Re: [PATCH 1/5] lib: Introduce 'virDomainQemuMonitorCommandWithFiles'

This API has the same semantics as 'virDomainQemuMonitorCommand' but accepts file descriptors which are then forwarded to qemu. Signed-off-by: Peter Krempa <pkrempa(a)redhat.com&gt; --- include/libvirt/libvirt-qemu.h | 6 +++ src/driver-hypervisor.h | 8 ++++ src/libvirt-qemu.c | 71 +++++++++++++++++++++++++++++ src/libvirt_qemu.syms | 5 ++ src/qemu_protocol-structs | 9 ++++ src/remote/qemu_protocol.x | 20 +++++++- src/remote/remote_daemon_dispatch.c | 42 +++++++++++++++++ src/remote/remote_driver.c | 40 ++++++++++++++++ 8 files changed, 200 insertions(+), 1 deletion(-) diff --git a/include/libvirt/libvirt-qemu.h b/include/libvirt/libvirt-qemu.h index 0cc2872821..eed691ec91 100644 --- a/include/libvirt/libvirt-qemu.h +++ b/include/libvirt/libvirt-qemu.h @@ -37,6 +37,12 @@ typedef enum { int virDomainQemuMonitorCommand(virDomainPtr domain, const char *cmd, char **result, unsigned int flags); +int virDomainQemuMonitorCommandWithFiles(virDomainPtr domain, + const char *cmd, + unsigned int nfiles, + int *files,

+ char **result, + unsigned int flags); virDomainPtr virDomainQemuAttach(virConnectPtr domain, unsigned int pid_value, diff --git a/src/driver-hypervisor.h b/src/driver-hypervisor.h index c83fb648a2..b3e55cf4ac 100644 --- a/src/driver-hypervisor.h +++ b/src/driver-hypervisor.h @@ -874,6 +874,13 @@ typedef int const char *cmd, char **result, unsigned int flags); +typedef int +(*virDrvDomainQemuMonitorCommandWithFiles)(virDomainPtr domain, + const char *cmd, + unsigned int nfiles, + int *files, + char **result, + unsigned int flags); typedef char * (*virDrvDomainQemuAgentCommand)(virDomainPtr domain, @@ -1597,6 +1604,7 @@ struct _virHypervisorDriver { virDrvDomainRevertToSnapshot domainRevertToSnapshot; virDrvDomainSnapshotDelete domainSnapshotDelete; virDrvDomainQemuMonitorCommand domainQemuMonitorCommand; + virDrvDomainQemuMonitorCommandWithFiles domainQemuMonitorCommandWithFiles; virDrvDomainQemuAttach domainQemuAttach; virDrvDomainQemuAgentCommand domainQemuAgentCommand; virDrvConnectDomainQemuMonitorEventRegister connectDomainQemuMonitorEventRegister; diff --git a/src/libvirt-qemu.c b/src/libvirt-qemu.c index 1afb5fe529..1dbe0cba54 100644 --- a/src/libvirt-qemu.c +++ b/src/libvirt-qemu.c @@ -96,6 +96,77 @@ virDomainQemuMonitorCommand(virDomainPtr domain, const char *cmd, } +/** + * virDomainQemuMonitorCommandWithFiles: + * @domain: a domain object + * @cmd: the qemu monitor command string + * @nfiles: number of filedescriptors passed in @files + * @files: filedescriptors to be passed to qemu with the command + * @result: a string returned by @cmd + * @flags: bitwise-or of supported virDomainQemuMonitorCommandFlags + * + * This API is QEMU specific, so it will only work with hypervisor + * connections to the QEMU driver with local connections using the unix socket. + * + * Send an arbitrary monitor command @cmd with file descriptors @files to + * @domain through the qemu monitor. There are several requirements to safely + * and successfully use this API: + * + * - A @cmd that queries state without making any modifications is safe + * - A @cmd that alters state that is also tracked by libvirt is unsafe, + * and may cause libvirtd to crash + * - A @cmd that alters state not tracked by the current version of + * libvirt is possible as a means to test new qemu features before + * they have support in libvirt, but no guarantees are made to safety + * + * If VIR_DOMAIN_QEMU_MONITOR_COMMAND_HMP is set, the command is + * considered to be a human monitor command and libvirt will automatically + * convert it into QMP if needed. In that case the @result will also + * be converted back from QMP. + * + * If successful, @result will be filled with the string output of the + * @cmd, and the caller must free this string. + * + * Returns 0 in case of success, -1 in case of failure + */ +int +virDomainQemuMonitorCommandWithFiles(virDomainPtr domain, + const char *cmd, + unsigned int nfiles, + int *files, + char **result, + unsigned int flags) +{ + virConnectPtr conn; + + VIR_DOMAIN_DEBUG(domain, "cmd=%s, nfiles=%u, files=%p, result=%p, flags=0x%x", + cmd, nfiles, files, result, flags); + + virResetLastError(); + + virCheckDomainReturn(domain, -1); + conn = domain->conn; + + virCheckNonNullArgGoto(result, error); + virCheckReadOnlyGoto(conn->flags, error);

+ + if (conn->driver->domainQemuMonitorCommandWithFiles) { + int ret; + ret = conn->driver->domainQemuMonitorCommandWithFiles(domain, cmd, + nfiles, files, + result, flags); + if (ret < 0) + goto error; + return ret; + } + + virReportUnsupportedError(); + + error: + virDispatchError(conn); + return -1; +}