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backends/iommufd: Introduce the iommufd object
Introduce an iommufd object which allows the interaction with the host /dev/iommu device. The /dev/iommu can have been already pre-opened outside of qemu, in which case the fd can be passed directly along with the iommufd object: This allows the iommufd object to be shared accross several subsystems (VFIO, VDPA, ...). For example, libvirt would open the /dev/iommu once. If no fd is passed along with the iommufd object, the /dev/iommu is opened by the qemu code. Suggested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com> Reviewed-by: Cédric Le Goater <clg@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Cédric Le Goater <clg@redhat.com>
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1 +1,5 @@ | ||
| source tpm/Kconfig | ||
|
|
||
| config IOMMUFD | ||
| bool | ||
| depends on VFIO |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,245 @@ | ||
| /* | ||
| * iommufd container backend | ||
| * | ||
| * Copyright (C) 2023 Intel Corporation. | ||
| * Copyright Red Hat, Inc. 2023 | ||
| * | ||
| * Authors: Yi Liu <yi.l.liu@intel.com> | ||
| * Eric Auger <eric.auger@redhat.com> | ||
| * | ||
| * SPDX-License-Identifier: GPL-2.0-or-later | ||
| */ | ||
|
|
||
| #include "qemu/osdep.h" | ||
| #include "sysemu/iommufd.h" | ||
| #include "qapi/error.h" | ||
| #include "qapi/qmp/qerror.h" | ||
| #include "qemu/module.h" | ||
| #include "qom/object_interfaces.h" | ||
| #include "qemu/error-report.h" | ||
| #include "monitor/monitor.h" | ||
| #include "trace.h" | ||
| #include <sys/ioctl.h> | ||
| #include <linux/iommufd.h> | ||
|
|
||
| static void iommufd_backend_init(Object *obj) | ||
| { | ||
| IOMMUFDBackend *be = IOMMUFD_BACKEND(obj); | ||
|
|
||
| be->fd = -1; | ||
| be->users = 0; | ||
| be->owned = true; | ||
| qemu_mutex_init(&be->lock); | ||
| } | ||
|
|
||
| static void iommufd_backend_finalize(Object *obj) | ||
| { | ||
| IOMMUFDBackend *be = IOMMUFD_BACKEND(obj); | ||
|
|
||
| if (be->owned) { | ||
| close(be->fd); | ||
| be->fd = -1; | ||
| } | ||
| } | ||
|
|
||
| static void iommufd_backend_set_fd(Object *obj, const char *str, Error **errp) | ||
| { | ||
| IOMMUFDBackend *be = IOMMUFD_BACKEND(obj); | ||
| int fd = -1; | ||
|
|
||
| fd = monitor_fd_param(monitor_cur(), str, errp); | ||
| if (fd == -1) { | ||
| error_prepend(errp, "Could not parse remote object fd %s:", str); | ||
| return; | ||
| } | ||
| qemu_mutex_lock(&be->lock); | ||
| be->fd = fd; | ||
| be->owned = false; | ||
| qemu_mutex_unlock(&be->lock); | ||
| trace_iommu_backend_set_fd(be->fd); | ||
| } | ||
|
|
||
| static bool iommufd_backend_can_be_deleted(UserCreatable *uc) | ||
| { | ||
| IOMMUFDBackend *be = IOMMUFD_BACKEND(uc); | ||
|
|
||
| return !be->users; | ||
| } | ||
|
|
||
| static void iommufd_backend_class_init(ObjectClass *oc, void *data) | ||
| { | ||
| UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc); | ||
|
|
||
| ucc->can_be_deleted = iommufd_backend_can_be_deleted; | ||
|
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| object_class_property_add_str(oc, "fd", NULL, iommufd_backend_set_fd); | ||
| } | ||
|
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||
| int iommufd_backend_connect(IOMMUFDBackend *be, Error **errp) | ||
