Re: [libvirt PATCHv2 08/10] qemu: add code for handling virtiofsd

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. https://bugzilla.redhat.com/show_bug.cgi?id=1694166 Introduced by QEMU commit TBD, pull request here: https://lists.nongnu.org/archive/html/qemu-devel/2020-01/msg05389.html Signed-off-by: Ján Tomko <jtomko(a)redhat.com&gt; --- po/POTFILES.in | 1 + src/qemu/Makefile.inc.am | 2 + src/qemu/qemu_domain.c | 3 + src/qemu/qemu_domain.h | 2 +- src/qemu/qemu_extdevice.c | 19 +++ src/qemu/qemu_virtiofs.c | 241 ++++++++++++++++++++++++++++++++++++++ src/qemu/qemu_virtiofs.h | 37 ++++++ tests/qemuxml2argvtest.c | 6 + 8 files changed, 310 insertions(+), 1 deletion(-) create mode 100644 src/qemu/qemu_virtiofs.c create mode 100644 src/qemu/qemu_virtiofs.h

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 4db0075b89..19b3eb0fab 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -1442,6 +1442,9 @@ qemuDomainFSPrivateNew(void) static void qemuDomainFSPrivateDispose(void *obj G_GNUC_UNUSED)

{ + qemuDomainFSPrivatePtr priv = obj; + + g_free(priv->vhostuser_fs_sock); }

diff --git a/src/qemu/qemu_extdevice.c b/src/qemu/qemu_extdevice.c index 463f76c21a..1f4b605eb3 100644 --- a/src/qemu/qemu_extdevice.c +++ b/src/qemu/qemu_extdevice.c

@@ -184,6 +186,16 @@ qemuExtDevicesStart(virQEMUDriverPtr driver, return -1; }

+ for (i = 0; i < def->nfss; i++) { + virDomainFSDefPtr fs = def->fss[i]; + + if (fs->fsdriver == VIR_DOMAIN_FS_DRIVER_TYPE_VIRTIOFS) { + if (qemuVirtioFSStart(driver, vm, fs) < 0) + return -1; + } + } + + return ret; } @@ -215,6 +227,13 @@ 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_VIRTIOFS) + qemuVirtioFSStop(driver, vm, fs);

+ } } diff --git a/src/qemu/qemu_virtiofs.c b/src/qemu/qemu_virtiofs.c new file mode 100644 index 0000000000..1a3bfd53f5 --- /dev/null +++ b/src/qemu/qemu_virtiofs.c @@ -0,0 +1,241 @@

+static virCommandPtr +qemuVirtioFSBuildCommandLine(virQEMUDriverConfigPtr cfg, + virDomainFSDefPtr fs, + int *fd) +{ + g_autoptr(virCommand) cmd = NULL; + g_auto(virBuffer) opts = VIR_BUFFER_INITIALIZER; + + if (!(cmd = virCommandNew(fs->binary))) + return NULL; + + virCommandAddArg(cmd, "--syslog");

+ virCommandAddArgFormat(cmd, "--fd=%d", *fd); + virCommandPassFD(cmd, *fd, VIR_COMMAND_PASS_FD_CLOSE_PARENT); + *fd = -1; + + virCommandAddArg(cmd, "-o"); + virBufferAsprintf(&opts, "source=%s,", fs->src->path); + if (fs->cache) + virBufferAsprintf(&opts, "cache=%s,", virDomainFSCacheModeTypeToString(fs->cache)); + if (fs->xattr) + virBufferAsprintf(&opts, "%sxattr,", fs->xattr == VIR_TRISTATE_SWITCH_OFF ? "no_" : ""); + if (fs->flock) + virBufferAsprintf(&opts, "%sflock,", fs->flock == VIR_TRISTATE_SWITCH_OFF ? "no_" : ""); + if (fs->posix_lock) + virBufferAsprintf(&opts, "%sposix_lock,", fs->posix_lock == VIR_TRISTATE_SWITCH_OFF ? "no_" : "");

+ virBufferTrim(&opts, ",", -1); + + virCommandAddArgBuffer(cmd, &opts); + if (cfg->virtiofsDebug) + virCommandAddArg(cmd, "-d"); + + return g_steal_pointer(&cmd); +} + +int +qemuVirtioFSStart(virQEMUDriverPtr driver, + virDomainObjPtr vm, + virDomainFSDefPtr fs) +{ + g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver); + g_autoptr(virCommand) cmd = NULL; + g_autofree char *socket_path = NULL; + g_autofree char *pidfile = NULL; + char errbuf[1024] = { 0 }; + 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; + + if (!(pidfile = qemuVirtioFSCreatePidFilename(cfg, vm->def, fs->info.alias))) + goto cleanup; + + if (!(socket_path = qemuVirtioFSCreateSocketFilename(vm, fs->info.alias))) + goto cleanup; + + if ((fd = qemuVirtioFSOpenChardev(driver, vm, socket_path)) < 0) + goto cleanup; + + if (!(cmd = qemuVirtioFSBuildCommandLine(cfg, fs, &fd))) + goto cleanup; + + virCommandSetPidFile(cmd, pidfile); + virCommandSetErrorFD(cmd, &errfd);

+ virCommandDaemonize(cmd); + + 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; + } + + QEMU_DOMAIN_FS_PRIVATE(fs)->vhostuser_fs_sock = g_steal_pointer(&socket_path); + ret = 0; + + cleanup: + if (socket_path) + unlink(socket_path); + return ret; + + error: + if (pid != -1) + virProcessKillPainfully(pid, true); + if (pidfile) + unlink(pidfile); + goto cleanup; +} + + +void +qemuVirtioFSStop(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 = qemuVirtioFSCreatePidFilename(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 (QEMU_DOMAIN_FS_PRIVATE(fs)->vhostuser_fs_sock) + unlink(QEMU_DOMAIN_FS_PRIVATE(fs)->vhostuser_fs_sock); + + cleanup: + virErrorRestore(&orig_err); +}

diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c index b923590930..5a517a4982 100644 --- a/tests/qemuxml2argvtest.c +++ b/tests/qemuxml2argvtest.c @@ -496,6 +496,12 @@ 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); + QEMU_DOMAIN_FS_PRIVATE(fs)->vhostuser_fs_sock = s; + } + if (vm->def->vsock) { virDomainVsockDefPtr vsock = vm->def->vsock; qemuDomainVsockPrivatePtr vsockPriv = -- 2.21.0