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[libvirt] [PATCH] qemu: Add shortcut for HMP pass through
by Jiri Denemark 03 Feb '11

03 Feb '11

Currently users who want to use virDomainQemuMonitorCommand() API or it's virsh equivalent has to use the same protocol as libvirt uses for communication to qemu. Since the protocol is QMP with current qemu and HMP much more usable for humans, one ends up typing something like the following: virsh qemu-monitor-command DOM \ '{"execute":"human-monitor-command","arguments":{"command-line":"info kvm"}}' which is not a very convenient way of debugging qemu. This patch introduces --hmp option to qemu-monitor-command, which says that the provided command is in HMP. If libvirt uses QMP to talk with qemu, the command will automatically be converted into QMP. So the example above is simplified to just virsh qemu-monitor-command --hmp DOM "info kvm" Also the result is converted from {"return":"kvm support: enabled\r\n"} to just plain HMP: kvm support: enabled If libvirt talks to qemu in HMP, --hmp flag is obviously a noop. --- include/libvirt/libvirt-qemu.h | 5 +++++ src/internal.h | 1 + src/qemu/qemu_driver.c | 7 +++++-- src/qemu/qemu_monitor.c | 9 ++++++--- src/qemu/qemu_monitor.h | 5 ++++- src/qemu/qemu_monitor_json.c | 27 ++++++++++++++++++++++++--- src/qemu/qemu_monitor_json.h | 3 ++- tools/virsh.c | 7 ++++++- 8 files changed, 53 insertions(+), 11 deletions(-) diff --git a/include/libvirt/libvirt-qemu.h b/include/libvirt/libvirt-qemu.h index 9c191c7..9257c2f 100644 --- a/include/libvirt/libvirt-qemu.h +++ b/include/libvirt/libvirt-qemu.h @@ -20,6 +20,11 @@ extern "C" { # endif +enum { + VIR_DOMAIN_QEMU_MONITOR_COMMAND_DEFAULT = 0, + VIR_DOMAIN_QEMU_MONITOR_COMMAND_HMP = (1 << 0), /* cmd is in HMP */ +} virDomainQemuMonitorCommandFlags; + int virDomainQemuMonitorCommand(virDomainPtr domain, const char *cmd, char **result, unsigned int flags); diff --git a/src/internal.h b/src/internal.h index 038b862..dc1d9cb 100644 --- a/src/internal.h +++ b/src/internal.h @@ -38,6 +38,7 @@ # define N_(str) str # include "libvirt/libvirt.h" +# include "libvirt/libvirt-qemu.h" # include "libvirt/virterror.h" # include "libvirt_internal.h" diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 23e0db0..bb50264 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -10226,8 +10226,9 @@ static int qemuDomainMonitorCommand(virDomainPtr domain, const char *cmd, virDomainObjPtr vm = NULL; int ret = -1; qemuDomainObjPrivatePtr priv; + bool hmp; - virCheckFlags(0, -1); + virCheckFlags(VIR_DOMAIN_QEMU_MONITOR_COMMAND_HMP, -1); qemuDriverLock(driver); vm = virDomainFindByUUID(&driver->domains, domain->uuid); @@ -10253,10 +10254,12 @@ static int qemuDomainMonitorCommand(virDomainPtr domain, const char *cmd, priv->monitor_warned = 1; } + hmp = !!(flags & VIR_DOMAIN_QEMU_MONITOR_COMMAND_HMP); + if (qemuDomainObjBeginJobWithDriver(driver, vm) < 0) goto cleanup; qemuDomainObjEnterMonitorWithDriver(driver, vm); - ret = qemuMonitorArbitraryCommand(priv->mon, cmd, result); + ret = qemuMonitorArbitraryCommand(priv->mon, cmd, result, hmp); qemuDomainObjExitMonitorWithDriver(driver, vm); if (qemuDomainObjEndJob(vm) == 0) { vm = NULL; diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index 0c14277..fdb6b79 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -2007,14 +2007,17 @@ int qemuMonitorDeleteSnapshot(qemuMonitorPtr mon, const char *name) return ret; } -int qemuMonitorArbitraryCommand(qemuMonitorPtr mon, const char *cmd, char **reply) +int qemuMonitorArbitraryCommand(qemuMonitorPtr mon, + const char *cmd, + char **reply, + bool hmp) { int