| { | ||
| int fd, ret = 0; | ||
|
|
||
| qemu_mutex_lock(&be->lock); | ||
| if (be->users == UINT32_MAX) { | ||
| error_setg(errp, "too many connections"); | ||
| ret = -E2BIG; | ||
| goto out; | ||
| } | ||
| if (be->owned && !be->users) { | ||
| fd = qemu_open_old("/dev/iommu", O_RDWR); | ||
| if (fd < 0) { | ||
| error_setg_errno(errp, errno, "/dev/iommu opening failed"); | ||
| ret = fd; | ||
| goto out; | ||
| } | ||
| be->fd = fd; | ||
| } | ||
| be->users++; | ||
| out: | ||
| trace_iommufd_backend_connect(be->fd, be->owned, | ||
| be->users, ret); | ||
| qemu_mutex_unlock(&be->lock); | ||
| return ret; | ||
| } | ||
|
|
||
| void iommufd_backend_disconnect(IOMMUFDBackend *be) | ||
| { | ||
| qemu_mutex_lock(&be->lock); | ||
| if (!be->users) { | ||
| goto out; | ||
| } | ||
| be->users--; | ||
| if (!be->users && be->owned) { | ||
| close(be->fd); | ||
| be->fd = -1; | ||
| } | ||
| out: | ||
| trace_iommufd_backend_disconnect(be->fd, be->users); | ||
| qemu_mutex_unlock(&be->lock); | ||
| } | ||
|
|
||
| int iommufd_backend_alloc_ioas(IOMMUFDBackend *be, uint32_t *ioas_id, | ||
| Error **errp) | ||
| { | ||
| int ret, fd = be->fd; | ||
| struct iommu_ioas_alloc alloc_data = { | ||
| .size = sizeof(alloc_data), | ||
| .flags = 0, | ||
| }; | ||
|
|
||
| ret = ioctl(fd, IOMMU_IOAS_ALLOC, &alloc_data); | ||
| if (ret) { | ||
| error_setg_errno(errp, errno, "Failed to allocate ioas"); | ||
| return ret; | ||
| } | ||
|
|
||
| *ioas_id = alloc_data.out_ioas_id; | ||
| trace_iommufd_backend_alloc_ioas(fd, *ioas_id, ret); | ||
|
|
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| return ret; | ||
| } | ||
|
|
||
| void iommufd_backend_free_id(IOMMUFDBackend *be, uint32_t id) | ||
| { | ||
| int ret, fd = be->fd; | ||
| struct iommu_destroy des = { | ||
| .size = sizeof(des), | ||
| .id = id, | ||
| }; | ||
|
|
||
| ret = ioctl(fd, IOMMU_DESTROY, &des); | ||
| trace_iommufd_backend_free_id(fd, id, ret); | ||
| if (ret) { | ||
| error_report("Failed to free id: %u %m", id); | ||
| } | ||
| } | ||
|
|
||
| int iommufd_backend_map_dma(IOMMUFDBackend *be, uint32_t ioas_id, hwaddr iova, | ||
| ram_addr_t size, void *vaddr, bool readonly) | ||
| { | ||
| int ret, fd = be->fd; | ||
| struct iommu_ioas_map map = { | ||
| .size = sizeof(map), | ||
| .flags = IOMMU_IOAS_MAP_READABLE | | ||
| IOMMU_IOAS_MAP_FIXED_IOVA, | ||
| .ioas_id = ioas_id, | ||
| .__reserved = 0, | ||
| .user_va = (uintptr_t)vaddr, | ||
| .iova = iova, | ||
| .length = size, | ||
| }; | ||
|
|
||
| if (!readonly) { | ||
| map.flags |= IOMMU_IOAS_MAP_WRITEABLE; | ||
| } | ||
|
|
||
| ret = ioctl(fd, IOMMU_IOAS_MAP, &map); | ||
| trace_iommufd_backend_map_dma(fd, ioas_id, iova, size, | ||
| vaddr, readonly, ret); | ||
| if (ret) { | ||
| ret = -errno; | ||
|
|
||
| /* TODO: Not support mapping hardware PCI BAR region for now. */ | ||
| if (errno == EFAULT) { | ||
| warn_report("IOMMU_IOAS_MAP failed: %m, PCI BAR?"); | ||
| } else { | ||
| error_report("IOMMU_IOAS_MAP failed: %m"); | ||
| } | ||
| } | ||
| return ret; | ||
| } | ||
|
|
||
| int iommufd_backend_unmap_dma(IOMMUFDBackend *be, uint32_t ioas_id, | ||
| hwaddr iova, ram_addr_t size) | ||
| { | ||
| int ret, fd = be->fd; | ||
| struct iommu_ioas_unmap unmap = { | ||
