[PATCH v2 09/22] vfio/common: init HostIOMMUContext per-container

[Liu Yi L <yi.l.liu@intel.com>]

In this patch, QEMU firstly gets iommu info from kernel to check the
supported capabilities by a VFIO_IOMMU_TYPE1_NESTING iommu. And inits
HostIOMMUContet instance.

Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Yi Sun <yi.y.sun@linux.intel.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
---
 hw/vfio/common.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 5f3534d..44b142c 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1226,10 +1226,89 @@ static int vfio_host_iommu_ctx_pasid_free(HostIOMMUContext *iommu_ctx,
     return 0;
 }
 
+/**
+ * Get iommu info from host. Caller of this funcion should free
+ * the memory pointed by the returned pointer stored in @info
+ * after a successful calling when finished its usage.
+ */
+static int vfio_get_iommu_info(VFIOContainer *container,
+                         struct vfio_iommu_type1_info **info)
+{
+
+    size_t argsz = sizeof(struct vfio_iommu_type1_info);
+
+    *info = g_malloc0(argsz);
+
+retry:
+    (*info)->argsz = argsz;
+
+    if (ioctl(container->fd, VFIO_IOMMU_GET_INFO, *info)) {
+        g_free(*info);
+        *info = NULL;
+        return -errno;
+    }
+
+    if (((*info)->argsz > argsz)) {
+        argsz = (*info)->argsz;
+        *info = g_realloc(*info, argsz);
+        goto retry;
+    }
+
+    return 0;
+}
+
+static struct vfio_info_cap_header *
+vfio_get_iommu_info_cap(struct vfio_iommu_type1_info *info, uint16_t id)
+{
+    struct vfio_info_cap_header *hdr;
+    void *ptr = info;
+
+    if (!(info->flags & VFIO_IOMMU_INFO_CAPS)) {
+        return NULL;
+    }
+
+    for (hdr = ptr + info->cap_offset; hdr != ptr; hdr = ptr + hdr->next) {
+        if (hdr->id == id) {
+            return hdr;
+        }
+    }
+
+    return NULL;
+}
+
+static int vfio_get_nesting_iommu_cap(VFIOContainer *container,
+                   struct vfio_iommu_type1_info_cap_nesting *cap_nesting)
+{
+    struct vfio_iommu_type1_info *info;
+    struct vfio_info_cap_header *hdr;
+    struct vfio_iommu_type1_info_cap_nesting *cap;
+    int ret;
+
+    ret = vfio_get_iommu_info(container, &info);
+    if (ret) {
+        return ret;
+    }
+
+    hdr = vfio_get_iommu_info_cap(info,
+                        VFIO_IOMMU_TYPE1_INFO_CAP_NESTING);
+    if (!hdr) {
+        g_free(info);
+        return -errno;
+    }
+
+    cap = container_of(hdr,
+                struct vfio_iommu_type1_info_cap_nesting, header);
+    *cap_nesting = *cap;
+
+    g_free(info);
+    return 0;
+}
+
 static int vfio_init_container(VFIOContainer *container, int group_fd,
                                Error **errp)
 {
     int iommu_type, ret;
+    uint64_t flags = 0;
 
     iommu_type = vfio_get_iommu_type(container, errp);
     if (iommu_type < 0) {
@@ -1257,6 +1336,26 @@ static int vfio_init_container(VFIOContainer *container, int group_fd,
         return -errno;
     }
 
+    if (iommu_type == VFIO_TYPE1_NESTING_IOMMU) {
+        struct vfio_iommu_type1_info_cap_nesting nesting = {
+                                         .nesting_capabilities = 0x0,
+                                         .stage1_formats = 0, };
+
+        ret = vfio_get_nesting_iommu_cap(container, &nesting);
+        if (ret) {
+            error_setg_errno(errp, -ret,
+                             "Failed to get nesting iommu cap");
+            return ret;
+        }
+
+        flags |= (nesting.nesting_capabilities & VFIO_IOMMU_PASID_REQS) ?
+                 HOST_IOMMU_PASID_REQUEST : 0;
+        host_iommu_ctx_init(&container->iommu_ctx,
+                            sizeof(container->iommu_ctx),
+                            TYPE_VFIO_HOST_IOMMU_CONTEXT,
+                            flags);
+    }
+
     container->iommu_type = iommu_type;
     return 0;
 }
-- 
2.7.4