ret; - DEBUG("mon=%p, cmd=%s, reply=%p", mon, cmd, reply); + DEBUG("mon=%p, cmd=%s, reply=%p, hmp=%d", mon, cmd, reply, hmp); if (mon->json) - ret = qemuMonitorJSONArbitraryCommand(mon, cmd, reply); + ret = qemuMonitorJSONArbitraryCommand(mon, cmd, reply, hmp); else ret = qemuMonitorTextArbitraryCommand(mon, cmd, reply); return ret; diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h index 92c550b..0ea1330 100644 --- a/src/qemu/qemu_monitor.h +++ b/src/qemu/qemu_monitor.h @@ -397,7 +397,10 @@ int qemuMonitorCreateSnapshot(qemuMonitorPtr mon, const char *name); int qemuMonitorLoadSnapshot(qemuMonitorPtr mon, const char *name); int qemuMonitorDeleteSnapshot(qemuMonitorPtr mon, const char *name); -int qemuMonitorArbitraryCommand(qemuMonitorPtr mon, const char *cmd, char **reply); +int qemuMonitorArbitraryCommand(qemuMonitorPtr mon, + const char *cmd, + char **reply, + bool hmp); /** * When running two dd process and using <> redirection, we need a diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index ca06e7e..9ac12f8 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -2457,20 +2457,41 @@ int qemuMonitorJSONDeleteSnapshot(qemuMonitorPtr mon, const char *name) int qemuMonitorJSONArbitraryCommand(qemuMonitorPtr mon, const char *cmd_str, - char **reply_str) + char **reply_str, + bool hmp) { virJSONValuePtr cmd = NULL; virJSONValuePtr reply = NULL; int ret = -1; - cmd = virJSONValueFromString(cmd_str); + if (!hmp) { + cmd = virJSONValueFromString(cmd_str); + } else { + cmd = qemuMonitorJSONMakeCommand("human-monitor-command", + "s:command-line", cmd_str, + NULL); + } + if (!cmd) return -1; if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0) goto cleanup; - *reply_str = virJSONValueToString(reply); + if (!hmp) { + *reply_str = virJSONValueToString(reply); + } else if (qemuMonitorJSONCheckError(cmd, reply)) { + goto cleanup; + } else { + const char *data; + if (!(data = virJSONValueObjectGetString(reply, "return"))) { + qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("human monitor command was missing return data")); + goto cleanup; + } + *reply_str = strdup(data); + } + if (!(*reply_str)) goto cleanup; diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h index 4c47f10..4ae472a 100644 --- a/src/qemu/qemu_monitor_json.h +++ b/src/qemu/qemu_monitor_json.h @@ -209,6 +209,7 @@ int qemuMonitorJSONDeleteSnapshot(qemuMonitorPtr mon, const char *name); int qemuMonitorJSONArbitraryCommand(qemuMonitorPtr mon, const char *cmd_str, - char **reply_str); + char **reply_str, + bool hmp); #endif /* QEMU_MONITOR_JSON_H */ diff --git a/tools/virsh.c b/tools/virsh.c index 4533d38..59d3de5 100644 --- a/tools/virsh.c +++ b/tools/virsh.c @@ -9932,6 +9932,7 @@ static const vshCmdInfo info_qemu_monitor_command[] = { static const vshCmdOptDef opts_qemu_monitor_command[] = { {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")}, {"cmd", VSH_OT_DATA, VSH_OFLAG_REQ, N_("command")}, + {"hmp", VSH_OT_BOOL, 0, N_("command is in human monitor protocol")}, {NULL, 0, 0, NULL} }; @@ -9942,6 +9943,7 @@ cmdQemuMonitorCommand(vshControl *ctl, const vshCmd *cmd) int ret = FALSE; char *monitor_cmd; char *result = NULL; + unsigned int flags = 0; if (!vshConnectionUsability(ctl, ctl->conn)) goto cleanup; @@ -9956,7 +9958,10 @@ cmdQemuMonitorCommand(vshControl *ctl, const vshCmd *cmd) goto cleanup; } - if (virDomainQemuMonitorCommand(dom, monitor_cmd, &result, 0) < 0) + if (vshCommandOptBool(cmd, "hmp")) + flags |= VIR_DOMAIN_QEMU_MONITOR_COMMAND_HMP; + + if (virDomainQemuMonitorCommand(dom, monitor_cmd, &result, flags) < 0) goto cleanup; printf("%s\n", result); -- 1.7.4

