On Tue, 2013-05-14 at 19:13 +1000, David Gibson wrote:
> The only model so far supported for VFIO passthrough devices is the model
> usually used on x86, where all of the guest's RAM is mapped into the
> (host) IOMMU and there is no IOMMU visible in the guest.
>
> This patch begins to relax this model, introducing the notion of a
> VFIOAddressSpace. This represents a logical DMA address space which will
> be visible to one or more VFIO devices by appropriate mapping in the (host)
> IOMMU. Thus the currently global list of containers becomes local to
> a VFIOAddressSpace, and we verify that we don't attempt to add a VFIO
> group to multiple address spaces.
>
> For now, only one VFIOAddressSpace is created and used, corresponding to
> main system memory, that will change in future patches.
>
> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
> ---
> hw/misc/vfio.c | 63
> ++++++++++++++++++++++++++++++++++++++++++--------------
> 1 file changed, 48 insertions(+), 15 deletions(-)
>
> diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
> index c4a8853..e557f69 100644
> --- a/hw/misc/vfio.c
> +++ b/hw/misc/vfio.c
> @@ -113,9 +113,17 @@ enum {
> VFIO_INT_MSIX = 3,
> };
>
> +typedef struct VFIOAddressSpace {
> + AddressSpace *as;
> + QLIST_HEAD(, VFIOContainer) containers;
> +} VFIOAddressSpace;
> +
> +static VFIOAddressSpace vfio_address_space_memory;
> +
> struct VFIOGroup;
>
> typedef struct VFIOContainer {
> + VFIOAddressSpace *space;
> int fd; /* /dev/vfio/vfio, empowered by the attached groups */
> struct {
> /* enable abstraction to support various iommu backends */
> @@ -178,9 +186,6 @@ typedef struct VFIOGroup {
>
> #define MSIX_CAP_LENGTH 12
>
> -static QLIST_HEAD(, VFIOContainer)
> - container_list = QLIST_HEAD_INITIALIZER(container_list);
> -
> static QLIST_HEAD(, VFIOGroup)
> group_list = QLIST_HEAD_INITIALIZER(group_list);
>
> @@ -2624,16 +2629,28 @@ static int vfio_load_rom(VFIODevice *vdev)
> return 0;
> }
>
> -static int vfio_connect_container(VFIOGroup *group)
> +static void vfio_address_space_init(VFIOAddressSpace *space, AddressSpace
> *as)
> +{
> + space->as = as;
> + QLIST_INIT(&space->containers);
> +}
> +
> +static int vfio_connect_container(VFIOGroup *group, VFIOAddressSpace *space)
> {
> VFIOContainer *container;
> int ret, fd;
>
> if (group->container) {
> - return 0;
> + if (group->container->space == space) {
> + return 0;
> + } else {
> + error_report("vfio: group %d used in multiple address spaces",
> + group->groupid);
> + return -EBUSY;
> + }
> }
>
> - QLIST_FOREACH(container, &container_list, next) {
> + QLIST_FOREACH(container, &space->containers, next) {
> if (!ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) {
> group->container = container;
> QLIST_INSERT_HEAD(&container->group_list, group, container_next);
> @@ -2656,6 +2673,7 @@ static int vfio_connect_container(VFIOGroup *group)
> }
>
> container = g_malloc0(sizeof(*container));
> + container->space = space;
> container->fd = fd;
>
> if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU)) {
> @@ -2678,7 +2696,8 @@ static int vfio_connect_container(VFIOGroup *group)
> container->iommu_data.listener = vfio_memory_listener;
> container->iommu_data.release = vfio_listener_release;
>
> - memory_listener_register(&container->iommu_data.listener,
> &address_space_memory);
> + memory_listener_register(&container->iommu_data.listener,
> + container->space->as);
> } else {
> error_report("vfio: No available IOMMU models");
> g_free(container);
> @@ -2687,7 +2706,7 @@ static int vfio_connect_container(VFIOGroup *group)
> }
>
> QLIST_INIT(&container->group_list);
> - QLIST_INSERT_HEAD(&container_list, container, next);
> + QLIST_INSERT_HEAD(&space->containers, container, next);
>
> group->container = container;
> QLIST_INSERT_HEAD(&container->group_list, group, container_next);
> @@ -2700,7 +2719,7 @@ static void vfio_disconnect_container(VFIOGroup *group)
> VFIOContainer *container = group->container;
>
> if (ioctl(group->fd, VFIO_GROUP_UNSET_CONTAINER, &container->fd)) {
> - error_report("vfio: error disconnecting group %d from container",
> + error_report("vfio: error disconnecting group %d from context",
> group->groupid);
> }
>
> @@ -2712,13 +2731,13 @@ static void vfio_disconnect_container(VFIOGroup
> *group)
> container->iommu_data.release(container);
> }
> QLIST_REMOVE(container, next);
> - DPRINTF("vfio_disconnect_container: close container->fd\n");
> + DPRINTF("vfio_disconnect: close container->fd\n");
> close(container->fd);
> g_free(container);
> }
> }
Drop the above two chunks.
> -static VFIOGroup *vfio_get_group(int groupid)
> +static VFIOGroup *vfio_get_group(int groupid, VFIOAddressSpace *space)
> {
> VFIOGroup *group;
> char path[32];
> @@ -2726,7 +2745,15 @@ static VFIOGroup *vfio_get_group(int groupid)
>
> QLIST_FOREACH(group, &group_list, next) {
> if (group->groupid == groupid) {
> - return group;
> + /* Found it. Now is it already in the right context? */
> + assert(group->container);
> + if (group->container->space == space) {
> + return group;
> + } else {
> + error_report("vfio: group %d used in multiple address
> spaces",
> + group->groupid);
> + return NULL;
> + }
> }
> }
>
> @@ -2759,8 +2786,8 @@ static VFIOGroup *vfio_get_group(int groupid)
> group->groupid = groupid;
> QLIST_INIT(&group->device_list);
>
> - if (vfio_connect_container(group)) {
> - error_report("vfio: failed to setup container for group %d",
> groupid);
> + if (vfio_connect_container(group, space)) {
> + error_report("vfio: failed to setup context for group %d", groupid);
s/container/context/ is unnecessary now.
> close(group->fd);
> g_free(group);
> return NULL;
> @@ -2992,7 +3019,12 @@ static int vfio_initfn(PCIDevice *pdev)
> DPRINTF("%s(%04x:%02x:%02x.%x) group %d\n", __func__, vdev->host.domain,
> vdev->host.bus, vdev->host.slot, vdev->host.function, groupid);
>
> - group = vfio_get_group(groupid);
> + if (pci_iommu_as(pdev) != &address_space_memory) {
> + error_report("vfio: DMA address space must be system memory");
> + return -ENXIO;
> + }
> +
> + group = vfio_get_group(groupid, &vfio_address_space_memory);
> if (!group) {
> error_report("vfio: failed to get group %d", groupid);
> return -ENOENT;
> @@ -3212,6 +3244,7 @@ static const TypeInfo vfio_pci_dev_info = {
>
> static void register_vfio_pci_dev_type(void)
> {
> + vfio_address_space_init(&vfio_address_space_memory,
> &address_space_memory);
> type_register_static(&vfio_pci_dev_info);
> }
>
