Allow drivers to be run against a different virtual root directory. The intent here is to allow the virt drivers to be run directly embedded in an arbitrary process without interfering with libvirtd. 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 an application like libguestfs which doesn't want its VMs to show up in the main libvirtd VM list. XXX make drivers reject root != "" until they are ported to support it. Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; --- src/driver-state.h | 1 + src/interface/interface_backend_netcf.c | 1 + src/interface/interface_backend_udev.c | 1 + src/libvirt.c | 2 ++ src/libvirt_internal.h | 1 + src/libxl/libxl_driver.c | 1 + src/lxc/lxc_driver.c | 2 ++ src/network/bridge_driver.c | 1 + src/node_device/node_device_hal.c | 1 + src/node_device/node_device_udev.c | 1 + src/nwfilter/nwfilter_driver.c | 1 + src/qemu/qemu_driver.c | 1 + src/remote/remote_daemon.c | 1 + src/remote/remote_driver.c | 1 + src/secret/secret_driver.c | 1 + src/storage/storage_driver.c | 1 + src/vz/vz_driver.c | 1 + 17 files changed, 19 insertions(+) diff --git a/src/driver-state.h b/src/driver-state.h index a8595662af..68bbf75e06 100644 --- a/src/driver-state.h +++ b/src/driver-state.h @@ -27,6 +27,7 @@ typedef int (*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 cf8eb9488d..e9a0fee606 100644 --- a/src/interface/interface_backend_netcf.c +++ b/src/interface/interface_backend_netcf.c @@ -76,6 +76,7 @@ virNetcfDriverStateDispose(void *obj) static int netcfStateInitialize(bool privileged, + const char *root ATTRIBUTE_UNUSED, virStateInhibitCallback callback ATTRIBUTE_UNUSED, void *opaque ATTRIBUTE_UNUSED) { diff --git a/src/interface/interface_backend_udev.c b/src/interface/interface_backend_udev.c index 1373356246..7c315c315a 100644 --- a/src/interface/interface_backend_udev.c +++ b/src/interface/interface_backend_udev.c @@ -1159,6 +1159,7 @@ udevInterfaceIsActive(virInterfacePtr ifinfo) static int udevStateInitialize(bool privileged, + const char *root ATTRIBUTE_UNUSED, virStateInhibitCallback callback ATTRIBUTE_UNUSED, void *opaque ATTRIBUTE_UNUSED) { diff --git a/src/libvirt.c b/src/libvirt.c index 7e665b6cba..677f1cef5f 100644 --- a/src/libvirt.c +++ b/src/libvirt.c @@ -638,6 +638,7 @@ virRegisterStateDriver(virStateDriverPtr driver) */ int virStateInitialize(bool privileged, + const char *root, virStateInhibitCallback callback, void *opaque) { @@ -651,6 +652,7 @@ virStateInitialize(bool privileged, VIR_DEBUG("Running global init for %s state driver", virStateDriverTab[i]->name); if (virStateDriverTab[i]->stateInitialize(privileged, + root, callback, opaque) < 0) { VIR_ERROR(_("Initialization of %s state driver failed: %s"), diff --git a/src/libvirt_internal.h b/src/libvirt_internal.h index 8be1257814..c3964d4c38 100644 --- a/src/libvirt_internal.h +++ b/src/libvirt_internal.h @@ -31,6 +31,7 @@ typedef void (*virStateInhibitCallback)(bool inhibit, void *opaque); int virStateInitialize(bool privileged, + const char *root, virStateInhibitCallback inhibit, void *opaque); int virStateCleanup(void); diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c index 2b9c6f1866..59e0d7229d 100644 --- a/src/libxl/libxl_driver.c +++ b/src/libxl/libxl_driver.c @@ -633,6 +633,7 @@ libxlAddDom0(libxlDriverPrivatePtr driver) static int libxlStateInitialize(bool privileged, + const char *root ATTRIBUTE_UNUSED, virStateInhibitCallback callback ATTRIBUTE_UNUSED, void *opaque