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[libvirt] [PATCH] Add check for binary existing in machine type probe
by Daniel P. Berrange 02 Feb '11

02 Feb '11

When probing machine types if the QEMU binary does not exist we get a hard to diagnose error, due to the execve() in the child failing error: internal error Child process exited with status 1. Add an explicit check so that we get error: Cannot find QEMU binary /usr/libexec/qem3u-kvm: No such file or directory * src/qemu/qemu_capabilities.c: Check for QEMU binary --- src/qemu/qemu_capabilities.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index 37a97aa..08c46be 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -172,6 +172,15 @@ qemuCapsProbeMachineTypes(const char *binary, int ret = -1; virCommandPtr cmd; + /* Make sure the binary we are about to try exec'ing exists. + * Technically we could catch the exec() failure, but that's + * in a sub-process so it's hard to feed back a useful error. + */ + if (access(binary, X_OK) < 0) { + virReportSystemError(errno, _("Cannot find QEMU binary %s"), binary); + return -1; + } + cmd = virCommandNewArgList(binary, "-M", "?", NULL); virCommandAddEnvPassCommon(cmd); virCommandSetOutputBuffer(cmd, &output); -- 1.7.3.5

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[libvirt] [PATCH] Add a little more debugging for async events
by Daniel P. Berrange 02 Feb '11

02 Feb '11

To make it easier to investigate problems with async event delivery, add two more debugging lines * daemon/remote.c: Debug when an event is queued for dispatch * src/remote/remote_driver.c: Debug when an event is received for processing --- daemon/remote.c | 2 ++ src/remote/remote_driver.c | 1 + 2 files changed, 3 insertions(+), 0 deletions(-) diff --git a/daemon/remote.c b/daemon/remote.c index aa6a1a4..f8f6ffa 100644 --- a/daemon/remote.c +++ b/daemon/remote.c @@ -5670,6 +5670,8 @@ remoteDispatchDomainEventSend (struct qemud_client *client, msg->async = 1; msg->bufferLength = len; msg->bufferOffset = 0; + + VIR_DEBUG("Queue event %d %d", procnr, msg->bufferLength); qemudClientMessageQueuePush(&client->tx, msg); qemudUpdateClientEvent(client); diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index 347b844..64af91c 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -9865,6 +9865,7 @@ processCallDispatch(virConnectPtr conn, struct private_data *priv, break; case REMOTE_MESSAGE: /* Async notifications */ + VIR_DEBUG("Dispatch event %d %d", hdr.proc, priv->bufferLength); rv = processCallDispatchMessage(conn, priv, flags & REMOTE_CALL_IN_OPEN, &hdr, &xdr); break; -- 1.7.3.5

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[libvirt] [PATCH] docs: more on qemu locking patterns
by Eric Blake 02 Feb '11

