Re: [PATCH] vfio/container: pass MemoryRegion to DMA operations

["Cédric Le Goater" <clg@redhat.com>]

On 5/21/25 23:55, John Levon wrote:
> Pass through the MemoryRegion to DMA operation handlers of vfio
> containers. The vfio-user container will need this later, to translate
> the vaddr into an offset for the dma map vfio-user message; CPR will
> also will need this.
> 
> Originally-by: John Johnson <john.g.johnson@oracle.com>
> Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
> Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
> Signed-off-by: John Levon <john.levon@nutanix.com>
> ---
>   include/hw/vfio/vfio-container-base.h | 9 +++++----
>   hw/vfio/container-base.c              | 4 ++--
>   hw/vfio/container.c                   | 3 ++-
>   hw/vfio/iommufd.c                     | 3 ++-
>   hw/vfio/listener.c                    | 6 +++---
>   5 files changed, 14 insertions(+), 11 deletions(-)

Steven,

Can you base the live update series on this patch ?

Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.



> 
> diff --git a/include/hw/vfio/vfio-container-base.h b/include/hw/vfio/vfio-container-base.h
> index f9e561cb08..3feb773e5f 100644
> --- a/include/hw/vfio/vfio-container-base.h
> +++ b/include/hw/vfio/vfio-container-base.h
> @@ -78,7 +78,7 @@ void vfio_address_space_insert(VFIOAddressSpace *space,
>   
>   int vfio_container_dma_map(VFIOContainerBase *bcontainer,
>                              hwaddr iova, ram_addr_t size,
> -                           void *vaddr, bool readonly);
> +                           void *vaddr, bool readonly, MemoryRegion *mr);
>   int vfio_container_dma_unmap(VFIOContainerBase *bcontainer,
>                                hwaddr iova, ram_addr_t size,
>                                IOMMUTLBEntry *iotlb, bool unmap_all);
> @@ -151,20 +151,21 @@ struct VFIOIOMMUClass {
>       /**
>        * @dma_map
>        *
> -     * Map an address range into the container.
> +     * Map an address range into the container. Note that the memory region is
> +     * referenced within an RCU read lock region across this call.
>        *
>        * @bcontainer: #VFIOContainerBase to use
>        * @iova: start address to map
>        * @size: size of the range to map
>        * @vaddr: process virtual address of mapping
>        * @readonly: true if mapping should be readonly
> +     * @mr: the memory region for this mapping
>        *
>        * Returns 0 to indicate success and -errno otherwise.
>        */
>       int (*dma_map)(const VFIOContainerBase *bcontainer,
>                      hwaddr iova, ram_addr_t size,
> -                   void *vaddr, bool readonly);
> -
> +                   void *vaddr, bool readonly, MemoryRegion *mr);
>       /**
>        * @dma_unmap
>        *
> diff --git a/hw/vfio/container-base.c b/hw/vfio/container-base.c
> index 1c6ca94b60..d834bd4822 100644
> --- a/hw/vfio/container-base.c
> +++ b/hw/vfio/container-base.c
> @@ -75,12 +75,12 @@ void vfio_address_space_insert(VFIOAddressSpace *space,
>   
>   int vfio_container_dma_map(VFIOContainerBase *bcontainer,
>                              hwaddr iova, ram_addr_t size,
> -                           void *vaddr, bool readonly)
> +                           void *vaddr, bool readonly, MemoryRegion *mr)
>   {
>       VFIOIOMMUClass *vioc = VFIO_IOMMU_GET_CLASS(bcontainer);
>   
>       g_assert(vioc->dma_map);
> -    return vioc->dma_map(bcontainer, iova, size, vaddr, readonly);
> +    return vioc->dma_map(bcontainer, iova, size, vaddr, readonly, mr);
>   }
>   
>   int vfio_container_dma_unmap(VFIOContainerBase *bcontainer,
> diff --git a/hw/vfio/container.c b/hw/vfio/container.c
> index a9f0dbaec4..a8c76eb481 100644
> --- a/hw/vfio/container.c
> +++ b/hw/vfio/container.c
> @@ -207,7 +207,8 @@ static int vfio_legacy_dma_unmap(const VFIOContainerBase *bcontainer,
>   }
>   
>   static int vfio_legacy_dma_map(const VFIOContainerBase *bcontainer, hwaddr iova,
> -                               ram_addr_t size, void *vaddr, bool readonly)
> +                               ram_addr_t size, void *vaddr, bool readonly,
> +                               MemoryRegion *mr)
>   {
>       const VFIOContainer *container = container_of(bcontainer, VFIOContainer,
>                                                     bcontainer);
> diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
> index 6b2696793f..46a3b36301 100644
> --- a/hw/vfio/iommufd.c
> +++ b/hw/vfio/iommufd.c
> @@ -34,7 +34,8 @@
>               TYPE_HOST_IOMMU_DEVICE_IOMMUFD "-vfio"
>   
>   static int iommufd_cdev_map(const VFIOContainerBase *bcontainer, hwaddr iova,
> -                            ram_addr_t size, void *vaddr, bool readonly)
> +                            ram_addr_t size, void *vaddr, bool readonly,
> +                            MemoryRegion *mr)
>   {
>       const VFIOIOMMUFDContainer *container =
>           container_of(bcontainer, VFIOIOMMUFDContainer, bcontainer);
> diff --git a/hw/vfio/listener.c b/hw/vfio/listener.c
> index 38e3dc82cf..7495866123 100644
> --- a/hw/vfio/listener.c
> +++ b/hw/vfio/listener.c
> @@ -170,7 +170,7 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
>            */
>           ret = vfio_container_dma_map(bcontainer, iova,
>                                        iotlb->addr_mask + 1, vaddr,
> -                                     read_only);
> +                                     read_only, mr);
>           if (ret) {
>               error_report("vfio_container_dma_map(%p, 0x%"HWADDR_PRIx", "
>                            "0x%"HWADDR_PRIx", %p) = %d (%s)",
> @@ -240,7 +240,7 @@ static int vfio_ram_discard_notify_populate(RamDiscardListener *rdl,
>           vaddr = memory_region_get_ram_ptr(section->mr) + start;
>   
>           ret = vfio_container_dma_map(bcontainer, iova, next - start,
> -                                     vaddr, section->readonly);
> +                                     vaddr, section->readonly, section->mr);
>           if (ret) {
>               /* Rollback */
>               vfio_ram_discard_notify_discard(rdl, section);
> @@ -564,7 +564,7 @@ static void vfio_listener_region_add(MemoryListener *listener,
>       }
>   
>       ret = vfio_container_dma_map(bcontainer, iova, int128_get64(llsize),
> -                                 vaddr, section->readonly);
> +                                 vaddr, section->readonly, section->mr);
>       if (ret) {
>           error_setg(&err, "vfio_container_dma_map(%p, 0x%"HWADDR_PRIx", "
>                      "0x%"HWADDR_PRIx", %p) = %d (%s)",