On 2/3/22 15:51, Peter Krempa wrote:
> This API has the same semantics as 'virDomainQemuMonitorCommand' but
> accepts file descriptors which are then forwarded to qemu.
>
> Signed-off-by: Peter Krempa <pkrempa@xxxxxxxxxx>
> ---
> 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,
Do we perhaps want to have another argument for fdOut (e.g. when QEMU
would want to return an FD)? I don't think there is a command that would
do that now, but who knows, maybe there will be someday.
> + 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);
Missing VIR_DRV_SUPPORTS_FEATURE(conn->driver, conn,
VIR_DRV_FEATURE_FD_PASSING); check.
> +
> + 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;
> +}
Michal
