vfio: Generalize region support

Both platform and PCI vfio drivers create a "slow", I/O memory region
with one or more mmap memory regions overlayed when supported by the
device. Generalize this to a set of common helpers in the core that
pulls the region info from vfio, fills the region data, configures
slow mapping, and adds helpers for comleting the mmap, enable/disable,
and teardown.  This can be immediately used by the PCI MSI-X code,
which needs to mmap around the MSI-X vector table.

This also changes VFIORegion.mem to be dynamically allocated because
otherwise we don't know how the caller has allocated VFIORegion and
therefore don't know whether to unreference it to destroy the
MemoryRegion or not.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 13 insertions, 59 deletions

diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
index f9b9c207ee..a2ab75d3f2 100644
--- a/hw/vfio/platform.c
+++ b/hw/vfio/platform.c
@@ -143,12 +143,8 @@ static void vfio_mmap_set_enabled(VFIOPlatformDevice *vdev, bool enabled)
 {
     int i;
 
-    trace_vfio_platform_mmap_set_enabled(enabled);
-
     for (i = 0; i < vdev->vbasedev.num_regions; i++) {
-        VFIORegion *region = vdev->regions[i];
-
-        memory_region_set_enabled(&region->mmap_mem, enabled);
+        vfio_region_mmaps_set_enabled(vdev->regions[i], enabled);
     }
 }
 
@@ -476,29 +472,16 @@ static int vfio_populate_device(VFIODevice *vbasedev)
     vdev->regions = g_new0(VFIORegion *, vbasedev->num_regions);
 
     for (i = 0; i < vbasedev->num_regions; i++) {
-        struct vfio_region_info *reg_info;
-        VFIORegion *ptr;
+        char *name = g_strdup_printf("VFIO %s region %d\n", vbasedev->name, i);
 
         vdev->regions[i] = g_new0(VFIORegion, 1);
-        ptr = vdev->regions[i];
-        ret = vfio_get_region_info(vbasedev, i, &reg_info);
+        ret = vfio_region_setup(OBJECT(vdev), vbasedev,
+                                vdev->regions[i], i, name);
+        g_free(name);
         if (ret) {
             error_report("vfio: Error getting region %d info: %m", i);
             goto reg_error;
         }
-        ptr->flags = reg_info->flags;
-        ptr->size = reg_info->size;
-        ptr->fd_offset = reg_info->offset;
-        ptr->nr = i;
-        ptr->vbasedev = vbasedev;
-
-        g_free(reg_info);
-
-        trace_vfio_platform_populate_regions(ptr->nr,
-                            (unsigned long)ptr->flags,
-                            (unsigned long)ptr->size,
-                            ptr->vbasedev->fd,
-                            (unsigned long)ptr->fd_offset);
     }
 
     vdev->mmap_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL,
@@ -535,6 +518,9 @@ irq_err:
     }
 reg_error:
     for (i = 0; i < vbasedev->num_regions; i++) {
+        if (vdev->regions[i]) {
+            vfio_region_finalize(vdev->regions[i]);
+        }
         g_free(vdev->regions[i]);
     }
     g_free(vdev->regions);
@@ -636,41 +622,6 @@ static int vfio_base_device_init(VFIODevice *vbasedev)
 }
 
 /**
- * vfio_map_region - initialize the 2 memory regions for a given
- * MMIO region index
- * @vdev: the VFIO platform device handle
- * @nr: the index of the region
- *
- * Init the top memory region and the mmapped memory region beneath
- * VFIOPlatformDevice is used since VFIODevice is not a QOM Object
- * and could not be passed to memory region functions
-*/
-static void vfio_map_region(VFIOPlatformDevice *vdev, int nr)
-{
-    VFIORegion *region = vdev->regions[nr];
-    uint64_t size = region->size;
-    char name[64];
-
-    if (!size) {
-        return;
-    }
-
-    g_snprintf(name, sizeof(name), "VFIO %s region %d",
-               vdev->vbasedev.name, nr);
-
-    /* A "slow" read/write mapping underlies all regions */
-    memory_region_init_io(&region->mem, OBJECT(vdev), &vfio_region_ops,
-                          region, name, size);
-
-    g_strlcat(name, " mmap", sizeof(name));
-
-    if (vfio_mmap_region(OBJECT(vdev), region, &region->mem,
-                         &region->mmap_mem, &region->mmap, size, 0, name)) {
-        error_report("%s unsupported. Performance may be slow", name);
-    }
-}
-
-/**
  * vfio_platform_realize  - the device realize function
  * @dev: device state pointer
  * @errp: error
@@ -700,8 +651,11 @@ static void vfio_platform_realize(DeviceState *dev, Error **errp)
     }
 
     for (i = 0; i < vbasedev->num_regions; i++) {
-        vfio_map_region(vdev, i);
-        sysbus_init_mmio(sbdev, &vdev->regions[i]->mem);
+        if (vfio_region_mmap(vdev->regions[i])) {
+            error_report("%s mmap unsupported. Performance may be slow",
+                         memory_region_name(vdev->regions[i]->mem));
+        }
+        sysbus_init_mmio(sbdev, vdev->regions[i]->mem);
     }
 }