[Qemu-devel] [PULL 02/19] vfio/pci: Pass an error object to vfio_populate_vga

[Alex Williamson <alex.williamson@redhat.com>]

From: Eric Auger <eric.auger@redhat.com>

Pass an error object to prepare for the same operation in
vfio_populate_device. Eventually this contributes to the migration
to VFIO-PCI realize.

We now report an error on vfio_get_region_info failure.

vfio_probe_igd_bar4_quirk is not involved in the migration to realize
and simply calls error_reportf_err.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 hw/vfio/pci-quirks.c |    4 +++-
 hw/vfio/pci.c        |   19 ++++++++++++-------
 hw/vfio/pci.h        |    2 +-
 3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c
index bec694c..806ea5d 100644
--- a/hw/vfio/pci-quirks.c
+++ b/hw/vfio/pci-quirks.c
@@ -1363,6 +1363,7 @@ static void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
     uint64_t *bdsm_size;
     uint32_t gmch;
     uint16_t cmd_orig, cmd;
+    Error *err = NULL;
 
     /*
      * This must be an Intel VGA device at address 00:02.0 for us to even
@@ -1464,7 +1465,8 @@ static void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
      * try to enable it.  Probably shouldn't be using legacy mode without VGA,
      * but also no point in us enabling VGA if disabled in hardware.
      */
-    if (!(gmch & 0x2) && !vdev->vga && vfio_populate_vga(vdev)) {
+    if (!(gmch & 0x2) && !vdev->vga && vfio_populate_vga(vdev, &err)) {
+        error_reportf_err(err, ERR_PREFIX, vdev->vbasedev.name);
         error_report("IGD device %s failed to enable VGA access, "
                      "legacy mode disabled", vdev->vbasedev.name);
         goto out;
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 417bf7f..9645a77 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -2134,7 +2134,7 @@ static VFIODeviceOps vfio_pci_ops = {
     .vfio_eoi = vfio_intx_eoi,
 };
 
-int vfio_populate_vga(VFIOPCIDevice *vdev)
+int vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
 {
     VFIODevice *vbasedev = &vdev->vbasedev;
     struct vfio_region_info *reg_info;
@@ -2142,15 +2142,18 @@ int vfio_populate_vga(VFIOPCIDevice *vdev)
 
     ret = vfio_get_region_info(vbasedev, VFIO_PCI_VGA_REGION_INDEX, &reg_info);
     if (ret) {
+        error_setg_errno(errp, -ret,
+                         "failed getting region info for VGA region index %d",
+                         VFIO_PCI_VGA_REGION_INDEX);
         return ret;
     }
 
     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)reg_info->flags,
-                     (unsigned long)reg_info->size);
+        error_setg(errp, "unexpected VGA info, flags 0x%lx, size 0x%lx",
+                   (unsigned long)reg_info->flags,
+                   (unsigned long)reg_info->size);
         g_free(reg_info);
         return -EINVAL;
     }
@@ -2205,6 +2208,7 @@ static int vfio_populate_device(VFIOPCIDevice *vdev)
     struct vfio_region_info *reg_info;
     struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info) };
     int i, ret = -1;
+    Error *err = NULL;
 
     /* Sanity check device */
     if (!(vbasedev->flags & VFIO_DEVICE_FLAGS_PCI)) {
@@ -2259,10 +2263,11 @@ static int vfio_populate_device(VFIOPCIDevice *vdev)
     g_free(reg_info);
 
     if (vdev->features & VFIO_FEATURE_ENABLE_VGA) {
-        ret = vfio_populate_vga(vdev);
+        ret = vfio_populate_vga(vdev, &err);
         if (ret) {
-            error_report(
-                "vfio: Device does not support requested feature x-vga");
+            error_append_hint(&err, "device does not support "
+                              "requested feature x-vga\n");
+            error_reportf_err(err, ERR_PREFIX, vdev->vbasedev.name);
             goto error;
         }
     }
diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
index 7d482d9..87a62f9 100644
--- a/hw/vfio/pci.h
+++ b/hw/vfio/pci.h
@@ -161,7 +161,7 @@ void vfio_bar_quirk_exit(VFIOPCIDevice *vdev, int nr);
 void vfio_bar_quirk_finalize(VFIOPCIDevice *vdev, int nr);
 void vfio_setup_resetfn_quirk(VFIOPCIDevice *vdev);
 
-int vfio_populate_vga(VFIOPCIDevice *vdev);
+int vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp);
 
 int vfio_pci_igd_opregion_init(VFIOPCIDevice *vdev,
                                struct vfio_region_info *info);