[RFC v3 22/25] vfio: add support for flush iommu stage-1 cache

["Liu, Yi L" <yi.l.liu@xxxxxxxxx>]

From: Liu Yi L <yi.l.liu@xxxxxxxxx>

This patch adds flush_stage1_cache() definition in DualStageIOMMUOops.
And adds corresponding implementation in VFIO. This is to expose a way
for vIOMMU to flush stage-1 cache in host side since guest owns stage-1
translation structures in dual stage DMA translation.

Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Eric Auger <eric.auger@xxxxxxxxxx>
Cc: Yi Sun <yi.y.sun@xxxxxxxxxxxxxxx>
Cc: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx>
---
 hw/iommu/dual_stage_iommu.c         | 13 +++++++++++++
 hw/vfio/common.c                    | 24 ++++++++++++++++++++++++
 include/hw/iommu/dual_stage_iommu.h | 14 ++++++++++++++
 3 files changed, 51 insertions(+)

diff --git a/hw/iommu/dual_stage_iommu.c b/hw/iommu/dual_stage_iommu.c
index 9d99e9e..abbd2f7 100644
--- a/hw/iommu/dual_stage_iommu.c
+++ b/hw/iommu/dual_stage_iommu.c
@@ -73,6 +73,19 @@ int ds_iommu_unbind_stage1_pgtbl(DualStageIOMMUObject *dsi_obj,
     return -ENOENT;
 }
 
+int ds_iommu_flush_stage1_cache(DualStageIOMMUObject *dsi_obj,
+                                DualIOMMUStage1Cache *cache)
+{
+    if (!dsi_obj) {
+        return -ENOENT;
+    }
+
+    if (dsi_obj->ops && dsi_obj->ops->flush_stage1_cache) {
+        return dsi_obj->ops->flush_stage1_cache(dsi_obj, cache);
+    }
+    return -ENOENT;
+}
+
 void ds_iommu_object_init(DualStageIOMMUObject *dsi_obj,
                           DualStageIOMMUOps *ops,
                           DualStageIOMMUInfo *uinfo)
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index d84bdc9..6f0933c 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1265,11 +1265,35 @@ static int vfio_ds_iommu_unbind_stage1_pgtbl(DualStageIOMMUObject *dsi_obj,
     return ret;
 }
 
+static int vfio_ds_iommu_flush_stage1_cache(DualStageIOMMUObject *dsi_obj,
+                                            DualIOMMUStage1Cache *cache)
+{
+    VFIOContainer *container = container_of(dsi_obj, VFIOContainer, dsi_obj);
+    struct vfio_iommu_type1_cache_invalidate *cache_inv;
+    unsigned long argsz;
+    int ret = 0;
+
+    argsz = sizeof(*cache_inv) + sizeof(cache->cache_info);
+    cache_inv = g_malloc0(argsz);
+    cache_inv->argsz = argsz;
+    cache_inv->flags = 0;
+    memcpy(&cache_inv->cache_info, &cache->cache_info,
+           sizeof(cache->cache_info));
+
+    if (ioctl(container->fd, VFIO_IOMMU_CACHE_INVALIDATE, cache_inv)) {
+        error_report("%s: iommu cache flush failed: %d", __func__, -errno);
+        ret = -errno;
+    }
+    g_free(cache_inv);
+    return ret;
+}
+
 static struct DualStageIOMMUOps vfio_ds_iommu_ops = {
     .pasid_alloc = vfio_ds_iommu_pasid_alloc,
     .pasid_free = vfio_ds_iommu_pasid_free,
     .bind_stage1_pgtbl = vfio_ds_iommu_bind_stage1_pgtbl,
     .unbind_stage1_pgtbl = vfio_ds_iommu_unbind_stage1_pgtbl,
+    .flush_stage1_cache = vfio_ds_iommu_flush_stage1_cache,
 };
 
 static int vfio_get_iommu_info(VFIOContainer *container,
diff --git a/include/hw/iommu/dual_stage_iommu.h b/include/hw/iommu/dual_stage_iommu.h
index 0eb983c..7daeb72 100644
--- a/include/hw/iommu/dual_stage_iommu.h
+++ b/include/hw/iommu/dual_stage_iommu.h
@@ -32,6 +32,7 @@ typedef struct DualStageIOMMUObject DualStageIOMMUObject;
 typedef struct DualStageIOMMUOps DualStageIOMMUOps;
 typedef struct DualStageIOMMUInfo DualStageIOMMUInfo;
 typedef struct DualIOMMUStage1BindData DualIOMMUStage1BindData;
+typedef struct DualIOMMUStage1Cache DualIOMMUStage1Cache;
 
 struct DualStageIOMMUOps {
     /* Allocate pasid from DualStageIOMMU (a.k.a. host IOMMU) */
@@ -52,6 +53,12 @@ struct DualStageIOMMUOps {
     /* Undo a previous bind. @bind_data specifies the unbind info. */
     int (*unbind_stage1_pgtbl)(DualStageIOMMUObject *dsi_obj,
                               DualIOMMUStage1BindData *bind_data);
+    /*
+     * Propagate stage-1 cache flush to DualStageIOMMU (a.k.a.
+     * host IOMMU), cache info specifid in @cache
+     */
+    int (*flush_stage1_cache)(DualStageIOMMUObject *dsi_obj,
+                              DualIOMMUStage1Cache *cache);
 };
 
 struct DualStageIOMMUInfo {
@@ -73,6 +80,11 @@ struct DualIOMMUStage1BindData {
     } bind_data;
 };
 
+struct DualIOMMUStage1Cache {
+    uint32_t pasid;
+    struct iommu_cache_invalidate_info cache_info;
+};
+
 int ds_iommu_pasid_alloc(DualStageIOMMUObject *dsi_obj, uint32_t min,
                          uint32_t max, uint32_t *pasid);
 int ds_iommu_pasid_free(DualStageIOMMUObject *dsi_obj, uint32_t pasid);
@@ -80,6 +92,8 @@ int ds_iommu_bind_stage1_pgtbl(DualStageIOMMUObject *dsi_obj,
                                DualIOMMUStage1BindData *bind_data);
 int ds_iommu_unbind_stage1_pgtbl(DualStageIOMMUObject *dsi_obj,
                                  DualIOMMUStage1BindData *bind_data);
+int ds_iommu_flush_stage1_cache(DualStageIOMMUObject *dsi_obj,
+                                DualIOMMUStage1Cache *cache);
 
 void ds_iommu_object_init(DualStageIOMMUObject *dsi_obj,
                           DualStageIOMMUOps *ops,
-- 
2.7.4