Re: [libvirt PATCH 16/16] qemu: implement virtiofs hotunplug
On Wed, Oct 06, 2021 at 09:15:22 +0200, Ján Tomko wrote:
Signed-off-by: Ján Tomko <jtomko(a)redhat.com>
---
src/conf/domain_conf.c | 24 ++++++++++++
src/conf/domain_conf.h | 2 +
src/libvirt_private.syms | 1 +
src/qemu/qemu_hotplug.c | 81 +++++++++++++++++++++++++++++++++++++++-
4 files changed, 106 insertions(+), 2 deletions(-)
[...]
diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index f5dad0b829..713da5ebfc 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -5180,6 +5180,45 @@ qemuDomainRemoveRedirdevDevice(virQEMUDriver *driver,
}
+static int
+qemuDomainRemoveFSDevice(virQEMUDriver *driver,
+ virDomainObj *vm,
+ virDomainFSDef *fs)
+{
+ g_autofree char *charAlias = NULL;
+ qemuDomainObjPrivate *priv = vm->privateData;
+ ssize_t idx;
+ int rc = 0;
+
+ VIR_DEBUG("Removing FS device %s from domain %p %s",
+ fs->info.alias, vm, vm->def->name);
+
+ charAlias = qemuDomainGetVhostUserChrAlias(fs->info.alias);
+
+ qemuDomainObjEnterMonitor(driver, vm);
+
+ if (qemuMonitorDetachCharDev(priv->mon, charAlias) < 0)
+ rc = -1;
Note that you must not assume here that the check below [1] that allows
only virtio-fs device unplug guards this code too.
The *Remove* code is executed always when we get a 'DEVICE_DELETED'
event from qemu thus also for guest-initiated unplug, which
theoretically can happen also for p9fs device.
+
+ if (qemuDomainObjExitMonitor(driver, vm) < 0)
+ return -1;
+
+ virDomainAuditFS(vm, fs, NULL, "detach", rc == 0);
+
+ if (rc < 0)
+ return -1;
+
+ if (!fs->sock)
+ qemuVirtioFSStop(driver, vm, fs);
+
+ if ((idx = virDomainFSDefFind(vm->def, fs)) >= 0)
+ virDomainFSRemove(vm->def, idx);
+ qemuDomainReleaseDeviceAddress(vm, &fs->info);
+ virDomainFSDefFree(fs);
+ return 0;
+}
+
+
static void
qemuDomainRemoveAuditDevice(virDomainObj *vm,
virDomainDeviceDef *detach,
[...]
@@ -6020,6 +6066,31 @@ qemuDomainDetachPrepVsock(virDomainObj *vm,
}
+static int
+qemuDomainDetachPrepFS(virDomainObj *vm,
+ virDomainFSDef *match,
+ virDomainFSDef **detach)
+{
+ ssize_t idx;
+
+ if ((idx = virDomainFSDefFind(vm->def, match)) < 0) {
+ virReportError(VIR_ERR_DEVICE_MISSING, "%s",
+ _("matching filesystem not found"));
+ return -1;
+ }
+
+ if (vm->def->fss[idx]->fsdriver != VIR_DOMAIN_FS_DRIVER_TYPE_VIRTIOFS) {
+ virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+ _("only virtiofs filesystems can be hotplugged"));
+ return -1;
+ }
[1]. This check only guards host-initiated delete.
+
+ *detach = vm->def->fss[idx];
+
+ return 0;
+}
+
+
static int
qemuDomainDetachDeviceLease(virQEMUDriver *driver,
virDomainObj *vm,