Re: [PATCH v3] multifd: Add colo support

[Peter Xu]

copy hailiang.

On Thu, Jun 22, 2023 at 01:18:46PM +0200, Lukas Straub wrote:
> Like in the normal ram_load() path, put the received pages into the
> colo cache and mark the pages in the bitmap so that they will be
> flushed to the guest later.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> ---
>  migration/meson.build    |  1 +
>  migration/multifd-colo.c | 53 ++++++++++++++++++++++++++++++++++++++++
>  migration/multifd-colo.h | 24 ++++++++++++++++++
>  migration/multifd.c      |  5 ++++
>  4 files changed, 83 insertions(+)
>  create mode 100644 migration/multifd-colo.c
>  create mode 100644 migration/multifd-colo.h
> 
> diff --git a/migration/meson.build b/migration/meson.build
> index 1ae28523a1..063e0e0a8c 100644
> --- a/migration/meson.build
> +++ b/migration/meson.build
> @@ -21,6 +21,7 @@ system_ss.add(files(
>    'migration.c',
>    'multifd.c',
>    'multifd-zlib.c',
> +  'multifd-colo.c',
>    'ram-compress.c',
>    'options.c',
>    'postcopy-ram.c',
> diff --git a/migration/multifd-colo.c b/migration/multifd-colo.c
> new file mode 100644
> index 0000000000..4872dc6d01
> --- /dev/null
> +++ b/migration/multifd-colo.c
> @@ -0,0 +1,53 @@
> +/*
> + * multifd colo implementation
> + *
> + * Copyright (c) Lukas Straub <lukasstraub2@web.de>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "exec/target_page.h"
> +#include "exec/ramblock.h"
> +#include "qemu/error-report.h"
> +#include "qapi/error.h"
> +#include "ram.h"
> +#include "multifd.h"
> +#include "options.h"
> +#include "io/channel-socket.h"
> +#include "migration/colo.h"
> +#include "multifd-colo.h"
> +
> +void multifd_colo_prepare_recv_pages(MultiFDRecvParams *p)
> +{
> +    if (!migrate_colo())
> +        return;
> +
> +    assert(p->block->colo_cache);
> +
> +    /*
> +     * While we're still in precopy state (not yet in colo state), we copy
> +     * received pages to both guest and cache. No need to set dirty bits,
> +     * since guest and cache memory are in sync.
> +     */
> +    if (migration_incoming_in_colo_state()) {
> +        colo_record_bitmap(p->block, p->normal, p->normal_num);
> +    }
> +    p->host = p->block->colo_cache;
> +}
> +
> +void multifd_colo_process_recv_pages(MultiFDRecvParams *p)
> +{
> +    if (!migrate_colo())
> +        return;
> +
> +    if (!migration_incoming_in_colo_state()) {
> +        for (int i = 0; i < p->normal_num; i++) {
> +            void *guest = p->block->host + p->normal[i];
> +            void *cache = p->host + p->normal[i];
> +            memcpy(guest, cache, p->page_size);
> +        }
> +    }
> +    p->host = p->block->host;
> +}
> diff --git a/migration/multifd-colo.h b/migration/multifd-colo.h
> new file mode 100644
> index 0000000000..58920a0583
> --- /dev/null
> +++ b/migration/multifd-colo.h
> @@ -0,0 +1,24 @@
> +/*
> + * multifd colo header
> + *
> + * Copyright (c) Lukas Straub <lukasstraub2@web.de>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#ifndef QEMU_MIGRATION_MULTIFD_COLO_H
> +#define QEMU_MIGRATION_MULTIFD_COLO_H
> +
> +#ifdef CONFIG_REPLICATION
> +
> +void multifd_colo_prepare_recv_pages(MultiFDRecvParams *p);
> +void multifd_colo_process_recv_pages(MultiFDRecvParams *p);
> +
> +#else
> +
> +static inline void multifd_colo_prepare_recv_pages(MultiFDRecvParams *p) {}
> +static inline void multifd_colo_process_recv_pages(MultiFDRecvParams *p) {}
> +
> +#endif
> +#endif
> diff --git a/migration/multifd.c b/migration/multifd.c
> index 3387d8277f..6b031c1fd2 100644
> --- a/migration/multifd.c
> +++ b/migration/multifd.c
> @@ -25,6 +25,7 @@
>  #include "qemu-file.h"
>  #include "trace.h"
>  #include "multifd.h"
> +#include "multifd-colo.h"
>  #include "threadinfo.h"
>  #include "options.h"
>  #include "qemu/yank.h"
> @@ -1134,10 +1135,14 @@ static void *multifd_recv_thread(void *opaque)
>          qemu_mutex_unlock(&p->mutex);
>  
>          if (p->normal_num) {
> +            multifd_colo_prepare_recv_pages(p);
> +
>              ret = multifd_recv_state->ops->recv_pages(p, &local_err);
>              if (ret != 0) {
>                  break;
>              }
> +
> +            multifd_colo_process_recv_pages(p);
>          }
>  
>          if (flags & MULTIFD_FLAG_SYNC) {
> -- 
> 2.39.2



-- 
Peter Xu