From: Eric Auger <eric.auger@xxxxxxxxxx> 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. The CONFIG_IOMMUFD option must be set to compile this new object. Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx> Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx> Suggested-by: Alex Williamson <alex.williamson@xxxxxxxxxx> --- MAINTAINERS | 7 ++ backends/Kconfig | 5 + backends/iommufd.c | 265 +++++++++++++++++++++++++++++++++++++++ backends/meson.build | 1 + backends/trace-events | 12 ++ include/sysemu/iommufd.h | 47 +++++++ qapi/qom.json | 16 ++- qemu-options.hx | 12 ++ 8 files changed, 364 insertions(+), 1 deletion(-) create mode 100644 backends/iommufd.c create mode 100644 include/sysemu/iommufd.h diff --git a/MAINTAINERS b/MAINTAINERS index 5580a36b68..c6aa4e7fd0 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1984,6 +1984,13 @@ F: hw/vfio/ap.c F: docs/system/s390x/vfio-ap.rst L: qemu-s390x@xxxxxxxxxx +iommufd +M: Yi Liu <yi.l.liu@xxxxxxxxx> +M: Eric Auger <eric.auger@xxxxxxxxxx> +S: Supported +F: backends/iommufd.c +F: include/sysemu/iommufd.h + vhost M: Michael S. Tsirkin <mst@xxxxxxxxxx> S: Supported diff --git a/backends/Kconfig b/backends/Kconfig index f35abc1609..aad57e8f53 100644 --- a/backends/Kconfig +++ b/backends/Kconfig @@ -1 +1,6 @@ source tpm/Kconfig + +config IOMMUFD + bool + default y + depends on LINUX diff --git a/backends/iommufd.c b/backends/iommufd.c new file mode 100644 index 0000000000..6a66948d5d --- /dev/null +++ b/backends/iommufd.c @@ -0,0 +1,265 @@ +/* + * iommufd container backend + * + * Copyright (C) 2022 Intel Corporation. + * Copyright Red Hat, Inc. 2022 + * + * Authors: Yi Liu <yi.l.liu@xxxxxxxxx> + * Eric Auger <eric.auger@xxxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + + * You should have received a copy of the GNU General Public License along + * with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#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 void iommufd_backend_class_init(ObjectClass *oc, void *data) +{ + object_class_property_add_str(oc, "fd", NULL, iommufd_backend_set_fd); +} + +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); +} + +static int iommufd_backend_alloc_ioas(int fd, uint32_t *ioas) +{ + int ret; + struct iommu_ioas_alloc alloc_data = { + .size = sizeof(alloc_data), + .flags = 0, + }; + + ret = ioctl(fd, IOMMU_IOAS_ALLOC, &alloc_data); + if (ret) { + error_report("Failed to allocate ioas %m"); + } + + *ioas = alloc_data.out_ioas_id; + trace_iommufd_backend_alloc_ioas(fd, *ioas, ret); + + return ret; +} + +static void iommufd_backend_free_ioas(int fd, uint32_t ioas) +{ + int ret; + struct iommu_destroy des = { + .size = sizeof(des), + .id = ioas, + }; + + ret = ioctl(fd, IOMMU_DESTROY, &des); + trace_iommufd_backend_free_ioas(fd, ioas, ret); + if (ret) { + error_report("Failed to free ioas: %u %m", ioas); + } +} + +int iommufd_backend_get_ioas(IOMMUFDBackend *be, uint32_t *ioas_id) +{ + int ret; + + ret = iommufd_backend_alloc_ioas(be->fd, ioas_id); + trace_iommufd_backend_get_ioas(be->fd, *ioas_id, ret); + return ret; +} + +void iommufd_backend_put_ioas(IOMMUFDBackend *be, uint32_t ioas) +{ + trace_iommufd_backend_put_ioas(be->fd, ioas); + iommufd_backend_free_ioas(be->fd, ioas); +} + +int iommufd_backend_unmap_dma(IOMMUFDBackend *be, uint32_t ioas, + hwaddr iova, ram_addr_t size) +{ + int ret; + struct iommu_ioas_unmap unmap = { + .size = sizeof(unmap), + .ioas_id = ioas, + .iova = iova, + .length = size, + }; + + ret = ioctl(be->fd, IOMMU_IOAS_UNMAP, &unmap); + trace_iommufd_backend_unmap_dma(be->fd, ioas, iova, size, ret); + if (ret) { + error_report("IOMMU_IOAS_UNMAP failed: %s", strerror(errno)); + } + return !ret ? 