The intent here is to allow the virt drivers to be run directly embedded in an arbitrary process without interfering with libvirtd. To achieve this they need to store all their configuration & state in a separate directory tree from the main system or session libvirtd instances. This can be useful for doing testing of the virt drivers in "make check" without interfering with the user's own libvirtd instances. It can also be used for applications using KVM/QEMU as a piece of infrastructure to build an service, rather than for general purpose OS hosting. A long standing example is libguestfs, which would prefer if its temporary VMs did show up in the main libvirtd VM list, because this confuses apps such as OpenStack Nova. A more recent example would be Kata which is using KVM as a technology to build containers. Reviewed-by: Cole Robinson <crobinso(a)redhat.com&gt; Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; --- src/driver-state.h | 1 + src/interface/interface_backend_netcf.c | 7 +++++++ src/interface/interface_backend_udev.c | 7 +++++++ src/libvirt.c | 21 +++++++++++++++++++++ src/libvirt_internal.h | 4 +++- src/libxl/libxl_driver.c | 7 +++++++ src/lxc/lxc_driver.c | 8 ++++++++ src/network/bridge_driver.c | 7 +++++++ src/node_device/node_device_hal.c | 7 +++++++ src/node_device/node_device_udev.c | 7 +++++++ src/nwfilter/nwfilter_driver.c | 7 +++++++ src/qemu/qemu_driver.c | 7 +++++++ src/remote/remote_daemon.c | 1 + src/remote/remote_driver.c | 1 + src/secret/secret_driver.c | 7 +++++++ src/storage/storage_driver.c | 7 +++++++ src/vz/vz_driver.c | 7 +++++++ 17 files changed, 112 insertions(+), 1 deletion(-) diff --git a/src/driver-state.h b/src/driver-state.h index 69e2678dfc..1e2f6ed247 100644 --- a/src/driver-state.h +++ b/src/driver-state.h @@ -32,6 +32,7 @@ typedef enum { typedef virDrvStateInitResult (*virDrvStateInitialize)(bool privileged, + const char *root, virStateInhibitCallback callback, void *opaque); diff --git a/src/interface/interface_backend_netcf.c b/src/interface/interface_backend_netcf.c index 65cb7eae62..06eb1ace08 100644 --- a/src/interface/interface_backend_netcf.c +++ b/src/interface/interface_backend_netcf.c @@ -89,9 +89,16 @@ virNetcfDriverStateDispose(void *obj) static int netcfStateInitialize(bool privileged, + const char *root, virStateInhibitCallback callback G_GNUC_UNUSED, void *opaque G_GNUC_UNUSED) { + if (root != NULL) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("Driver does not support embedded mode")); + return -1; + } + if (virNetcfDriverStateInitialize() < 0) return VIR_DRV_STATE_INIT_ERROR; diff --git a/src/interface/interface_backend_udev.c b/src/interface/interface_backend_udev.c index 7cc098eb33..e87b884c17 100644 --- a/src/interface/interface_backend_udev.c +++ b/src/interface/interface_backend_udev.c @@ -1145,11 +1145,18 @@ udevStateCleanup(void); static int udevStateInitialize(bool privileged, + const char *root, virStateInhibitCallback callback G_GNUC_UNUSED, void *opaque G_GNUC_UNUSED) { int ret = VIR_DRV_STATE_INIT_ERROR; + if (root != NULL) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("Driver does not support embedded mode")); + return -1; + } + if (VIR_ALLOC(driver) < 0) goto cleanup; diff --git a/src/libvirt.c b/src/libvirt.c index 9d783761e6..bd2952d036 100644 --- a/src/libvirt.c +++ b/src/libvirt.c @@ -637,16 +637,36 @@ virRegisterStateDriver(virStateDriverPtr driver) * virStateInitialize: * @privileged: set to true if running with root privilege, false otherwise * @mandatory: set to true if all drivers must report success, not skipped + * @root: directory to use for embedded mode * @callback: callback to invoke to inhibit shutdown of the daemon * @opaque: data to pass to @callback * * Initialize all virtualization drivers. * + * Passing a non-NULL @root instructs the driver to run in embedded mode. + * Instead of using the compile time $prefix as the basis for directory + * paths, @root should be used instead. In addition any '/libvirt' + * component of the paths should be stripped. + * + * eg consider a build with prefix=/usr/local. A driver might use the + * locations + * + * /usr/local/etc/libvirt/$DRIVER/ + * /usr/local/var/lib/libvirt/$DRIVER/ + * /usr/local/run/libvirt/$DRIVER/ + * + * When run with @root, the locations should instead be + * + * @root/etc/$DRIVER/ + * @root/var/lib/$DRIVER/ + * @root/run/$DRIVER/ + * * Returns 0 if all succeed, -1 upon any failure. */ int virStateInitialize(bool privileged, bool mandatory, + const char *root, virStateInhibitCallback callback, void *opaque) { @@ -661,6 +681,7 @@ virStateInitialize(bool privileged, VIR_DEBUG("Running global init for %s state driver", virStateDriverTab[i]->name); ret = virStateDriverTab[i]->stateInitialize(privileged, + root, callback, opaque); VIR_DEBUG("State init result %d (mandatory=%d)", ret, mandatory); diff --git a/src/libvirt_internal.h b/src/libvirt_internal.h index 4a74dbc2af..00ef7aaf25 100644 --- a/src/libvirt_internal.h +++ b/src/libvirt_internal.h @@ -31,8 +31,10 @@ typedef void (*virStateInhibitCallback)(bool inhibit, int virStateInitialize(bool privileged, bool mandatory, + const char *root, virStateInhibitCallback inhibit, - void *opaque); + void *opaque) + ATTRIBUTE_NONNULL(2); int virStateCleanup(void); int virStateReload(void); int virStateStop(void); diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c index b2f191b2ac..e719b2799d 100644 --- a/src/libxl/libxl_driver.c +++ b/src/libxl/libxl_driver.c @@ -647,6 +647,7 @@ libxlAddDom0(libxlDriverPrivatePtr driver) static int libxlStateInitialize(bool privileged, + const char *root, virStateInhibitCallback callback G_GNUC_UNUSED, void *opaque G_GNUC_UNUSED) { @@ -655,6 +656,12 @@ libxlStateInitialize(bool privileged, char ebuf[1024]; bool autostart = true; + if (root != NULL) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("Driver does not support embedded mode")); + return -1; + } + if (!libxlDriverShouldLoad(privileged)) return VIR_DRV_STATE_INIT_SKIPPED; diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c index 780c6ed4a2..47175d92b8 100644 --- a/src/lxc/lxc_driver.c +++ b/src/lxc/lxc_driver.c @@ -85,6 +85,7 @@ VIR_LOG_INIT("lxc.lxc_driver"); static int lxcStateInitialize(bool privileged, + const char *root, virStateInhibitCallback callback, void *opaque); static int lxcStateCleanup(void); @@ -1526,12 +1527,19 @@ lxcSecurityInit(virLXCDriverConfigPtr cfg) static int lxcStateInitialize(bool privileged, + const char *root, virStateInhibitCallback callback G_GNUC_UNUSED, void *opaque G_GNUC_UNUSED) { virLXCDriverConfigPtr cfg = NULL; bool autostart = true; + if (root != NULL) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("Driver does not support embedded mode")); + return -1; + } + /* Check that the user is root, silently disable if not */ if (!privileged) { VIR_INFO("Not running privileged, disabling driver"); diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c index c9c45df758..b66135f2d9 100644 --- a/src/network/bridge_driver.c +++ b/src/network/bridge_driver.c @@ -702,6 +702,7 @@ firewalld_dbus_filter_bridge(DBusConnection *connection G_GNUC_UNUSED, */ static int networkStateInitialize(bool privileged, + const char *root, virStateInhibitCallback callback G_GNUC_UNUSED, void *opaque G_GNUC_UNUSED) { @@ -713,6 +714,12 @@ networkStateInitialize(bool privileged, DBusConnection *sysbus = NULL; #endif + if (root != NULL) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("Driver does not support embedded mode")); + return -1; + } + if (VIR_ALLOC(network_driver) < 0) goto error; diff --git a/src/node_device/node_device_hal.c b/src/node_device/node_device_hal.c index cf12854fe9..878df644cc 100644 --- a/src/node_device/node_device_hal.c +++ b/src/node_device/node_device_hal.c @@ -588,6 +588,7 @@ device_prop_modified(LibHalContext *ctx G_GNUC_UNUSED, static int nodeStateInitialize(bool privileged G_GNUC_UNUSED, + const char *root, virStateInhibitCallback callback G_GNUC_UNUSED, void *opaque G_GNUC_UNUSED) { @@ -599,6 +600,12 @@ nodeStateInitialize(bool privileged G_GNUC_UNUSED, DBusConnection *sysbus; DBusError err; + if (root != NULL) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("Driver does not support embedded mode")); + return -1; + } + /* Ensure caps_tbl is sorted by capability name */ qsort(caps_tbl, G_N_ELEMENTS(caps_tbl), sizeof(caps_tbl[0]), cmpstringp); diff --git a/src/node_device/node_device_udev.c b/src/node_device/node_device_udev.c index eedcd123a3..4579297336 100644 --- a/src/node_device/node_device_udev.c +++ b/src/node_device/node_device_udev.c @@ -1781,6 +1781,7 @@ udevPCITranslateInit(bool privileged G_GNUC_UNUSED) static int nodeStateInitialize(bool privileged, + const char *root, virStateInhibitCallback callback G_GNUC_UNUSED, void *opaque G_GNUC_UNUSED) { @@ -1788,6 +1789,12 @@ nodeStateInitialize(bool privileged, struct udev *udev = NULL; virThread enumThread; + if (root != NULL) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("Driver does not support embedded mode")); + return -1; + } + if (VIR_ALLOC(driver) < 0) return VIR_DRV_STATE_INIT_ERROR; diff --git a/src/nwfilter/nwfilter_driver.c b/src/nwfilter/nwfilter_driver.c index cc3ce98cc5..1c407727db 100644 --- a/src/nwfilter/nwfilter_driver.c +++ b/src/nwfilter/nwfilter_driver.c @@ -177,11 +177,18 @@ virNWFilterTriggerRebuildImpl(void *opaque) */ static int nwfilterStateInitialize(bool privileged, + const char *root, virStateInhibitCallback callback G_GNUC_UNUSED, void *opaque G_GNUC_UNUSED) { DBusConnection *sysbus = NULL; + if (root != NULL) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("Driver does not support embedded mode")); + return -1; + } + if (virDBusHasSystemBus() && !