From mboxrd@z Thu Jan 1 00:00:00 1970 From: Auger Eric Subject: Re: [RFC PATCH v2 1/5] iommu: Add virtio-iommu driver Date: Mon, 15 Jan 2018 16:12:44 +0100 Message-ID: <54320f26-05a5-9a09-f6cf-ae610c41e077@redhat.com> References: <20171117185211.32593-1-jean-philippe.brucker@arm.com> <20171117185211.32593-2-jean-philippe.brucker@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:60890 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933952AbeAOPNp (ORCPT ); Mon, 15 Jan 2018 10:13:45 -0500 In-Reply-To: <20171117185211.32593-2-jean-philippe.brucker@arm.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Jean-Philippe Brucker , iommu@lists.linux-foundation.org, devel@acpica.org, linux-acpi@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, virtualization@lists.linux-foundation.org, virtio-dev@lists.oasis-open.org Cc: jasowang@redhat.com, mst@redhat.com, lv.zheng@intel.com, robert.moore@intel.com, joro@8bytes.org, alex.williamson@redhat.com, sudeep.holla@arm.com, hanjun.guo@linaro.org, lorenzo.pieralisi@arm.com, lenb@kernel.org, rjw@rjwysocki.net, marc.zyngier@arm.com, robin.murphy@arm.com, will.deacon@arm.com, bharat.bhushan@nxp.com, Jayachandran.Nair@cavium.com, ashok.raj@intel.com, peterx@redhat.com Hi Jean-Philippe, please find some comments below. On 17/11/17 19:52, Jean-Philippe Brucker wrote: > The virtio IOMMU is a para-virtualized device, allowing to send IOMMU > requests such as map/unmap over virtio-mmio transport without emulating > page tables. This implementation handle ATTACH, DETACH, MAP and UNMAP handles > requests. > > The bulk of the code is to create requests and send them through virtio. > Implementing the IOMMU API is fairly straightforward since the > virtio-iommu MAP/UNMAP interface is almost identical. > > Signed-off-by: Jean-Philippe Brucker > --- > drivers/iommu/Kconfig | 11 + > drivers/iommu/Makefile | 1 + > drivers/iommu/virtio-iommu.c | 958 ++++++++++++++++++++++++++++++++++++++ > include/uapi/linux/virtio_ids.h | 1 + > include/uapi/linux/virtio_iommu.h | 140 ++++++ > 5 files changed, 1111 insertions(+) > create mode 100644 drivers/iommu/virtio-iommu.c > create mode 100644 include/uapi/linux/virtio_iommu.h > > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig > index 17b212f56e6a..7271e59e8b23 100644 > --- a/drivers/iommu/Kconfig > +++ b/drivers/iommu/Kconfig > @@ -403,4 +403,15 @@ config QCOM_IOMMU > help > Support for IOMMU on certain Qualcomm SoCs. > > +config VIRTIO_IOMMU > + bool "Virtio IOMMU driver" > + depends on VIRTIO_MMIO > + select IOMMU_API > + select INTERVAL_TREE > + select ARM_DMA_USE_IOMMU if ARM > + help > + Para-virtualised IOMMU driver with virtio. > + > + Say Y here if you intend to run this kernel as a guest. > + > endif # IOMMU_SUPPORT > diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile > index dca71fe1c885..432242f3a328 100644 > --- a/drivers/iommu/Makefile > +++ b/drivers/iommu/Makefile > @@ -31,3 +31,4 @@ obj-$(CONFIG_EXYNOS_IOMMU) += exynos-iommu.o > obj-$(CONFIG_FSL_PAMU) += fsl_pamu.o fsl_pamu_domain.o > obj-$(CONFIG_S390_IOMMU) += s390-iommu.o > obj-$(CONFIG_QCOM_IOMMU) += qcom_iommu.o > +obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o > diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c > new file mode 100644 > index 000000000000..feb8c8925c3a > --- /dev/null > +++ b/drivers/iommu/virtio-iommu.c > @@ -0,0 +1,958 @@ > +/* > + * Virtio driver for the paravirtualized IOMMU > + * > + * Copyright (C) 2017 ARM Limited > + * Author: Jean-Philippe Brucker > + * > + * SPDX-License-Identifier: GPL-2.0 > + */ > + > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include > + > +#define MSI_IOVA_BASE 0x8000000 > +#define MSI_IOVA_LENGTH 0x100000 > + > +struct viommu_dev { > + struct iommu_device iommu; > + struct device *dev; > + struct virtio_device *vdev; > + > + struct ida domain_ids; > + > + struct virtqueue *vq; > + /* Serialize anything touching the request queue */ > + spinlock_t request_lock; > + > + /* Device configuration */ > + struct iommu_domain_geometry geometry; > + u64 pgsize_bitmap; > + u8 domain_bits; > +}; > + > +struct viommu_mapping { > + phys_addr_t paddr; > + struct interval_tree_node iova; > + union { > + struct virtio_iommu_req_map map; > + struct virtio_iommu_req_unmap unmap; > + } req; > +}; > + > +struct viommu_domain { > + struct iommu_domain domain; > + struct viommu_dev *viommu; > + struct mutex mutex; > + unsigned int id; > + > + spinlock_t mappings_lock; > + struct rb_root_cached mappings; > + > + /* Number of endpoints attached to this domain */ > + refcount_t endpoints; > +}; > + > +struct viommu_endpoint { > + struct viommu_dev *viommu; > + struct viommu_domain *vdomain; > +}; > + > +struct viommu_request { > + struct scatterlist top; > + struct scatterlist bottom; > + > + int written; > + struct list_head list; > +}; > + > +#define to_viommu_domain(domain) container_of(domain, struct viommu_domain, domain) > + > +/* Virtio transport */ > + > +static int viommu_status_to_errno(u8 status) > +{ > + switch (status) { > + case VIRTIO_IOMMU_S_OK: > + return 0; > + case VIRTIO_IOMMU_S_UNSUPP: > + return -ENOSYS; > + case VIRTIO_IOMMU_S_INVAL: > + return -EINVAL; > + case VIRTIO_IOMMU_S_RANGE: > + return -ERANGE; > + case VIRTIO_IOMMU_S_NOENT: > + return -ENOENT; > + case VIRTIO_IOMMU_S_FAULT: > + return -EFAULT; > + case VIRTIO_IOMMU_S_IOERR: > + case VIRTIO_IOMMU_S_DEVERR: > + default: > + return -EIO; > + } > +} > + > +/* > + * viommu_get_req_size - compute request size > + * > + * A virtio-iommu request is split into one device-read-only part (top) and one > + * device-write-only part (bottom). Given a request, return the sizes of the two > + * parts in @top and @bottom. for all but virtio_iommu_req_probe, which has a variable bottom size > + * > + * Return 0 on success, or an error when the request seems invalid. > + */ > +static int viommu_get_req_size(struct viommu_dev *viommu, > + struct virtio_iommu_req_head *req, size_t *top, > + size_t *bottom) > +{ > + size_t size; > + union virtio_iommu_req *r = (void *)req; > + > + *bottom = sizeof(struct virtio_iommu_req_tail); > + > + switch (req->type) { > + case VIRTIO_IOMMU_T_ATTACH: > + size = sizeof(r->attach); > + break; > + case VIRTIO_IOMMU_T_DETACH: > + size = sizeof(r->detach); > + break; > + case VIRTIO_IOMMU_T_MAP: > + size = sizeof(r->map); > + break; > + case VIRTIO_IOMMU_T_UNMAP: > + size = sizeof(r->unmap); > + break; > + default: > + return -EINVAL; > + } > + > + *top = size - *bottom; > + return 0; > +} > + > +static int viommu_receive_resp(struct viommu_dev *viommu, int nr_sent, > + struct list_head *sent) > +{ > + > + unsigned int len; > + int nr_received = 0; > + struct viommu_request *req, *pending; > + > + pending = list_first_entry_or_null(sent, struct viommu_request, list); > + if (WARN_ON(!pending)) > + return 0; > + > + while ((req = virtqueue_get_buf(viommu->vq, &len)) != NULL) { > + if (req != pending) { > + dev_warn(viommu->dev, "discarding stale request\n"); > + continue; > + } > + > + pending->written = len; > + > + if (++nr_received == nr_sent) { > + WARN_ON(!list_is_last(&pending->list, sent)); > + break; > + } else if (WARN_ON(list_is_last(&pending->list, sent))) { > + break; > + } > + > + pending = list_next_entry(pending, list); > + } > + > + return nr_received; > +} > + > +/* Must be called with request_lock held */ > +static int _viommu_send_reqs_sync(struct viommu_dev *viommu, > + struct viommu_request *req, int nr, > + int *nr_sent) > +{ > + int i, ret; > + ktime_t timeout; > + LIST_HEAD(pending); > + int nr_received = 0; > + struct scatterlist *sg[2]; > + /* > + * Yes, 1s timeout. As a guest, we don't necessarily have a precise > + * notion of time and this just prevents locking up a CPU if the device > + * dies. > + */ > + unsigned long timeout_ms = 1000; > + > + *nr_sent = 0; > + > + for (i = 0; i < nr; i++, req++) { > + req->written = 0; > + > + sg[0] = &req->top; > + sg[1] = &req->bottom; > + > + ret = virtqueue_add_sgs(viommu->vq, sg, 1, 1, req, > + GFP_ATOMIC); > + if (ret) > + break; > + > + list_add_tail(&req->list, &pending); > + } > + > + if (i && !virtqueue_kick(viommu->vq)) > + return -EPIPE; > + > + timeout = ktime_add_ms(ktime_get(), timeout_ms * i); I don't really understand how you choose your timeout value: 1s per sent request. > + while (nr_received < i && ktime_before(ktime_get(), timeout)) { > + nr_received += viommu_receive_resp(viommu, i - nr_received, > + &pending); > + if (nr_received < i) { > + /* > + * FIXME: what's a good way to yield to host? A second > + * virtqueue_kick won't have any effect since we haven't > + * added any descriptor. > + */ > + udelay(10); could you explain why udelay gets used here? > + } > + } > + > + if (nr_received != i) > + ret = -ETIMEDOUT; > + > + if (ret == -ENOSPC && nr_received) > + /* > + * We've freed some space since virtio told us that the ring is > + * full, tell the caller to come back for more. > + */ > + ret = -EAGAIN; > + > + *nr_sent = nr_received; > + > + return ret; > +} > + > +/* > + * viommu_send_reqs_sync - add a batch of requests, kick the host and wait for > + * them to return > + * > + * @req: array of requests > + * @nr: array length > + * @nr_sent: on return, contains the number of requests actually sent > + * > + * Return 0 on success, or an error if we failed to send some of the requests. > + */ > +static int viommu_send_reqs_sync(struct viommu_dev *viommu, > + struct viommu_request *req, int nr, > + int *nr_sent) > +{ > + int ret; > + int sent = 0; > + unsigned long flags; > + > + *nr_sent = 0; > + do { > + spin_lock_irqsave(&viommu->request_lock, flags); > + ret = _viommu_send_reqs_sync(viommu, req, nr, &sent); > + spin_unlock_irqrestore(&viommu->request_lock, flags); > + > + *nr_sent += sent; > + req += sent; > + nr -= sent; > + } while (ret == -EAGAIN); > + > + return ret; > +} > + > +/* > + * viommu_send_req_sync - send one request and wait for reply > + * > + * @top: pointer to a virtio_iommu_req_* structure > + * > + * Returns 0 if the request was successful, or an error number otherwise. No > + * distinction is done between transport and request errors. > + */ > +static int viommu_send_req_sync(struct viommu_dev *viommu, void *top) > +{ > + int ret; > + int nr_sent; > + void *bottom; > + struct viommu_request req = {0}; ^ drivers/iommu/virtio-iommu.c:326:9: warning: (near initialization for ‘req.top’) [-Wmissing-braces] > + size_t top_size, bottom_size; > + struct virtio_iommu_req_tail *tail; > + struct virtio_iommu_req_head *head = top; > + > + ret = viommu_get_req_size(viommu, head, &top_size, &bottom_size); > + if (ret) > + return ret; > + > + bottom = top + top_size; > + tail = bottom + bottom_size - sizeof(*tail); > + > + sg_init_one(&req.top, top, top_size); > + sg_init_one(&req.bottom, bottom, bottom_size); > + > + ret = viommu_send_reqs_sync(viommu, &req, 1, &nr_sent); > + if (ret || !req.written || nr_sent != 1) { > + dev_err(viommu->dev, "failed to send request\n"); > + return -EIO; > + } > + > + return viommu_status_to_errno(tail->status); > +} > + > +/* > + * viommu_add_mapping - add a mapping to the internal tree > + * > + * On success, return the new mapping. Otherwise return NULL. > + */ > +static struct viommu_mapping * > +viommu_add_mapping(struct viommu_domain *vdomain, unsigned long iova, > + phys_addr_t paddr, size_t size) > +{ > + unsigned long flags; > + struct viommu_mapping *mapping; > + > + mapping = kzalloc(sizeof(*mapping), GFP_ATOMIC); > + if (!mapping) > + return NULL; > + > + mapping->paddr = paddr; > + mapping->iova.start = iova; > + mapping->iova.last = iova + size - 1; > + > + spin_lock_irqsave(&vdomain->mappings_lock, flags); > + interval_tree_insert(&mapping->iova, &vdomain->mappings); > + spin_unlock_irqrestore(&vdomain->mappings_lock, flags); > + > + return mapping; > +} > + > +/* > + * viommu_del_mappings - remove mappings from the internal tree > + * > + * @vdomain: the domain > + * @iova: start of the range > + * @size: size of the range. A size of 0 corresponds to the entire address > + * space. > + * @out_mapping: if not NULL, the first removed mapping is returned in there. > + * This allows the caller to reuse the buffer for the unmap request. Caller > + * must always free the returned mapping, whether the function succeeds or > + * not. if unmapped > 0? > + * > + * On success, returns the number of unmapped bytes (>= size) > + */ > +static size_t viommu_del_mappings(struct viommu_domain *vdomain, > + unsigned long iova, size_t size, > + struct viommu_mapping **out_mapping) > +{ > + size_t unmapped = 0; > + unsigned long flags; > + unsigned long last = iova + size - 1; > + struct viommu_mapping *mapping = NULL; > + struct interval_tree_node *node, *next; > + > + spin_lock_irqsave(&vdomain->mappings_lock, flags); > + next = interval_tree_iter_first(&vdomain->mappings, iova, last); > + > + if (next) { > + mapping = container_of(next, struct viommu_mapping, iova); > + /* Trying to split a mapping? */ > + if (WARN_ON(mapping->iova.start < iova)) > + next = NULL; > + } > + > + while (next) { > + node = next; > + mapping = container_of(node, struct viommu_mapping, iova); > + > + next = interval_tree_iter_next(node, iova, last); > + > + /* > + * Note that for a partial range, this will return the full > + * mapping so we avoid sending split requests to the device. > + */ > + unmapped += mapping->iova.last - mapping->iova.start + 1; > + > + interval_tree_remove(node, &vdomain->mappings); > + > + if (out_mapping && !(*out_mapping)) > + *out_mapping = mapping; > + else > + kfree(mapping); > + } > + spin_unlock_irqrestore(&vdomain->mappings_lock, flags); > + > + return unmapped; > +} > + > +/* > + * viommu_replay_mappings - re-send MAP requests > + * > + * When reattaching a domain that was previously detached from all devices, > + * mappings were deleted from the device. Re-create the mappings available in > + * the internal tree. > + * > + * Caller should hold the mapping lock if necessary. the only caller does not hold the lock. At this point we are attaching our fisrt ep to the domain. I think it would be worth a comment in the caller. > + */ > +static int viommu_replay_mappings(struct viommu_domain *vdomain) > +{ > + int i = 1, ret, nr_sent; > + struct viommu_request *reqs; > + struct viommu_mapping *mapping; > + struct interval_tree_node *node; > + size_t top_size, bottom_size; > + > + node = interval_tree_iter_first(&vdomain->mappings, 0, -1UL); > + if (!node) > + return 0; > + > + while ((node = interval_tree_iter_next(node, 0, -1UL)) != NULL) > + i++; > + > + reqs = kcalloc(i, sizeof(*reqs), GFP_KERNEL); > + if (!reqs) > + return -ENOMEM; > + > + bottom_size = sizeof(struct virtio_iommu_req_tail); > + top_size = sizeof(struct virtio_iommu_req_map) - bottom_size; > + > + i = 0; > + node = interval_tree_iter_first(&vdomain->mappings, 0, -1UL); > + while (node) { > + mapping = container_of(node, struct viommu_mapping, iova); > + sg_init_one(&reqs[i].top, &mapping->req.map, top_size); > + sg_init_one(&reqs[i].bottom, &mapping->req.map.tail, > + bottom_size); > + > + node = interval_tree_iter_next(node, 0, -1UL); > + i++; > + } > + > + ret = viommu_send_reqs_sync(vdomain->viommu, reqs, i, &nr_sent); > + kfree(reqs); > + > + return ret; > +} > + > +/* IOMMU API */ > + > +static bool viommu_capable(enum iommu_cap cap) > +{ > + return false; /* :( */ > +} > + > +static struct iommu_domain *viommu_domain_alloc(unsigned type) > +{ > + struct viommu_domain *vdomain; > + > + if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA) > + return NULL; > + > + vdomain = kzalloc(sizeof(*vdomain), GFP_KERNEL); > + if (!vdomain) > + return NULL; > + > + mutex_init(&vdomain->mutex); > + spin_lock_init(&vdomain->mappings_lock); > + vdomain->mappings = RB_ROOT_CACHED; > + refcount_set(&vdomain->endpoints, 0); > + > + if (type == IOMMU_DOMAIN_DMA && > + iommu_get_dma_cookie(&vdomain->domain)) { > + kfree(vdomain); > + return NULL; > + } > + > + return &vdomain->domain; > +} > + > +static int viommu_domain_finalise(struct viommu_dev *viommu, > + struct iommu_domain *domain) > +{ > + int ret; > + struct viommu_domain *vdomain = to_viommu_domain(domain); > + /* ida limits size to 31 bits. A value of 0 means "max" */ > + unsigned int max_domain = viommu->domain_bits >= 31 ? 0 : > + 1U << viommu->domain_bits; > + > + vdomain->viommu = viommu; > + > + domain->pgsize_bitmap = viommu->pgsize_bitmap; > + domain->geometry = viommu->geometry; > + > + ret = ida_simple_get(&viommu->domain_ids, 0, max_domain, GFP_KERNEL); > + if (ret >= 0) > + vdomain->id = (unsigned int)ret; > + > + return ret > 0 ? 0 : ret; > +} > + > +static void viommu_domain_free(struct iommu_domain *domain) > +{ > + struct viommu_domain *vdomain = to_viommu_domain(domain); > + > + iommu_put_dma_cookie(domain); > + > + /* Free all remaining mappings (size 2^64) */ > + viommu_del_mappings(vdomain, 0, 0, NULL); > + > + if (vdomain->viommu) > + ida_simple_remove(&vdomain->viommu->domain_ids, vdomain->id); > + > + kfree(vdomain); > +} > + > +static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev) > +{ > + int i; > + int ret = 0; > + struct virtio_iommu_req_attach *req; > + struct iommu_fwspec *fwspec = dev->iommu_fwspec; > + struct viommu_endpoint *vdev = fwspec->iommu_priv; > + struct viommu_domain *vdomain = to_viommu_domain(domain); > + > + mutex_lock(&vdomain->mutex); > + if (!vdomain->viommu) { > + /* > + * Initialize the domain proper now that we know which viommu > + * owns it. > + */ > + ret = viommu_domain_finalise(vdev->viommu, domain); > + } else if (vdomain->viommu != vdev->viommu) { > + dev_err(dev, "cannot attach to foreign vIOMMU\n"); > + ret = -EXDEV; > + } > + mutex_unlock(&vdomain->mutex); > + > + if (ret) > + return ret; > + > + /* > + * When attaching the device to a new domain, it will be detached from > + * the old one and, if as as a result the old domain isn't attached to as as > + * any device, all mappings are removed from the old domain and it is > + * freed. (Note that we can't use get_domain_for_dev here, it returns > + * the default domain during initial attach.) I don't see where the old domain is freed. I see you descrement the endpoints ref count. Also if you replay the mapping, I guess the mappings were not destroyed? > + * > + * Take note of the device disappearing, so we can ignore unmap request > + * on stale domains (that is, between this detach and the upcoming > + * free.) > + * > + * vdev->vdomain is protected by group->mutex > + */ > + if (vdev->vdomain) > + refcount_dec(&vdev->vdomain->endpoints); > + > + /* DMA to the stack is forbidden, store request on the heap */ > + req = kzalloc(sizeof(*req), GFP_KERNEL); > + if (!req) > + return -ENOMEM; > + > + *req = (struct virtio_iommu_req_attach) { > + .head.type = VIRTIO_IOMMU_T_ATTACH, > + .domain = cpu_to_le32(vdomain->id), > + }; > + > + for (i = 0; i < fwspec->num_ids; i++) { > + req->endpoint = cpu_to_le32(fwspec->ids[i]); > + > + ret = viommu_send_req_sync(vdomain->viommu, req); > + if (ret) > + break; > + } > + > + kfree(req); > + > + if (ret) > + return ret; > + > + if (!refcount_read(&vdomain->endpoints)) { > + /* > + * This endpoint is the first to be attached to the domain. > + * Replay existing mappings if any. > + */ > + ret = viommu_replay_mappings(vdomain); > + if (ret) > + return ret; > + } > + > + refcount_inc(&vdomain->endpoints); This does not work for me as the ref counter is initialized to 0 and ref_count does not work if the counter is 0. It emits a WARN_ON and stays at 0. I worked around the issue by explicitly setting recount_set(&vdomain->endpoints, 1) if it was 0 and reffount_inc otherwise. > + vdev->vdomain = vdomain; > + > + return 0; > +} > + > +static int viommu_map(struct iommu_domain *domain, unsigned long iova, > + phys_addr_t paddr, size_t size, int prot) > +{ > + int ret; > + int flags; > + struct viommu_mapping *mapping; > + struct viommu_domain *vdomain = to_viommu_domain(domain); > + > + mapping = viommu_add_mapping(vdomain, iova, paddr, size); > + if (!mapping) > + return -ENOMEM; > + > + flags = (prot & IOMMU_READ ? VIRTIO_IOMMU_MAP_F_READ : 0) | > + (prot & IOMMU_WRITE ? VIRTIO_IOMMU_MAP_F_WRITE : 0); > + > + mapping->req.map = (struct virtio_iommu_req_map) { > + .head.type = VIRTIO_IOMMU_T_MAP, > + .domain = cpu_to_le32(vdomain->id), > + .virt_addr = cpu_to_le64(iova), > + .phys_addr = cpu_to_le64(paddr), > + .size = cpu_to_le64(size), > + .flags = cpu_to_le32(flags), > + }; > + > + if (!refcount_read(&vdomain->endpoints)) > + return 0; > + > + ret = viommu_send_req_sync(vdomain->viommu, &mapping->req); > + if (ret) > + viommu_del_mappings(vdomain, iova, size, NULL); > + > + return ret; > +} > + > +static size_t viommu_unmap(struct iommu_domain *domain, unsigned long iova, > + size_t size) > +{ > + int ret = 0; > + size_t unmapped; > + struct viommu_mapping *mapping = NULL; > + struct viommu_domain *vdomain = to_viommu_domain(domain); > + > + unmapped = viommu_del_mappings(vdomain, iova, size, &mapping); > + if (unmapped < size) { > + ret = -EINVAL; > + goto out_free; > + } > + > + /* Device already removed all mappings after detach. */ > + if (!refcount_read(&vdomain->endpoints)) > + goto out_free; > + > + if (WARN_ON(!mapping)) > + return 0; > + > + mapping->req.unmap = (struct virtio_iommu_req_unmap) { > + .head.type = VIRTIO_IOMMU_T_UNMAP, > + .domain = cpu_to_le32(vdomain->id), > + .virt_addr = cpu_to_le64(iova), > + .size = cpu_to_le64(unmapped), > + }; > + > + ret = viommu_send_req_sync(vdomain->viommu, &mapping->req); > + > +out_free: > + if (mapping) > + kfree(mapping); > + > + return ret ? 0 : unmapped; > +} > + > +static phys_addr_t viommu_iova_to_phys(struct iommu_domain *domain, > + dma_addr_t iova) > +{ > + u64 paddr = 0; > + unsigned long flags; > + struct viommu_mapping *mapping; > + struct interval_tree_node *node; > + struct viommu_domain *vdomain = to_viommu_domain(domain); > + > + spin_lock_irqsave(&vdomain->mappings_lock, flags); > + node = interval_tree_iter_first(&vdomain->mappings, iova, iova); > + if (node) { > + mapping = container_of(node, struct viommu_mapping, iova); > + paddr = mapping->paddr + (iova - mapping->iova.start); > + } > + spin_unlock_irqrestore(&vdomain->mappings_lock, flags); > + > + return paddr; > +} > + > +static struct iommu_ops viommu_ops; > +static struct virtio_driver virtio_iommu_drv; > + > +static int viommu_match_node(struct device *dev, void *data) > +{ > + return dev->parent->fwnode == data; > +} > + > +static struct viommu_dev *viommu_get_by_fwnode(struct fwnode_handle *fwnode) > +{ > + struct device *dev = driver_find_device(&virtio_iommu_drv.driver, NULL, > + fwnode, viommu_match_node); > + put_device(dev); > + > + return dev ? dev_to_virtio(dev)->priv : NULL; > +} > + > +static int viommu_add_device(struct device *dev) > +{ > + struct iommu_group *group; > + struct viommu_endpoint *vdev; > + struct viommu_dev *viommu = NULL; > + struct iommu_fwspec *fwspec = dev->iommu_fwspec; > + > + if (!fwspec || fwspec->ops != &viommu_ops) > + return -ENODEV; > + > + viommu = viommu_get_by_fwnode(fwspec->iommu_fwnode); > + if (!viommu) > + return -ENODEV; > + > + vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); > + if (!vdev) > + return -ENOMEM; > + > + vdev->viommu = viommu; > + fwspec->iommu_priv = vdev; > + > + /* > + * Last step creates a default domain and attaches to it. Everything > + * must be ready. > + */ > + group = iommu_group_get_for_dev(dev); > + if (!IS_ERR(group)) > + iommu_group_put(group); > + > + return PTR_ERR_OR_ZERO(group); > +} > + > +static void viommu_remove_device(struct device *dev) > +{ > + kfree(dev->iommu_fwspec->iommu_priv); > +} > + > +static struct iommu_group *viommu_device_group(struct device *dev) > +{ > + if (dev_is_pci(dev)) > + return pci_device_group(dev); > + else > + return generic_device_group(dev); > +} > + > +static int viommu_of_xlate(struct device *dev, struct of_phandle_args *args) > +{ > + return iommu_fwspec_add_ids(dev, args->args, 1); > +} > + > +static void viommu_get_resv_regions(struct device *dev, struct list_head *head) > +{ > + struct iommu_resv_region *region; > + int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO; > + > + region = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH, prot, > + IOMMU_RESV_SW_MSI); > + if (!region) > + return; > + > + list_add_tail(®ion->list, head); > +} > + > +static void viommu_put_resv_regions(struct device *dev, struct list_head *head) > +{ > + struct iommu_resv_region *entry, *next; > + > + list_for_each_entry_safe(entry, next, head, list) > + kfree(entry); > +} > + > +static struct iommu_ops viommu_ops = { > + .capable = viommu_capable, > + .domain_alloc = viommu_domain_alloc, > + .domain_free = viommu_domain_free, > + .attach_dev = viommu_attach_dev, > + .map = viommu_map, > + .unmap = viommu_unmap, > + .map_sg = default_iommu_map_sg, > + .iova_to_phys = viommu_iova_to_phys, > + .add_device = viommu_add_device, > + .remove_device = viommu_remove_device, > + .device_group = viommu_device_group, > + .of_xlate = viommu_of_xlate, > + .get_resv_regions = viommu_get_resv_regions, > + .put_resv_regions = viommu_put_resv_regions, > +}; > + > +static int viommu_init_vq(struct viommu_dev *viommu) > +{ > + struct virtio_device *vdev = dev_to_virtio(viommu->dev); > + const char *name = "request"; > + void *ret; > + > + ret = virtio_find_single_vq(vdev, NULL, name); > + if (IS_ERR(ret)) { > + dev_err(viommu->dev, "cannot find VQ\n"); > + return PTR_ERR(ret); > + } > + > + viommu->vq = ret; > + > + return 0; > +} > + > +static int viommu_probe(struct virtio_device *vdev) > +{ > + struct device *parent_dev = vdev->dev.parent; > + struct viommu_dev *viommu = NULL; > + struct device *dev = &vdev->dev; > + u64 input_start = 0; > + u64 input_end = -1UL; > + int ret; > + > + viommu = kzalloc(sizeof(*viommu), GFP_KERNEL); > + if (!viommu) > + return -ENOMEM; > + > + spin_lock_init(&viommu->request_lock); > + ida_init(&viommu->domain_ids); > + viommu->dev = dev; > + viommu->vdev = vdev; > + > + ret = viommu_init_vq(viommu); > + if (ret) > + goto err_free_viommu; > + > + virtio_cread(vdev, struct virtio_iommu_config, page_size_mask, > + &viommu->pgsize_bitmap); > + > + if (!viommu->pgsize_bitmap) { > + ret = -EINVAL; > + goto err_free_viommu; > + } > + > + viommu->domain_bits = 32; > + > + /* Optional features */ > + virtio_cread_feature(vdev, VIRTIO_IOMMU_F_INPUT_RANGE, > + struct virtio_iommu_config, input_range.start, > + &input_start); > + > + virtio_cread_feature(vdev, VIRTIO_IOMMU_F_INPUT_RANGE, > + struct virtio_iommu_config, input_range.end, > + &input_end); > + > + virtio_cread_feature(vdev, VIRTIO_IOMMU_F_DOMAIN_BITS, > + struct virtio_iommu_config, domain_bits, > + &viommu->domain_bits); > + > + viommu->geometry = (struct iommu_domain_geometry) { > + .aperture_start = input_start, > + .aperture_end = input_end, > + .force_aperture = true, > + }; > + > + viommu_ops.pgsize_bitmap = viommu->pgsize_bitmap; > + > + virtio_device_ready(vdev); > + > + ret = iommu_device_sysfs_add(&viommu->iommu, dev, NULL, "%s", > + virtio_bus_name(vdev)); > + if (ret) > + goto err_free_viommu; > + > + iommu_device_set_ops(&viommu->iommu, &viommu_ops); > + iommu_device_set_fwnode(&viommu->iommu, parent_dev->fwnode); > + > + iommu_device_register(&viommu->iommu); > + > +#ifdef CONFIG_PCI > + if (pci_bus_type.iommu_ops != &viommu_ops) { > + pci_request_acs(); > + ret = bus_set_iommu(&pci_bus_type, &viommu_ops); > + if (ret) > + goto err_unregister; > + } > +#endif > +#ifdef CONFIG_ARM_AMBA > + if (amba_bustype.iommu_ops != &viommu_ops) { > + ret = bus_set_iommu(&amba_bustype, &viommu_ops); > + if (ret) > + goto err_unregister; > + } > +#endif > + if (platform_bus_type.iommu_ops != &viommu_ops) { > + ret = bus_set_iommu(&platform_bus_type, &viommu_ops); > + if (ret) > + goto err_unregister; > + } > + > + vdev->priv = viommu; > + > + dev_info(dev, "input address: %u bits\n", > + order_base_2(viommu->geometry.aperture_end)); > + dev_info(dev, "page mask: %#llx\n", viommu->pgsize_bitmap); > + > + return 0; > + > +err_unregister: > + iommu_device_unregister(&viommu->iommu); > + > +err_free_viommu: > + kfree(viommu); > + > + return ret; > +} > + > +static void viommu_remove(struct virtio_device *vdev) > +{ > + struct viommu_dev *viommu = vdev->priv; > + > + iommu_device_unregister(&viommu->iommu); > + kfree(viommu); > + > + dev_info(&vdev->dev, "device removed\n"); > +} > + > +static void viommu_config_changed(struct virtio_device *vdev) > +{ > + dev_warn(&vdev->dev, "config changed\n"); > +} > + > +static unsigned int features[] = { > + VIRTIO_IOMMU_F_MAP_UNMAP, > + VIRTIO_IOMMU_F_DOMAIN_BITS, > + VIRTIO_IOMMU_F_INPUT_RANGE, > +}; > + > +static struct virtio_device_id id_table[] = { > + { VIRTIO_ID_IOMMU, VIRTIO_DEV_ANY_ID }, > + { 0 }, > +}; > + > +static struct virtio_driver virtio_iommu_drv = { > + .driver.name = KBUILD_MODNAME, > + .driver.owner = THIS_MODULE, > + .id_table = id_table, > + .feature_table = features, > + .feature_table_size = ARRAY_SIZE(features), > + .probe = viommu_probe, > + .remove = viommu_remove, > + .config_changed = viommu_config_changed, > +}; > + > +module_virtio_driver(virtio_iommu_drv); > + > +IOMMU_OF_DECLARE(viommu, "virtio,mmio", NULL); > + > +MODULE_DESCRIPTION("Virtio IOMMU driver"); > +MODULE_AUTHOR("Jean-Philippe Brucker "); > +MODULE_LICENSE("GPL v2"); > diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h > index 6d5c3b2d4f4d..934ed3d3cd3f 100644 > --- a/include/uapi/linux/virtio_ids.h > +++ b/include/uapi/linux/virtio_ids.h > @@ -43,5 +43,6 @@ > #define VIRTIO_ID_INPUT 18 /* virtio input */ > #define VIRTIO_ID_VSOCK 19 /* virtio vsock transport */ > #define VIRTIO_ID_CRYPTO 20 /* virtio crypto */ > +#define VIRTIO_ID_IOMMU 61216 /* virtio IOMMU (temporary) */ > > #endif /* _LINUX_VIRTIO_IDS_H */ > diff --git a/include/uapi/linux/virtio_iommu.h b/include/uapi/linux/virtio_iommu.h > new file mode 100644 > index 000000000000..2b4cd2042897 > --- /dev/null > +++ b/include/uapi/linux/virtio_iommu.h > @@ -0,0 +1,140 @@ > +/* > + * Virtio-iommu definition v0.5 > + * > + * Copyright (C) 2017 ARM Ltd. > + * > + * This header is BSD licensed so anyone can use the definitions > + * to implement compatible drivers/servers: > + * > + * Redistribution and use in source and binary forms, with or without > + * modification, are permitted provided that the following conditions > + * are met: > + * 1. Redistributions of source code must retain the above copyright > + * notice, this list of conditions and the following disclaimer. > + * 2. Redistributions in binary form must reproduce the above copyright > + * notice, this list of conditions and the following disclaimer in the > + * documentation and/or other materials provided with the distribution. > + * 3. Neither the name of ARM Ltd. nor the names of its contributors > + * may be used to endorse or promote products derived from this software > + * without specific prior written permission. > + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS > + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT > + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS > + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL IBM OR > + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, > + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT > + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF > + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND > + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, > + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT > + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF > + * SUCH DAMAGE. > + */ > +#ifndef _UAPI_LINUX_VIRTIO_IOMMU_H > +#define _UAPI_LINUX_VIRTIO_IOMMU_H > + > +/* Feature bits */ > +#define VIRTIO_IOMMU_F_INPUT_RANGE 0 > +#define VIRTIO_IOMMU_F_DOMAIN_BITS 1 > +#define VIRTIO_IOMMU_F_MAP_UNMAP 2 > +#define VIRTIO_IOMMU_F_BYPASS 3 > + > +struct virtio_iommu_config { > + /* Supported page sizes */ > + __u64 page_size_mask; Get a warning ./usr/include/linux/virtio_iommu.h:45: found __[us]{8,16,32,64} type without #include > + /* Supported IOVA range */ > + struct virtio_iommu_range { > + __u64 start; > + __u64 end; > + } input_range; > + /* Max domain ID size */ > + __u8 domain_bits; > +} __packed; > + > +/* Request types */ > +#define VIRTIO_IOMMU_T_ATTACH 0x01 > +#define VIRTIO_IOMMU_T_DETACH 0x02 > +#define VIRTIO_IOMMU_T_MAP 0x03 > +#define VIRTIO_IOMMU_T_UNMAP 0x04 > + > +/* Status types */ > +#define VIRTIO_IOMMU_S_OK 0x00 > +#define VIRTIO_IOMMU_S_IOERR 0x01 > +#define VIRTIO_IOMMU_S_UNSUPP 0x02 > +#define VIRTIO_IOMMU_S_DEVERR 0x03 > +#define VIRTIO_IOMMU_S_INVAL 0x04 > +#define VIRTIO_IOMMU_S_RANGE 0x05 > +#define VIRTIO_IOMMU_S_NOENT 0x06 > +#define VIRTIO_IOMMU_S_FAULT 0x07 > + > +struct virtio_iommu_req_head { > + __u8 type; > + __u8 reserved[3]; > +} __packed; > + > +struct virtio_iommu_req_tail { > + __u8 status; > + __u8 reserved[3]; > +} __packed; > + > +struct virtio_iommu_req_attach { > + struct virtio_iommu_req_head head; > + > + __le32 domain; > + __le32 endpoint; > + __le32 reserved; > + > + struct virtio_iommu_req_tail tail; > +} __packed; > + > +struct virtio_iommu_req_detach { > + struct virtio_iommu_req_head head; > + > + __le32 endpoint; > + __le32 reserved; > + > + struct virtio_iommu_req_tail tail; > +} __packed; > + > +#define VIRTIO_IOMMU_MAP_F_READ (1 << 0) > +#define VIRTIO_IOMMU_MAP_F_WRITE (1 << 1) > +#define VIRTIO_IOMMU_MAP_F_EXEC (1 << 2) > + > +#define VIRTIO_IOMMU_MAP_F_MASK (VIRTIO_IOMMU_MAP_F_READ | \ > + VIRTIO_IOMMU_MAP_F_WRITE | \ > + VIRTIO_IOMMU_MAP_F_EXEC) > + > +struct virtio_iommu_req_map { > + struct virtio_iommu_req_head head; > + > + __le32 domain; > + __le64 virt_addr; > + __le64 phys_addr; > + __le64 size; > + __le32 flags; > + > + struct virtio_iommu_req_tail tail; > +} __packed; > + > +__packed > +struct virtio_iommu_req_unmap { > + struct virtio_iommu_req_head head; > + > + __le32 domain; > + __le64 virt_addr; > + __le64 size; > + __le32 reserved; > + > + struct virtio_iommu_req_tail tail; > +} __packed; > + > +union virtio_iommu_req { > + struct virtio_iommu_req_head head; > + > + struct virtio_iommu_req_attach attach; > + struct virtio_iommu_req_detach detach; > + struct virtio_iommu_req_map map; > + struct virtio_iommu_req_unmap unmap; > +}; > + > +#endif > Thanks Eric From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-2966-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [66.179.20.138]) by lists.oasis-open.org (Postfix) with ESMTP id 8AA9B58180AD for ; Mon, 15 Jan 2018 07:13:49 -0800 (PST) From: Auger Eric References: <20171117185211.32593-1-jean-philippe.brucker@arm.com> <20171117185211.32593-2-jean-philippe.brucker@arm.com> Message-ID: <54320f26-05a5-9a09-f6cf-ae610c41e077@redhat.com> Date: Mon, 15 Jan 2018 16:12:44 +0100 MIME-Version: 1.0 In-Reply-To: <20171117185211.32593-2-jean-philippe.brucker@arm.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: quoted-printable Subject: [virtio-dev] Re: [RFC PATCH v2 1/5] iommu: Add virtio-iommu driver To: Jean-Philippe Brucker , iommu@lists.linux-foundation.org, devel@acpica.org, linux-acpi@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, virtualization@lists.linux-foundation.org, virtio-dev@lists.oasis-open.org Cc: jasowang@redhat.com, mst@redhat.com, lv.zheng@intel.com, robert.moore@intel.com, joro@8bytes.org, alex.williamson@redhat.com, sudeep.holla@arm.com, hanjun.guo@linaro.org, lorenzo.pieralisi@arm.com, lenb@kernel.org, rjw@rjwysocki.net, marc.zyngier@arm.com, robin.murphy@arm.com, will.deacon@arm.com, bharat.bhushan@nxp.com, Jayachandran.Nair@cavium.com, ashok.raj@intel.com, peterx@redhat.com List-ID: Hi Jean-Philippe, please find some comments below. On 17/11/17 19:52, Jean-Philippe Brucker wrote: > The virtio IOMMU is a para-virtualized device, allowing to send IOMMU > requests such as map/unmap over virtio-mmio transport without emulating > page tables. This implementation handle ATTACH, DETACH, MAP and UNMAP handles > requests. >=20 > The bulk of the code is to create requests and send them through virtio. > Implementing the IOMMU API is fairly straightforward since the > virtio-iommu MAP/UNMAP interface is almost identical. >=20 > Signed-off-by: Jean-Philippe Brucker > --- > drivers/iommu/Kconfig | 11 + > drivers/iommu/Makefile | 1 + > drivers/iommu/virtio-iommu.c | 958 ++++++++++++++++++++++++++++++++= ++++++ > include/uapi/linux/virtio_ids.h | 1 + > include/uapi/linux/virtio_iommu.h | 140 ++++++ > 5 files changed, 1111 insertions(+) > create mode 100644 drivers/iommu/virtio-iommu.c > create mode 100644 include/uapi/linux/virtio_iommu.h >=20 > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig > index 17b212f56e6a..7271e59e8b23 100644 > --- a/drivers/iommu/Kconfig > +++ b/drivers/iommu/Kconfig > @@ -403,4 +403,15 @@ config QCOM_IOMMU > help > Support for IOMMU on certain Qualcomm SoCs. > =20 > +config VIRTIO_IOMMU > + bool "Virtio IOMMU driver" > + depends on VIRTIO_MMIO > + select IOMMU_API > + select INTERVAL_TREE > + select ARM_DMA_USE_IOMMU if ARM > + help > + Para-virtualised IOMMU driver with virtio. > + > + Say Y here if you intend to run this kernel as a guest. > + > endif # IOMMU_SUPPORT > diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile > index dca71fe1c885..432242f3a328 100644 > --- a/drivers/iommu/Makefile > +++ b/drivers/iommu/Makefile > @@ -31,3 +31,4 @@ obj-$(CONFIG_EXYNOS_IOMMU) +=3D exynos-iommu.o > obj-$(CONFIG_FSL_PAMU) +=3D fsl_pamu.o fsl_pamu_domain.o > obj-$(CONFIG_S390_IOMMU) +=3D s390-iommu.o > obj-$(CONFIG_QCOM_IOMMU) +=3D qcom_iommu.o > +obj-$(CONFIG_VIRTIO_IOMMU) +=3D virtio-iommu.o > diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c > new file mode 100644 > index 000000000000..feb8c8925c3a > --- /dev/null > +++ b/drivers/iommu/virtio-iommu.c > @@ -0,0 +1,958 @@ > +/* > + * Virtio driver for the paravirtualized IOMMU > + * > + * Copyright (C) 2017 ARM Limited > + * Author: Jean-Philippe Brucker > + * > + * SPDX-License-Identifier: GPL-2.0 > + */ > + > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include > + > +#define MSI_IOVA_BASE 0x8000000 > +#define MSI_IOVA_LENGTH 0x100000 > + > +struct viommu_dev { > + struct iommu_device iommu; > + struct device *dev; > + struct virtio_device *vdev; > + > + struct ida domain_ids; > + > + struct virtqueue *vq; > + /* Serialize anything touching the request queue */ > + spinlock_t request_lock; > + > + /* Device configuration */ > + struct iommu_domain_geometry geometry; > + u64 pgsize_bitmap; > + u8 domain_bits; > +}; > + > +struct viommu_mapping { > + phys_addr_t paddr; > + struct interval_tree_node iova; > + union { > + struct virtio_iommu_req_map map; > + struct virtio_iommu_req_unmap unmap; > + } req; > +}; > + > +struct viommu_domain { > + struct iommu_domain domain; > + struct viommu_dev *viommu; > + struct mutex mutex; > + unsigned int id; > + > + spinlock_t mappings_lock; > + struct rb_root_cached mappings; > + > + /* Number of endpoints attached to this domain */ > + refcount_t endpoints; > +}; > + > +struct viommu_endpoint { > + struct viommu_dev *viommu; > + struct viommu_domain *vdomain; > +}; > + > +struct viommu_request { > + struct scatterlist top; > + struct scatterlist bottom; > + > + int written; > + struct list_head list; > +}; > + > +#define to_viommu_domain(domain) container_of(domain, struct viommu_doma= in, domain) > + > +/* Virtio transport */ > + > +static int viommu_status_to_errno(u8 status) > +{ > + switch (status) { > + case VIRTIO_IOMMU_S_OK: > + return 0; > + case VIRTIO_IOMMU_S_UNSUPP: > + return -ENOSYS; > + case VIRTIO_IOMMU_S_INVAL: > + return -EINVAL; > + case VIRTIO_IOMMU_S_RANGE: > + return -ERANGE; > + case VIRTIO_IOMMU_S_NOENT: > + return -ENOENT; > + case VIRTIO_IOMMU_S_FAULT: > + return -EFAULT; > + case VIRTIO_IOMMU_S_IOERR: > + case VIRTIO_IOMMU_S_DEVERR: > + default: > + return -EIO; > + } > +} > + > +/* > + * viommu_get_req_size - compute request size > + * > + * A virtio-iommu request is split into one device-read-only part (top) = and one > + * device-write-only part (bottom). Given a request, return the sizes of= the two > + * parts in @top and @bottom. for all but virtio_iommu_req_probe, which has a variable bottom size > + * > + * Return 0 on success, or an error when the request seems invalid. > + */ > +static int viommu_get_req_size(struct viommu_dev *viommu, > + struct virtio_iommu_req_head *req, size_t *top, > + size_t *bottom) > +{ > + size_t size; > + union virtio_iommu_req *r =3D (void *)req; > + > + *bottom =3D sizeof(struct virtio_iommu_req_tail); > + > + switch (req->type) { > + case VIRTIO_IOMMU_T_ATTACH: > + size =3D sizeof(r->attach); > + break; > + case VIRTIO_IOMMU_T_DETACH: > + size =3D sizeof(r->detach); > + break; > + case VIRTIO_IOMMU_T_MAP: > + size =3D sizeof(r->map); > + break; > + case VIRTIO_IOMMU_T_UNMAP: > + size =3D sizeof(r->unmap); > + break; > + default: > + return -EINVAL; > + } > + > + *top =3D size - *bottom; > + return 0; > +} > + > +static int viommu_receive_resp(struct viommu_dev *viommu, int nr_sent, > + struct list_head *sent) > +{ > + > + unsigned int len; > + int nr_received =3D 0; > + struct viommu_request *req, *pending; > + > + pending =3D list_first_entry_or_null(sent, struct viommu_request, list); > + if (WARN_ON(!pending)) > + return 0; > + > + while ((req =3D virtqueue_get_buf(viommu->vq, &len)) !=3D NULL) { > + if (req !=3D pending) { > + dev_warn(viommu->dev, "discarding stale request\n"); > + continue; > + } > + > + pending->written =3D len; > + > + if (++nr_received =3D=3D nr_sent) { > + WARN_ON(!list_is_last(&pending->list, sent)); > + break; > + } else if (WARN_ON(list_is_last(&pending->list, sent))) { > + break; > + } > + > + pending =3D list_next_entry(pending, list); > + } > + > + return nr_received; > +} > + > +/* Must be called with request_lock held */ > +static int _viommu_send_reqs_sync(struct viommu_dev *viommu, > + struct viommu_request *req, int nr, > + int *nr_sent) > +{ > + int i, ret; > + ktime_t timeout; > + LIST_HEAD(pending); > + int nr_received =3D 0; > + struct scatterlist *sg[2]; > + /* > + * Yes, 1s timeout. As a guest, we don't necessarily have a precise > + * notion of time and this just prevents locking up a CPU if the device > + * dies. > + */ > + unsigned long timeout_ms =3D 1000; > + > + *nr_sent =3D 0; > + > + for (i =3D 0; i < nr; i++, req++) { > + req->written =3D 0; > + > + sg[0] =3D &req->top; > + sg[1] =3D &req->bottom; > + > + ret =3D virtqueue_add_sgs(viommu->vq, sg, 1, 1, req, > + GFP_ATOMIC); > + if (ret) > + break; > + > + list_add_tail(&req->list, &pending); > + } > + > + if (i && !virtqueue_kick(viommu->vq)) > + return -EPIPE; > + > + timeout =3D ktime_add_ms(ktime_get(), timeout_ms * i); I don't really understand how you choose your timeout value: 1s per sent request. > + while (nr_received < i && ktime_before(ktime_get(), timeout)) { > + nr_received +=3D viommu_receive_resp(viommu, i - nr_received, > + &pending); > + if (nr_received < i) { > + /* > + * FIXME: what's a good way to yield to host? A second > + * virtqueue_kick won't have any effect since we haven't > + * added any descriptor. > + */ > + udelay(10); could you explain why udelay gets used here? > + } > + } > + > + if (nr_received !