qemuAgentFSInfoToPublic() currently only sets the devAlias for PCI devices. However, the QEMU guest agent could also provide the device name in the "dev" field of the response for other devices instead (well, at least after fixing another problem in the current QEMU guest agent...). So if creating the devAlias from the PCI information failed, let's fall back to the name provided by the guest agent. This helps to fix the empty "Target" fields that occur when running "virsh domfsinfo" on s390x where CCW devices are used for the guest instead of PCI devices. Also add a proper debug message here in case we completely failed to set the device alias, since this problem here was very hard to debug: The only two error messages that I've seen were "Unable to get filesystem information" and "Unable to encode message payload" - which only indicates that something went wrong in the RPC call. No debug message indicated the real problem, so I had to learn the hard way why the RPC call failed (it apparently does not like devAlias left to be NULL) and where the real problem comes from. Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1755075 Signed-off-by: Thomas Huth <thuth(a)redhat.com&gt; --- src/qemu/qemu_driver.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index d185666ed8..e45c61ee20 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -21935,14 +21935,17 @@ qemuAgentFSInfoToPublic(qemuAgentFSInfoPtr agent, qemuAgentDiskInfoPtr agentdisk = agent->disks[i]; virDomainDiskDefPtr diskDef; - if (!(diskDef = virDomainDiskByAddress(vmdef, - &agentdisk->pci_controller, - agentdisk->bus, - agentdisk->target, - agentdisk->unit))) - continue; - - ret->devAlias[i] = g_strdup(diskDef->dst); + diskDef = virDomainDiskByAddress(vmdef, + &agentdisk->pci_controller, + agentdisk->bus, + agentdisk->target, + agentdisk->unit);

+ if (diskDef != NULL) + ret->devAlias[i] = g_strdup(diskDef->dst); + else if (agentdisk->devnode != NULL) + ret->devAlias[i] = g_strdup(agentdisk->devnode);

+ else + VIR_DEBUG("Missing devnode name for '%s'.", ret->mountpoint); }

qemuAgentFSInfoToPublic() currently only sets the devAlias for PCI devices. However, the QEMU guest agent could also provide the device name in the "dev" field of the response for other devices instead (well, at least after fixing another problem in the current QEMU guest agent...). So if creating the devAlias from the PCI information failed, let's fall back to the name provided by the guest agent. This helps to fix the empty "Target" fields that occur when running "virsh domfsinfo" on s390x where CCW devices are used for the guest instead of PCI devices. Also add a proper debug message here in case we completely failed to set the device alias, since this problem here was very hard to debug: The only two error messages that I've seen were "Unable to get filesystem information" and "Unable to encode message payload" - which only indicates that something went wrong in the RPC call. No debug message indicated the real problem, so I had to learn the hard way why the RPC call failed (it apparently does not like devAlias left to be NULL) and where the real problem comes from. Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1755075 Signed-off-by: Thomas Huth <thuth(a)redhat.com&gt; --- src/qemu/qemu_driver.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index d185666ed8..e45c61ee20 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -21935,14 +21935,17 @@ qemuAgentFSInfoToPublic(qemuAgentFSInfoPtr agent, qemuAgentDiskInfoPtr agentdisk = agent->disks[i]; virDomainDiskDefPtr diskDef; - if (!(diskDef = virDomainDiskByAddress(vmdef, - &agentdisk->pci_controller, - agentdisk->bus, - agentdisk->target, - agentdisk->unit))) - continue; - - ret->devAlias[i] = g_strdup(diskDef->dst); + diskDef = virDomainDiskByAddress(vmdef, + &agentdisk->pci_controller, + agentdisk->bus, + agentdisk->target, + agentdisk->unit); + if (diskDef != NULL) + ret->devAlias[i] = g_strdup(diskDef->dst); + else if (agentdisk->devnode != NULL) + ret->devAlias[i] = g_strdup(agentdisk->devnode); + else + VIR_DEBUG("Missing devnode name for '%s'.", ret->mountpoint); } return ret;

On 07/08/2020 18.22, Thomas Huth wrote: > On 20/07/2020 12.22, Thomas Huth wrote: >> qemuAgentFSInfoToPublic() currently only sets the devAlias for PCI devices. >> However, the QEMU guest agent could also provide the device name in the >> "dev" field of the response for other devices instead (well, at least after >> fixing another problem in the current QEMU guest agent...). So if creating >> the devAlias from the PCI information failed, let's fall back to the name >> provided by the guest agent. This helps to fix the empty "Target" fields >> that occur when running "virsh domfsinfo" on s390x where CCW devices are >> used for the guest instead of PCI devices. >> >> Also add a proper debug message here in case we completely failed to set the >> device alias, since this problem here was very hard to debug: The only two >> error messages that I've seen were "Unable to get filesystem information" >> and "Unable to encode message payload" - which only indicates that something >> went wrong in the RPC call. No debug message indicated the real problem, so >> I had to learn the hard way why the RPC call failed (it apparently does not >> like devAlias left to be NULL) and where the real problem comes from. >> >> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1755075 >> Signed-off-by: Thomas Huth <thuth(a)redhat.com&gt; >> --- >> src/qemu/qemu_driver.c | 19 +++++++++++-------- >> 1 file changed, 11 insertions(+), 8 deletions(-) >> >> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c >> index d185666ed8..e45c61ee20 100644 >> --- a/src/qemu/qemu_driver.c >> +++ b/src/qemu/qemu_driver.c >> @@ -21935,14 +21935,17 @@ qemuAgentFSInfoToPublic(qemuAgentFSInfoPtr agent, >> qemuAgentDiskInfoPtr agentdisk = agent->disks[i]; >> virDomainDiskDefPtr diskDef; >> >> - if (!(diskDef = virDomainDiskByAddress(vmdef, >> - &agentdisk->pci_controller, >> - agentdisk->bus, >> - agentdisk->target, >> - agentdisk->unit))) >> - continue; >> - >> - ret->devAlias[i] = g_strdup(diskDef->dst); >> + diskDef = virDomainDiskByAddress(vmdef, >> + &agentdisk->pci_controller, >> + agentdisk->bus, >> + agentdisk->target, >> + agentdisk->unit); >> + if (diskDef != NULL) >> + ret->devAlias[i] = g_strdup(diskDef->dst); >> + else if (agentdisk->devnode != NULL) >> + ret->devAlias[i] = g_strdup(agentdisk->devnode); >> + else >> + VIR_DEBUG("Missing devnode name for '%s'.", ret->mountpoint); >> } >> >> return ret; >> > > Friendly ping! > > Any more comments here? Is it ok this way or shall I change the order? Ping again! Is the patch ok, or do I have to rework it?