[RFC PATCH 4/5] qemu: Update Cgroup and namespace for qemu to access iommufd paths

Allow access to /dev/iommu and /dev/vfio/devices/vfio* when launching a qemu VM with iommufd feature enabled. Signed-off-by: Nathan Chen <nathanc(a)nvidia.com&gt; --- src/qemu/qemu_cgroup.c | 47 +++++++++++++++++++++++++++++++++++++++ src/qemu/qemu_cgroup.h | 1 + src/qemu/qemu_namespace.c | 36 ++++++++++++++++++++++++++++++ 3 files changed, 84 insertions(+) diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c index 48af467bf9..df4e73ad15 100644 --- a/src/qemu/qemu_cgroup.c +++ b/src/qemu/qemu_cgroup.c @@ -462,6 +462,47 @@ qemuTeardownInputCgroup(virDomainObj *vm, } +int +qemuSetupIommufdCgroup(virDomainObj *vm) +{ + qemuDomainObjPrivate *priv = vm->privateData; + g_autoptr(DIR) dir = NULL; + struct dirent *dent; + g_autofree char *path = NULL; + + if (vm->def->iommu && vm->def->niommus > 0 && + /* Check if iommufd is enabled */ + vm->def->iommu[0]->iommufd) { + if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_DEVICES)) + return 0; + if (virDirOpen(&dir, "/dev/vfio/devices") < 0) { + if (errno == ENOENT) + return 0; + return -1; + } + while (virDirRead(dir, &dent, "/dev/vfio/devices") > 0) { + if (STRPREFIX(dent->d_name, "vfio")) { + path = g_strdup_printf("/dev/vfio/devices/%s", dent->d_name); + } + if (path && + qemuCgroupAllowDevicePath(vm, path, + VIR_CGROUP_DEVICE_RW, false) < 0) { + return -1; + } + path = NULL; + } + if (virFileExists("/dev/iommu")) + path = g_strdup("/dev/iommu"); + if (path && + qemuCgroupAllowDevicePath(vm, path, + VIR_CGROUP_DEVICE_RW, false) < 0) { + return -1; + } + } + return 0; +} + + /** * qemuSetupHostdevCgroup: * vm: domain object @@ -830,6 +871,12 @@ qemuSetupDevicesCgroup(virDomainObj *vm) return -1; } + if (vm->def->iommu && vm->def->niommus > 0 && + vm->def->iommu[0]->iommufd) { + if (qemuSetupIommufdCgroup(vm) < 0) + return -1; + } + for (i = 0; i < vm->def->nmems; i++) { if (qemuSetupMemoryDevicesCgroup(vm, vm->def->mems[i]) < 0) return -1; diff --git a/src/qemu/qemu_cgroup.h b/src/qemu/qemu_cgroup.h index 3668034cde..bea677ba3c 100644 --- a/src/qemu/qemu_cgroup.h +++ b/src/qemu/qemu_cgroup.h @@ -42,6 +42,7 @@ int qemuSetupHostdevCgroup(virDomainObj *vm, int qemuTeardownHostdevCgroup(virDomainObj *vm, virDomainHostdevDef *dev) G_GNUC_WARN_UNUSED_RESULT; +int qemuSetupIommufdCgroup(virDomainObj *vm); int qemuSetupMemoryDevicesCgroup(virDomainObj *vm, virDomainMemoryDef *mem); int qemuTeardownMemoryDevicesCgroup(virDomainObj *vm, diff --git a/src/qemu/qemu_namespace.c b/src/qemu/qemu_namespace.c index 59421ec9d1..150c6ceae3 100644 --- a/src/qemu/qemu_namespace.c +++ b/src/qemu/qemu_namespace.c @@ -676,6 +676,39 @@ qemuDomainSetupLaunchSecurity(virDomainObj *vm, } +static int +qemuDomainSetupIommufd(virDomainObj *vm, + GSList **paths) +{ + g_autoptr(DIR) dir = NULL; + struct dirent *dent; + g_autofree char *path = NULL; + + /* Check if iommufd is enabled */ + if (vm->def->iommu && vm->def->niommus > 0 && + vm->def->iommu[0]->iommufd) { + if (virDirOpen(&dir, "/dev/vfio/devices") < 0) { + if (errno == ENOENT) + return 0; + return -1; + } + while (virDirRead(dir, &dent, "/dev/vfio/devices") > 0) { + if (STRPREFIX(dent->d_name, "vfio")) { + path = g_strdup_printf("/dev/vfio/devices/%s", dent->d_name); + *paths = g_slist_prepend(*paths, g_steal_pointer(&path)); + } + } + path = NULL; + if (virFileExists("/dev/iommu")) + path = g_strdup("/dev/iommu"); + if (path) + *paths = g_slist_prepend(*paths, g_steal_pointer(&path)); + } + + return 0; +} + + static int qemuNamespaceMknodPaths(virDomainObj *vm, GSList *paths, @@ -699,6 +732,9 @@ qemuDomainBuildNamespace(virQEMUDriverConfig *cfg, if (qemuDomainSetupAllDisks(vm, &paths) < 0) return -1; + if (qemuDomainSetupIommufd(vm, &paths) < 0) + return -1; + if (qemuDomainSetupAllHostdevs(vm, &paths) < 0) return -1; -- 2.43.0