0 : -errno; +} + +int iommufd_backend_map_dma(IOMMUFDBackend *be, uint32_t ioas, hwaddr iova, + ram_addr_t size, void *vaddr, bool readonly) +{ + int ret; + struct iommu_ioas_map map = { + .size = sizeof(map), + .flags = IOMMU_IOAS_MAP_READABLE | + IOMMU_IOAS_MAP_FIXED_IOVA, + .ioas_id = ioas, + .__reserved = 0, + .user_va = (int64_t)vaddr, + .iova = iova, + .length = size, + }; + + if (!readonly) { + map.flags |= IOMMU_IOAS_MAP_WRITEABLE; + } + + ret = ioctl(be->fd, IOMMU_IOAS_MAP, &map); + trace_iommufd_backend_map_dma(be->fd, ioas, iova, size, + vaddr, readonly, ret); + if (ret) { + error_report("IOMMU_IOAS_MAP failed: %s", strerror(errno)); + } + return !ret ? 0 : -errno; +} + +int iommufd_backend_copy_dma(IOMMUFDBackend *be, uint32_t src_ioas, + uint32_t dst_ioas, hwaddr iova, + ram_addr_t size, bool readonly) +{ + int ret; + struct iommu_ioas_copy copy = { + .size = sizeof(copy), + .flags = IOMMU_IOAS_MAP_READABLE | + IOMMU_IOAS_MAP_FIXED_IOVA, + .dst_ioas_id = dst_ioas, + .src_ioas_id = src_ioas, + .length = size, + .dst_iova = iova, + .src_iova = iova, + }; + + if (!readonly) { + copy.flags |= IOMMU_IOAS_MAP_WRITEABLE; + } + + ret = ioctl(be->fd, IOMMU_IOAS_COPY, ©); + trace_iommufd_backend_copy_dma(be->fd, src_ioas, dst_ioas, + iova, size, readonly, ret); + if (ret) { + error_report("IOMMU_IOAS_COPY failed: %s", strerror(errno)); + } + return !ret ? 0 : -errno; +} + +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); diff --git a/backends/meson.build b/backends/meson.build index b1884a88ec..5cbdd3a858 100644 --- a/backends/meson.build +++ b/backends/meson.build @@ -15,6 +15,7 @@ softmmu_ss.add(when: 'CONFIG_LINUX', if_true: files('hostmem-memfd.c')) if have_vhost_user softmmu_ss.add(when: 'CONFIG_VIRTIO', if_true: files('vhost-user.c')) endif +specific_ss.add(when: 'CONFIG_IOMMUFD', if_true: files('iommufd.c')) softmmu_ss.add(when: 'CONFIG_VIRTIO_CRYPTO', if_true: files('cryptodev-vhost.c')) if have_vhost_user_crypto softmmu_ss.add(when: 'CONFIG_VIRTIO_CRYPTO', if_true: files('cryptodev-vhost-user.c')) diff --git a/backends/trace-events b/backends/trace-events index 652eb76a57..2c8af3e726 100644 --- a/backends/trace-events +++ b/backends/trace-events @@ -5,3 +5,15 @@ dbus_vmstate_pre_save(void) dbus_vmstate_post_load(int version_id) "version_id: %d" dbus_vmstate_loading(const char *id) "id: %s" dbus_vmstate_saving(const char *id) "id: %s" + +# iommufd.c +iommufd_backend_connect(int fd, bool owned, uint32_t users, int ret) "fd=%d owned=%d users=%d (%d)" +iommufd_backend_disconnect(int fd, uint32_t users) "fd=%d users=%d" +iommu_backend_set_fd(int fd) "pre-opened /dev/iommu fd=%d" +iommufd_backend_get_ioas(int iommufd, uint32_t ioas, int ret) " iommufd=%d ioas=%d (%d)" +iommufd_backend_put_ioas(int iommufd, uint32_t ioas) " iommufd=%d ioas=%d" +iommufd_backend_unmap_dma(int iommufd, uint32_t ioas, uint64_t iova, uint64_t size, int ret) " iommufd=%d ioas=%d iova=0x%"PRIx64" size=0x%"PRIx64" (%d)" +iommufd_backend_map_dma(int iommufd, uint32_t ioas, uint64_t iova, uint64_t size, void *vaddr, bool readonly, int ret) " iommufd=%d ioas=%d iova=0x%"PRIx64" size=0x%"PRIx64" addr=%p readonly=%d (%d)" +iommufd_backend_copy_dma(int iommufd, uint32_t src_ioas, uint32_t dst_ioas, uint64_t iova, uint64_t size, bool readonly, int ret) " iommufd=%d src_ioas=%d dst_ioas=%d iova=0x%"PRIx64" size=0x%"PRIx64" readonly=%d (%d)" +iommufd_backend_alloc_ioas(int