(sysbus = virDBusGetSystemBus())) return VIR_DRV_STATE_INIT_ERROR; diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index ec8faf384c..1e284dd90e 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -632,6 +632,7 @@ qemuDomainFindMaxID(virDomainObjPtr vm, */ static int qemuStateInitialize(bool privileged, + const char *root, virStateInhibitCallback callback, void *opaque) { @@ -645,6 +646,12 @@ qemuStateInitialize(bool privileged, const char *defsecmodel = NULL; g_autofree virSecurityManagerPtr *sec_managers = NULL; + if (root != NULL) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("Driver does not support embedded mode")); + return -1; + } + if (VIR_ALLOC(qemu_driver) < 0) return VIR_DRV_STATE_INIT_ERROR; diff --git a/src/remote/remote_daemon.c b/src/remote/remote_daemon.c index 5893492875..65aaa506a6 100644 --- a/src/remote/remote_daemon.c +++ b/src/remote/remote_daemon.c @@ -833,6 +833,7 @@ static void daemonRunStateInit(void *opaque) * seriously delay OS bootup process */ if (virStateInitialize(virNetDaemonIsPrivileged(dmn), mandatory, + NULL, daemonInhibitCallback, dmn) < 0) { VIR_ERROR(_("Driver state initialization failed")); diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index c11f73ab4d..9b60cc5161 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -235,6 +235,7 @@ static int remoteSplitURIScheme(virURIPtr uri, static int remoteStateInitialize(bool privileged G_GNUC_UNUSED, + const char *root G_GNUC_UNUSED, virStateInhibitCallback callback G_GNUC_UNUSED, void *opaque G_GNUC_UNUSED) { diff --git a/src/secret/secret_driver.c b/src/secret/secret_driver.c index 096672f114..e0a55e51ca 100644 --- a/src/secret/secret_driver.c +++ b/src/secret/secret_driver.c @@ -452,9 +452,16 @@ secretStateCleanup(void) static int secretStateInitialize(bool privileged, + const char *root, virStateInhibitCallback callback G_GNUC_UNUSED, void *opaque G_GNUC_UNUSED) { + if (root != NULL) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("Driver does not support embedded mode")); + return -1; + } + if (VIR_ALLOC(driver) < 0) return VIR_DRV_STATE_INIT_ERROR; diff --git a/src/storage/storage_driver.c b/src/storage/storage_driver.c index a33328db37..950a6c9143 100644 --- a/src/storage/storage_driver.c +++ b/src/storage/storage_driver.c @@ -251,6 +251,7 @@ storageDriverAutostart(void) */ static int storageStateInitialize(bool privileged, + const char *root, virStateInhibitCallback callback G_GNUC_UNUSED, void *opaque G_GNUC_UNUSED) { @@ -258,6 +259,12 @@ storageStateInitialize(bool privileged, g_autofree char *rundir = NULL; bool autostart = true; + if (root != NULL) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("Driver does not support embedded mode")); + return -1; + } + if (VIR_ALLOC(driver) < 0) return VIR_DRV_STATE_INIT_ERROR; diff --git a/src/vz/vz_driver.c b/src/vz/vz_driver.c index bcdbb50404..e833f59235 100644 --- a/src/vz/vz_driver.c +++ b/src/vz/vz_driver.c @@ -4094,12 +4094,19 @@ vzStateCleanup(void) static int vzStateInitialize(bool privileged, + const char *root, virStateInhibitCallback callback G_GNUC_UNUSED, void *opaque G_GNUC_UNUSED) { if (!privileged) return VIR_DRV_STATE_INIT_SKIPPED; + if (root != NULL) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("Driver does not support embedded mode")); + return -1; + } + vz_driver_privileged = privileged; if (virFileMakePathWithMode(VZ_STATEDIR, S_IRWXU) < 0) { -- 2.23.0

This enables support for running QEMU embedded to the calling application process using a URI: qemu:///embed?root=/some/path Note that it is important to keep the path reasonably short to avoid risk of hitting the limit on UNIX socket path names which is 108 characters. When using the embedded mode with a root=/var/tmp/embed, the driver will use the following paths: logDir: /var/tmp/embed/log/qemu swtpmLogDir: /var/tmp/embed/log/swtpm configBaseDir: /var/tmp/embed/etc/qemu stateDir: /var/tmp/embed/run/qemu swtpmStateDir: /var/tmp/embed/run/swtpm cacheDir: /var/tmp/embed/cache/qemu libDir: /var/tmp/embed/lib/qemu swtpmStorageDir: /var/tmp/embed/lib/swtpm defaultTLSx509certdir: /var/tmp/embed/etc/pki/qemu These are identical whether the embedded driver is privileged or unprivileged. This compares with the system instance which uses logDir: /var/log/libvirt/qemu swtpmLogDir: /var/log/swtpm/libvirt/qemu configBaseDir: /etc/libvirt/qemu stateDir: /run/libvirt/qemu swtpmStateDir: /run/libvirt/qemu/swtpm cacheDir: /var/cache/libvirt/qemu libDir: /var/lib/libvirt/qemu swtpmStorageDir: /var/lib/libvirt/swtpm defaultTLSx509certdir: /etc/pki/qemu At this time all features present in the QEMU driver are available when running in embedded mode, availability matching whether the embedded driver is privileged or unprivileged. Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; --- docs/drvqemu.html.in | 84 +++++++++++++++++++++++++++++++++++++++++ src/qemu/qemu_conf.c | 38 +++++++++++++++++-- src/qemu/qemu_conf.h | 6 ++- src/qemu/qemu_driver.c | 26 +++++++------ src/qemu/qemu_process.c | 15 ++++++-- tests/domaincapstest.c | 2 +- tests/testutilsqemu.c | 3 +- 7 files changed, 151 insertions(+), 23 deletions(-) diff --git a/docs/drvqemu.html.in b/docs/drvqemu.html.in index 8beb28655c..1800369b7e 100644 --- a/docs/drvqemu.html.in +++ b/docs/drvqemu.html.in @@ -63,6 +63,90 @@ qemu+tcp://example.com/system (remote access, SASl/Kerberos) qemu+ssh://root@example.com/system (remote access, SSH tunnelled) </pre> + <h3><a id="uriembedded">Embedded driver</a></h3> + + <p> + Since 6.0.0 the QEMU driver has experimental support for operating + in an embedded mode. In this scenario, rather than connecting to + the libvirtd daemon, the QEMU driver runs in the client application + process directly. To use this the client