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[PATCH v4 07/15] vfio/common: Track whether DMA Translation is enabled on the vIOMMU

Joao Martins posted 15 patches 2 years, 7 months ago
Maintainers: "Michael S. Tsirkin" <mst@redhat.com>, Peter Xu <peterx@redhat.com>, Jason Wang <jasowang@redhat.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Eduardo Habkost <eduardo@habkost.net>, Alex Williamson <alex.williamson@redhat.com>, "Cédric Le Goater" <clg@redhat.com>, David Hildenbrand <david@redhat.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>
[PATCH v4 07/15] vfio/common: Track whether DMA Translation is enabled on the vIOMMU
Posted by Joao Martins 2 years, 7 months ago 
vfio_get_group() allocates and fills the group/container/space on
success which will store the AddressSpace inside the VFIOSpace struct.
Use the newly added pci_device_iommu_get_attr() to see if DMA
translation is enabled or not. Assume that by default it is enabled.

Today, this means only intel-iommu supports it.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
---
 include/hw/vfio/vfio-common.h |  1 +
 hw/vfio/pci.c                 | 15 ++++++++++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index eed244f25f34..f41860988d6b 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -70,6 +70,7 @@ typedef struct VFIOMigration {
 
 typedef struct VFIOAddressSpace {
     AddressSpace *as;
+    bool no_dma_translation;
     QLIST_HEAD(, VFIOContainer) containers;
     QLIST_ENTRY(VFIOAddressSpace) list;
 } VFIOAddressSpace;
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 73874a94de12..8a98e6ffc480 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -2900,6 +2900,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
     VFIOPCIDevice *vdev = VFIO_PCI(pdev);
     VFIODevice *vbasedev = &vdev->vbasedev;
     VFIODevice *vbasedev_iter;
+    VFIOAddressSpace *space;
     VFIOGroup *group;
     char *tmp, *subsys, group_path[PATH_MAX], *group_name;
     Error *err = NULL;
@@ -2907,7 +2908,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
     struct stat st;
     int groupid;
     int i, ret;
-    bool is_mdev;
+    bool is_mdev, dma_translation;
     char uuid[UUID_FMT_LEN];
     char *name;
 
@@ -2961,6 +2962,18 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
         goto error;
     }
 
+    space = group->container->space;
+
+    /*
+     * Support for toggling DMA translation is optional.
+     * By default, DMA translation is assumed to be enabled i.e.
+     * space::no_dma_translation is 0.
+     */
+    dma_translation = true;
+    pci_device_iommu_get_attr(pdev, IOMMU_ATTR_DMA_TRANSLATION,
+                              &dma_translation);
+    space->no_dma_translation = !dma_translation;
+
     QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
         if (strcmp(vbasedev_iter->name, vbasedev->name) == 0) {
             error_setg(errp, "device is already attached");
-- 
2.17.2
Re: [PATCH v4 07/15] vfio/common: Track whether DMA Translation is enabled on the vIOMMU
Posted by Eric Auger 2 years, 4 months ago 
Hi Joao,

On 6/22/23 23:48, Joao Martins wrote:
> vfio_get_group() allocates and fills the group/container/space on
> success which will store the AddressSpace inside the VFIOSpace struct.
VFIOAddressSpace
> Use the newly added pci_device_iommu_get_attr() to see if DMA
> translation is enabled or not. Assume that by default it is enabled.
> 
> Today, this means only intel-iommu supports it.
> 
> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
> ---
>  include/hw/vfio/vfio-common.h |  1 +
>  hw/vfio/pci.c                 | 15 ++++++++++++++-
>  2 files changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index eed244f25f34..f41860988d6b 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -70,6 +70,7 @@ typedef struct VFIOMigration {
>  
>  typedef struct VFIOAddressSpace {
>      AddressSpace *as;
> +    bool no_dma_translation;
>      QLIST_HEAD(, VFIOContainer) containers;
>      QLIST_ENTRY(VFIOAddressSpace) list;
>  } VFIOAddressSpace;
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 73874a94de12..8a98e6ffc480 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -2900,6 +2900,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>      VFIOPCIDevice *vdev = VFIO_PCI(pdev);
>      VFIODevice *vbasedev = &vdev->vbasedev;
>      VFIODevice *vbasedev_iter;
> +    VFIOAddressSpace *space;
>      VFIOGroup *group;
>      char *tmp, *subsys, group_path[PATH_MAX], *group_name;
>      Error *err = NULL;
> @@ -2907,7 +2908,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>      struct stat st;
>      int groupid;
>      int i, ret;
> -    bool is_mdev;
> +    bool is_mdev, dma_translation;
>      char uuid[UUID_FMT_LEN];
>      char *name;
>  
> @@ -2961,6 +2962,18 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>          goto error;
>      }
>  
> +    space = group->container->space;
> +
> +    /*
> +     * Support for toggling DMA translation is optional.
> +     * By default, DMA translation is assumed to be enabled i.e.
> +     * space::no_dma_translation is 0.
> +     */
> +    dma_translation = true;
nit can be set at init.
> +    pci_device_iommu_get_attr(pdev, IOMMU_ATTR_DMA_TRANSLATION,
> +                              &dma_translation);> +    space->no_dma_translation = !dma_translation;
> +
>      QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
>          if (strcmp(vbasedev_iter->name, vbasedev->name) == 0) {
>              error_setg(errp, "device is already attached");

Thanks

Eric
Re: [PATCH v4 07/15] vfio/common: Track whether DMA Translation is enabled on the vIOMMU
Posted by Avihai Horon 2 years, 7 months ago 
On 23/06/2023 0:48, Joao Martins wrote:
> External email: Use caution opening links or attachments
>
>
> vfio_get_group() allocates and fills the group/container/space on
> success which will store the AddressSpace inside the VFIOSpace struct.
> Use the newly added pci_device_iommu_get_attr() to see if DMA
> translation is enabled or not. Assume that by default it is enabled.
>
> Today, this means only intel-iommu supports it.
>
> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
> ---
>   include/hw/vfio/vfio-common.h |  1 +
>   hw/vfio/pci.c                 | 15 ++++++++++++++-
>   2 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index eed244f25f34..f41860988d6b 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -70,6 +70,7 @@ typedef struct VFIOMigration {
>
>   typedef struct VFIOAddressSpace {
>       AddressSpace *as;
> +    bool no_dma_translation;

I find this negation a bit confusing, especially when below local 
variable is "dma_translation" (there is also double negation in next patch).
Maybe rename to "dma_translation" or "have_dma_translation"?

