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Re: [Qemu-devel] [PATCH 4/6] memory: find dirty range
From: |
Avi Kivity |
Subject: |
Re: [Qemu-devel] [PATCH 4/6] memory: find dirty range |
Date: |
Sun, 11 Dec 2011 11:30:40 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:8.0) Gecko/20111115 Thunderbird/8.0 |
On 12/10/2011 06:45 PM, Blue Swirl wrote:
> Instead of each target knowing or guessing the guest page size,
> iterate through the dirty ranges.
>
> Signed-off-by: Blue Swirl <address@hidden>
> ---
> cpu-all.h | 30 ++++++++++++++++++++++++++++++
> hw/tcx.c | 54 ++++++++++++++++++++++--------------------------------
> hw/vga.c | 16 +++++++---------
> memory.c | 16 ++++++++++++++++
> memory.h | 24 ++++++++++++++++++++++++
> 5 files changed, 99 insertions(+), 41 deletions(-)
>
> diff --git a/cpu-all.h b/cpu-all.h
> index 0cb62ca..a5c6670 100644
> --- a/cpu-all.h
> +++ b/cpu-all.h
> @@ -574,6 +574,36 @@ int cpu_physical_memory_set_dirty_tracking(int enable);
>
> int cpu_physical_memory_get_dirty_tracking(void);
>
> +static inline void cpu_physical_memory_range_find_dirty(ram_addr_t start,
> + ram_addr_t end,
> + ram_addr_t *pstart,
> + ram_addr_t *pend,
> + int flags)
> +{
> + ram_addr_t idx;
> +
> + start >>= TARGET_PAGE_BITS;
> + end += TARGET_PAGE_SIZE - 1;
> + end >>= TARGET_PAGE_BITS;
> +
> + for (idx = start; idx < end; idx++) {
> + if (ram_list.phys_dirty[idx] & flags) {
> + *pstart = idx << TARGET_PAGE_BITS;
> + for (; idx < end; idx++) {
> + if (!(ram_list.phys_dirty[idx] & flags)) {
> + *pend = (idx << TARGET_PAGE_BITS) - 1;
> + return;
> + }
> + }
> + *pend = (end << TARGET_PAGE_BITS) - 1;
This uses a convention of fully inclusive ranges, not semi inclusive
which is what we usually use.
> + return;
> + }
> + }
> + /* everything pristine */
> + *pstart = (end << TARGET_PAGE_BITS) - 1;
> + *pend = (end << TARGET_PAGE_BITS) - 1;
> +}
> +
I prefer this to be implemented using memory_region primitives, less
work for me to covert afterwards.
Also, no need to inline this.
> int cpu_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
> target_phys_addr_t end_addr);
>
> diff --git a/hw/tcx.c b/hw/tcx.c
> index fd45ce8..d031cbd 100644
> --- a/hw/tcx.c
> +++ b/hw/tcx.c
> @@ -212,7 +212,7 @@ static inline void reset_dirty(TCXState *ts,
> ram_addr_t page_min,
> static void tcx_update_display(void *opaque)
> {
> TCXState *ts = opaque;
> - ram_addr_t page, page_min, page_max;
> + ram_addr_t page, page_min, page_max, p;
> int y, y_start, dd, ds;
> uint8_t *d, *s;
> void (*f)(TCXState *s1, uint8_t *dst, const uint8_t *src, int width);
> @@ -244,37 +244,28 @@ static void tcx_update_display(void *opaque)
> return;
> }
>
> - for(y = 0; y < ts->height; y += 4, page += TARGET_PAGE_SIZE) {
> - if (memory_region_get_dirty(&ts->vram_mem, page, DIRTY_MEMORY_VGA)) {
> - if (y_start < 0)
> - y_start = y;
> - if (page < page_min)
> - page_min = page;
> - if (page > page_max)
> - page_max = page;
> - f(ts, d, s, ts->width);
> - d += dd;
> - s += ds;
> - f(ts, d, s, ts->width);
> - d += dd;
> - s += ds;
> - f(ts, d, s, ts->width);
> - d += dd;
> - s += ds;
> - f(ts, d, s, ts->width);
> - d += dd;
> - s += ds;
> - } else {
> - if (y_start >= 0) {
> - /* flush to display */
> - dpy_update(ts->ds, 0, y_start,
> - ts->width, y - y_start);
> - y_start = -1;
> - }
> - d += dd * 4;
> - s += ds * 4;
> + assert(MAXX == 1024);
> + y = 0;
> + for (p = 0; p < MAXX * MAXY;) {
> + target_phys_addr_t dirty_start, dirty_end;
> +
> + memory_region_find_dirty(&ts->vram_mem, p, MAXX * MAXY, &dirty_start,
> + &dirty_end, DIRTY_MEMORY_VGA);
> + if (dirty_start == MAXX * MAXY - 1) {
> + break;
> + }
Gives no way to indicate that just that one byte is dirty (possible if
MAXX * MAXY == 1 (mod TARGET_PAGE_SIZE))
> + page = dirty_start;
> + f(ts, d + (page >> 10) * dd, s + page, dirty_end - dirty_start);
> + if (y_start < 0) {
> + page_min = dirty_start;
> + /* divide by MAXX */
> + y_start = page_min >> 10;
page_min / MAXX?
> }
> + page_max = dirty_end;
> + y = page_max >> 10;
> + p = dirty_end + 1;
> }
> +
> if (y_start >= 0) {
> /* flush to display */
> dpy_update(ts->ds, 0, y_start,
> @@ -282,8 +273,7 @@ static void tcx_update_display(void *opaque)
> }
> /* reset modified pages */
> if (page_max >= page_min) {
> - memory_region_reset_dirty(&ts->vram_mem,
> - page_min, page_max + TARGET_PAGE_SIZE,
> + memory_region_reset_dirty(&ts->vram_mem, page_min, page_max,
> DIRTY_MEMORY_VGA);
fully-inclusive/semi-inclusive mixup
> /**
> + * memory_region_find_dirty: Find dirty ranges in a memory range for a
> + * specified client.
> + *
> + * Returns lowest contiguous dirty memory range within the specified
> memory range.
> + * Dirty logging must be enabled.
> + *
> + * @mr: the memory region being queried.
> + * @start: the start address (relative to the start of the region) of the
> + * region being searched.
> + * @end: the end address (relative to the start of the region) of the
> + * region being searched.
> + * address@hidden: the returned start address (relative to the start of the
> region)
> + * of the lowest contiguous dirty range found, or @end if not found.
> + * address@hidden: the returned end address (relative to the start of the
> region)
> + * of the lowest contiguous dirty range found.
> + * @client: the user of the logging information; %DIRTY_MEMORY_MIGRATION or
> + * %DIRTY_MEMORY_VGA.
> + */
> +void memory_region_find_dirty(MemoryRegion *mr, target_phys_addr_t start,
> + target_phys_addr_t end,
> + target_phys_addr_t *pstart,
> + target_phys_addr_t *pend,
> + unsigned client);
>
Might wrap in a MEMORY_REGION_FOR_EACH_DIRTY_RANGE() macro.
--
error compiling committee.c: too many arguments to function