ATTRIBUTE_UNUSED) { diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c index 9db2a02dee..6d0d3a8ace 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 ATTRIBUTE_UNUSED, virStateInhibitCallback callback, void *opaque); static int lxcStateCleanup(void); @@ -1536,6 +1537,7 @@ lxcSecurityInit(virLXCDriverConfigPtr cfg) static int lxcStateInitialize(bool privileged, + const char *root ATTRIBUTE_UNUSED, virStateInhibitCallback callback ATTRIBUTE_UNUSED, void *opaque ATTRIBUTE_UNUSED) { diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c index 26f7f80418..ca9deaab4b 100644 --- a/src/network/bridge_driver.c +++ b/src/network/bridge_driver.c @@ -588,6 +588,7 @@ firewalld_dbus_filter_bridge(DBusConnection *connection ATTRIBUTE_UNUSED, */ static int networkStateInitialize(bool privileged, + const char *root ATTRIBUTE_UNUSED, virStateInhibitCallback callback ATTRIBUTE_UNUSED, void *opaque ATTRIBUTE_UNUSED) { diff --git a/src/node_device/node_device_hal.c b/src/node_device/node_device_hal.c index d1eb6c7851..7b11d4d7f7 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 ATTRIBUTE_UNUSED, static int nodeStateInitialize(bool privileged ATTRIBUTE_UNUSED, + const char *root ATTRIBUTE_UNUSED, virStateInhibitCallback callback ATTRIBUTE_UNUSED, void *opaque ATTRIBUTE_UNUSED) { diff --git a/src/node_device/node_device_udev.c b/src/node_device/node_device_udev.c index 5df2fd72f3..2d772d85c3 100644 --- a/src/node_device/node_device_udev.c +++ b/src/node_device/node_device_udev.c @@ -1800,6 +1800,7 @@ udevPCITranslateInit(bool privileged ATTRIBUTE_UNUSED) static int nodeStateInitialize(bool privileged, + const char *root ATTRIBUTE_UNUSED, virStateInhibitCallback callback ATTRIBUTE_UNUSED, void *opaque ATTRIBUTE_UNUSED) { diff --git a/src/nwfilter/nwfilter_driver.c b/src/nwfilter/nwfilter_driver.c index fdfc6f48fa..58adcdbeb1 100644 --- a/src/nwfilter/nwfilter_driver.c +++ b/src/nwfilter/nwfilter_driver.c @@ -176,6 +176,7 @@ virNWFilterTriggerRebuildImpl(void *opaque) */ static int nwfilterStateInitialize(bool privileged, + const char *root ATTRIBUTE_UNUSED, virStateInhibitCallback callback ATTRIBUTE_UNUSED, void *opaque ATTRIBUTE_UNUSED) { diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 0a425b82e5..659d7b89e1 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -574,6 +574,7 @@ qemuDomainFindMaxID(virDomainObjPtr vm, */ static int qemuStateInitialize(bool privileged, + const char *root ATTRIBUTE_UNUSED, virStateInhibitCallback callback, void *opaque) { diff --git a/src/remote/remote_daemon.c b/src/remote/remote_daemon.c index c3782971f1..2e47263bb9 100644 --- a/src/remote/remote_daemon.c +++ b/src/remote/remote_daemon.c @@ -796,6 +796,7 @@ static void daemonRunStateInit(void *opaque) * we're ready, since it can take a long time and this will * seriously delay OS bootup process */ if (virStateInitialize(virNetDaemonIsPrivileged(dmn), + "", daemonInhibitCallback, dmn) < 0) { VIR_ERROR(_("Driver state initialization failed")); diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index 5c4dd41227..244e384607 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -184,6 +184,7 @@ static int remoteSplitURIScheme(virURIPtr uri, static int remoteStateInitialize(bool privileged ATTRIBUTE_UNUSED, + const char *root ATTRIBUTE_UNUSED, virStateInhibitCallback callback ATTRIBUTE_UNUSED, void *opaque ATTRIBUTE_UNUSED) { diff --git a/src/secret/secret_driver.c b/src/secret/secret_driver.c index ac85f5d195..1b4826e597 100644 --- a/src/secret/secret_driver.c +++ b/src/secret/secret_driver.c @@ -444,6 +444,7 @@ secretStateCleanup(void) static int secretStateInitialize(bool privileged, + const char *root ATTRIBUTE_UNUSED, virStateInhibitCallback callback ATTRIBUTE_UNUSED, void *opaque ATTRIBUTE_UNUSED) { diff --git a/src/storage/storage_driver.c b/src/storage/storage_driver.c index 496d51b1e0..a13eabf134 100644 --- a/src/storage/storage_driver.c +++ b/src/storage/storage_driver.c @@ -247,6 +247,7 @@ storageDriverAutostart(void) */ static int storageStateInitialize(bool privileged, + const char *root ATTRIBUTE_UNUSED, virStateInhibitCallback callback ATTRIBUTE_UNUSED, void *opaque ATTRIBUTE_UNUSED) { diff --git a/src/vz/vz_driver.c b/src/vz/vz_driver.c index dfd49e7cc7..92a9cfeaac 100644 --- a/src/vz/vz_driver.c +++ b/src/vz/vz_driver.c @@ -4096,6 +4096,7 @@ vzStateCleanup(void) static int vzStateInitialize(bool privileged ATTRIBUTE_UNUSED, + const char *root ATTRIBUTE_UNUSED, virStateInhibitCallback callback ATTRIBUTE_UNUSED, void *opaque ATTRIBUTE_UNUSED) { -- 2.21.0

The driver URI: "qemu:///embed?root=/some/path" enables a new way to use the QEMU driver by embedding it directly in the calling process. To use this the process must have a thread running the libvirt event loop. This URI will then cause libvirt to dynamically load the QEMU driver module and call its global initialization function. The application can now make normal libvirt API calls which are all serviced in-process with no RPC layer involved. To avoid conflicting with the existing libvirtd daemon it is important to specify an alternative root directory. All the paths the QEMU driver normal creates will be placed under this root. For example using the path /home/berrange/tmp/embed, as an unprivileged process cause the creation of the following directories /home/berrange/tmp/embed/home/berrange/.config/libvirt/qemu/lib /home/berrange/tmp/embed/home/berrange/.config/libvirt/qemu/snapshot /home/berrange/tmp/embed/home/berrange/.config/libvirt/qemu/save /home/berrange/tmp/embed/home/berrange/.config/libvirt/qemu/channel/target /home/berrange/tmp/embed/home/berrange/.config/libvirt/qemu/ram/libvirt /home/berrange/tmp/embed/home/berrange/.config/libvirt/qemu/ram/libvirt/qemu /home/berrange/tmp/embed/home/berrange/.config/libvirt/qemu/nvram /home/berrange/tmp/embed/home/berrange/.config/libvirt/qemu/dump /home/berrange/tmp/embed/home/berrange/.cache/libvirt/qemu/cache/capabilities /home/berrange/tmp/embed/home/berrange/.cache/libvirt/qemu/log /home/berrange/tmp/embed/run/user/501/libvirt/qemu/run The application is responsible for purging everything underneath this root directory when no longer required. Note that QEMU is still daemonized right now and so the application embedding the QEMU driver can quit & restart and still have its VMs present, just as libvirtd would. A future patch will hook up VIR_DOMAIN_CREATE_AUTO_DESTROY flag such that the VM are not daemonized and still retain the parent/child relationship forcing them to die the the application exits. Thanks to previous refactoring, it is still possible to use functionality that calls out to other secondary drivers. For example it can open the network, secret or storage drivers. The network driver stuff is not fully functional though until the pending refactoring is done to introduce the virNetworkPort object concept. A key thing to note is that for this to work, the application that links to libvirt *MUST* be built with -Wl,--export-dynamic to ensure that symbols from libvirt.so are exported & thus available to the dynamically loaded QEMU driver module. If libvirt.so itself was dynamically loaded then RTLD_GLOBAL must be passed to dlopen(). Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; --- src/libvirt.c | 39 +++++++++++++++++++++++++++++++++++++- src/qemu/qemu_driver.c | 6 ++++-- src/remote/remote_driver.c | 7 +++++++ 3 files changed, 49 insertions(+), 3 deletions(-) diff --git a/src/libvirt.c b/src/libvirt.c index 677f1cef5f..e34fd5c96d 100644 --- a/src/libvirt.c +++ b/src/libvirt.c @@ -87,6 +87,7 @@ #ifdef WITH_BHYVE # include "bhyve/bhyve_driver.h" #endif +#include "access/viraccessmanager.h" #define VIR_FROM_THIS VIR_FROM_NONE @@ -841,6 +842,7 @@ virConnectOpenInternal(const char *name, virConnectPtr ret; virConfPtr conf = NULL; char *uristr = NULL; + bool embed = false; ret = virGetConnect(); if (ret == NULL) @@ -939,6 +941,36 @@ virConnectOpenInternal(const char *name, ret->uri) < 0) { goto failed; } + + if (STREQ(ret->uri->scheme, "qemu") && + STREQ(ret->uri->path, "/embed")) { + const char *root = NULL; + for (i = 0; i < ret->uri->paramsCount; i++) { + virURIParamPtr var = &ret->uri->params[i]; + if (STREQ(var->name, "root")) + root = var->value; + } + + if (!root) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("root parameter required for embedded driver")); + goto failed; + } + + if (virDriverLoadModule("qemu", "qemuRegister", false) < 0) + goto failed; + + if (virAccessManagerGetDefault() == NULL) { + virAccessManagerPtr acl; + acl = virAccessManagerNew("none"); + virAccessManagerSetDefault(acl); + } + + if (virStateInitialize(geteuid() == 0, root, NULL, NULL) < 0) + goto failed; + + embed = true; + } } else { VIR_DEBUG("no name, allowing driver auto-select"); } @@ -1011,7 +1043,12 @@ virConnectOpenInternal(const char *name, continue; } } else { - VIR_DEBUG("Matching any URI scheme for '%s'", ret->uri ? ret->uri->scheme : ""); + if (embed) { + VIR_DEBUG("Skipping wildcard for embedded URI"); + continue; + } else { + VIR_DEBUG("Matching any URI scheme for '%s'", ret->uri ? ret->uri->scheme : ""); + } } /* before starting the new connection, check if the driver only works diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 019f6b2bf3..cdd483a338 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -1105,14 +1105,16 @@ static virDrvOpenStatus qemuConnectOpen(virConnectPtr conn, if (virQEMUDriverIsPrivileged(qemu_driver)) { if (STRNEQ(conn->uri->path, "/system") && - STRNEQ(conn->uri->path, "/session")) { + STRNEQ(conn->uri->path, "/session") && + STRNEQ(conn->uri->path, "/embed")) { virReportError(VIR_ERR_INTERNAL_ERROR, _("unexpected QEMU URI path '%s', try qemu:///system"), conn->uri->path); return VIR_DRV_OPEN_ERROR; } } else { - if (STRNEQ(conn->uri->path, "/session")) { + if (STRNEQ(conn->uri->path, "/session") && + STRNEQ(conn->uri->path, "/embed")) { virReportError(VIR_ERR_INTERNAL_ERROR, _("unexpected QEMU URI path '%s', try qemu:///session"), conn->uri->path); diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index 244e384607..976f311060 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -1343,6 +1343,13 @@ remoteConnectOpen(virConnectPtr conn, if (flags & VIR_CONNECT_RO) rflags |= VIR_DRV_OPEN_REMOTE_RO; + if (conn->uri && + conn->uri->path && + STREQ(conn->uri->path, "/embed")) { + ret = VIR_DRV_OPEN_DECLINED; + goto cleanup; + } + /* * If no servername is given, and no +XXX * transport is listed, or transport is unix, -- 2.21.0