Re: [libvirt] [PATCH v2 2/2] domain_conf: Relax SCSI addr used check

In domain_conf.c we have virDomainSCSIDriveAddressIsUsed() function which returns true or false if given drive address is already in use for given domain config or not. However, it also takes a shortcut and returns true (meaning address in use) if the unit number equals 7. This is because for some controllers this is reserved address. The limitation comes mostly from vmware and applies to lsilogic, buslogic, spapr-vscsi and vmpvscsi models. On the other hand, we were not checking for the maximum unit number (aka LUN number) which is also relevant and differs from model to model. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/conf/domain_conf.c | 53 ++++++++++++++++++++++++++++++++++++++---- 1 file changed, 48 insertions(+), 5 deletions(-) diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 69c486f382..3e7603891f 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -4813,11 +4813,54 @@ bool virDomainSCSIDriveAddressIsUsed(const virDomainDef *def, const virDomainDeviceDriveAddress *addr) { - /* In current implementation, the maximum unit number of a controller - * is either 16 or 7 (narrow SCSI bus), and if the maximum unit number - * is 16, the controller itself is on unit 7 */ - if (addr->unit == 7) - return true; + const virDomainControllerDef *cont; + + cont = virDomainDeviceFindSCSIController(def, addr); + if (cont) { + int max = -1; + int reserved = -1; + + /* Different controllers have different limits. These limits here are + * taken from QEMU source code, but nevertheless they should apply to + * other hypervisors too. */ + switch ((virDomainControllerModelSCSI) cont->model) { + case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_SCSI: + case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_TRANSITIONAL: + case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_NON_TRANSITIONAL: + max = 16383; + break; + case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_IBMVSCSI: + max = 31; + reserved = 7; + break; + case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSISAS1068: + max = 1; + break; + case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSISAS1078: + max = 255; + break; + case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSILOGIC: + max = 0;

+ if (max != -1 && addr->unit >= max) + return true;

+ if (reserved != -1 && addr->unit == reserved) + return true; + } if (virDomainDriveAddressIsUsedByDisk(def, VIR_DOMAIN_DISK_BUS_SCSI, addr) ||