Re: [PATCH] hvf: Avoid mapping regions < PAGE_SIZE as ram

[Philippe Mathieu-Daudé]

Hi Alex,

On 10/25/21 10:25, Alexander Graf wrote:
> HVF has generic memory listener code that adds all RAM regions as HVF RAM
> regions. However, HVF can only handle page aligned, page granule regions.
> 
> So let's ignore regions that are not page aligned and sized. They will be
> trapped as MMIO instead.
> 
> Signed-off-by: Alexander Graf <agraf@csgraf.de>
> ---
>  accel/hvf/hvf-accel-ops.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/accel/hvf/hvf-accel-ops.c b/accel/hvf/hvf-accel-ops.c
> index 6bf319d34c..090155853a 100644
> --- a/accel/hvf/hvf-accel-ops.c
> +++ b/accel/hvf/hvf-accel-ops.c
> @@ -135,6 +135,12 @@ static void hvf_set_phys_mem(MemoryRegionSection 
> *section, bool add)
>          }
>      }
>  
> +    if (int128_get64(section->size) & (qemu_real_host_page_size - 1) ||
> +        section->offset_within_address_space & (qemu_real_host_page_size - 
> 1)) {

Could we use QEMU_IS_ALIGNED() instead?

> +        /* Not page aligned, so we can not map as RAM */
> +        add = false;
> +    }
> +
>      mem = hvf_find_overlap_slot(
>              section->offset_within_address_space,
>              int128_get64(section->size));
>