02 Feb '11

* src/qemu/THREADS.txt: Improve documentation. --- I'm trying to make sure we don't have any qemu locking gotchas, given that I've had a bug report of a qemu monitor callback being able to result in a domaing being unreferenced while in the middle of another command. As a first shot, I found that our documentation needed some help. Also, I have a question. I updated the documentation to match existing code: qemuDomainObjExitMonitor() - - Acquires the virDomainObjPtr lock - Releases the qemuMonitorObjPtr lock + - Acquires the virDomainObjPtr lock But I'm wondering if that was correct, or if the code should instead be swapped to match the original ordering in the documentation. src/qemu/THREADS.txt | 100 ++++++++++++++++++++++++++++++++++++++----------- 1 files changed, 77 insertions(+), 23 deletions(-) diff --git a/src/qemu/THREADS.txt b/src/qemu/THREADS.txt index 1af1b83..1e0b5ab 100644 --- a/src/qemu/THREADS.txt +++ b/src/qemu/THREADS.txt @@ -4,7 +4,7 @@ This document describes how thread safety is ensured throughout the QEMU driver. The criteria for this model are: - - Objects must never be exclusively locked for any pro-longed time + - Objects must never be exclusively locked for any prolonged time - Code which sleeps must be able to time out after suitable period - Must be safe against dispatch asynchronous events from monitor @@ -36,11 +36,11 @@ There are a number of locks on various objects Once the lock is held, you must *NOT* try to lock the driver. You must release all virDomainObjPtr locks before locking the driver, or deadlock - *WILL* occurr. + *WILL* occur. If the lock needs to be dropped & then re-acquired for a short period of time, the reference count must be incremented first using virDomainObjRef(). - If the reference count is incremented in this way, it is not neccessary + If the reference count is incremented in this way, it is not necessary to have the driver locked when re-acquiring the dropped locked, since the reference count prevents it being freed by another thread. @@ -51,15 +51,20 @@ There are a number of locks on various objects * qemuMonitorPrivatePtr: Job condition - Since virDomainObjPtr lock must not be held during sleeps, the job condition - provides additional protection for code making updates. + Since virDomainObjPtr lock must not be held during sleeps, the job + condition provides additional protection for code making updates. - Immediately after acquiring the virDomainObjPtr lock, any method which intends - to update state, must acquire the job condition. The virDomainObjPtr lock - is released while blocking on this condition variable. Once the job condition - is acquired a method can safely release the virDomainObjPtr lock whenever it - hits a piece of code which may sleep/wait, and re-acquire it after the sleep/ - wait. + Immediately after acquiring the virDomainObjPtr lock, any method + which intends to update state must acquire the job condition. The + virDomainObjPtr lock is released while blocking on this condition + variable. Once the job condition is acquired, a method can safely + release the virDomainObjPtr lock whenever it hits a piece of code + which may sleep/wait, and re-acquire it after the sleep/wait. + + Since the virDomainObjPtr lock was dropped while waiting for the + job condition, it is possible that the domain is no longer active + when the condition is finally obtained. The monitor lock is only + safe to grab after verifying that the domain is still