[libvirt] [PATCH 8/9] wip: start virtiofsd
Ján Tomko
jtomko at redhat.com
Fri Nov 1 12:16:06 UTC 2019
Start virtiofsd for each <filesystem> device using it.
Pre-create the socket for communication with QEMU and pass it
to virtiofsd.
Note that virtiofsd needs to run as root.
---
src/conf/domain_conf.h | 1 +
src/qemu/qemu_extdevice.c | 191 ++++++++++++++++++++++++++++++++++++++
tests/qemuxml2argvtest.c | 6 ++
3 files changed, 198 insertions(+)
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 54a7e7c52f..78f88a0c2f 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -817,6 +817,7 @@ struct _virDomainFSDef {
unsigned long long space_soft_limit; /* in bytes */
bool symlinksResolved;
virDomainVirtioOptionsPtr virtio;
+ char *vhost_user_fs_path; /* TODO put this in private data */
};
diff --git a/src/qemu/qemu_extdevice.c b/src/qemu/qemu_extdevice.c
index 463f76c21a..cb44ca325f 100644
--- a/src/qemu/qemu_extdevice.c
+++ b/src/qemu/qemu_extdevice.c
@@ -20,6 +20,7 @@
#include <config.h>
+#include "qemu_command.h"
#include "qemu_extdevice.h"
#include "qemu_vhost_user_gpu.h"
#include "qemu_domain.h"
@@ -149,6 +150,178 @@ qemuExtDevicesCleanupHost(virQEMUDriverPtr driver,
qemuExtTPMCleanupHost(def);
}
+static char *
+qemuExtVirtioFSCreatePidFilename(virQEMUDriverConfigPtr cfg,
+ const virDomainDef *def,
+ const char *alias)
+{
+ g_autofree char *shortName = NULL;
+ g_autofree char *name = NULL;
+
+ if (!(shortName = virDomainDefGetShortName(def)) ||
+ virAsprintf(&name, "%s-%s-virtiofsd", shortName, alias) < 0)
+ return NULL;
+
+ return virPidFileBuildPath(cfg->stateDir, name);
+}
+
+
+static char *
+qemuExtVirtioFSCreateSocketFilename(virQEMUDriverConfigPtr cfg,
+ const virDomainDef *def,
+ const char *alias)
+{
+ g_autofree char *shortName = NULL;
+ g_autofree char *name = NULL;
+
+ if (!(shortName = virDomainDefGetShortName(def)) ||
+ virAsprintf(&name, "%s-%s-virtiofsd", shortName, alias) < 0)
+ return NULL;
+
+ return virFileBuildPath(cfg->stateDir, name, ".sock");
+}
+
+
+static int
+qemuExtVirtioFSdStart(virQEMUDriverPtr driver,
+ virDomainObjPtr vm,
+ virDomainFSDefPtr fs)
+{
+ g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
+ g_autoptr(virCommand) cmd = NULL;
+ g_autofree char *pidfile = NULL;
+ char errbuf[1024] = { 0 };
+ virDomainChrSourceDefPtr chrdev = virDomainChrSourceDefNew(NULL);
+ pid_t pid = (pid_t) -1;
+ VIR_AUTOCLOSE errfd = -1;
+ VIR_AUTOCLOSE fd = -1;
+ int exitstatus = 0;
+ int cmdret = 0;
+ int ret = -1;
+ int rc;
+
+ chrdev->type = VIR_DOMAIN_CHR_TYPE_UNIX;
+ chrdev->data.nix.listen = true;
+
+ if (!(pidfile = qemuExtVirtioFSCreatePidFilename(cfg, vm->def, fs->info.alias)))
+ goto cleanup;
+
+ if (!(chrdev->data.nix.path = qemuExtVirtioFSCreateSocketFilename(cfg, vm->def, fs->info.alias)))
+ goto cleanup;
+
+ if (qemuSecuritySetDaemonSocketLabel(driver->securityManager, vm->def) < 0)
+ goto cleanup;
+ fd = qemuOpenChrChardevUNIXSocket(chrdev);
+ if (fd < 0)
+ goto cleanup;
+ if (qemuSecurityClearSocketLabel(driver->securityManager, vm->def) < 0)
+ goto cleanup;
+
+ /* TODO: do not call this here */
+ virDomainChrDef chr = { .source = chrdev };
+ if (qemuSecuritySetChardevLabel(driver, vm, &chr) < 0)
+ goto cleanup;
+
+ /* TODO: configure path */
+ if (!(cmd = virCommandNew("/usr/libexec/virtiofsd")))
+ goto cleanup;
+
+ virCommandSetPidFile(cmd, pidfile);
+ virCommandSetErrorFD(cmd, &errfd);
+ virCommandDaemonize(cmd);