iommufd, uint32_t ioas, int ret) " iommufd=%d ioas=%d (%d)" +iommufd_backend_free_ioas(int iommufd, uint32_t ioas, int ret) " iommufd=%d ioas=%d (%d)" diff --git a/include/sysemu/iommufd.h b/include/sysemu/iommufd.h new file mode 100644 index 0000000000..06a866d1bd --- /dev/null +++ b/include/sysemu/iommufd.h @@ -0,0 +1,47 @@ +#ifndef SYSEMU_IOMMUFD_H +#define SYSEMU_IOMMUFD_H + +#include "qom/object.h" +#include "qemu/thread.h" +#include "exec/hwaddr.h" +#include "exec/ram_addr.h" + +#define TYPE_IOMMUFD_BACKEND "iommufd" +OBJECT_DECLARE_TYPE(IOMMUFDBackend, IOMMUFDBackendClass, + IOMMUFD_BACKEND) +#define IOMMUFD_BACKEND(obj) \ + OBJECT_CHECK(IOMMUFDBackend, (obj), TYPE_IOMMUFD_BACKEND) +#define IOMMUFD_BACKEND_GET_CLASS(obj) \ + OBJECT_GET_CLASS(IOMMUFDBackendClass, (obj), TYPE_IOMMUFD_BACKEND) +#define IOMMUFD_BACKEND_CLASS(klass) \ + OBJECT_CLASS_CHECK(IOMMUFDBackendClass, (klass), TYPE_IOMMUFD_BACKEND) +struct IOMMUFDBackendClass { + ObjectClass parent_class; +}; + +struct IOMMUFDBackend { + Object parent; + + /*< protected >*/ + int fd; /* /dev/iommu file descriptor */ + bool owned; /* is the /dev/iommu opened internally */ + QemuMutex lock; + uint32_t users; + + /*< public >*/ +}; + +int iommufd_backend_connect(IOMMUFDBackend *be, Error **errp); +void iommufd_backend_disconnect(IOMMUFDBackend *be); + +int iommufd_backend_get_ioas(IOMMUFDBackend *be, uint32_t *ioas_id); +void iommufd_backend_put_ioas(IOMMUFDBackend *be, uint32_t ioas_id); +int iommufd_backend_unmap_dma(IOMMUFDBackend *be, uint32_t ioas, + hwaddr iova, ram_addr_t size); +int iommufd_backend_map_dma(IOMMUFDBackend *be, uint32_t ioas, hwaddr iova, + ram_addr_t size, void *vaddr, bool readonly); +int iommufd_backend_copy_dma(IOMMUFDBackend *be, uint32_t src_ioas, + uint32_t dst_ioas, hwaddr iova, + ram_addr_t size, bool readonly); + +#endif diff --git a/qapi/qom.json b/qapi/qom.json index 6a653c6636..f609e7f667 100644 --- a/qapi/qom.json +++ b/qapi/qom.json @@ -734,6 +734,18 @@ { 'struct': 'RemoteObjectProperties', 'data': { 'fd': 'str', 'devid': 'str' } } +## +# @IOMMUFDProperties: +# +# Properties for IOMMUFDbackend objects. +# +# fd: file descriptor name +# +# Since: 7.2 +## +{ 'struct': 'IOMMUFDProperties', + 'data': { '*fd': 'str' } } + ## # @RngProperties: # @@ -862,6 +874,7 @@ 'qtest', 'rng-builtin', 'rng-egd', + 'iommufd', { 'name': 'rng-random', 'if': 'CONFIG_POSIX' }, 'secret', @@ -938,7 +951,8 @@ 'tls-creds-psk': 'TlsCredsPskProperties', 'tls-creds-x509': 'TlsCredsX509Properties', 'tls-cipher-suites': 'TlsCredsProperties', - 'x-remote-object': 'RemoteObjectProperties' + 'x-remote-object': 'RemoteObjectProperties', + 'iommufd': 'IOMMUFDProperties' } } ## diff --git a/qemu-options.hx b/qemu-options.hx index 60cf188da4..2f7204d826 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4860,6 +4860,18 @@ SRST The ``share`` boolean option is on by default with memfd. + ``-object iommufd,id=id[,fd=fd]`` + Creates an iommufd backend which allows control of DMA mapping + through the /dev/iommu device. + + The ``id`` parameter is a unique ID which frontends (such as + vfio-pci of vdpa) will use to connect withe the iommufd backend. + + The ``fd`` parameter is an optional pre-opened file descriptor + resulting from /dev/iommu opening. Usually the iommufd is shared + accross all subsystems, bringing the benefit of centralized + reference counting. + ``-object rng-builtin,id=id`` Creates a random number generator backend which obtains entropy from QEMU builtin functions. The ``id`` parameter is a unique ID -- 2.27.0
