[RFC v3 11/19] vfio-user: get region info

[John Johnson]

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
---
 hw/vfio/user-protocol.h       | 14 ++++++++++++
 include/hw/vfio/vfio-common.h |  4 +++-
 hw/vfio/common.c              | 30 +++++++++++++++++++++++++-
 hw/vfio/user.c                | 50 +++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/hw/vfio/user-protocol.h b/hw/vfio/user-protocol.h
index 13e44eb..104bf4f 100644
--- a/hw/vfio/user-protocol.h
+++ b/hw/vfio/user-protocol.h
@@ -95,4 +95,18 @@ typedef struct {
     uint32_t cap_offset;
 } VFIOUserDeviceInfo;
 
+/*
+ * VFIO_USER_DEVICE_GET_REGION_INFO
+ * imported from struct_vfio_region_info
+ */
+typedef struct {
+    VFIOUserHdr hdr;
+    uint32_t argsz;
+    uint32_t flags;
+    uint32_t index;
+    uint32_t cap_offset;
+    uint64_t size;
+    uint64_t offset;
+} VFIOUserRegionInfo;
+
 #endif /* VFIO_USER_PROTOCOL_H */
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 224dbf8..e2d7ee1 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -56,6 +56,7 @@ typedef struct VFIORegion {
     uint32_t nr_mmaps;
     VFIOMmap *mmaps;
     uint8_t nr; /* cache the region number for debug */
+    int remfd; /* fd if exported from remote process */
 } VFIORegion;
 
 typedef struct VFIOMigration {
@@ -150,8 +151,9 @@ typedef struct VFIODevice {
     VFIOMigration *migration;
     Error *migration_blocker;
     OnOffAuto pre_copy_dirty_page_tracking;
-    struct vfio_region_info **regions;
     VFIOProxy *proxy;
+    struct vfio_region_info **regions;
+    int *regfds;
 } VFIODevice;
 
 struct VFIODeviceOps {
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 41fdd78..47ec28f 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -40,6 +40,7 @@
 #include "trace.h"
 #include "qapi/error.h"
 #include "migration/migration.h"
+#include "hw/vfio/user.h"
 
 VFIOGroupList vfio_group_list =
     QLIST_HEAD_INITIALIZER(vfio_group_list);
@@ -1491,6 +1492,16 @@ bool vfio_get_info_dma_avail(struct 
vfio_iommu_type1_info *info,
     return true;
 }
 
+static int vfio_get_region_info_remfd(VFIODevice *vbasedev, int index)
+{
+    struct vfio_region_info *info;
+
+    if (vbasedev->regions == NULL || vbasedev->regions[index] == NULL) {
+        vfio_get_region_info(vbasedev, index, &info);
+    }
+    return vbasedev->regfds != NULL ? vbasedev->regfds[index] : -1;
+}
+
 static int vfio_setup_region_sparse_mmaps(VFIORegion *region,
                                           struct vfio_region_info *info)
 {
@@ -1544,6 +1555,7 @@ int vfio_region_setup(Object *obj, VFIODevice *vbasedev, 
VFIORegion *region,
     region->size = info->size;
     region->fd_offset = info->offset;
     region->nr = index;
+    region->remfd = vfio_get_region_info_remfd(vbasedev, index);
 
     if (region->size) {
         region->mem = g_new0(MemoryRegion, 1);
@@ -1587,6 +1599,7 @@ int vfio_region_mmap(VFIORegion *region)
 {
     int i, prot = 0;
     char *name;
+    int fd;
 
     if (!region->mem) {
         return 0;
@@ -1595,9 +1608,11 @@ int vfio_region_mmap(VFIORegion *region)
     prot |= region->flags & VFIO_REGION_INFO_FLAG_READ ? PROT_READ : 0;
     prot |= region->flags & VFIO_REGION_INFO_FLAG_WRITE ? PROT_WRITE : 0;
 