application must have + registered &amp; be running an instance of the event loop. To open + the driver in embedded mode the app use the new URI path and specify + a virtual root directory under which the driver will create content. + </p> + + <pre> + qemu:///embed?root=/some/dir + </pre> + + <p> + Under the specified root directory the following locations will + be used + </p> + + <pre> +/some/dir + | + +- log + | | + | +- qemu + | +- swtpm + | + +- etc + | | + | +- qemu + | +- pki + | | + | +- qemu + | + +- run + | | + | +- qemu + | +- swtpm + | + +- cache + | | + | +- qemu + | + +- lib + | + +- qemu + +- swtpm + </pre> + + <p> + Note that UNIX domain sockets used for QEMU virtual machines had + a maximum filename length of 108 characters. Bear this in mind + when picking a root directory to avoid risk of exhausting the + filename space. The application is responsible for recursively + purging the contents of this directory tree once they no longer + require a connection, though it can also be left intact for reuse + when opening a future connection. + </p> + + <p> + Broadly speaking the range of functionality is intended to be + on a par with that seen when using the traditional system or + session libvirt connections to QEMU. The features will of course + differ depending on whether the application using the embedded + driver is running privileged or unprivileged. For example PCI + device assignment or TAP based networking are only available + when running privileged. While the embedded mode is still classed + as experimental some features may change their default settings + between releases. + </p> + + <p> + By default if the application uses any APIs associated with + secondary drivers, these will result in a connection being + opened to the corresponding driver in libvirtd. For example, + this allows a virtual machine from the embedded QEMU to connect + its NIC to a virtual network or connect its disk to a storage + volume. Some of the secondary drivers will also be able to support + running in embedded mode. Currently this is supported by the + secrets driver, to allow for use of VMs with encrypted disks + </p> + <h2><a id="security">Driver security architecture</a></h2> <p> diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c index c07a844dfc..048b15d1f6 100644 --- a/src/qemu/qemu_conf.c +++ b/src/qemu/qemu_conf.c @@ -104,7 +104,8 @@ qemuDriverUnlock(virQEMUDriverPtr driver) #endif -virQEMUDriverConfigPtr virQEMUDriverConfigNew(bool privileged) +virQEMUDriverConfigPtr virQEMUDriverConfigNew(bool privileged, + const char *root) { g_autoptr(virQEMUDriverConfig) cfg = NULL; @@ -130,7 +131,24 @@ virQEMUDriverConfigPtr virQEMUDriverConfigNew(bool privileged) cfg->cgroupControllers = -1; /* -1 == auto-detect */ - if (privileged) { + if (root != NULL) { + cfg->logDir = g_strdup_printf("%s/log/qemu", root); + cfg->swtpmLogDir = g_strdup_printf("%s/log/swtpm", root); + cfg->configBaseDir = g_strdup_printf("%s/etc", root); + cfg->stateDir = g_strdup_printf("%s/run/qemu", root); + cfg->swtpmStateDir = g_strdup_printf("%s/run/swtpm", root); + cfg->cacheDir = g_strdup_printf("%s/cache/qemu", root); + cfg->libDir = g_strdup_printf("%s/lib/qemu", root); + cfg->swtpmStorageDir = g_strdup_printf("%s/lib/swtpm", root); + + cfg->saveDir = g_strdup_printf("%s/save", cfg->libDir); + cfg->snapshotDir = g_strdup_printf("%s/snapshot", cfg->libDir); + cfg->checkpointDir = g_strdup_printf("%s/checkpoint", cfg->libDir); + cfg->autoDumpPath = g_strdup_printf("%s/dump", cfg->libDir); + cfg->channelTargetDir = g_strdup_printf("%s/channel/target", cfg->libDir); + cfg->nvramDir = g_strdup_printf("%s/nvram", cfg->libDir); + cfg->memoryBackingDir = g_strdup_printf("%s/ram", cfg->libDir); + } else if (privileged) { cfg->logDir = g_strdup_printf("%s/log/libvirt/qemu", LOCALSTATEDIR); cfg->swtpmLogDir = g_strdup_printf("%s/log/swtpm/libvirt/qemu", @@ -189,6 +207,16 @@ virQEMUDriverConfigPtr virQEMUDriverConfigNew(bool privileged) cfg->memoryBackingDir = g_strdup_printf("%s/qemu/ram", cfg->configBaseDir); cfg->swtpmStorageDir = g_strdup_printf("%s/qemu/swtpm", cfg->configBaseDir); + } + + if (privileged) { + if (!virDoesUserExist("tss") || + virGetUserID("tss", &cfg->swtpm_user) < 0) + cfg->swtpm_user = 0; /* fall back to root */ + if (!virDoesGroupExist("tss") || + virGetGroupID("tss", &cfg->swtpm_group) < 0) + cfg->swtpm_group = 0; /* fall back to root */ + } else { cfg->swtpm_user = (uid_t)-1; cfg->swtpm_group = (gid_t)-1; } @@ -201,7 +229,11 @@ virQEMUDriverConfigPtr virQEMUDriverConfigNew(bool privileged) * This will then be used as a fallback if the service specific * directory doesn't exist (although we don't check if this exists). */ - cfg->defaultTLSx509certdir = g_strdup(SYSCONFDIR "/pki/qemu"); + if (root == NULL) { + cfg->defaultTLSx509certdir = g_strdup(SYSCONFDIR "pki/qemu"); + } else { + cfg->defaultTLSx509certdir = g_strdup_printf("%s/etc/pki/qemu", root); + } cfg->vncListen = g_strdup(VIR_LOOPBACK_IPV4_ADDR); cfg->spiceListen = g_strdup(VIR_LOOPBACK_IPV4_ADDR); diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h index b9401635d7..9f370a8652 100644 --- a/src/qemu/qemu_conf.h +++ b/src/qemu/qemu_conf.h @@ -240,8 +240,9 @@ struct _virQEMUDriver { /* Atomic inc/dec only */ unsigned int nactive; - /* Immutable value */ + /* Immutable values */ bool privileged; + bool embedded; /* Immutable pointers. Caller must provide locking */ virStateInhibitCallback inhibitCallback; @@ -313,7 +314,8 @@ struct _virQEMUDriver { virHashAtomicPtr migrationErrors; }; -virQEMUDriverConfigPtr virQEMUDriverConfigNew(bool privileged); +virQEMUDriverConfigPtr virQEMUDriverConfigNew(bool privileged, + const char *root); int virQEMUDriverConfigLoadFile(virQEMUDriverConfigPtr cfg, const char *filename, diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 1e284dd90e..d4ae068d25 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -646,12 +646,6 @@ qemuStateInitialize(bool privileged, const char *defsecmodel = NULL; g_autofree virSecurityManagerPtr *sec_managers = NULL; - if (root != NULL) { - virReportError(VIR_ERR_INVALID_ARG, "%s", - _("Driver does not support embedded mode")); - return -1; - } - if (VIR_ALLOC(qemu_driver) < 0) return VIR_DRV_STATE_INIT_ERROR; @@ -669,6 +663,7 @@ qemuStateInitialize(bool privileged, qemu_driver->privileged = privileged; qemu_driver->hostarch = virArchFromHost(); + qemu_driver->embedded = root != NULL; if (!(qemu_driver->domains = virDomainObjListNew())) goto error; @@ -682,7 +677,7 @@ qemuStateInitialize(bool privileged, if (privileged) qemu_driver->hostsysinfo = virSysinfoRead(); - if (!(qemu_driver->config = cfg = virQEMUDriverConfigNew(privileged))) + if (!(qemu_driver->config = cfg = virQEMUDriverConfigNew(privileged, root))) goto error; if (!(driverConf = g_strdup_printf("%s/qemu.conf", cfg->configBaseDir))) @@ -1188,10 +1183,18 @@ static virDrvOpenStatus qemuConnectOpen(virConnectPtr conn, return VIR_DRV_OPEN_ERROR; } - if (!virConnectValidateURIPath(conn->uri->path, - "qemu", - virQEMUDriverIsPrivileged(qemu_driver))) - return VIR_DRV_OPEN_ERROR; + if (qemu_driver->embedded) { + if (STRNEQ(conn->uri->path, "/embed")) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("URI must be qemu:///embed")); + return VIR_DRV_OPEN_ERROR; + } + } else { + if (!virConnectValidateURIPath(conn->uri->path, + "qemu", + virQEMUDriverIsPrivileged(qemu_driver))) + return VIR_DRV_OPEN_ERROR; + } if (virConnectOpenEnsureACL(conn) < 0) return VIR_DRV_OPEN_ERROR; @@ -23141,6 +23144,7 @@ static virHypervisorDriver qemuHypervisorDriver = { static virConnectDriver qemuConnectDriver = { .localOnly = true, .uriSchemes = (const char *[]){ "qemu", NULL }, + .embeddable = true, .hypervisorDriver = &qemuHypervisorDriver, }; diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 7e1db50e8f..36c990dce6 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -6770,10 +6770,17 @@ qemuProcessLaunch(virConnectPtr conn, cfg = virQEMUDriverGetConfig(driver); - if ((flags & VIR_QEMU_PROCESS_START_AUTODESTROY) && !conn) { - virReportError(VIR_ERR_INTERNAL_ERROR, "%s", - _("Domain autodestroy requires a connection handle")); - return -1; + if (flags & VIR_QEMU_PROCESS_START_AUTODESTROY) { + if (!conn) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("Domain autodestroy requires a connection handle")); + return -1; + } + if (driver->embedded) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("Domain autodestroy not supported for embedded drivers yet")); + return -1; + } } hookData.vm = vm; diff --git a/tests/domaincapstest.c b/tests/domaincapstest.c index 9f5eab3230..fb803eaa47 100644 --- a/tests/domaincapstest.c +++ b/tests/domaincapstest.c @@ -369,7 +369,7 @@ mymain(void) #endif #if WITH_QEMU - virQEMUDriverConfigPtr cfg = virQEMUDriverConfigNew(false); + virQEMUDriverConfigPtr cfg = virQEMUDriverConfigNew(false, ""); if (!cfg) return EXIT_FAILURE; diff --git a/tests/testutilsqemu.c b/tests/testutilsqemu.c index f0c2dbf50e..280684086c 100644 --- a/tests/testutilsqemu.c +++ b/tests/testutilsqemu.c @@ -377,8 +377,7 @@ int qemuTestDriverInit(virQEMUDriver *driver) return -1; driver->hostarch = virArchFromHost(); - - driver->config = virQEMUDriverConfigNew(false); + driver->config = virQEMUDriverConfigNew(false, ""); if (!driver->config) goto error; -- 2.23.0

The previous "QEMU shim" proof of concept was taking an approach of only caring about initial spawning of the QEMU process. It was then registered with the libvirtd daemon who took over management of it. The intent was that later libvirtd would be refactored so that the shim retained control over the QEMU monitor and libvirt just forwarded APIs to each shim as needed. This forwarding of APIs would require quite alot of significant refactoring of libvirtd to achieve. This impl thus takes a quite different approach, explicitly deciding to keep the VMs completely separate from those seen & managed by libvirtd. Instead it uses the new "qemu:///embed" URI scheme to embed the entire QEMU driver in the shim, running with a custom root directory. Once the driver is initialization, the shim starts a VM and then waits to shutdown automatically when QEMU shuts down, or should kill QEMU if it is terminated itself. This ought to use the AUTO_DESTROY feature but that is not yet available in embedded mode, so we rely on installing a few signal handlers to gracefully kill QEMU. This isn't reliable if we crash of course, but you can restart with the same root dir. Note this program does not expose any way to manage the QEMU process, since there's no RPC interface enabled. It merely starts the VM and cleans up when the guest shuts down at the end. This program is installed to /usr/bin/virt-qemu-run enabling direct use by end users. Most use cases will probably want to integrate the concept directly into their respective application codebases. This standalone binary serves as a nice demo though, and also provides a way to measure performance of the startup process quite simply. Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; --- build-aux/syntax-check.mk | 2 +- docs/Makefile.am | 5 + docs/manpages/index.rst | 1 + docs/manpages/virt-qemu-run.rst | 114 +++++++++++ libvirt.spec.in | 2 + src/Makefile.am | 1 + src/qemu/Makefile.inc.am | 13 ++ src/qemu/qemu_shim.c | 322 ++++++++++++++++++++++++++++++++ 8 files changed, 459 insertions(+), 1 deletion(-) create mode 100644 docs/manpages/virt-qemu-run.rst create mode 100644 src/qemu/qemu_shim.c diff --git a/build-aux/syntax-check.mk b/build-aux/syntax-check.mk index 8abf1520ed..630b3f8033 100644 --- a/build-aux/syntax-check.mk +++ b/build-aux/syntax-check.mk @@ -2334,7 +2334,7 @@ exclude_file_name_regexp--sc_prohibit_devname = \ ^(tools/virsh.pod|build-aux/syntax-check\.mk|docs/.*)$$ exclude_file_name_regexp--sc_prohibit_virXXXFree = \ - ^(docs/|tests/|examples/|tools/|build-aux/syntax-check\.mk|src/test/test_driver.c|src/libvirt_public.syms|include/libvirt/libvirt-(domain|network|nodedev|storage|stream|secret|nwfilter|interface|domain-snapshot).h|src/libvirt-(domain|qemu|network|nodedev|storage|stream|secret|nwfilter|interface|domain-snapshot).c$$) + ^(docs/|tests/|examples/|tools/|build-aux/syntax-check\.mk|src/test/test_driver.c|src/libvirt_public.syms|include/libvirt/libvirt-(domain|network|nodedev|storage|stream|secret|nwfilter|interface|domain-snapshot).h|src/libvirt-(domain|qemu|network|nodedev|storage|stream|secret|nwfilter|interface|domain-snapshot).c|src/qemu/qemu_shim.c$$) exclude_file_name_regexp--sc_prohibit_sysconf_pagesize = \ ^(build-aux/syntax-check\.mk|src/util/virutil\.c)$$ diff --git a/docs/Makefile.am b/docs/Makefile.am index 66f164a1ac..6d593dfb62 100644 --- a/docs/Makefile.am +++ b/docs/Makefile.am @@ -248,6 +248,11 @@ if WITH_SANLOCK else ! WITH_SANLOCK manpages_rst += manpages/virt-sanlock-cleanup.rst endif ! WITH_SANLOCK +if WITH_QEMU + manpages1_rst += manpages/virt-qemu-run.rst +else ! WITH_QEMU + manpages_rst += manpages/virt-qemu-run.rst +endif ! WITH_QEMU manpages_rst_html_in = \ $(manpages_rst:%.rst=%.html.in) manpages_html = \ diff --git a/docs/manpages/index.rst b/docs/manpages/index.rst index 4945ad59e2..2e71f81962 100644 --- a/docs/manpages/index.rst +++ b/docs/manpages/index.rst @@ -19,6 +19,7 @@ Tools * `virt-login-shell(1) <virt-login-shell.html>`__ - tool to execute a shell within a container * `virt-admin(1) <virt-admin.html>`__ - daemon administration interface * `virsh(1) <virsh.html>`__ - management user interface +* `virt-qemu-run(1) <virt-qemu-run.html)`__ - run standalone QEMU instances Key codes ========= diff --git a/docs/manpages/virt-qemu-run.rst b/docs/manpages/virt-qemu-run.rst new file mode 100644 index 0000000000..7f66f7c3ab --- /dev/null +++ b/docs/manpages/virt-qemu-run.rst @@ -0,0 +1,114 @@ +============= +virt-qemu-run +============= + +--------------------------- +Run a standalone QEMU guest +--------------------------- + +:Manual section: 1 +:Manual group: Virtualization Support + +.. contents:: + +SYNOPSIS +======== + +``virt-qemu-run [OPTIONS...] [IGUEST-XML] + +DESCRIPTION +=========== + +This tool provides a way to run a standalone QEMU guest such that it +is completely independant of libvirtd. It makes use of the embedded +QEMU driver support to run the VM placing files under an isolated +directory tree. When the guest is run with this tool it is invisible +to libvirtd and thus also invisible to other libvirt tools such as +virsh. + +The virt-qemu-run program will run the QEMU virtual machine, and then +block until the guest OS shuts down, at which point it will exit. + +If the virt-qemu-run program is interrupted (eg Ctrl-C) it will +immediately terminate the virtual machine without giving the guest +OS any opportunity to gracefully shutdown. + +OPTIONS +======= + +``GUEST-XML`` + +The full path to the XML file describing the guest virtual machine +to be booted. + +``-h``, ``--help`` + +Display the command line help + +``-v``, ``--verbose`` + +Display verbose information about startup + +``-r DIR``, ``--root=DIR`` + +Specify the root directory to use for storing state associated with +the virtual machine. The caller is responsible for deleting this +directory when it is no longer required. + +If this parameter is omitted, then a random temporary directory +will be created, and its contents be automaticlaly deleted at +VM shutdown. + +``-s XML-FILE,VALUE-FILE``, ``--secret=XML-FILE,VALUE-FILE`` + +Specify a secret to be loaded