vfio: Wrap VFIO_DEVICE_GET_REGION_INFO

In preparation for supporting capability chains on regions, wrap
ioctl(VFIO_DEVICE_GET_REGION_INFO) so we don't duplicate the code for
each caller.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

hw/vfio/common.c

@@ -959,6 +959,24 @@ void vfio_put_base_device(VFIODevice *vbasedev)
     close(vbasedev->fd);
 }
 
+int vfio_get_region_info(VFIODevice *vbasedev, int index,
+                         struct vfio_region_info **info)
+{
+    size_t argsz = sizeof(struct vfio_region_info);
+
+    *info = g_malloc0(argsz);
+
+    (*info)->index = index;
+    (*info)->argsz = argsz;
+
+    if (ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, *info)) {
+        g_free(*info);
+        return -errno;
+    }
+
+    return 0;
+}
+
 static int vfio_container_do_ioctl(AddressSpace *as, int32_t groupid,
                                    int req, void *param)
 {

hw/vfio/pci.c

@@ -783,25 +783,25 @@ static void vfio_update_msi(VFIOPCIDevice *vdev)
 
 static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
 {
-    struct vfio_region_info reg_info = {
-        .argsz = sizeof(reg_info),
-        .index = VFIO_PCI_ROM_REGION_INDEX
-    };
+    struct vfio_region_info *reg_info;
     uint64_t size;
     off_t off = 0;
     ssize_t bytes;
 
-    if (ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info)) {
+    if (vfio_get_region_info(&vdev->vbasedev,
+                             VFIO_PCI_ROM_REGION_INDEX, &reg_info)) {
         error_report("vfio: Error getting ROM info: %m");
         return;
     }
 
-    trace_vfio_pci_load_rom(vdev->vbasedev.name, (unsigned long)reg_info.size,
-                            (unsigned long)reg_info.offset,
-                            (unsigned long)reg_info.flags);
+    trace_vfio_pci_load_rom(vdev->vbasedev.name, (unsigned long)reg_info->size,
+                            (unsigned long)reg_info->offset,
+                            (unsigned long)reg_info->flags);
+
+    vdev->rom_size = size = reg_info->size;
+    vdev->rom_offset = reg_info->offset;
 
-    vdev->rom_size = size = reg_info.size;
-    vdev->rom_offset = reg_info.offset;
+    g_free(reg_info);
 
     if (!vdev->rom_size) {
         vdev->rom_read_failed = true;
@@ -2027,7 +2027,7 @@ static VFIODeviceOps vfio_pci_ops = {
 static int vfio_populate_device(VFIOPCIDevice *vdev)
 {
     VFIODevice *vbasedev = &vdev->vbasedev;
-    struct vfio_region_info reg_info = { .argsz = sizeof(reg_info) };
+    struct vfio_region_info *reg_info;
     struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info) };
     int i, ret = -1;
 
@@ -2049,72 +2049,73 @@ static int vfio_populate_device(VFIOPCIDevice *vdev)
     }
 
     for (i = VFIO_PCI_BAR0_REGION_INDEX; i < VFIO_PCI_ROM_REGION_INDEX; i++) {
-        reg_info.index = i;
-
-        ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
+        ret = vfio_get_region_info(vbasedev, i, &reg_info);
         if (ret) {
             error_report("vfio: Error getting region %d info: %m", i);
             goto error;
         }
 
         trace_vfio_populate_device_region(vbasedev->name, i,
-                                          (unsigned long)reg_info.size,
-                                          (unsigned long)reg_info.offset,
-                                          (unsigned long)reg_info.flags);
+                                          (unsigned long)reg_info->size,
+                                          (unsigned long)reg_info->offset,
+                                          (unsigned long)reg_info->flags);
 
         vdev->bars[i].region.vbasedev = vbasedev;
-        vdev->bars[i].region.flags = reg_info.flags;
-        vdev->bars[i].region.size = reg_info.size;
-        vdev->bars[i].region.fd_offset = reg_info.offset;
+        vdev->bars[i].region.flags = reg_info->flags;
+        vdev->bars[i].region.size = reg_info->size;
+        vdev->bars[i].region.fd_offset = reg_info->offset;
         vdev->bars[i].region.nr = i;
         QLIST_INIT(&vdev->bars[i].quirks);
-    }
 
-    reg_info.index = VFIO_PCI_CONFIG_REGION_INDEX;
+        g_free(reg_info);
+    }
 
