From 6f43c505d99b38f8454881d77270d615fb0057b4 Mon Sep 17 00:00:00 2001 From: Michal Privoznik Date: Tue, 17 Sep 2019 10:06:26 +0200 Subject: [PATCH] qemu: Explicitly add/remove /dev/vfio/vfio to/from NS/CGroups In near future, the decision what to do with /dev/vfio/vfio with respect to domain namespace and CGroup is going to be moved out of qemuDomainGetHostdevPath() because there will be some other types of devices than hostdevs that need access to VFIO. All functions that I'm changing (except qemuSetupHostdevCgroup()) assume that hostdev we are adding/removing to VM is not in the definition yet (because of how qemuDomainNeedsVFIO() is written). Fortunately, this assumption is true. For qemuSetupHostdevCgroup(), the worst thing that may happen is that we allow /dev/vfio/vfio which was already allowed. Signed-off-by: Michal Privoznik Reviewed-by: Cole Robinson --- src/qemu/qemu_cgroup.c | 48 +++++++++++++++++++++++++++++++++++++++++- src/qemu/qemu_domain.c | 36 +++++++++++++++++++++++++++++++ 2 files changed, 83 insertions(+), 1 deletion(-) diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c index 31cf71146b..e451ebdb3a 100644 --- a/src/qemu/qemu_cgroup.c +++ b/src/qemu/qemu_cgroup.c @@ -25,6 +25,7 @@ #include "qemu_domain.h" #include "qemu_process.h" #include "qemu_extdevice.h" +#include "qemu_hostdev.h" #include "virlog.h" #include "viralloc.h" #include "virerror.h" @@ -359,6 +360,16 @@ qemuTeardownInputCgroup(virDomainObjPtr vm, } +/** + * qemuSetupHostdevCgroup: + * vm: domain object + * @dev: device to allow + * + * For given host device @dev allow access to in Cgroups. + * + * Returns: 0 on success, + * -1 otherwise. + */ int qemuSetupHostdevCgroup(virDomainObjPtr vm, virDomainHostdevDefPtr dev) @@ -385,6 +396,16 @@ qemuSetupHostdevCgroup(virDomainObjPtr vm, goto cleanup; } + if (qemuHostdevNeedsVFIO(dev)) { + VIR_DEBUG("Cgroup allow %s perms=%d", QEMU_DEV_VFIO, VIR_CGROUP_DEVICE_RW); + rv = virCgroupAllowDevicePath(priv->cgroup, QEMU_DEV_VFIO, + VIR_CGROUP_DEVICE_RW, false); + virDomainAuditCgroupPath(vm, priv->cgroup, "allow", + QEMU_DEV_VFIO, "rw", rv); + if (rv < 0) + goto cleanup; + } + ret = 0; cleanup: @@ -395,9 +416,21 @@ qemuSetupHostdevCgroup(virDomainObjPtr vm, return ret; } + +/** + * qemuTeardownHostdevCgroup: + * @vm: doamin object + * @dev: device to tear down + * + * For given host device @dev deny access to it in CGroups. + * Note, @dev must not be in @vm's definition. + * + * Returns: 0 on success, + * -1 otherwise. + */ int qemuTeardownHostdevCgroup(virDomainObjPtr vm, - virDomainHostdevDefPtr dev) + virDomainHostdevDefPtr dev) { qemuDomainObjPrivatePtr priv = vm->privateData; char **path = NULL; @@ -421,6 +454,17 @@ qemuTeardownHostdevCgroup(virDomainObjPtr vm, goto cleanup; } + if (qemuHostdevNeedsVFIO(dev) && + !qemuDomainNeedsVFIO(vm->def)) { + VIR_DEBUG("Cgroup deny " QEMU_DEV_VFIO); + rv = virCgroupDenyDevicePath(priv->cgroup, QEMU_DEV_VFIO, + VIR_CGROUP_DEVICE_RWM, false); + virDomainAuditCgroupPath(vm, priv->cgroup, "deny", + QEMU_DEV_VFIO, "rwm", rv); + if (rv < 0) + goto cleanup; + } + ret = 0; cleanup: for (i = 0; i < npaths; i++) @@ -803,6 +847,8 @@ qemuSetupDevicesCgroup(virDomainObjPtr vm) goto cleanup; for (i = 0; i < vm->def->nhostdevs; i++) { + /* This may allow /dev/vfio/vfio multiple times, but that + * is not a problem. Kernel will have only one record. */ if (qemuSetupHostdevCgroup(vm, vm->def->hostdevs[i]) < 0) goto cleanup; } diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 4b38da802e..88509ce9ae 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -14503,6 +14503,10 @@ qemuDomainSetupHostdev(virQEMUDriverConfigPtr cfg G_GNUC_UNUSED, goto cleanup; } + if (qemuHostdevNeedsVFIO(dev) && + qemuDomainCreateDevice(QEMU_DEV_VFIO, data, false) < 0) + goto cleanup; + ret = 0; cleanup: for (i = 0; i < npaths; i++) @@ -15526,6 +15530,17 @@ qemuDomainNamespaceTeardownDisk(virDomainObjPtr vm G_GNUC_UNUSED, } +/** + * qemuDomainNamespaceSetupHostdev: + * @vm: domain object + * @hostdev: hostdev to create in @vm's namespace + * + * For given @hostdev, create its devfs representation (if it has one) in + * domain namespace. Note, @hostdev must not be in @vm's definition. + * + * Returns: 0 on success, + * -1 otherwise. + */ int qemuDomainNamespaceSetupHostdev(virDomainObjPtr vm, virDomainHostdevDefPtr hostdev) @@ -15540,6 +15555,11 @@ qemuDomainNamespaceSetupHostdev(virDomainObjPtr vm, if (qemuDomainNamespaceMknodPaths(vm, (const char **)paths, npaths) < 0) goto cleanup; + if (qemuHostdevNeedsVFIO(hostdev) && + !qemuDomainNeedsVFIO(vm->def) && + qemuDomainNamespaceMknodPath(vm, QEMU_DEV_VFIO) < 0) + goto cleanup; + ret = 0; cleanup: for (i = 0; i < npaths; i++) @@ -15549,6 +15569,17 @@ qemuDomainNamespaceSetupHostdev(virDomainObjPtr vm, } +/** + * qemuDomainNamespaceTeardownHostdev: + * @vm: domain object + * @hostdev: hostdev to remove in @vm's namespace + * + * For given @hostdev, remove its devfs representation (if it has one) in + * domain namespace. Note, @hostdev must not be in @vm's definition. + * + * Returns: 0 on success, + * -1 otherwise. + */ int qemuDomainNamespaceTeardownHostdev(virDomainObjPtr vm, virDomainHostdevDefPtr hostdev) @@ -15564,6 +15595,11 @@ qemuDomainNamespaceTeardownHostdev(virDomainObjPtr vm, if (qemuDomainNamespaceUnlinkPaths(vm, (const char **)paths, npaths) < 0) goto cleanup; + if (qemuHostdevNeedsVFIO(hostdev) && + !qemuDomainNeedsVFIO(vm->def) && + qemuDomainNamespaceUnlinkPath(vm, QEMU_DEV_VFIO) < 0) + goto cleanup; + ret = 0; cleanup: for (i = 0; i < npaths; i++) -- 2.39.5