qemu-ga: make get-fsinfo work over pci bridges

Iterate over the PCI bridges to lookup the PCI device associated with
the block device.

This allows to lookup the driver under the following syspath:
/sys/devices/pci0000:00/0000:00:02.2/0000:03:00.0/virtio2/block/vda/vda3

It also works with an "old-style" Q35 libvirt hierarchy: root complex
-> DMI-PCI bridge -> PCI-PCI bridge -> virtio controller, ex:
/sys/devices/pci0000:00/0000:00:03.0/0000:01:01.0/0000:02:01.0/virtio1/block/vda/vda3

The setup can be reproduced with the following qemu command line
(Thanks Marcel for help):

qemu-system-x86_64 -M q35 \
  -device i82801b11-bridge,id=dmi2pci_bridge,bus=pcie.0
  -device pci-bridge,id=pci_bridge,bus=dmi2pci_bridge,addr=0x1,chassis_nr=1
  -device virtio-blk-pci,scsi=off,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1,bus=pci_bridge,addr=0x1

For consistency with other syspath-related debug messages, replace a
\"%s\" in the message with '%s'.

Fixes:
https://bugzilla.redhat.com/show_bug.cgi?id=1567041

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
This commit is contained in:
Marc-André Lureau 2018-05-14 14:38:55 +02:00 committed by Michael Roth
parent a972304d18
commit 743c71d03c

View File

@ -876,13 +876,28 @@ static void build_guest_fsinfo_for_real_device(char const *syspath,
p = strstr(syspath, "/devices/pci");
if (!p || sscanf(p + 12, "%*x:%*x/%x:%x:%x.%x%n",
pci, pci + 1, pci + 2, pci + 3, &pcilen) < 4) {
g_debug("only pci device is supported: sysfs path \"%s\"", syspath);
g_debug("only pci device is supported: sysfs path '%s'", syspath);
return;
}
driver = get_pci_driver(syspath, (p + 12 + pcilen) - syspath, errp);
if (!driver) {
goto cleanup;
p += 12 + pcilen;
while (true) {
driver = get_pci_driver(syspath, p - syspath, errp);
if (driver && (g_str_equal(driver, "ata_piix") ||
g_str_equal(driver, "sym53c8xx") ||
g_str_equal(driver, "virtio-pci") ||
g_str_equal(driver, "ahci"))) {
break;
}
if (sscanf(p, "/%x:%x:%x.%x%n",
pci, pci + 1, pci + 2, pci + 3, &pcilen) == 4) {
p += pcilen;
continue;
}
g_debug("unsupported driver or sysfs path '%s'", syspath);
return;
}
p = strstr(syspath, "/target");