-    ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
+    ret = vfio_get_region_info(vbasedev,
+                               VFIO_PCI_CONFIG_REGION_INDEX, &reg_info);
     if (ret) {
         error_report("vfio: Error getting config info: %m");
         goto error;
     }
 
     trace_vfio_populate_device_config(vdev->vbasedev.name,
-                                      (unsigned long)reg_info.size,
-                                      (unsigned long)reg_info.offset,
-                                      (unsigned long)reg_info.flags);
+                                      (unsigned long)reg_info->size,
+                                      (unsigned long)reg_info->offset,
+                                      (unsigned long)reg_info->flags);
 
-    vdev->config_size = reg_info.size;
+    vdev->config_size = reg_info->size;
     if (vdev->config_size == PCI_CONFIG_SPACE_SIZE) {
         vdev->pdev.cap_present &= ~QEMU_PCI_CAP_EXPRESS;
     }
-    vdev->config_offset = reg_info.offset;
+    vdev->config_offset = reg_info->offset;
+
+    g_free(reg_info);
 
     if ((vdev->features & VFIO_FEATURE_ENABLE_VGA) &&
         vbasedev->num_regions > VFIO_PCI_VGA_REGION_INDEX) {
-        struct vfio_region_info vga_info = {
-            .argsz = sizeof(vga_info),
-            .index = VFIO_PCI_VGA_REGION_INDEX,
-         };
-
-        ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_REGION_INFO, &vga_info);
+        ret = vfio_get_region_info(vbasedev,
+                                   VFIO_PCI_VGA_REGION_INDEX, &reg_info);
         if (ret) {
             error_report(
                 "vfio: Device does not support requested feature x-vga");
             goto error;
         }
 
-        if (!(vga_info.flags & VFIO_REGION_INFO_FLAG_READ) ||
-            !(vga_info.flags & VFIO_REGION_INFO_FLAG_WRITE) ||
-            vga_info.size < 0xbffff + 1) {
+        if (!(reg_info->flags & VFIO_REGION_INFO_FLAG_READ) ||
+            !(reg_info->flags & VFIO_REGION_INFO_FLAG_WRITE) ||
+            reg_info->size < 0xbffff + 1) {
             error_report("vfio: Unexpected VGA info, flags 0x%lx, size 0x%lx",
-                         (unsigned long)vga_info.flags,
-                         (unsigned long)vga_info.size);
+                         (unsigned long)reg_info->flags,
+                         (unsigned long)reg_info->size);
+            g_free(reg_info);
+            ret = -1;
             goto error;
         }
 
-        vdev->vga.fd_offset = vga_info.offset;
+        vdev->vga.fd_offset = reg_info->offset;
         vdev->vga.fd = vdev->vbasedev.fd;
 
+        g_free(reg_info);
+
         vdev->vga.region[QEMU_PCI_VGA_MEM].offset = QEMU_PCI_VGA_MEM_BASE;
         vdev->vga.region[QEMU_PCI_VGA_MEM].nr = QEMU_PCI_VGA_MEM;
         QLIST_INIT(&vdev->vga.region[QEMU_PCI_VGA_MEM].quirks);

hw/vfio/platform.c

@@ -476,23 +476,24 @@ 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 = { .argsz = sizeof(reg_info) };
+        struct vfio_region_info *reg_info;
         VFIORegion *ptr;
 
         vdev->regions[i] = g_new0(VFIORegion, 1);
         ptr = vdev->regions[i];
-        reg_info.index = i;
-        ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
+        ret = vfio_get_region_info(vbasedev, i, &reg_info);
         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->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,

include/hw/vfio/vfio-common.h

@@ -25,6 +25,9 @@
 #include "exec/memory.h"
 #include "qemu/queue.h"
 #include "qemu/notify.h"
+#ifdef CONFIG_LINUX
+#include <linux/vfio.h>
+#endif
 
 /*#define DEBUG_VFIO*/
 #ifdef DEBUG_VFIO
@@ -139,4 +142,8 @@ extern const MemoryRegionOps vfio_region_ops;
 extern QLIST_HEAD(vfio_group_head, VFIOGroup) vfio_group_list;
 extern QLIST_HEAD(vfio_as_head, VFIOAddressSpace) vfio_address_spaces;
 
+#ifdef CONFIG_LINUX
+int vfio_get_region_info(VFIODevice *vbasedev, int index,
+                         struct vfio_region_info **info);
+#endif
 #endif /* !HW_VFIO_VFIO_COMMON_H */