On 07/16/2015 08:23 AM, Ján Tomko wrote: > On Mon, Jun 22, 2015 at 05:05:07PM -0400, John Ferlan wrote: >> https://bugzilla.redhat.com/show_bug.cgi?id=1210587 (completed) >> >> When generating the default drive address for a SCSI <disk> device, >> check the generated address to ensure it doesn't conflict with a SCSI >> <hostdev> address. The <disk> address generation algorithm uses the >> <target> "dev" name in order to determine which controller and unit >> in order to place the device. Since a SCSI <hostdev> device doesn't >> require a target device name, its placement on the guest SCSI address >> "could" conflict. For instance, if a SCSI <hostdev> exists at >> controller=0 unit=0 and an attempt to hotplug 'sda' into the guest >> made, there would be a conflict if the <hostdev> is already using >> /dev/sda. >> >> Signed-off-by: John Ferlan <jferlan@xxxxxxxxxx> >> --- >> src/conf/domain_conf.c | 40 +++++++++++++++++++++++++++++----------- >> src/conf/domain_conf.h | 3 ++- >> src/qemu/qemu_command.c | 4 ++-- >> src/vmx/vmx.c | 22 ++++++++++++---------- >> src/vmx/vmx.h | 3 ++- >> 5 files changed, 47 insertions(+), 25 deletions(-) >> >> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c >> index 6259d4a..0999e86 100644 >> --- a/src/conf/domain_conf.c >> +++ b/src/conf/domain_conf.c >> @@ -5672,7 +5672,8 @@ virDomainDiskFindByBusAndDst(virDomainDefPtr def, >> >> int >> virDomainDiskDefAssignAddress(virDomainXMLOptionPtr xmlopt, >> - virDomainDiskDefPtr def) >> + virDomainDiskDefPtr def, >> + const virDomainDef *vmdef) >> { >> int idx = virDiskNameToIndex(def->dst); >> if (idx < 0) { >> @@ -5683,7 +5684,10 @@ virDomainDiskDefAssignAddress(virDomainXMLOptionPtr xmlopt, >> } >> >> switch (def->bus) { >> - case VIR_DOMAIN_DISK_BUS_SCSI: >> + case VIR_DOMAIN_DISK_BUS_SCSI: { >> + unsigned int controller; >> + unsigned int unit; >> + >> def->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_DRIVE; >> >> if (xmlopt->config.hasWideSCSIBus) { >> @@ -5692,22 +5696,36 @@ virDomainDiskDefAssignAddress(virDomainXMLOptionPtr xmlopt, >> * Unit 7 is the SCSI controller itself. Therefore unit 7 >> * cannot be assigned to disks and is skipped. >> */ >> - def->info.addr.drive.controller = idx / 15; >> - def->info.addr.drive.bus = 0; >> - def->info.addr.drive.unit = idx % 15; >> + controller = idx / 15; >> + unit = idx % 15; >> >> /* Skip the SCSI controller at unit 7 */ >> - if (def->info.addr.drive.unit >= 7) >> - ++def->info.addr.drive.unit; >> + if (unit >= 7) >> + ++unit; >> } else { >> /* For a narrow SCSI bus we define the default mapping to be >> * 7 units per bus, 1 bus per controller, many controllers */ >> - def->info.addr.drive.controller = idx / 7; >> - def->info.addr.drive.bus = 0; >> - def->info.addr.drive.unit = idx % 7; >> + controller = idx / 7; >> + unit = idx % 7; >> + } >> + > > This mixes non-functional and functional changes. > OK - I can separate out out just the non-functional into its own patch. Do you want me to send it out again or trust that I know what I'm doing? >> + if (virDomainDriveAddressIsUsedByHostdev(vmdef, >> + VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI, >> + controller, 0, 0, unit)) { >> + virReportError(VIR_ERR_XML_ERROR, >> + _("address generated using disk target name '%s' " >> + "may conflict with SCSI host device address " >> + "controller='%u' bus='%u' target='%u' unit='%u"), >> + def->dst, controller, 0, 0, unit); > > 'may conflict' sounds ambiguous. Either it does conflict and we should > reject it, or it does not and there is no error. > > And this seems like a problem of libvirt's address generation algorithm, > not an XML error. > > Jan > Right - it does conflict... The issue is that the 'idx' is generated as a result of the target device name ("dst"). The assumption being "sda" would be controller = unit = 0, 'sdb' would be ctlr = 0, unit = 1, 'sdc' would be ctlr = 0, unit = 2, etc. However, for hostdev's there is no such "dst" logic - it's a straight assignment. When the guest boots, whatever is assigned to "c = 0, u = 0" is assigned to 'sda' (regardless of whether it's a hostdev or disk). So if the hostdev which had it's address provided in the XML, but the disk which didn't *and* is using "<target dev='sda'.../>", then there's a possible conflict because "sda" resolves to "c = 0, b = 0". The error message I guess should thus state : "using disk target name '%s' conflicts with SCSI host device address ..." Would you still call that an XML error or perhaps CONFIG_UNSUPPORTED John -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list