active. * qemuMonitorPtr: Mutex @@ -110,13 +115,15 @@ To acquire the job mutex qemuDomainObjBeginJob() (if driver is unlocked) - Increments ref count on virDomainObjPtr - - Wait qemuDomainObjPrivate condition 'jobActive != 0' using virDomainObjPtr mutex + - Wait qemuDomainObjPrivate condition 'jobActive != 0' using + virDomainObjPtr mutex - Sets jobActive to 1 qemuDomainObjBeginJobWithDriver() (if driver needs to be locked) - Unlocks driver - Increments ref count on virDomainObjPtr - - Wait qemuDomainObjPrivate condition 'jobActive != 0' using virDomainObjPtr mutex + - Wait qemuDomainObjPrivate condition 'jobActive != 0' using + virDomainObjPtr mutex - Sets jobActive to 1 - Unlocks virDomainObjPtr - Locks driver @@ -140,10 +147,10 @@ To acquire the QEMU monitor lock - Releases the virDomainObjPtr lock qemuDomainObjExitMonitor() - - Acquires the virDomainObjPtr lock - Releases the qemuMonitorObjPtr lock + - Acquires the virDomainObjPtr lock - NB: caller must take care to drop the driver lock if neccessary + NB: caller must take care to drop the driver lock if necessary To acquire the QEMU monitor lock with the driver lock held @@ -154,11 +161,25 @@ To acquire the QEMU monitor lock with the driver lock held - Releases the driver lock qemuDomainObjExitMonitorWithDriver() + - Releases the qemuMonitorObjPtr lock - Acquires the driver lock - Acquires the virDomainObjPtr lock - - Releases the qemuMonitorObjPtr lock - NB: caller must take care to drop the driver lock if neccessary + NB: caller must take care to drop the driver lock if necessary + + +To keep a domain alive while waiting on a remote command, starting +with the driver lock held + + qemuDomainObjEnterRemoterWithDriver() + - Increments ref count on virDomainObjPtr + - Releases the virDomainObjPtr lock + - Releases the driver lock + + qemuDomainObjExitRemoteWithDriver() + - Acquires the driver lock + - Acquires the virDomainObjPtr lock + - Decrements ref count on virDomainObjPtr Design patterns @@ -236,9 +257,11 @@ Design patterns ...do prep work... - qemuDomainObjEnterMonitor(obj); - qemuMonitorXXXX(priv->mon); - qemuDomainObjExitMonitor(obj); + if (virDomainObjIsActive(vm)) { + qemuDomainObjEnterMonitor(obj); + qemuMonitorXXXX(priv->mon); + qemuDomainObjExitMonitor(obj); + } ...do final work... @@ -261,9 +284,11 @@ Design patterns ...do prep work... - qemuDomainObjEnterMonitorWithDriver(driver, obj); - qemuMonitorXXXX(priv->mon); - qemuDomainObjExitMonitorWithDriver(driver, obj); + if (virDomainObjIsActive(vm)) { + qemuDomainObjEnterMonitorWithDriver(driver, obj); + qemuMonitorXXXX(priv->mon); + qemuDomainObjExitMonitorWithDriver(driver, obj); + } ...do final work... @@ -272,6 +297,35 @@ Design patterns qemuDriverUnlock(driver); + * Coordinating with a remote server for migraion + + virDomainObjPtr obj; + qemuDomainObjPrivatePtr priv; + + qemuDriverLock(driver); + obj = virDomainFindByUUID(driver->domains, dom->uuid); + + qemuDomainObjBeginJobWithDriver(obj); + + ...do prep work... + + if (virDomainObjIsActive(vm)) { + qemuDomainObjEnterRemoteWithDriver(driver, obj); + ...communicate with remote... + qemuDomainObjExitRemoteWithDriver(driver, obj); + /* domain may have been stopped while we were talking to remote */ + if (!virDomainObjIsActive(vm)) { + qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("guest unexpectedly quit")); + } + } + + ...do final work... + + qemuDomainObjEndJob(obj); + virDomainObjUnlock(obj); + qemuDriverUnlock(driver); + Summary ------- -- 1.7.3.5

