[RFC v3.1 13/22] vfio: add bind stage-1 page table support

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

This patch adds bind_stage1_pgtbl() definition in HostIOMMUOops, also
adds corresponding implementation in VFIO. This is to expose a way for
vIOMMU to setup dual stage DMA translation for passthru devices on hardware.

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/iommu/host_iommu_context.c         | 20 ++++++++++++++
 hw/vfio/common.c                      | 49 +++++++++++++++++++++++++++++++++++
 include/hw/iommu/host_iommu_context.h | 23 ++++++++++++++++
 3 files changed, 92 insertions(+)

diff --git a/hw/iommu/host_iommu_context.c b/hw/iommu/host_iommu_context.c
index 689a087..5f7eb92 100644
--- a/hw/iommu/host_iommu_context.c
+++ b/hw/iommu/host_iommu_context.c
@@ -41,6 +41,26 @@ int host_iommu_ctx_pasid_free(HostIOMMUContext *host_icx, uint32_t pasid)
     return -ENOENT;
 }
 
+int host_iommu_ctx_bind_stage1_pgtbl(HostIOMMUContext *host_icx,
+                                     DualIOMMUStage1BindData *data)
+{
+    if (host_icx && (host_icx->flags & HOST_IOMMU_NESTING) &&
+        host_icx->ops && host_icx->ops->bind_stage1_pgtbl) {
+        return host_icx->ops->bind_stage1_pgtbl(host_icx, data);
+    }
+    return -ENOENT;
+}
+
+int host_iommu_ctx_unbind_stage1_pgtbl(HostIOMMUContext *host_icx,
+                                       DualIOMMUStage1BindData *data)
+{
+    if (host_icx && (host_icx->flags & HOST_IOMMU_NESTING) &&
+        host_icx->ops && host_icx->ops->unbind_stage1_pgtbl) {
+        return host_icx->ops->unbind_stage1_pgtbl(host_icx, data);
+    }
+    return -ENOENT;
+}
+
 void host_iommu_ctx_init(HostIOMMUContext *host_icx,
                          uint64_t flags, HostIOMMUOps *ops,
                          HostIOMMUInfo *uinfo)
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 8f30a52..b560fdb 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1223,9 +1223,57 @@ static int vfio_host_icx_pasid_free(HostIOMMUContext *host_icx,
     return 0;
 }
 
+static int vfio_host_icx_bind_stage1_pgtbl(HostIOMMUContext *host_icx,
+                                           DualIOMMUStage1BindData *bind_data)
+{
+    VFIOContainer *container = container_of(host_icx, VFIOContainer, host_icx);
+    struct vfio_iommu_type1_bind *bind;
+    unsigned long argsz;
+    int ret = 0;
+
+    argsz = sizeof(*bind) + sizeof(bind_data->bind_data);
+    bind = g_malloc0(argsz);
+    bind->argsz = argsz;
+    bind->flags = VFIO_IOMMU_BIND_GUEST_PGTBL;
+    memcpy(&bind->data, &bind_data->bind_data, sizeof(bind_data->bind_data));
+
+    if (ioctl(container->fd, VFIO_IOMMU_BIND, bind)) {
+        ret = -errno;
+        error_report("%s: pasid (%u) bind failed: %d",
+                      __func__, bind_data->pasid, ret);
+    }
+    g_free(bind);
+    return ret;
+}
+
+static int vfio_host_icx_unbind_stage1_pgtbl(HostIOMMUContext *host_icx,
+                                        DualIOMMUStage1BindData *bind_data)
+{
+    VFIOContainer *container = container_of(host_icx, VFIOContainer, host_icx);
+    struct vfio_iommu_type1_bind *bind;
+    unsigned long argsz;
+    int ret = 0;
+
+    argsz = sizeof(*bind) + sizeof(bind_data->bind_data);
+    bind = g_malloc0(argsz);
+    bind->argsz = argsz;
+    bind->flags = VFIO_IOMMU_UNBIND_GUEST_PGTBL;
+    memcpy(&bind->data, &bind_data->bind_data, sizeof(bind_data->bind_data));
+
+    if (ioctl(container->fd, VFIO_IOMMU_BIND, bind)) {
+        ret = -errno;
+        error_report("%s: pasid (%u) unbind failed: %d",
+                      __func__, bind_data->pasid, ret);
+    }
+    g_free(bind);
+    return ret;
+}
+
 static struct HostIOMMUOps vfio_host_icx_ops = {
     .pasid_alloc = vfio_host_icx_pasid_alloc,
     .pasid_free = vfio_host_icx_pasid_free,
+    .bind_stage1_pgtbl = vfio_host_icx_bind_stage1_pgtbl,
+    .unbind_stage1_pgtbl = vfio_host_icx_unbind_stage1_pgtbl,
 };
 
