RE: [PATCH V4 03/24] x86/ioreq: Provide out-of-line wrapper for the handle_mmio()

[Paul Durrant <xadimgnik@xxxxxxxxx>]

> -----Original Message-----
> From: Xen-devel <xen-devel-bounces@xxxxxxxxxxxxxxxxxxxx> On Behalf Of 
> Oleksandr Tyshchenko
> Sent: 12 January 2021 21:52
> To: xen-devel@xxxxxxxxxxxxxxxxxxxx
> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>; Paul Durrant 
> <paul@xxxxxxx>; Jan Beulich
> <jbeulich@xxxxxxxx>; Andrew Cooper <andrew.cooper3@xxxxxxxxxx>; Roger Pau 
> Monné
> <roger.pau@xxxxxxxxxx>; Wei Liu <wl@xxxxxxx>; Julien Grall <julien@xxxxxxx>; 
> Stefano Stabellini
> <sstabellini@xxxxxxxxxx>; Julien Grall <julien.grall@xxxxxxx>
> Subject: [PATCH V4 03/24] x86/ioreq: Provide out-of-line wrapper for the 
> handle_mmio()
> 
> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
> 
> The IOREQ is about to be common feature and Arm will have its own
> implementation.
> 
> But the name of the function is pretty generic and can be confusing
> on Arm (we already have a try_handle_mmio()).
> 
> In order not to rename the function (which is used for a varying
> set of purposes on x86) globally and get non-confusing variant on Arm
> provide a wrapper arch_ioreq_complete_mmio() to be used on common
> and Arm code.
> 
> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>

Reviewed-by: Paul Durrant <paul@xxxxxxx>

> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
> CC: Julien Grall <julien.grall@xxxxxxx>
> [On Arm only]
> Tested-by: Wei Chen <Wei.Chen@xxxxxxx>
> 
> ---
> Please note, this is a split/cleanup/hardening of Julien's PoC:
> "Add support for Guest IO forwarding to a device emulator"
> 
> Changes RFC -> V1:
>    - new patch
> 
> Changes V1 -> V2:
>    - remove "handle"
>    - add Jan's A-b
> 
> Changes V2 -> V3:
>    - remove Jan's A-b
>    - update patch subject/description
>    - use out-of-line function instead of #define
>    - put earlier in the series to avoid breakage
> 
> Changes V3 -> V4:
>    - add Jan's R-b
>    - rename ioreq_complete_mmio() to arch_ioreq_complete_mmio()
> ---
>  xen/arch/x86/hvm/ioreq.c        | 7 ++++++-
>  xen/include/asm-x86/hvm/ioreq.h | 1 +
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/xen/arch/x86/hvm/ioreq.c b/xen/arch/x86/hvm/ioreq.c
> index ff9a546..00c68f5 100644
> --- a/xen/arch/x86/hvm/ioreq.c
> +++ b/xen/arch/x86/hvm/ioreq.c
> @@ -35,6 +35,11 @@
>  #include <public/hvm/ioreq.h>
>  #include <public/hvm/params.h>
> 
> +bool arch_ioreq_complete_mmio(void)
> +{
> +    return handle_mmio();
> +}
> +
>  static void set_ioreq_server(struct domain *d, unsigned int id,
>                               struct hvm_ioreq_server *s)
>  {
> @@ -225,7 +230,7 @@ bool handle_hvm_io_completion(struct vcpu *v)
>          break;
> 
>      case HVMIO_mmio_completion:
> -        return handle_mmio();
> +        return arch_ioreq_complete_mmio();
> 
>      case HVMIO_pio_completion:
>          return handle_pio(vio->io_req.addr, vio->io_req.size,
> diff --git a/xen/include/asm-x86/hvm/ioreq.h b/xen/include/asm-x86/hvm/ioreq.h
> index f140ef4..0e64e76 100644
> --- a/xen/include/asm-x86/hvm/ioreq.h
> +++ b/xen/include/asm-x86/hvm/ioreq.h
> @@ -58,6 +58,7 @@ unsigned int hvm_broadcast_ioreq(ioreq_t *p, bool buffered);
> 
>  void hvm_ioreq_init(struct domain *d);
> 
> +bool arch_ioreq_complete_mmio(void);
>  bool arch_vcpu_ioreq_completion(enum hvm_io_completion io_completion);
>  int arch_ioreq_server_map_pages(struct hvm_ioreq_server *s);
>  void arch_ioreq_server_unmap_pages(struct hvm_ioreq_server *s);
> --
> 2.7.4
>