| .size = sizeof(unmap), | ||
| .ioas_id = ioas_id, | ||
| .iova = iova, | ||
| .length = size, | ||
| }; | ||
|
|
||
| ret = ioctl(fd, IOMMU_IOAS_UNMAP, &unmap); | ||
| /* | ||
| * IOMMUFD takes mapping as some kind of object, unmapping | ||
| * nonexistent mapping is treated as deleting a nonexistent | ||
| * object and return ENOENT. This is different from legacy | ||
| * backend which allows it. vIOMMU may trigger a lot of | ||
| * redundant unmapping, to avoid flush the log, treat them | ||
| * as succeess for IOMMUFD just like legacy backend. | ||
| */ | ||
| if (ret && errno == ENOENT) { | ||
| trace_iommufd_backend_unmap_dma_non_exist(fd, ioas_id, iova, size, ret); | ||
| ret = 0; | ||
| } else { | ||
| trace_iommufd_backend_unmap_dma(fd, ioas_id, iova, size, ret); | ||
| } | ||
|
|
||
| if (ret) { | ||
| ret = -errno; | ||
| error_report("IOMMU_IOAS_UNMAP failed: %m"); | ||
| } | ||
| return ret; | ||
| } | ||
|
|
||
| static const TypeInfo iommufd_backend_info = { | ||
| .name = TYPE_IOMMUFD_BACKEND, | ||
| .parent = TYPE_OBJECT, | ||
| .instance_size = sizeof(IOMMUFDBackend), | ||
| .instance_init = iommufd_backend_init, | ||
| .instance_finalize = iommufd_backend_finalize, | ||
| .class_size = sizeof(IOMMUFDBackendClass), | ||
| .class_init = iommufd_backend_class_init, | ||
| .interfaces = (InterfaceInfo[]) { | ||
| { TYPE_USER_CREATABLE }, | ||
| { } | ||
| } | ||
| }; | ||
|
|
||
| static void register_types(void) | ||
| { | ||
| type_register_static(&iommufd_backend_info); | ||
| } | ||
|
|
||
| type_init(register_types); |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,38 @@ | ||
| #ifndef SYSEMU_IOMMUFD_H | ||
| #define SYSEMU_IOMMUFD_H | ||
|
|
||
| #include "qom/object.h" | ||
| #include "qemu/thread.h" | ||
| #include "exec/hwaddr.h" | ||
| #include "exec/cpu-common.h" | ||
|
|
||
| #define TYPE_IOMMUFD_BACKEND "iommufd" | ||
| OBJECT_DECLARE_TYPE(IOMMUFDBackend, IOMMUFDBackendClass, IOMMUFD_BACKEND) | ||
|
|
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| struct IOMMUFDBackendClass { | ||
| ObjectClass parent_class; | ||
| }; | ||
|
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| struct IOMMUFDBackend { | ||
| Object parent; | ||
|
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| /*< protected >*/ | ||
| int fd; /* /dev/iommu file descriptor */ | ||
| bool owned; /* is the /dev/iommu opened internally */ | ||
| QemuMutex lock; | ||
| uint32_t users; | ||
|
|
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| /*< public >*/ | ||
| }; | ||
|
|
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| int iommufd_backend_connect(IOMMUFDBackend *be, Error **errp); | ||
| void iommufd_backend_disconnect(IOMMUFDBackend *be); | ||
|
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| int iommufd_backend_alloc_ioas(IOMMUFDBackend *be, uint32_t *ioas_id, | ||
| Error **errp); | ||
| void iommufd_backend_free_id(IOMMUFDBackend *be, uint32_t id); | ||
| int iommufd_backend_map_dma(IOMMUFDBackend *be, uint32_t ioas_id, hwaddr iova, | ||
| ram_addr_t size, void *vaddr, bool readonly); | ||
| int iommufd_backend_unmap_dma(IOMMUFDBackend *be, uint32_t ioas_id, | ||
| hwaddr iova, ram_addr_t size); | ||
| #endif |
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