Re: [Qemu-devel] [PATCH V2 4/5] xen: Change memory access behavior during migration.

[Stefano Stabellini]

On Fri, 9 Dec 2011, Anthony PERARD wrote:
> Do not allocate RAM during pre-migration runstate.
> Do not actually "do" set_memory during migration.
> 
> Signed-off-by: Anthony PERARD <address@hidden>
> ---
>  xen-all.c |   13 +++++++++++++
>  1 files changed, 13 insertions(+), 0 deletions(-)
> 
> diff --git a/xen-all.c b/xen-all.c
> index b2e9853..c1fed87 100644
> --- a/xen-all.c
> +++ b/xen-all.c
> @@ -189,6 +189,11 @@ void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size)
>  
>      trace_xen_ram_alloc(ram_addr, size);
>  
> +    if (runstate_check(RUN_STATE_PREMIGRATE)) {
> +        /* RAM already populated in Xen */
> +        return;
> +    }

It is probably worth printing out a message about the address and size
qemu wanted to allocated


>      nr_pfn = size >> TARGET_PAGE_BITS;
>      pfn_list = g_malloc(sizeof (*pfn_list) * nr_pfn);
>  
> @@ -269,6 +274,13 @@ go_physmap:
>      DPRINTF("mapping vram to %llx - %llx, from %llx\n",
>              start_addr, start_addr + size, phys_offset);
>  
> +    if (runstate_check(RUN_STATE_INMIGRATE)) {
> +        /* The mapping should already be done and can not be done a second
> +         * time. So we just add to the physmap list instead.
> +         */
> +        goto done;
> +    }

same here, printing a message would be useful