into the secret driver. The ``XML-FILE`` +is a path to the XML description of the secret, whose UUID should +match a secret referenced in the guest domain XML. The ``VALUE-FILE`` +is a path containing the raw value of the secret. + +EXIT STATUS +=========== + +Upon successful shutdown, an exit status of 0 will be set. Upon +failure a non-zero status will be set. + +AUTHOR +====== + +Daniel P. Berrangé + + +BUGS +==== + +Please report all bugs you discover. This should be done via either: + +#. the mailing list + + `https://libvirt.org/contact.html <https://libvirt.org/contact.html>`_ + +#. the bug tracker + + `https://libvirt.org/bugs.html <https://libvirt.org/bugs.html>`_ + +Alternatively, you may report bugs to your software distributor / vendor. + + +COPYRIGHT +========= + +Copyright (C) 2019 by Red Hat, Inc. + + +LICENSE +======= + +``virt-run-qemu`` is distributed under the terms of the GNU LGPL v2+. +This is free software; see the source for copying conditions. There +is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR +PURPOSE + +SEE ALSO +======== + +virsh(1), `https://libvirt.org/ <https://libvirt.org/>`_ diff --git a/libvirt.spec.in b/libvirt.spec.in index 249a4b5425..1c0fc76f77 100644 --- a/libvirt.spec.in +++ b/libvirt.spec.in @@ -1758,6 +1758,8 @@ exit 0 %{_libdir}/%{name}/connection-driver/libvirt_driver_qemu.so %dir %attr(0711, root, root) %{_localstatedir}/lib/libvirt/swtpm/ %dir %attr(0711, root, root) %{_localstatedir}/log/swtpm/libvirt/qemu/ +%{_bindir}/virt-qemu-run +%{_mandir}/man1/virt-qemu-run.1* %endif %if %{with_lxc} diff --git a/src/Makefile.am b/src/Makefile.am index cd01796d67..a5a757c148 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -87,6 +87,7 @@ OPENRC_INIT_FILES_IN = OPENRC_CONF_FILES = SYSCONF_FILES = sbin_PROGRAMS = +bin_PROGRAMS = DRIVER_SOURCES = COMMON_UNIT_VARS = \ diff --git a/src/qemu/Makefile.inc.am b/src/qemu/Makefile.inc.am index 967f6e75a2..c6b04c3217 100644 --- a/src/qemu/Makefile.inc.am +++ b/src/qemu/Makefile.inc.am @@ -243,3 +243,16 @@ EXTRA_DIST += \ qemu/THREADS.txt \ libvirt_qemu_probes.d \ $(NULL) + +QEMU_SHIM_SOURCES = qemu/qemu_shim.c + +EXTRA_DIST += $(QEMU_SHIM_SOURCES) + +if WITH_QEMU +bin_PROGRAMS += virt-qemu-run + +virt_qemu_run_SOURCES = $(QEMU_SHIM_SOURCES) + +virt_qemu_run_LDADD = libvirt.la +virt_qemu_run_LDFLAGS = -Wl,--export-dynamic +endif WITH_QEMU diff --git a/src/qemu/qemu_shim.c b/src/qemu/qemu_shim.c new file mode 100644 index 0000000000..b10d95c996 --- /dev/null +++ b/src/qemu/qemu_shim.c @@ -0,0 +1,322 @@ +/* + * qemu_shim.c: standalone binary for running QEMU instances + * + * Copyright (C) 2019 Red Hat, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>;. + */ + +#include <config.h> + +#include <stdio.h> +#include <stdbool.h> + +#include "virfile.h" +#include "virstring.h" +#include "virgettext.h" + +#define VIR_FROM_THIS VIR_FROM_QEMU + +static bool eventQuitFlag; +static int eventQuitFD = -1; +static virDomainPtr dom; + +static void * +qemuShimEventLoop(void *opaque G_GNUC_UNUSED) +{ + while (!eventQuitFlag) + virEventRunDefaultImpl(); + + return NULL; +} + +/* Runs in event loop thread context */ +static void +qemuShimEventLoopStop(int watch G_GNUC_UNUSED, + int fd G_GNUC_UNUSED, + int event G_GNUC_UNUSED, + void *opaque G_GNUC_UNUSED) +{ + char c; + ignore_value(read(fd, &c, 1)); + eventQuitFlag = true; +} + +/* Runs in event loop thread context */ +static int +qemuShimDomShutdown(virConnectPtr econn G_GNUC_UNUSED, + virDomainPtr edom G_GNUC_UNUSED, + int event, + int detail G_GNUC_UNUSED, + void *opaque G_GNUC_UNUSED) +{ + if (event == VIR_DOMAIN_EVENT_STOPPED) + eventQuitFlag = true; + + return 0; +} + +/* Runs in unknown thread context */ +static void +qemuShimSigShutdown(int sig G_GNUC_UNUSED) +{ + if (dom) + virDomainDestroy(dom); + ignore_value(safewrite(eventQuitFD, "c", 1)); +} + +static void +qemuShimQuench(void *userData G_GNUC_UNUSED, + virErrorPtr error G_GNUC_UNUSED) +{ +} + +int main(int argc, char **argv) +{ + GThread *eventLoopThread = NULL; + virConnectPtr conn = NULL; + virConnectPtr sconn = NULL; + g_autofree char *xml = NULL; + g_autofree char *uri = NULL; + g_autofree char *suri = NULL; + char *root = NULL; + bool tmproot = false; + int ret = 1; + g_autoptr(GError) error = NULL; + g_auto(GStrv) secrets = NULL; + gboolean verbose = false; + gboolean debug = false; + GStrv tmpsecrets; + GOptionContext *ctx; + GOptionEntry entries[] = { + { "secret", 's', 0, G_OPTION_ARG_STRING_ARRAY, &secrets, "Load secret file", "SECRET-XML-FILE,SECRET-VALUE-FILE" }, + { "root", 'r', 0, G_OPTION_ARG_STRING, &root, "Root directory", "DIR"}, + { "debug", 'd', 0, G_OPTION_ARG_NONE, &debug, "Debug output", NULL }, + { "verbose", 'v', 0, G_OPTION_ARG_NONE, &verbose, "Verbose output", NULL }, + { NULL } + }; + int quitfd[2] = {-1, -1}; + long long start = g_get_monotonic_time(); + +#define deltams() ((long long)g_get_monotonic_time() - start) + + ctx = g_option_context_new("- run a standalone QEMU process"); + g_option_context_add_main_entries(ctx, entries, PACKAGE); + if (!g_option_context_parse(ctx, &argc, &argv, &error)) { + g_printerr("%s: option parsing failed: %s\n", + argv[0], error->message); + return 1; + } + + if (argc != 2) { + g_autofree char *help = g_option_context_get_help(ctx, TRUE, NULL); + g_printerr("%s", help); + return 1; + } + + if (verbose) + g_printerr("%s: %lld: initializing libvirt\n", + argv[0], deltams()); + + if (virInitialize() < 0) { + g_printerr("%s: cannot initialize libvirt\n", argv[0]); + return 1; + } + if (virGettextInitialize() < 0) { + g_printerr("%s: cannot initialize libvirt translations\n", argv[0]); + return 1; + } + + virSetErrorFunc(NULL, qemuShimQuench); + + if (verbose) + g_printerr("%s: %lld: initializing signal handlers\n", + argv[0], deltams()); + + signal(SIGTERM, qemuShimSigShutdown); + signal(SIGINT, qemuShimSigShutdown); + signal(SIGQUIT, qemuShimSigShutdown); + signal(SIGHUP, qemuShimSigShutdown); + + if (root == NULL) { + if (!(root = g_dir_make_tmp("libvirt-qemu-shim-XXXXXX", &error))) { + g_printerr("%s: cannot create temporary dir: %s\n", + argv[0], error->message); + return 1; + } + tmproot = true; + } + + virFileActivateDirOverrideForProg(argv[0]); + + if (verbose) + g_printerr("%s: %lld: preparing event loop thread\n", + argv[0], deltams()); + virEventRegisterDefaultImpl(); + + if (pipe(quitfd) < 0) { + g_printerr("%s: cannot create event loop pipe: %s", + argv[0], g_strerror(errno)); + goto cleanup; + } + + if (virEventAddHandle(quitfd[0], VIR_EVENT_HANDLE_READABLE, qemuShimEventLoopStop, NULL, NULL) < 0) { + VIR_FORCE_CLOSE(quitfd[0]); + VIR_FORCE_CLOSE(quitfd[1]); + quitfd[0] = quitfd[1] = -1; + g_printerr("%s: cannot register event loop handle: %s", + argv[0], virGetLastErrorMessage()); + goto cleanup; + } + eventQuitFD = quitfd[1]; + + eventLoopThread = g_thread_new("event-loop", qemuShimEventLoop, NULL); + + if (secrets && *secrets) { + suri = g_strdup_printf("secret:///embed?root=%s", root); + + if (verbose) + g_printerr("%s: %lld: opening %s\n", + argv[0], deltams(), suri); + + sconn = virConnectOpen(suri); + if (!sconn) { + g_printerr("%s: cannot open %s: %s\n", + argv[0], suri, virGetLastErrorMessage()); + goto cleanup; + } + + tmpsecrets = secrets; + while (tmpsecrets && *tmpsecrets) { + g_auto(GStrv) bits = g_strsplit(*tmpsecrets, ",", 2); + g_autofree char *sxml = NULL; + g_autofree char *value = NULL; + virSecretPtr sec; + size_t nvalue; + + if (!bits || bits[0] == NULL || bits[1] == NULL) { + g_printerr("%s: expected a pair of filenames for --secret argument\n", + argv[0]); + goto cleanup; + } + + if (verbose) + g_printerr("%s: %lld: loading secret %s and %s\n", + argv[0], deltams(), bits[0], bits[1]); + + if (!g_file_get_contents(bits[0], &sxml, NULL, &error)) { + g_printerr("%s: cannot read secret XML %s: %s\n", + argv[0], bits[0], error->message); + goto cleanup; + } + + if (!g_file_get_contents(bits[1], &value, &nvalue, &error)) { + g_printerr("%s: cannot read secret value %s: %s\n", + argv[0], bits[1], error->message); + goto cleanup; + } + + if (!(sec = virSecretDefineXML(sconn, sxml, 0))) { + g_printerr("%s: cannot define secret %s: %s\n", + argv[0], bits[0], virGetLastErrorMessage()); + goto cleanup; + } + + if (virSecretSetValue(sec, (unsigned char *)value, nvalue, 0) < 0) { + virSecretFree(sec); + g_printerr("%s: cannot set value for secret %s: %s\n", + argv[0], bits[0], virGetLastErrorMessage()); + goto cleanup; + } + virSecretFree(sec); + + tmpsecrets++; + } + } + + uri = g_strdup_printf("qemu:///embed?root=%s", root); + + if (verbose) + g_printerr("%s: %lld: opening %s\n", + argv[0], deltams(), uri); + + conn = virConnectOpen(uri); + if (!conn) { + g_printerr("%s: cannot open %s: %s\n", + argv[0], uri, virGetLastErrorMessage()); + goto cleanup; + } + + if (virConnectDomainEventRegisterAny( + conn, dom, VIR_DOMAIN_EVENT_ID_LIFECYCLE, + VIR_DOMAIN_EVENT_CALLBACK(qemuShimDomShutdown), + NULL, NULL) < 0) { + g_printerr("%s: cannot regiser for lifecycle events: %s\n", + argv[0], virGetLastErrorMessage()); + goto cleanup; + } + + if (verbose) + g_printerr("%s: %lld: starting guest %s\n", + argv[0], deltams(), argv[1]); + + if (!g_file_get_contents(argv[1], &xml, NULL, &error)) { + g_printerr("%s: cannot read %s: %s\n", + argv[0], argv[1], error->message); + goto cleanup; + } + + dom = virDomainCreateXML(conn, xml, 0); + if (!dom) { + g_printerr("%s: cannot start VM: %s\n", + argv[0], virGetLastErrorMessage()); + goto cleanup; + } + if (verbose) + g_printerr("%s: %lld: guest running, Ctrl-C to stop nowbbbb\n", + argv[0], deltams()); + + if (debug) { + g_autofree char *newxml = NULL; + newxml = virDomainGetXMLDesc(dom, 0); + g_printerr("%s: XML: %s\n", argv[0], newxml); + } + + ret = 0; + + cleanup: + if (ret != 0 && eventQuitFD != -1) + ignore_value(safewrite(eventQuitFD, "c", 1)); + + if (eventLoopThread != NULL && (ret == 0 || eventQuitFD != -1)) + g_thread_join(eventLoopThread); + + VIR_FORCE_CLOSE(quitfd[0]); + VIR_FORCE_CLOSE(quitfd[1]); + + if (dom != NULL) + virDomainFree(dom); + if (sconn != NULL) + virConnectClose(sconn); + if (conn != NULL) + virConnectClose(conn); + if (tmproot) + virFileDeleteTree(root); + + if (verbose) + g_printerr("%s: %lld: cleaned up, exiting\n", + argv[0], deltams()); + return ret; +} -- 2.23.0