[Qemu-devel] [PATCH v4 15/18] spapr_pci_vfio: Enable multiple groups per container

[Alexey Kardashevskiy <aik@ozlabs.ru>]

This enables multiple IOMMU groups in one VFIO container which means
that multiple devices from different groups can share the same IOMMU table
and locked pages counting can be done once as there is no need to have
several containers for two or more groups.

This removes a group id from vfio_container_ioctl(). The kernel support
is required for this.

This adds a check that there is just one VFIO container per PHB address
space.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 hw/ppc/spapr_pci_vfio.c |  9 +++------
 hw/vfio/common.c        | 33 +++++++++++++++------------------
 include/hw/vfio/vfio.h  |  2 +-
 3 files changed, 19 insertions(+), 25 deletions(-)

diff --git a/hw/ppc/spapr_pci_vfio.c b/hw/ppc/spapr_pci_vfio.c
index b20ac90..257181d 100644
--- a/hw/ppc/spapr_pci_vfio.c
+++ b/hw/ppc/spapr_pci_vfio.c
@@ -33,11 +33,10 @@ static int spapr_pci_vfio_ddw_query(sPAPRPHBState *sphb,
                                     uint32_t *dma32_window_size,
                                     uint64_t *dma64_window_size)
 {
-    sPAPRPHBVFIOState *svphb = SPAPR_PCI_VFIO_HOST_BRIDGE(sphb);
     struct vfio_iommu_spapr_tce_info info = { .argsz = sizeof(info) };
     int ret;
 
-    ret = vfio_container_ioctl(&sphb->iommu_as, svphb->iommugroupid,
+    ret = vfio_container_ioctl(&sphb->iommu_as,
                                VFIO_IOMMU_SPAPR_TCE_GET_INFO, &info);
     if (ret) {
         return ret;
@@ -55,7 +54,6 @@ static int spapr_pci_vfio_ddw_create(sPAPRPHBState *sphb, uint32_t liobn,
                                      uint32_t page_shift, uint32_t window_shift,
                                      sPAPRTCETable **ptcet)
 {
-    sPAPRPHBVFIOState *svphb = SPAPR_PCI_VFIO_HOST_BRIDGE(sphb);
     struct vfio_iommu_spapr_tce_create create = {
         .argsz = sizeof(create),
         .page_shift = page_shift,
@@ -65,7 +63,7 @@ static int spapr_pci_vfio_ddw_create(sPAPRPHBState *sphb, uint32_t liobn,
     };
     int ret;
 
-    ret = vfio_container_ioctl(&sphb->iommu_as, svphb->iommugroupid,
+    ret = vfio_container_ioctl(&sphb->iommu_as,
                                VFIO_IOMMU_SPAPR_TCE_CREATE, &create);
     if (ret) {
         return ret;
@@ -87,7 +85,6 @@ static int spapr_pci_vfio_ddw_create(sPAPRPHBState *sphb, uint32_t liobn,
 
 static int spapr_pci_vfio_ddw_remove(sPAPRPHBState *sphb, sPAPRTCETable *tcet)
 {
-    sPAPRPHBVFIOState *svphb = SPAPR_PCI_VFIO_HOST_BRIDGE(sphb);
     struct vfio_iommu_spapr_tce_remove remove = {
         .argsz = sizeof(remove),
         .start_addr = tcet->bus_offset
@@ -95,7 +92,7 @@ static int spapr_pci_vfio_ddw_remove(sPAPRPHBState *sphb, sPAPRTCETable *tcet)
     int ret;
 
     spapr_pci_ddw_remove(sphb, tcet);
-    ret = vfio_container_ioctl(&sphb->iommu_as, svphb->iommugroupid,
+    ret = vfio_container_ioctl(&sphb->iommu_as,
                                VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove);
 
     return ret;
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 1cafcf8..a26cbae 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1011,34 +1011,31 @@ void vfio_put_base_device(VFIODevice *vbasedev)
     close(vbasedev->fd);
 }
 
-static int vfio_container_do_ioctl(AddressSpace *as, int32_t groupid,
+static int vfio_container_do_ioctl(AddressSpace *as,
                                    int req, void *param)
 {
-    VFIOGroup *group;
     VFIOContainer *container;
-    int ret = -1;
+    int ret;
+    VFIOAddressSpace *space;
 
-    group = vfio_get_group(groupid, as);
-    if (!group) {
-        error_report("vfio: group %d not registered", groupid);
-        return ret;
-    }
+    space = vfio_get_address_space(as);
+    container = QLIST_FIRST(&space->containers);
 
-    container = group->container;
-    if (group->container) {
-        ret = ioctl(container->fd, req, param);
-        if (ret < 0) {
-            error_report("vfio: failed to ioctl container: ret=%d, %s",
-                         ret, strerror(errno));
-        }
+    if (!container || QLIST_NEXT(container, next)) {
+        error_report("vfio: multiple containers per PHB are not supported");
+        return -1;
     }
 
-    vfio_put_group(group);
+    ret = ioctl(container->fd, req, param);
+    if (ret < 0) {
+        error_report("vfio: failed to ioctl container: ret=%d, %s",
+                     ret, strerror(errno));
+    }
 
     return ret;
 }
 
-int vfio_container_ioctl(AddressSpace *as, int32_t groupid,
+int vfio_container_ioctl(AddressSpace *as,
                          int req, void *param)
 {
     /* We allow only certain ioctls to the container */
@@ -1054,5 +1051,5 @@ int vfio_container_ioctl(AddressSpace *as, int32_t groupid,
         return -1;
     }
 
-    return vfio_container_do_ioctl(as, groupid, req, param);
+    return vfio_container_do_ioctl(as, req, param);
 }
diff --git a/include/hw/vfio/vfio.h b/include/hw/vfio/vfio.h
index 0b26cd8..76b5744 100644
--- a/include/hw/vfio/vfio.h
+++ b/include/hw/vfio/vfio.h
@@ -3,7 +3,7 @@
 
 #include "qemu/typedefs.h"
 
-extern int vfio_container_ioctl(AddressSpace *as, int32_t groupid,
+extern int vfio_container_ioctl(AddressSpace *as,
                                 int req, void *param);
 
 #endif
-- 
2.0.0