+
+ virCommandAddArg(cmd, "--syslog");
+ virCommandAddArgFormat(cmd, "--fd=%d", fd);
+ virCommandPassFD(cmd, fd, VIR_COMMAND_PASS_FD_CLOSE_PARENT);
+ fd = -1;
+
+ virCommandAddArg(cmd, "-o");
+ /* TODO: validate path? */
+ virCommandAddArgFormat(cmd, "source=%s", fs->src->path);
+ virCommandAddArg(cmd, "-d");
+
+ if (qemuExtDeviceLogCommand(driver, vm, cmd, "virtiofsd") < 0)
+ goto cleanup;
+
+ cmdret = virCommandRun(cmd, &exitstatus);
+
+ if (cmdret < 0 || exitstatus != 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Could not start 'virtiofsd'. exitstatus: %d"), exitstatus);
+ goto error;
+ }
+
+ rc = virPidFileReadPath(pidfile, &pid);
+ if (rc < 0) {
+ virReportSystemError(-rc,
+ _("Unable to read virtiofsd pidfile '%s'"),
+ pidfile);
+ goto error;
+ }
+
+ if (virProcessKill(pid, 0) != 0) {
+ if (saferead(errfd, errbuf, sizeof(errbuf) - 1) < 0) {
+ virReportSystemError(errno, "%s",
+ _("virtiofsd died unexpectedly"));
+ } else {
+ virReportError(VIR_ERR_OPERATION_FAILED,
+ _("virtiofsd died and reported: %s"), errbuf);
+ }
+ goto error;
+ }
+
+ fs->vhost_user_fs_path = g_steal_pointer(&chrdev->data.nix.path);
+ ret = 0;
+
+ cleanup:
+ if (chrdev->data.nix.path)
+ unlink(chrdev->data.nix.path);
+ virObjectUnref(chrdev);
+ return ret;
+
+ error:
+ if (pid != -1)
+ virProcessKillPainfully(pid, true);
+ if (pidfile)
+ unlink(pidfile);
+ goto cleanup;
+}
+
+
+static void
+qemuExtVirtioFSdStop(virQEMUDriverPtr driver,
+ virDomainObjPtr vm,
+ virDomainFSDefPtr fs)
+{
+ g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
+ g_autofree char *pidfile = NULL;
+ virErrorPtr orig_err;
+ pid_t pid = -1;
+ int rc;
+
+ virErrorPreserveLast(&orig_err);
+
+ if (!(pidfile = qemuExtVirtioFSCreatePidFilename(cfg, vm->def, fs->info.alias)))
+ goto cleanup;
+
+ rc = virPidFileReadPathIfAlive(pidfile, &pid, NULL);
+ if (rc >= 0 && pid != (pid_t) -1)
+ virProcessKillPainfully(pid, true);
+
+ if (unlink(pidfile) < 0 &&
+ errno != ENOENT) {
+ virReportSystemError(errno,
+ _("Unable to remove stale pidfile %s"),
+ pidfile);
+ }
+
+ if (fs->vhost_user_fs_path)
+ unlink(fs->vhost_user_fs_path);
+
+ cleanup:
+ virErrorRestore(&orig_err);
+}
+
int
qemuExtDevicesStart(virQEMUDriverPtr driver,
@@ -184,6 +357,17 @@ qemuExtDevicesStart(virQEMUDriverPtr driver,
return -1;
}
+ for (i = 0; i < def->nfss; i++) {
+ /* FIXME: use private data */
+ virDomainFSDefPtr fs = def->fss[i];
+
+ if (fs->fsdriver == VIR_DOMAIN_FS_DRIVER_TYPE_VIRTIO_FS) {
+ if (qemuExtVirtioFSdStart(driver, vm, fs) < 0)
+ return -1;
+ }
+ }
+
+
return ret;
}
@@ -215,6 +399,13 @@ qemuExtDevicesStop(virQEMUDriverPtr driver,
if (slirp)
qemuSlirpStop(slirp, vm, driver, net, false);
}
+
+ for (i = 0; i < def->nfss; i++) {
+ virDomainFSDefPtr fs = def->fss[i];
+
+ if (fs->fsdriver == VIR_DOMAIN_FS_DRIVER_TYPE_VIRTIO_FS)
+ qemuExtVirtioFSdStop(driver, vm, fs);
+ }
}
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 24df0a48e7..bf3366f953 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -501,6 +501,12 @@ testCompareXMLToArgv(const void *data)
}
}
+ for (i = 0; i < vm->def->nfss; i++) {
+ virDomainFSDefPtr fs = vm->def->fss[i];
+ char *s = g_strdup_printf("/tmp/lib/domain--1-guest/fs%zu.vhost-fs.sock", i);
+ fs->vhost_user_fs_path = s;
+ }
+
if (vm->def->vsock) {
virDomainVsockDefPtr vsock = vm->def->vsock;
qemuDomainVsockPrivatePtr vsockPriv =
--
2.21.0
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