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[libvirt] Strange nodedev-dumpxml ??
by arnaud.champion＠devatom.fr 02 Feb '11

02 Feb '11

?Hi, I have maybe a strange thing on a nodedev-dumpxml virsh result : virsh # nodedev-dumpxml block_sr0 <device> <name>block_sr0</name> <parent>scsi_0_0_1_0</parent> <capability type='storage'> <block>/dev/sr0</block> <bus>scsi</bus> <drive_type>cdrom</drive_type> <model>DVD RW DRU-190S</model> <vendor>SONY</vendor> <capability type='removable'> <media_available>0</media_available> <media_size>0</media_size> </capability> </capability> </device> I think (note I'm not sure), the capabilty type removable should be in the device element, like this : virsh # nodedev-dumpxml block_sr0 <device> <name>block_sr0</name> <parent>scsi_0_0_1_0</parent> <capability type='storage'> <block>/dev/sr0</block> <bus>scsi</bus> <drive_type>cdrom</drive_type> <model>DVD RW DRU-190S</model> <vendor>SONY</vendor> </capability> <capability type='removable'> <media_available>0</media_available> <media_size>0</media_size> </capability> </device> Let me know if I'm wrong. Regards, Arnaud

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[libvirt] Node devices capability xml
by arnaud.champion＠devatom.fr 02 Feb '11

02 Feb '11

?Hi, I'm looking for informations about node devices capibility xml (not driver capabilities), and there's nothing on libvirt.org, can anyone can point me to find the infos ? regards, Arnaud

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[libvirt] nodedev-list and qemu
by arnaud.champion＠devatom.fr 02 Feb '11

02 Feb '11

?Hi, I've just installed libvirt 0.8.7 on my fedora x86_64 14 test host. It seems that the function virNodeNumOfDevices is no more supported by the qemu driver. Is that true ? or I'm wrong anywhere ? Regards, Arnaud

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[libvirt] Connecting with a remote libvirt
by Marcela Castro León 02 Feb '11

02 Feb '11

Hello i'm trying to connect with a remote libvirt. The option I selected was tcp because it's a development environment and a secure and isolated network, I've configured listen_tcp = 1 tcp_port = "16509" in libvirtd.conf at the destition. I've tried to connect to host "santacruz" from a remote host "aoniken" and locally but pn both cases I've got: REMOTE marcela@aoniken:~$ virsh -c qemu+tcp://santacruz:16509 list error: unable to connect to libvirtd at 'santacruz': Connection refused error: failed to connect to the hypervisor LOCALLY radic@santacruz:/etc/libvirt$ virsh -c qemu+tcp://santacruz:16509 list error: unable to connect to libvirtd at 'santacruz': Connection refused error: failed to connect to the hypervisor I've try to use ssh but i've got an error two on both cases. REMOTE (SSH) marcela@aoniken:~$ virsh -c qemu+ssh://radic@santacruz list radic@santacruz's password: error: internal error no QEMU URI path given, try qemu:///system error: failed to connect to the hypervisor marcela@aoniken:~$ radic@santacruz:/etc/libvirt$ virsh -c qemu+ssh://radic@santacruz list radic@santacruz's password: error: internal error no QEMU URI path given, try qemu:///system error: failed to connect to the hypervisor Can you help me? Thank you

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[libvirt] [PATCH] docs: renamed hudson project link to jenkins, matching project rename
by Justin Clift 02 Feb '11

02 Feb '11

--- docs/apps.html.in | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/docs/apps.html.in b/docs/apps.html.in index 2516844..d8bc265 100644 --- a/docs/apps.html.in +++ b/docs/apps.html.in @@ -132,10 +132,10 @@ </dl> <dl> - <dt><a href="http://wiki.hudson-ci.org/display/HUDSON/Libvirt+Slaves+Plugin">Hudson</a></dt> + <dt><a href="http://wiki.jenkins-ci.org/display/JENKINS/Libvirt+Slaves+Plugin">Jenkins</a></dt> <dd> - This plugin for Hudson adds a way to control guest domains hosted - on Xen or QEMU/KVM. You configure a Hudson Slave, + This plugin for Jenkins adds a way to control guest domains hosted + on Xen or QEMU/KVM. You configure a Jenkins Slave, selecting the guest domain and hypervisor. When you need to build a job on a specific Slave, its guest domain is started, then the job is run. When the build process is finished, the guest domain is shut -- 1.7.3.5

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[libvirt] Logging VM startup and shutdown
by Ed Swierk 01 Feb '11

01 Feb '11

When troubleshooting a libvirt system the most obvious question I face is when a given VM started and stopped. The only way I've been able to obtain this information is by setting log_level = 1 in libvirtd.conf, which turns on the firehose, generating an enormous amount of output. I then have to sift through the logs for magic strings like "virExecWithHook" to see when a VM started, and "Shutting down VM" to see when a VM stopped. Is there no concise message that indicates a VM starting up? "virExecWithHook" doesn't exactly jump out. I'd consider starting up and shutting down a VM to be at least worth an info-level message in the log. I monkeyed with the log_filters setting but I couldn't figure out how to filter those two strings. Any hints? --Ed

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