Re: [libvirt] [PATCH 3/5] qemu: add a public API to trigger QEMU driver to connect to running guest

Currently the QEMU driver will reconnect to running guests during libvirtd startup. To support the ability to launch a fully supported guest externally to the main libvirtd daemon, this adds a QEMU specific public API virDomainQemuReconnect(conn, name, flags); This accepts a domain name, and simply runs the normal reconnect logic that the QEMU driver would do at startup. Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; --- include/libvirt/libvirt-qemu.h | 4 ++++ src/driver-hypervisor.h | 5 +++++ src/libvirt-qemu.c | 48 ++++++++++++++++++++++++++++++++++++++++++ src/libvirt_qemu.syms | 5 +++++ src/remote/qemu_protocol.x | 18 +++++++++++++++- src/remote/remote_driver.c | 1 + 6 files changed, 80 insertions(+), 1 deletion(-)

diff --git a/include/libvirt/libvirt-qemu.h b/include/libvirt/libvirt-qemu.h index 2bb8ee8685..0d38d2f9f8 100644 --- a/include/libvirt/libvirt-qemu.h +++ b/include/libvirt/libvirt-qemu.h @@ -44,6 +44,10 @@ virDomainPtr virDomainQemuAttach(virConnectPtr domain, unsigned int pid_value, unsigned int flags); +virDomainPtr virDomainQemuReconnect(virConnectPtr domain, + const char *name, + unsigned int flags); + typedef enum { VIR_DOMAIN_QEMU_AGENT_COMMAND_MIN = -2, VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK = -2, diff --git a/src/driver-hypervisor.h b/src/driver-hypervisor.h index ce0e2b2525..2e923e730f 100644 --- a/src/driver-hypervisor.h +++ b/src/driver-hypervisor.h @@ -848,6 +848,10 @@ typedef virDomainPtr (*virDrvDomainQemuAttach)(virConnectPtr conn, unsigned int pid_value, unsigned int flags); +typedef virDomainPtr +(*virDrvDomainQemuReconnect)(virConnectPtr conn, + const char *name, + unsigned int flags); typedef int (*virDrvConnectDomainQemuMonitorEventRegister)(virConnectPtr conn, @@ -1463,6 +1467,7 @@ struct _virHypervisorDriver { virDrvDomainSnapshotDelete domainSnapshotDelete; virDrvDomainQemuMonitorCommand domainQemuMonitorCommand; virDrvDomainQemuAttach domainQemuAttach; + virDrvDomainQemuReconnect domainQemuReconnect; virDrvDomainQemuAgentCommand domainQemuAgentCommand; virDrvConnectDomainQemuMonitorEventRegister connectDomainQemuMonitorEventRegister; virDrvConnectDomainQemuMonitorEventDeregister connectDomainQemuMonitorEventDeregister; diff --git a/src/libvirt-qemu.c b/src/libvirt-qemu.c index 43f63839eb..c5859cf312 100644 --- a/src/libvirt-qemu.c +++ b/src/libvirt-qemu.c @@ -164,6 +164,54 @@ virDomainQemuAttach(virConnectPtr conn, return NULL; } +/** + * virDomainQemuReconnect: + * @conn: pointer to a hypervisor connection + * @name: the libvirt guest name + * @flags: optional flags, currently unused + * + * This API is QEMU specific, so it will only work with hypervisor + * connections to the QEMU driver. + * + * This API will attach to an QEMU process that a separate libvirt + * helper has launched. The external QEMU must fully follow the + * normal libvirt QEMU configuration. + * + * If successful, then the guest will appear in the list of running + * domains for this connection, and other APIs should operate + * normally (provided the above requirements were honored). + * + * Returns a new domain object on success, NULL otherwise + */ +virDomainPtr +virDomainQemuReconnect(virConnectPtr conn, + const char *name, + unsigned int flags) +{ + VIR_DEBUG("conn=%p, name=%s, flags=0x%x", conn, name, flags); + + virResetLastError(); + + virCheckConnectReturn(conn, NULL); + virCheckNonNullArgGoto(name, error); + + virCheckReadOnlyGoto(conn->flags, error); + + if (conn->driver->domainQemuReconnect) { + virDomainPtr ret; + ret = conn->driver->domainQemuReconnect(conn, name, flags); + if (!ret) + goto error; + return ret; + } + + virReportUnsupportedError(); + + error: + virDispatchError(conn); + return NULL; +} + /** * virDomainQemuAgentCommand: diff --git a/src/libvirt_qemu.syms b/src/libvirt_qemu.syms index 3a297e3a2b..a109fcc0d0 100644 --- a/src/libvirt_qemu.syms +++ b/src/libvirt_qemu.syms @@ -30,3 +30,8 @@ LIBVIRT_QEMU_1.2.3 { virConnectDomainQemuMonitorEventDeregister; virConnectDomainQemuMonitorEventRegister; } LIBVIRT_QEMU_0.10.0; + +LIBVIRT_QEMU_4.1.0 { + global: + virDomainQemuReconnect; +} LIBVIRT_QEMU_1.2.3; diff --git a/src/remote/qemu_protocol.x b/src/remote/qemu_protocol.x index f6b88a984c..b5307bf9dd 100644 --- a/src/remote/qemu_protocol.x +++ b/src/remote/qemu_protocol.x @@ -82,6 +82,15 @@ struct qemu_domain_monitor_event_msg { remote_string details; }; +struct qemu_domain_reconnect_args { + remote_nonnull_string name; + unsigned int flags; +}; + +struct qemu_domain_reconnect_ret { + remote_nonnull_domain dom; +}; + /* Define the program number, protocol version and procedure numbers here. */ const QEMU_PROGRAM = 0x20008087; const QEMU_PROTOCOL_VERSION = 1; @@ -154,5 +163,12 @@ enum qemu_procedure { * @generate: both * @acl: none */ - QEMU_PROC_DOMAIN_MONITOR_EVENT = 6 + QEMU_PROC_DOMAIN_MONITOR_EVENT = 6, + + /** + * @generate: both + * @acl: domain:start + * @acl: domain:write + */ + QEMU_PROC_DOMAIN_RECONNECT = 7 }; diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index f8fa64af99..b76242fe2e 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -8431,6 +8431,7 @@ static virHypervisorDriver hypervisor_driver = { .domainSnapshotDelete = remoteDomainSnapshotDelete, /* 0.8.0 */ .domainQemuMonitorCommand = remoteDomainQemuMonitorCommand, /* 0.8.3 */ .domainQemuAttach = remoteDomainQemuAttach, /* 0.9.4 */ + .domainQemuReconnect = remoteDomainQemuReconnect, /* 4.1.0 */ .domainQemuAgentCommand = remoteDomainQemuAgentCommand, /* 0.10.0 */ .connectDomainQemuMonitorEventRegister = remoteConnectDomainQemuMonitorEventRegister, /* 1.2.3 */ .connectDomainQemuMonitorEventDeregister = remoteConnectDomainQemuMonitorEventDeregister, /* 1.2.3 */