libvirt/src/qemu/qemu_vhost_user_gpu.c

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/*
* qemu_vhost_user_gpu.c: QEMU vhost-user GPU support
*
* 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 "qemu_vhost_user_gpu.h"
#include "qemu_vhost_user.h"
#include "qemu_extdevice.h"
#include "conf/domain_conf.h"
#include "configmake.h"
#include "vircommand.h"
#include "viralloc.h"
#include "virlog.h"
#include "virfile.h"
#include "virstring.h"
#include "virtime.h"
#include "virpidfile.h"
#define VIR_FROM_THIS VIR_FROM_NONE
VIR_LOG_INIT("qemu.vhost_user_gpu");
static char *
qemuVhostUserGPUCreatePidFilename(const char *stateDir,
const char *shortName,
const char *alias)
{
g_autofree char *devicename = NULL;
devicename = g_strdup_printf("%s-%s-vhost-user-gpu", shortName, alias);
return virPidFileBuildPath(stateDir, devicename);
}
/*
* qemuVhostUserGPUGetPid:
* @binpath: path of executable associated with the pidfile
* @stateDir: the directory where vhost-user-gpu writes the pidfile into
* @shortName: short name of the domain
* @alias: video device alias
* @pid: pointer to pid
*
* Return -1 upon error, or zero on successful reading of the pidfile.
* If the PID was not still alive, zero will be returned, and @pid will be
* set to -1;
*/
static int
qemuVhostUserGPUGetPid(const char *binPath,
const char *stateDir,
const char *shortName,
const char *alias,
pid_t *pid)
{
g_autofree char *pidfile = NULL;
if (!(pidfile = qemuVhostUserGPUCreatePidFilename(stateDir, shortName, alias)))
return -1;
if (virPidFileReadPathIfAlive(pidfile, pid, binPath) < 0)
return -1;
return 0;
}
int qemuExtVhostUserGPUPrepareDomain(virQEMUDriverPtr driver,
virDomainVideoDefPtr video)
{
return qemuVhostUserFillDomainGPU(driver, video);
}
/*
* qemuExtVhostUserGPUStart:
* @driver: QEMU driver
* @vm: the VM domain
* @video: the video device
*
* Start the external vhost-user-gpu process:
* - open a socketpair for vhost-user communication
* - have the command line built
* - start the external process and sync with it before QEMU start
*/
int qemuExtVhostUserGPUStart(virQEMUDriverPtr driver,
virDomainObjPtr vm,
virDomainVideoDefPtr video)
{
g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
g_autofree char *shortname = NULL;
g_autofree char *pidfile = NULL;
g_autoptr(virCommand) cmd = NULL;
int pair[2] = { -1, -1 };
int cmdret = 0, rc;
int exitstatus = 0;
pid_t pid;
int ret = -1;
shortname = virDomainDefGetShortName(vm->def);
if (!shortname)
goto error;
/* stop any left-over for this VM */
qemuExtVhostUserGPUStop(driver, vm, video);
if (!(pidfile = qemuVhostUserGPUCreatePidFilename(
cfg->stateDir, shortname, video->info.alias)))
goto error;
if (qemuSecuritySetSocketLabel(driver->securityManager, vm->def) < 0)
goto error;
if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) < 0) {
virReportSystemError(errno, "%s", _("failed to create socket"));
goto error;
}
if (qemuSecurityClearSocketLabel(driver->securityManager, vm->def) < 0)
goto error;
cmd = virCommandNew(video->driver->vhost_user_binary);
if (!cmd)
goto error;
virCommandClearCaps(cmd);
virCommandSetPidFile(cmd, pidfile);
virCommandDaemonize(cmd);
if (qemuExtDeviceLogCommand(driver, vm, cmd, "vhost-user-gpu") < 0)
goto error;
virCommandAddArgFormat(cmd, "--fd=%d", pair[0]);
virCommandPassFD(cmd, pair[0], VIR_COMMAND_PASS_FD_CLOSE_PARENT);
pair[0] = -1;
if (video->accel) {
if (video->accel->accel3d)
virCommandAddArg(cmd, "--virgl");
if (video->accel->rendernode)
virCommandAddArgFormat(cmd, "--render-node=%s", video->accel->rendernode);
}
if (qemuSecurityStartVhostUserGPU(driver, vm, cmd,
&exitstatus, &cmdret) < 0)
goto error;
if (cmdret < 0 || exitstatus != 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Could not start 'vhost-user-gpu'. exitstatus: %d"), exitstatus);
goto cleanup;
}
rc = virPidFileReadPath(pidfile, &pid);
if (rc < 0) {
virReportSystemError(-rc,
_("Unable to read vhost-user-gpu pidfile '%s'"),
pidfile);
goto cleanup;
}
ret = 0;
QEMU_DOMAIN_VIDEO_PRIVATE(video)->vhost_user_fd = pair[1];
pair[1] = -1;
cleanup:
VIR_FORCE_CLOSE(pair[0]);
VIR_FORCE_CLOSE(pair[1]);
return ret;
error:
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("vhost-user-gpu failed to start"));
goto cleanup;
}
/*
* qemuExtVhostUserGPUStop:
*
* @driver: QEMU driver
* @vm: the VM domain
* @video: the video device
*
* Check if vhost-user process pidfile is around, kill the process,
* and remove the pidfile.
*/
void qemuExtVhostUserGPUStop(virQEMUDriverPtr driver,
virDomainObjPtr vm,
virDomainVideoDefPtr video)
{
g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
g_autofree char *pidfile = NULL;
g_autofree char *shortname = NULL;
virErrorPtr orig_err;
shortname = virDomainDefGetShortName(vm->def);
if (!(pidfile = qemuVhostUserGPUCreatePidFilename(
cfg->stateDir, shortname, video->info.alias))) {
VIR_WARN("Unable to construct vhost-user-gpu pidfile path");
return;
}
virErrorPreserveLast(&orig_err);
if (virPidFileForceCleanupPath(pidfile) < 0)
VIR_WARN("Unable to kill vhost-user-gpu process");
virErrorRestore(&orig_err);
}
/*
* qemuExtVhostUserGPUSetupCgroup:
*
* @driver: QEMU driver
* @def: domain definition
* @video: the video device
* @cgroupe: a cgroup
*
* Add the vhost-user-gpu PID to the given cgroup.
*/
int
qemuExtVhostUserGPUSetupCgroup(virQEMUDriverPtr driver,
virDomainDefPtr def,
virDomainVideoDefPtr video,
virCgroupPtr cgroup)
{
g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
g_autofree char *shortname = NULL;
int rc;
pid_t pid;
shortname = virDomainDefGetShortName(def);
if (!shortname)
return -1;
rc = qemuVhostUserGPUGetPid(video->driver->vhost_user_binary,
cfg->stateDir, shortname, video->info.alias, &pid);
if (rc < 0 || (rc == 0 && pid == (pid_t)-1)) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Could not get process id of vhost-user-gpu"));
return -1;
}
if (virCgroupAddProcess(cgroup, pid) < 0)
return -1;
return 0;
}