defined(DEBUG_SUBPAGE)
> - printf("%s: %p start %08x end %08x idx %08x eidx %08x section %d\n",
> - __func__, mmio, start, end, idx, eidx, section);
> -#endif
> + trace_subpage_register(mmio, start, end, idx, eidx, section);
> for (; idx <= eidx; idx++) {
> mmio->sub_section[idx] = section;
> }
> @@ -2986,10 +2972,7 @@ static subpage_t *subpage_init(FlatView *fv, hwaddr base)
> memory_region_init_io(&mmio->iomem, NULL, &subpage_ops, mmio,
> NULL, TARGET_PAGE_SIZE);
> mmio->iomem.subpage = true;
> -#if defined(DEBUG_SUBPAGE)
> - printf("%s: %p base " HWADDR_FMT_plx " len %08x\n", __func__,
> - mmio, base, TARGET_PAGE_SIZE);
> -#endif
> + trace_subpage_init(mmio, base, TARGET_PAGE_SIZE);
>
> return mmio;
> }
> diff --git a/system/trace-events b/system/trace-events
> index 82856e44f2e..6d29a823f04 100644
> --- a/system/trace-events
> +++ b/system/trace-events
> @@ -35,6 +35,12 @@ find_ram_offset_loop(uint64_t size, uint64_t candidate, uint64_t offset, uint64_
> ram_block_discard_range(const char *rbname, void *hva, size_t length, bool need_madvise, bool need_fallocate, int ret) "%s@%p + 0x%zx: madvise: %d fallocate: %d ret: %d"
> qemu_ram_alloc_shared(const char *name, size_t size, size_t max_size, int fd, void *host) "%s size %zu max_size %zu fd %d host %p"
>
> +subpage_register(void *subpage, uint32_t start, uint32_t end, int idx, int eidx, uint16_t section) "subpage %p start 0x%08x end 0x%08x idx 0x%08x eidx 0x%08x section %u"
> +subpage_init(void *subpage, uint64_t base, uint64_t len) "subpage %p base 0x%08" PRIx64 " len 0x%08" PRIx64
> +subpage_accepts(void *subpage, char access, unsigned len, uint64_t addr) "subpage %p %c len %u addr 0x%" PRIx64
> +subpage_read(void *subpage, unsigned len, uint64_t addr) "subpage %p len %u addr 0x%" PRIx64
> +subpage_write(void *subpage, unsigned len, uint64_t addr, uint64_t value) "subpage %p len %u addr 0x%" PRIx64 " value 0x%" PRIx64
> +
> # cpus.c
> vm_stop_flush_all(int ret) "ret %d"
>
> --
> 2.52.0
>