Re: [Qemu-devel] [PATCHv2 1/2] Revert "migration: do not sent zero pages in bulk stage"

[Wenchao Xia]

clear patch, I don't see any issue.

Reviewed-by: Wenchao Xia <address@hidden>

> Not sending zero pages breaks migration if a page is zero
> at the source but not at the destination. This can e.g. happen
> if different BIOS versions are used at source and destination.
> It has also been reported that migration on pseries is completely
> broken with this patch.
> 
> This effectively reverts commit f1c72795af573b24a7da5eb52375c9aba8a37972.
> 
> Conflicts:
> 
>       arch_init.c
> 
> Signed-off-by: Peter Lieven <address@hidden>
> ---
>   arch_init.c |   13 ++++---------
>   1 file changed, 4 insertions(+), 9 deletions(-)
> 
> diff --git a/arch_init.c b/arch_init.c
> index 5d32ecf..08fccf6 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -457,15 +457,10 @@ static int ram_save_block(QEMUFile *f, bool last_stage)
>               bytes_sent = -1;
>               if (is_zero_page(p)) {
>                   acct_info.dup_pages++;
> -                if (!ram_bulk_stage) {
> -                    bytes_sent = save_block_hdr(f, block, offset, cont,
> -                                                RAM_SAVE_FLAG_COMPRESS);
> -                    qemu_put_byte(f, 0);
> -                    bytes_sent++;
> -                } else {
> -                    acct_info.skipped_pages++;
> -                    bytes_sent = 0;
> -                }
> +                bytes_sent = save_block_hdr(f, block, offset, cont,
> +                                            RAM_SAVE_FLAG_COMPRESS);
> +                qemu_put_byte(f, 0);
> +                bytes_sent++;
>               } else if (!ram_bulk_stage && migrate_use_xbzrle()) {
>                   current_addr = block->offset + offset;
>                   bytes_sent = save_xbzrle_page(f, p, current_addr, block,
> 


-- 
Best Regards

Wenchao Xia