Open iommufd FD from libvirt backend without exposing these FDs to XML users, i.e. one per domain for /dev/iommu, and pass the FD to qemu command line. Signed-off-by: Nathan Chen <nathanc@nvidia.com> --- src/qemu/qemu_command.c | 8 ++++-- src/qemu/qemu_domain.c | 1 + src/qemu/qemu_domain.h | 2 ++ src/qemu/qemu_process.c | 56 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 65 insertions(+), 2 deletions(-) diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 9b08f66175..99c310cf31 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -5229,12 +5229,14 @@ qemuBuildAcpiNodesetProps(virCommand *cmd, static int qemuBuildHostdevCommandLine(virCommand *cmd, const virDomainDef *def, - virQEMUCaps *qemuCaps) + virQEMUCaps *qemuCaps, + virDomainObj *vm) { size_t i; g_autoptr(virJSONValue) props = NULL; int iommufd = 0; const char * iommufdId = "iommufd0"; + qemuDomainObjPrivate *priv = vm->privateData; for (i = 0; i < def->nhostdevs; i++) { virDomainHostdevDef *hostdev = def->hostdevs[i]; @@ -5265,8 +5267,10 @@ qemuBuildHostdevCommandLine(virCommand *cmd, if (subsys->u.pci.driver.iommufd == VIR_TRISTATE_BOOL_YES && iommufd == 0) { iommufd = 1; + virCommandPassFD(cmd, priv->iommufd, VIR_COMMAND_PASS_FD_CLOSE_PARENT); if (qemuMonitorCreateObjectProps(&props, "iommufd", iommufdId, + "S:fd", g_strdup_printf("%d", priv->iommufd), NULL) < 0) return -1; @@ -10967,7 +10971,7 @@ qemuBuildCommandLine(virDomainObj *vm, if (qemuBuildRedirdevCommandLine(cmd, def, qemuCaps) < 0) return NULL; - if (qemuBuildHostdevCommandLine(cmd, def, qemuCaps) < 0) + if (qemuBuildHostdevCommandLine(cmd, def, qemuCaps, vm) < 0) return NULL; if (migrateURI) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 7601bdbb2b..d569dd5ad9 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -2042,6 +2042,7 @@ qemuDomainObjPrivateAlloc(void *opaque) priv->blockjobs = virHashNew(virObjectUnref); priv->fds = virHashNew(g_object_unref); + priv->iommufd = -1; priv->pidMonitored = -1; /* agent commands block by default, user can choose different behavior */ diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h index 4736f1ede5..e55ba1c968 100644 --- a/src/qemu/qemu_domain.h +++ b/src/qemu/qemu_domain.h @@ -264,6 +264,8 @@ struct _qemuDomainObjPrivate { /* named file descriptor groups associated with the VM */ GHashTable *fds; + int iommufd; + char *memoryBackingDir; }; diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index bf245ee8af..83b8a586a1 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -10272,6 +10272,38 @@ qemuProcessHandleNbdkitExit(qemuNbdkitProcess *nbdkit, virObjectUnlock(vm); } +/** + * qemuProcessOpenIommuFd: + * @vm: domain object + * @iommuFd: returned file descriptor + * + * Opens /dev/iommu file descriptor for the VM. + * + * Returns: 0 on success, -1 on failure + */ +static int +qemuProcessOpenIommuFd(virDomainObj *vm, int *iommuFd) +{ + int fd = -1; + + VIR_DEBUG("Opening IOMMU FD for domain %s", vm->def->name); + + if ((fd = open("/dev/iommu", O_RDWR | O_CLOEXEC)) < 0) { + if (errno == ENOENT) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("IOMMU FD support requires /dev/iommu device")); + } else { + virReportSystemError(errno, "%s", + _("cannot open /dev/iommu")); + } + return -1; + } + + *iommuFd = fd; + VIR_DEBUG("Opened IOMMU FD %d for domain %s", fd, vm->def->name); + return 0; +} + /** * qemuProcessOpenVfioDeviceFd: * @hostdev: host device definition @@ -10329,6 +10361,8 @@ qemuProcessOpenVfioDeviceFd(virDomainHostdevDef *hostdev, int qemuProcessOpenVfioFds(virDomainObj *vm) { + qemuDomainObjPrivate *priv = vm->privateData; + bool needsIommuFd = false; size_t i; /* Check if we have any hostdevs that need VFIO FDs */ @@ -10342,6 +10376,8 @@ qemuProcessOpenVfioFds(virDomainObj *vm) if (hostdev->source.subsys.u.pci.driver.name == VIR_DEVICE_HOSTDEV_PCI_DRIVER_NAME_VFIO && hostdev->source.subsys.u.pci.driver.iommufd == VIR_TRISTATE_BOOL_YES) { + needsIommuFd = true; + if (!hostdev->privateData) { if (!(hostdev->privateData = qemuDomainHostdevPrivateNew())) goto error; @@ -10363,6 +10399,18 @@ qemuProcessOpenVfioFds(virDomainObj *vm) } } + /* Open IOMMU FD if needed */ + if (needsIommuFd) { + int iommuFd = -1; + + if (qemuProcessOpenIommuFd(vm, &iommuFd) < 0) + goto error; + + priv->iommufd = iommuFd; + + VIR_DEBUG("Stored IOMMU FD %d", priv->iommufd); + } + return 0; error: @@ -10379,6 +10427,7 @@ qemuProcessOpenVfioFds(virDomainObj *vm) void qemuProcessCloseVfioFds(virDomainObj *vm) { + qemuDomainObjPrivate *priv = vm->privateData; size_t i; /* Close all VFIO device FDs */ @@ -10396,4 +10445,11 @@ qemuProcessCloseVfioFds(virDomainObj *vm) VIR_FORCE_CLOSE(hostdevPriv->vfioDeviceFd); } } + + /* Close IOMMU FD */ + if (priv->iommufd >= 0) { + VIR_DEBUG("Closing IOMMU FD %d", priv->iommufd); + VIR_FORCE_CLOSE(priv->iommufd); + priv->iommufd = -1; + } } -- 2.43.0