Thanks.

>       QLIST_HEAD(, VFIOContainer) containers;
>       QLIST_ENTRY(VFIOAddressSpace) list;
>   } VFIOAddressSpace;
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 73874a94de12..8a98e6ffc480 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -2900,6 +2900,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>       VFIOPCIDevice *vdev = VFIO_PCI(pdev);
>       VFIODevice *vbasedev = &vdev->vbasedev;
>       VFIODevice *vbasedev_iter;
> +    VFIOAddressSpace *space;
>       VFIOGroup *group;
>       char *tmp, *subsys, group_path[PATH_MAX], *group_name;
>       Error *err = NULL;
> @@ -2907,7 +2908,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>       struct stat st;
>       int groupid;
>       int i, ret;
> -    bool is_mdev;
> +    bool is_mdev, dma_translation;
>       char uuid[UUID_FMT_LEN];
>       char *name;
>
> @@ -2961,6 +2962,18 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>           goto error;
>       }
>
> +    space = group->container->space;
> +
> +    /*
> +     * Support for toggling DMA translation is optional.
> +     * By default, DMA translation is assumed to be enabled i.e.
> +     * space::no_dma_translation is 0.
> +     */
> +    dma_translation = true;
> +    pci_device_iommu_get_attr(pdev, IOMMU_ATTR_DMA_TRANSLATION,
> +                              &dma_translation);
> +    space->no_dma_translation = !dma_translation;
> +
>       QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
>           if (strcmp(vbasedev_iter->name, vbasedev->name) == 0) {
>               error_setg(errp, "device is already attached");
> --
> 2.17.2
>
Re: [PATCH v4 07/15] vfio/common: Track whether DMA Translation is enabled on the vIOMMU
Posted by Joao Martins 2 years, 7 months ago 
On 09/07/2023 16:10, Avihai Horon wrote:
> On 23/06/2023 0:48, Joao Martins wrote:
>> vfio_get_group() allocates and fills the group/container/space on
>> success which will store the AddressSpace inside the VFIOSpace struct.
>> Use the newly added pci_device_iommu_get_attr() to see if DMA
>> translation is enabled or not. Assume that by default it is enabled.
>>
>> Today, this means only intel-iommu supports it.
>>
>> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
>> ---
>>   include/hw/vfio/vfio-common.h |  1 +
>>   hw/vfio/pci.c                 | 15 ++++++++++++++-
>>   2 files changed, 15 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
>> index eed244f25f34..f41860988d6b 100644
>> --- a/include/hw/vfio/vfio-common.h
>> +++ b/include/hw/vfio/vfio-common.h
>> @@ -70,6 +70,7 @@ typedef struct VFIOMigration {
>>
>>   typedef struct VFIOAddressSpace {
>>       AddressSpace *as;
>> +    bool no_dma_translation;
> 
> I find this negation a bit confusing, especially when below local variable is
> "dma_translation" (there is also double negation in next patch).
> Maybe rename to "dma_translation" or "have_dma_translation"?
> 

Good idea -- I can switch to that.

> Thanks.
> 
>>       QLIST_HEAD(, VFIOContainer) containers;
>>       QLIST_ENTRY(VFIOAddressSpace) list;
>>   } VFIOAddressSpace;
>> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
>> index 73874a94de12..8a98e6ffc480 100644
>> --- a/hw/vfio/pci.c
>> +++ b/hw/vfio/pci.c
>> @@ -2900,6 +2900,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>>       VFIOPCIDevice *vdev = VFIO_PCI(pdev);
>>       VFIODevice *vbasedev = &vdev->vbasedev;
>>       VFIODevice *vbasedev_iter;
>> +    VFIOAddressSpace *space;
>>       VFIOGroup *group;
>>       char *tmp, *subsys, group_path[PATH_MAX], *group_name;
>>       Error *err = NULL;
>> @@ -2907,7 +2908,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>>       struct stat st;
>>       int groupid;
>>       int i, ret;
>> -    bool is_mdev;
>> +    bool is_mdev, dma_translation;
>>       char uuid[UUID_FMT_LEN];
>>       char *name;
>>
>> @@ -2961,6 +2962,18 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>>           goto error;
>>       }
>>
>> +    space = group->container->space;
>> +
>> +    /*
>> +     * Support for toggling DMA translation is optional.
>> +     * By default, DMA translation is assumed to be enabled i.e.
>> +     * space::no_dma_translation is 0.
>> +     */
>> +    dma_translation = true;
>> +    pci_device_iommu_get_attr(pdev, IOMMU_ATTR_DMA_TRANSLATION,
>> +                              &dma_translation);
>> +    space->no_dma_translation = !dma_translation;
>> +
>>       QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
>>           if (strcmp(vbasedev_iter->name, vbasedev->name) == 0) {
>>               error_setg(errp, "device is already attached");
>> -- 
>> 2.17.2
>>

Patchew 2.1-devel-b67e4c2

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