Virtio-mmio devices can directly access guest memory and do so in cache
coherent fashion. Tell the guest about that fact when it's using ACPI.

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 hw/arm/virt-acpi-build.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 07a10ac..8955a9d 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -135,6 +135,7 @@ static void acpi_dsdt_add_virtio(Aml *scope,
         Aml *dev = aml_device("VR%02u", i);
         aml_append(dev, aml_name_decl("_HID", aml_string("LNRO0005")));
         aml_append(dev, aml_name_decl("_UID", aml_int(i)));
+        aml_append(dev, aml_name_decl("_CCA", aml_int(1)));
 
         Aml *crs = aml_resource_template();
         aml_append(crs, aml_memory32_fixed(base, size, AML_READ_WRITE));
-- 
2.10.0

On 2017/2/9 20:53, Alexander Graf wrote:
> Virtio-mmio devices can directly access guest memory and do so in cache
> coherent fashion. Tell the guest about that fact when it's using ACPI.
> 
> Signed-off-by: Alexander Graf <agraf@suse.de>
> ---
>  hw/arm/virt-acpi-build.c | 1 +
>  1 file changed, 1 insertion(+)
> 
Reviewed-by: Shannon Zhao <shannon.zhao@linaro.org>

> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index 07a10ac..8955a9d 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -135,6 +135,7 @@ static void acpi_dsdt_add_virtio(Aml *scope,
>          Aml *dev = aml_device("VR%02u", i);
>          aml_append(dev, aml_name_decl("_HID", aml_string("LNRO0005")));
>          aml_append(dev, aml_name_decl("_UID", aml_int(i)));
> +        aml_append(dev, aml_name_decl("_CCA", aml_int(1)));
>  
>          Aml *crs = aml_resource_template();
>          aml_append(crs, aml_memory32_fixed(base, size, AML_READ_WRITE));
> 

-- 
Shannon