Re: [PATCH V2 05/22] vl: memfd-alloc option

[Daniel P . Berrangé]

On Tue, Jan 05, 2021 at 07:41:53AM -0800, Steve Sistare wrote:
> Allocate anonymous memory using memfd_create if the memfd-alloc option is
> set.
> 
> Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
> ---
>  exec.c                  | 38 ++++++++++++++++++++++++++++++--------
>  include/sysemu/sysemu.h |  1 +
>  qemu-options.hx         | 11 +++++++++++
>  softmmu/vl.c            |  4 ++++
>  trace-events            |  1 +
>  5 files changed, 47 insertions(+), 8 deletions(-)

> diff --git a/qemu-options.hx b/qemu-options.hx
> index 708583b..455b43b7 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -4094,6 +4094,17 @@ SRST
>      an unmigratable state.
>  ERST
>  
> +#ifdef __linux__
> +DEF("memfd-alloc", 0,  QEMU_OPTION_memfd_alloc, \
> +    "-memfd-alloc         allocate anonymous memory using memfd_create\n",
> +    QEMU_ARCH_ALL)
> +#endif
> +
> +SRST
> +``-memfd-alloc``
> +    Allocate anonymous memory using memfd_create (Linux only).
> +ERST

Do we really need a new arg for this ? It is already possible to request
use of memfd for the guest RAM using

  -object memory-backend-memfd,id=ram-node0,size=NNNN

this memory backend object framework was intended to remove the need to
add new ad-hoc CLI args for controlling memory allocation.

Regards,
Daniel
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