 /**
@@ -1354,6 +1402,7 @@ static int vfio_init_container(VFIOContainer *container, int group_fd,
         uinfo.stage1_format = nesting.stage1_format;
         flags |= (nesting.nesting_capabilities & VFIO_IOMMU_PASID_REQS) ?
                  HOST_IOMMU_PASID_REQUEST : 0;
+        flags |= HOST_IOMMU_NESTING;
         host_iommu_ctx_init(&container->host_icx, flags,
                             &vfio_host_icx_ops, &uinfo);
     }
diff --git a/include/hw/iommu/host_iommu_context.h b/include/hw/iommu/host_iommu_context.h
index 6797f6d..660fab8 100644
--- a/include/hw/iommu/host_iommu_context.h
+++ b/include/hw/iommu/host_iommu_context.h
@@ -31,6 +31,7 @@
 typedef struct HostIOMMUContext HostIOMMUContext;
 typedef struct HostIOMMUOps HostIOMMUOps;
 typedef struct HostIOMMUInfo HostIOMMUInfo;
+typedef struct DualIOMMUStage1BindData DualIOMMUStage1BindData;
 
 struct HostIOMMUOps {
     /* Allocate pasid from HostIOMMUContext (a.k.a. host software) */
@@ -41,6 +42,16 @@ struct HostIOMMUOps {
     /* Reclaim pasid from HostIOMMUContext (a.k.a. host software) */
     int (*pasid_free)(HostIOMMUContext *host_icx,
                       uint32_t pasid);
+    /*
+     * Bind stage-1 page table to a hostIOMMU w/ dual stage
+     * DMA translation capability.
+     * @bind_data specifies the bind configurations.
+     */
+    int (*bind_stage1_pgtbl)(HostIOMMUContext *dsi_obj,
+                             DualIOMMUStage1BindData *bind_data);
+    /* Undo a previous bind. @bind_data specifies the unbind info. */
+    int (*unbind_stage1_pgtbl)(HostIOMMUContext *dsi_obj,
+                               DualIOMMUStage1BindData *bind_data);
 };
 
 struct HostIOMMUInfo {
@@ -52,14 +63,26 @@ struct HostIOMMUInfo {
  */
 struct HostIOMMUContext {
 #define HOST_IOMMU_PASID_REQUEST (1ULL << 0)
+#define HOST_IOMMU_NESTING       (1ULL << 1)
     uint64_t flags;
     HostIOMMUOps *ops;
     HostIOMMUInfo uinfo;
 };
 
+struct DualIOMMUStage1BindData {
+    uint32_t pasid;
+    union {
+        struct iommu_gpasid_bind_data gpasid_bind;
+    } bind_data;
+};
+
 int host_iommu_ctx_pasid_alloc(HostIOMMUContext *host_icx, uint32_t min,
                                uint32_t max, uint32_t *pasid);
 int host_iommu_ctx_pasid_free(HostIOMMUContext *host_icx, uint32_t pasid);
+int host_iommu_ctx_bind_stage1_pgtbl(HostIOMMUContext *host_icx,
+                                     DualIOMMUStage1BindData *data);
+int host_iommu_ctx_unbind_stage1_pgtbl(HostIOMMUContext *host_icx,
+                                       DualIOMMUStage1BindData *data);
 
 void host_iommu_ctx_init(HostIOMMUContext *host_icx,
                          uint64_t flags, HostIOMMUOps *ops,
-- 
2.7.4