Re: [RFC PATCH-for-7.2 2/4] hw/display/qxl: Document qxl_phys2virt()

[Marc-André Lureau]

On Fri, Nov 25, 2022 at 7:41 PM Philippe Mathieu-Daudé
<philmd@linaro.org> wrote:
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>


> ---
>  hw/display/qxl.h | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
>
> diff --git a/hw/display/qxl.h b/hw/display/qxl.h
> index e74de9579d..78b3a6c9ba 100644
> --- a/hw/display/qxl.h
> +++ b/hw/display/qxl.h
> @@ -147,6 +147,25 @@ OBJECT_DECLARE_SIMPLE_TYPE(PCIQXLDevice, PCI_QXL)
>  #define QXL_DEFAULT_REVISION (QXL_REVISION_STABLE_V12 + 1)
>
>  /* qxl.c */
> +/**
> + * qxl_phys2virt: Get a pointer within a PCI VRAM memory region.
> + *
> + * @qxl: QXL device
> + * @phys: physical offset of buffer within the VRAM
> + * @group_id: memory slot group
> + *
> + * Returns a host pointer to a buffer placed at offset @phys within the
> + * active slot @group_id of the PCI VGA RAM memory region associated with
> + * the @qxl device. If the slot is inactive, or the offset is out
> + * of the memory region, returns NULL.
> + *
> + * Use with care; by the time this function returns, the returned pointer is
> + * not protected by RCU anymore.  If the caller is not within an RCU critical
> + * section and does not hold the iothread lock, it must have other means of
> + * protecting the pointer, such as a reference to the region that includes
> + * the incoming ram_addr_t.
> + *
> + */
>  void *qxl_phys2virt(PCIQXLDevice *qxl, QXLPHYSICAL phys, int group_id);
>  void qxl_set_guest_bug(PCIQXLDevice *qxl, const char *msg, ...)
>      G_GNUC_PRINTF(2, 3);
> --
> 2.38.1
>
>


--
Marc-André Lureau