[Libguestfs] [PATCH] aarch64: Enable virtio-pci, replacing virtio-mmio.

[Richard W.M. Jones]

Thanks: Laine Stump, Andrea Bolognani, Marcel Apfelbaum.
---
 src/guestfs-internal.h |  6 +++---
 src/launch-libvirt.c   | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/src/guestfs-internal.h b/src/guestfs-internal.h
index d437b9a..428da7f 100644
--- a/src/guestfs-internal.h
+++ b/src/guestfs-internal.h
@@ -137,17 +137,17 @@
 /* Differences in device names on ARM (virtio-mmio) vs normal
  * hardware with PCI.
  */
-#if !defined(__arm__) && !defined(__aarch64__)
+#if !defined(__arm__)
 #define VIRTIO_BLK "virtio-blk-pci"
 #define VIRTIO_SCSI "virtio-scsi-pci"
 #define VIRTIO_SERIAL "virtio-serial-pci"
 #define VIRTIO_NET "virtio-net-pci"
-#else /* ARM */
+#else /* ARMv7 */
 #define VIRTIO_BLK "virtio-blk-device"
 #define VIRTIO_SCSI "virtio-scsi-device"
 #define VIRTIO_SERIAL "virtio-serial-device"
 #define VIRTIO_NET "virtio-net-device"
-#endif /* ARM */
+#endif /* ARMv7 */
 
 /* Machine types. */
 #ifdef __arm__
diff --git a/src/launch-libvirt.c b/src/launch-libvirt.c
index d8479dc..1ac5604 100644
--- a/src/launch-libvirt.c
+++ b/src/launch-libvirt.c
@@ -950,6 +950,13 @@ static int construct_libvirt_xml_disk_source_hosts (guestfs_h *g, xmlTextWriterP
 static int construct_libvirt_xml_disk_source_seclabel (guestfs_h *g, const struct backend_libvirt_data *data, xmlTextWriterPtr xo);
 static int construct_libvirt_xml_appliance (guestfs_h *g, const struct libvirt_xml_params *params, xmlTextWriterPtr xo);
 
+static int construct_libvirt_xml_virtio_pci_address (guestfs_h *g, xmlTextWriterPtr xo, int slot);
+/* Don't use slot 1, since can be used by video. */
+#define VIRTIO_PCI_SLOT_RNG     2
+#define VIRTIO_PCI_SLOT_SCSI    3
+#define VIRTIO_PCI_SLOT_SERIAL  4
+#define VIRTIO_PCI_SLOT_NETWORK 5
+
 /* These macros make it easier to write XML, but they also make a lot
  * of assumptions:
  *
@@ -1337,6 +1344,9 @@ construct_libvirt_xml_devices (guestfs_h *g,
           attribute ("model", "random");
           string ("/dev/urandom");
         } end_element ();
+        if (construct_libvirt_xml_virtio_pci_address (g, xo,
+                                                      VIRTIO_PCI_SLOT_RNG) == -1)
+          return -1;
       } end_element ();
     }
 
@@ -1345,6 +1355,9 @@ construct_libvirt_xml_devices (guestfs_h *g,
       attribute ("type", "scsi");
       attribute ("index", "0");
       attribute ("model", "virtio-scsi");
+      if (construct_libvirt_xml_virtio_pci_address (g, xo,
+                                                    VIRTIO_PCI_SLOT_SCSI) == -1)
+        return -1;
     } end_element ();
 
     /* Disks. */
@@ -1382,6 +1395,9 @@ construct_libvirt_xml_devices (guestfs_h *g,
         attribute ("type", "virtio");
         attribute ("name", "org.libguestfs.channel.0");
       } end_element ();
+      if (construct_libvirt_xml_virtio_pci_address (g, xo,
+                                                    VIRTIO_PCI_SLOT_SERIAL) == -1)
+        return -1;
     } end_element ();
 
     /* Connect to libvirt bridge (see: RHBZ#1148012). */
@@ -1394,6 +1410,9 @@ construct_libvirt_xml_devices (guestfs_h *g,
         start_element ("model") {
           attribute ("type", "virtio");
         } end_element ();
+        if (construct_libvirt_xml_virtio_pci_address (g, xo,
+                                                      VIRTIO_PCI_SLOT_NETWORK) == -1)
+          return -1;
       } end_element ();
     }
 
@@ -1986,6 +2005,28 @@ find_secret (guestfs_h *g,
   return 0;
 }
 
+/**
+ * On aarch64 only, to force libvirt to use virtio-pci instead of
+ * virtio-mmio, we assign every virtio device to a unique function
+ * within the (implicitly created) pcie-root bus.  Every virtio device
+ * must have a unique slot number.
+ */
+static int
+construct_libvirt_xml_virtio_pci_address (guestfs_h *g,
+                                          xmlTextWriterPtr xo,
+                                          int slot)
+{
+#if defined(__aarch64__)
+  start_element ("address") {
+    attribute ("type", "pci");
+    attribute ("bus", "0");
+    attribute_format ("slot", "%d", slot);
+  } end_element ();
+#endif
+
+  return 0;
+}
+
 static int
 is_blk (const char *path)
 {
-- 
2.9.3