+    fd = region->remfd != -1 ? region->remfd : region->vbasedev->fd;
+
     for (i = 0; i < region->nr_mmaps; i++) {
         region->mmaps[i].mmap = mmap(NULL, region->mmaps[i].size, prot,
-                                     MAP_SHARED, region->vbasedev->fd,
+                                     MAP_SHARED, fd,
                                      region->fd_offset +
                                      region->mmaps[i].offset);
         if (region->mmaps[i].mmap == MAP_FAILED) {
@@ -2379,10 +2394,17 @@ void vfio_put_base_device(VFIODevice *vbasedev)
         int i;
 
         for (i = 0; i < vbasedev->num_regions; i++) {
+            if (vbasedev->regfds != NULL && vbasedev->regfds[i] != -1) {
+                close(vbasedev->regfds[i]);
+            }
             g_free(vbasedev->regions[i]);
         }
         g_free(vbasedev->regions);
         vbasedev->regions = NULL;
+        if (vbasedev->regfds != NULL) {
+            g_free(vbasedev->regfds);
+            vbasedev->regfds = NULL;
+        }
     }
 
     if (!vbasedev->group) {
@@ -2405,6 +2427,9 @@ int vfio_get_region_info(VFIODevice *vbasedev, int index,
     if (vbasedev->regions == NULL) {
         vbasedev->regions = g_new0(struct vfio_region_info *,
                                    vbasedev->num_regions);
+        if (vbasedev->proxy != NULL) {
+            vbasedev->regfds = g_new0(int, vbasedev->num_regions);
+        }
     }
     /* check cache */
     if (vbasedev->regions[index] != NULL) {
@@ -2441,6 +2466,9 @@ retry:
     /* fill cache */
     vbasedev->regions[index] = g_malloc0(argsz);
     memcpy(vbasedev->regions[index], *info, argsz);
+    if (vbasedev->regfds != NULL) {
+        vbasedev->regfds[index] = fd;
+    }
 
     return 0;
 }
diff --git a/hw/vfio/user.c b/hw/vfio/user.c
index ed2a4d7..b40c4ed 100644
--- a/hw/vfio/user.c
+++ b/hw/vfio/user.c
@@ -923,6 +923,40 @@ static int vfio_user_get_info(VFIOProxy *proxy, struct 
vfio_device_info *info)
     return 0;
 }
 
+static int vfio_user_get_region_info(VFIOProxy *proxy,
+                                     struct vfio_region_info *info,
+                                     VFIOUserFDs *fds)
+{
+    g_autofree VFIOUserRegionInfo *msgp = NULL;
+    uint32_t size;
+
+    /* data returned can be larger than vfio_region_info */
+    if (info->argsz < sizeof(*info)) {
+        error_printf("vfio_user_get_region_info argsz too small\n");
+        return -EINVAL;
+    }
+    if (fds != NULL && fds->send_fds != 0) {
+        error_printf("vfio_user_get_region_info can't send FDs\n");
+        return -EINVAL;
+    }
+
+    size = info->argsz + sizeof(VFIOUserHdr);
+    msgp = g_malloc0(size);
+
+    vfio_user_request_msg(&msgp->hdr, VFIO_USER_DEVICE_GET_REGION_INFO,
+                          sizeof(*msgp), 0);
+    msgp->argsz = info->argsz;
+    msgp->index = info->index;
+
+    vfio_user_send_wait(proxy, &msgp->hdr, fds, size, false);
+    if (msgp->hdr.flags & VFIO_USER_ERROR) {
+        return -msgp->hdr.error_reply;
+    }
+
+    memcpy(info, &msgp->argsz, info->argsz);
+    return 0;
+}
+
 
 /*
  * Socket-based io_ops
@@ -941,7 +975,23 @@ static int vfio_user_io_get_info(VFIODevice *vbasedev,
     return VDEV_VALID_INFO(vbasedev, info);
 }
 
+static int vfio_user_io_get_region_info(VFIODevice *vbasedev,
+                                        struct vfio_region_info *info,
+                                        int *fd)
+{
+    int ret;
+    VFIOUserFDs fds = { 0, 1, fd};
+
+    ret = vfio_user_get_region_info(vbasedev->proxy, info, &fds);
+    if (ret) {
+        return ret;
+    }
+
+    return VDEV_VALID_REGION_INFO(vbasedev, info, fd);
+}
+
 VFIODevIO vfio_dev_io_sock = {
     .get_info = vfio_user_io_get_info,
+    .get_region_info = vfio_user_io_get_region_info,
 };
 
-- 
1.8.3.1