Re: [PATCH 2/2] tpm_crb: mark memory as protected

[David Hildenbrand]

On 20.06.23 21:50, Laurent Vivier wrote:
> This memory is not correctly aligned and cannot be registered
> by vDPA and VFIO.
>
> An error is reported for vhost-vdpa case:
> qemu-kvm: vhost_vdpa_listener_region_add received unaligned region
>
> To make it ignored by VFIO and vDPA devices, mark it as RAM_PROTECTED.
>
> The RAM_PROTECTED flag has been introduced to skip memory
> region that looks like RAM but is not accessible via normal
> mechanims, including DMA.
>
> See 56918a126a ("memory: Add RAM_PROTECTED flag to skip IOMMU mappings")
>
> Bug: https://bugzilla.redhat.com/show_bug.cgi?id=2141965
>
> cc: peter.maydell@linaro.org
> cc: marcandre.lureau@redhat.com
> cc: eric.auger@redhat.com
> cc: mst@redhat.com
> cc: jasowang@redhat.com
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> ---
>   hw/tpm/tpm_crb.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/tpm/tpm_crb.c b/hw/tpm/tpm_crb.c
> index ea930da545af..0a93c488f2fa 100644
> --- a/hw/tpm/tpm_crb.c
> +++ b/hw/tpm/tpm_crb.c
> @@ -296,7 +296,7 @@ static void tpm_crb_realize(DeviceState *dev, Error **errp)
>   
>       memory_region_init_io(&s->mmio, OBJECT(s), &tpm_crb_memory_ops, s,
>           "tpm-crb-mmio", sizeof(s->regs));
> -    memory_region_init_ram(&s->cmdmem, OBJECT(s),
> +    memory_region_init_ram_protected(&s->cmdmem, OBJECT(s),
>           "tpm-crb-cmd", CRB_CTRL_CMD_SIZE, errp);
>   
>       memory_region_add_subregion(get_system_memory(),

Reviewed-by: David Hildenbrand <david@redhat.com>

--
Cheers,

David / dhildenb