Re: [Qemu-devel] [PATCH RFC 3/4] exec: don't exit unconditionally if failed to allocate memory

[Paolo Bonzini <pbonzini@redhat.com>]

Il 14/06/2014 06:48, Hu Tao ha scritto:
> return -1 instead.
>
> Now user can add objects memory-backend-ram on-the-fly, fail it if
> cannot allocate memory rather than quit qemu.
>
> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>

This needs an audit of all callers or, alternatively, we need to add 
memory_region_init_ram_nofail.  Better leave it for after the merge.

Paolo

> ---
>  backends/hostmem-ram.c | 3 +++
>  exec.c                 | 6 +++++-
>  2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/backends/hostmem-ram.c b/backends/hostmem-ram.c
> index d9a8290..afb305d 100644
> --- a/backends/hostmem-ram.c
> +++ b/backends/hostmem-ram.c
> @@ -28,6 +28,9 @@ ram_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
>      path = object_get_canonical_path_component(OBJECT(backend));
>      memory_region_init_ram(&backend->mr, OBJECT(backend), path,
>                             backend->size);
> +    if (backend->mr.ram_addr == -1) {
> +        error_setg(errp, "can't allocate memory");
> +    }
>      g_free(path);
>  }
>
> diff --git a/exec.c b/exec.c
> index 8705cc5..74560e5 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1228,7 +1228,7 @@ static ram_addr_t ram_block_add(RAMBlock *new_block)
>              if (!new_block->host) {
>                  fprintf(stderr, "Cannot set up guest memory '%s': %s\n",
>                          new_block->mr->name, strerror(errno));
> -                exit(1);
> +                return -1;
>              }
>              memory_try_enable_merging(new_block->host, new_block->length);
>          }
> @@ -1356,6 +1356,10 @@ void qemu_ram_free(ram_addr_t addr)
>  {
>      RAMBlock *block;
>
> +    if (addr == -1) {
> +        return;
> +    }
> +
>      /* This assumes the iothread lock is taken here too.  */
>      qemu_mutex_lock_ramlist();
>      QTAILQ_FOREACH(block, &ram_list.blocks, next) {
>