[Qemu-devel] Re: [PATCH v3 2/6] Introduce bit-based phys_ram_dirty for VGA, CODE, MIGRATION and MASTER.

[Yoshiaki Tamura]

Avi Kivity wrote:
> On 04/19/2010 12:43 PM, Yoshiaki Tamura wrote:
> > Replaces byte-based phys_ram_dirty bitmap with four bit-based
> > phys_ram_dirty
> > bitmap. On allocation, it sets all bits in the bitmap.
> >
> > Signed-off-by: Yoshiaki Tamura<address@hidden>
> > ---
> > exec.c | 16 +++++++++++-----
> > qemu-common.h | 3 +++
> > 2 files changed, 14 insertions(+), 5 deletions(-)
> >
> > diff --git a/exec.c b/exec.c
> > index c74b0a4..b85cb26 100644
> > --- a/exec.c
> > +++ b/exec.c
> > @@ -110,7 +110,7 @@ uint8_t *code_gen_ptr;
> >
> > #if !defined(CONFIG_USER_ONLY)
> > int phys_ram_fd;
> > -uint8_t *phys_ram_dirty;
> > +unsigned long *phys_ram_dirty[NUM_DIRTY_IDX];
> > static int in_migration;
> >
> > typedef struct RAMBlock {
> > @@ -2825,10 +2825,16 @@ ram_addr_t qemu_ram_alloc(ram_addr_t size)
> > new_block->next = ram_blocks;
> > ram_blocks = new_block;
> >
> > - phys_ram_dirty = qemu_realloc(phys_ram_dirty,
> > - (last_ram_offset + size)>> TARGET_PAGE_BITS);
> > - memset(phys_ram_dirty + (last_ram_offset>> TARGET_PAGE_BITS),
> > - 0xff, size>> TARGET_PAGE_BITS);
> > + if (BITMAP_SIZE(last_ram_offset + size) !=
> > BITMAP_SIZE(last_ram_offset)) {
>
> This check is unneeded - the code will work fine even if the bitmap size
> doesn't change.

OK.  I'll remove it.

> > + int i;
> > + for (i = MASTER_DIRTY_IDX; i< NUM_DIRTY_IDX; i++) {
> > + phys_ram_dirty[i]
> > + = qemu_realloc(phys_ram_dirty[i],
> > + BITMAP_SIZE(last_ram_offset + size));
> > + memset((uint8_t *)phys_ram_dirty[i] +
> > + BITMAP_SIZE(last_ram_offset), 0xff, BITMAP_SIZE(size));
> > + }
> > + }
> >
> > last_ram_offset += size;