[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 01/15] postcopy: Transmit and compare individual
From: |
Juan Quintela |
Subject: |
Re: [Qemu-devel] [PATCH 01/15] postcopy: Transmit and compare individual page sizes |
Date: |
Wed, 25 Jan 2017 10:47:51 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) |
"Dr. David Alan Gilbert (git)" <address@hidden> wrote:
> From: "Dr. David Alan Gilbert" <address@hidden>
>
> When using postcopy with hugepages, we require the source
> and destination page sizes for any RAMBlock to match.
>
> Transmit them as part of the RAM information header and
> fail if there's a difference.
>
> Signed-off-by: Dr. David Alan Gilbert <address@hidden>
> ---
> migration/ram.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/migration/ram.c b/migration/ram.c
> index a1c8089..39998f5 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -1970,6 +1970,9 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
> qemu_put_byte(f, strlen(block->idstr));
> qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
> qemu_put_be64(f, block->used_length);
> + if (migrate_postcopy_ram() && block->page_size !=
> qemu_host_page_size) {
> + qemu_put_be64(f, block->page_size);
> + }
Hi
1- can different block have different page_size?
2- can we remove the migrate_postocpy_ram() check and just send it for
newer versions and not for older ones?
> }
>
> rcu_read_unlock();
> @@ -2536,6 +2539,18 @@ static int ram_load(QEMUFile *f, void *opaque, int
> version_id)
> error_report_err(local_err);
> }
> }
> + /* For postcopy we need to check hugepage sizes match */
> + if (migrate_postcopy_ram() &&
> + block->page_size != qemu_host_page_size) {
> + uint64_t remote_page_size = qemu_get_be64(f);
> + if (remote_page_size != block->page_size) {
> + error_report("Mismatched RAM page size %s "
> + "(local) %" PRId64 "!= %" PRId64,
> + id, block->page_size,
> + remote_page_size);
> + ret = -EINVAL;
> + }
> + }
> ram_control_load_hook(f, RAM_CONTROL_BLOCK_REG,
> block->idstr);
> } else {