Re: [libvirt] [PATCH 1/3] qemu: hot-plug: Fix broken SCSI disk hot-plug

The commit "qemu: hot-plug: Assume support for -device in qemuDomainAttachSCSIDisk" dropped the code for the automatic SCSI controller creation used in SCSI disk hot-plugging. If we are hot-plugging a SCSI disk to a domain and there is no proper SCSI controller defined, it results in an "error: internal error: Could not find scsi controller with index X required for device" error. For that reason reverting a hunk of the commit d4d32005d6e8b2cc0a2f26b483ca1de10171db6d.

This patch also adds an extra comment to the code to clarify the loop. Reviewed-by: Boris Fiuczynski <fiuczy(a)linux.vnet.ibm.com&gt; Reviewed-by: Bjoern Walk <bwalk(a)linux.vnet.ibm.com&gt; Signed-off-by: Marc Hartmayer <mhartmay(a)linux.vnet.ibm.com&gt; --- src/qemu/qemu_hotplug.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c index e0b8230..5e6a8cb 100644 --- a/src/qemu/qemu_hotplug.c +++ b/src/qemu/qemu_hotplug.c @@ -544,7 +544,9 @@ qemuDomainAttachSCSIDisk(virConnectPtr conn, virDomainObjPtr vm, virDomainDiskDefPtr disk) { + size_t i; qemuDomainObjPrivatePtr priv = vm->privateData; + virDomainControllerDefPtr cont = NULL;

char *drivestr = NULL; char *devstr = NULL; int ret = -1; @@ -561,6 +563,24 @@ qemuDomainAttachSCSIDisk(virConnectPtr conn, goto error; } + /* Let's make sure the disk has a controller defined and loaded before + * trying to add it. The controller used by the disk must exist before a + * qemu command line string is generated. + * + * Ensure that the given controller and all controllers with a smaller index + * exist; there must not be any missing index in between. + */ + for (i = 0; i <= disk->info.addr.drive.controller; i++) { + cont = qemuDomainFindOrCreateSCSIDiskController(driver, vm, i); + if (!cont) + goto error;

+ } + + /* Tell clang that "cont" is non-NULL. + This is because disk->info.addr.driver.controller is unsigned, + and hence the above loop must iterate at least once. */ + sa_assert(cont);

+ if (qemuAssignDeviceDiskAlias(vm->def, disk, priv->qemuCaps) < 0) goto error;