=3D i) > + ret =3D -ETIMEDOUT; > + > + if (ret =3D=3D -ENOSPC && nr_received) > + /* > + * We've freed some space since virtio told us that the ring is > + * full, tell the caller to come back for more. > + */ > + ret =3D -EAGAIN; > + > + *nr_sent =3D nr_received; > + > + return ret; > +} > + > +/* > + * viommu_send_reqs_sync - add a batch of requests, kick the host and wa= it for > + * them to return > + * > + * @req: array of requests > + * @nr: array length > + * @nr_sent: on return, contains the number of requests actually sent > + * > + * Return 0 on success, or an error if we failed to send some of the req= uests. > + */ > +static int viommu_send_reqs_sync(struct viommu_dev *viommu, > + struct viommu_request *req, int nr, > + int *nr_sent) > +{ > + int ret; > + int sent =3D 0; > + unsigned long flags; > + > + *nr_sent =3D 0; > + do { > + spin_lock_irqsave(&viommu->request_lock, flags); > + ret =3D _viommu_send_reqs_sync(viommu, req, nr, &sent); > + spin_unlock_irqrestore(&viommu->request_lock, flags); > + > + *nr_sent +=3D sent; > + req +=3D sent; > + nr -=3D sent; > + } while (ret =3D=3D -EAGAIN); > + > + return ret; > +} > + > +/* > + * viommu_send_req_sync - send one request and wait for reply > + * > + * @top: pointer to a virtio_iommu_req_* structure > + * > + * Returns 0 if the request was successful, or an error number otherwise= . No > + * distinction is done between transport and request errors. > + */ > +static int viommu_send_req_sync(struct viommu_dev *viommu, void *top) > +{ > + int ret; > + int nr_sent; > + void *bottom; > + struct viommu_request req =3D {0}; ^ drivers/iommu/virtio-iommu.c:326:9: warning: (near initialization for =91req.top=92) [-Wmissing-braces] > + size_t top_size, bottom_size; > + struct virtio_iommu_req_tail *tail; > + struct virtio_iommu_req_head *head =3D top; > + > + ret =3D viommu_get_req_size(viommu, head, &top_size, &bottom_size); > + if (ret) > + return ret; > + > + bottom =3D top + top_size; > + tail =3D bottom + bottom_size - sizeof(*tail); > + > + sg_init_one(&req.top, top, top_size); > + sg_init_one(&req.bottom, bottom, bottom_size); > + > + ret =3D viommu_send_reqs_sync(viommu, &req, 1, &nr_sent); > + if (ret || !req.written || nr_sent !=3D 1) { > + dev_err(viommu->dev, "failed to send request\n"); > + return -EIO; > + } > + > + return viommu_status_to_errno(tail->status); > +} > + > +/* > + * viommu_add_mapping - add a mapping to the internal tree > + * > + * On success, return the new mapping. Otherwise return NULL. > + */ > +static struct viommu_mapping * > +viommu_add_mapping(struct viommu_domain *vdomain, unsigned long iova, > + phys_addr_t paddr, size_t size) > +{ > + unsigned long flags; > + struct viommu_mapping *mapping; > + > + mapping =3D kzalloc(sizeof(*mapping), GFP_ATOMIC); > + if (!mapping) > + return NULL; > + > + mapping->paddr =3D paddr; > + mapping->iova.start =3D iova; > + mapping->iova.last =3D iova + size - 1; > + > + spin_lock_irqsave(&vdomain->mappings_lock, flags); > + interval_tree_insert(&mapping->iova, &vdomain->mappings); > + spin_unlock_irqrestore(&vdomain->mappings_lock, flags); > + > + return mapping; > +} > + > +/* > + * viommu_del_mappings - remove mappings from the internal tree > + * > + * @vdomain: the domain > + * @iova: start of the range > + * @size: size of the range. A size of 0 corresponds to the entire addre= ss > + * space. > + * @out_mapping: if not NULL, the first removed mapping is returned in t= here. > + * This allows the caller to reuse the buffer for the unmap request. Cal= ler > + * must always free the returned mapping, whether the function succeeds = or > + * not. if unmapped > 0? > + * > + * On success, returns the number of unmapped bytes (>=3D size) > + */ > +static size_t viommu_del_mappings(struct viommu_domain *vdomain, > + unsigned long iova, size_t size, > + struct viommu_mapping **out_mapping) > +{ > + size_t unmapped =3D 0; > + unsigned long flags; > + unsigned long last =3D iova + size - 1; > + struct viommu_mapping *mapping =3D NULL; > + struct interval_tree_node *node, *next; > + > + spin_lock_irqsave(&vdomain->mappings_lock, flags); > + next =3D interval_tree_iter_first(&vdomain->mappings, iova, last); > + > + if (next) { > + mapping =3D container_of(next, struct viommu_mapping, iova); > + /* Trying to split a mapping? */ > + if (WARN_ON(mapping->iova.start < iova)) > + next =3D NULL; > + } > + > + while (next) { > + node =3D next; > + mapping =3D container_of(node, struct viommu_mapping, iova); > + > + next =3D interval_tree_iter_next(node, iova, last); > + > + /* > + * Note that for a partial range, this will return the full > + * mapping so we avoid sending split requests to the device. > + */ > + unmapped +=3D mapping->iova.last - mapping->iova.start + 1; > + > + interval_tree_remove(node, &vdomain->mappings); > + > + if (out_mapping && !(*out_mapping)) > + *out_mapping =3D mapping; > + else > + kfree(mapping); > + } > + spin_unlock_irqrestore(&vdomain->mappings_lock, flags); > + > + return unmapped; > +} > + > +/* > + * viommu_replay_mappings - re-send MAP requests > + * > + * When reattaching a domain that was previously detached from all devic= es, > + * mappings were deleted from the device. Re-create the mappings availab= le in > + * the internal tree. > + * > + * Caller should hold the mapping lock if necessary. the only caller does not hold the lock. At this point we are attaching our fisrt ep to the domain. I think it would be worth a comment in the caller. > + */ > +static int viommu_replay_mappings(struct viommu_domain *vdomain) > +{ > + int i =3D 1, ret, nr_sent; > + struct viommu_request *reqs; > + struct viommu_mapping *mapping; > + struct interval_tree_node *node; > + size_t top_size, bottom_size; > + > + node =3D interval_tree_iter_first(&vdomain->mappings, 0, -1UL); > + if (!node) > + return 0; > + > + while ((node =3D interval_tree_iter_next(node, 0, -1UL)) !=3D NULL) > + i++; > + > + reqs =3D kcalloc(i, sizeof(*reqs), GFP_KERNEL); > + if (!reqs) > + return -ENOMEM; > + > + bottom_size =3D sizeof(struct virtio_iommu_req_tail); > + top_size =3D sizeof(struct virtio_iommu_req_map) - bottom_size; > + > + i =3D 0; > + node =3D interval_tree_iter_first(&vdomain->mappings, 0, -1UL); > + while (node) { > + mapping =3D container_of(node, struct viommu_mapping, iova); > + sg_init_one(&reqs[i].top, &mapping->req.map, top_size); > + sg_init_one(&reqs[i].bottom, &mapping->req.map.tail, > + bottom_size); > + > + node =3D interval_tree_iter_next(node, 0, -1UL); > + i++; > + } > + > + ret =3D viommu_send_reqs_sync(vdomain->viommu, reqs, i, &nr_sent); > + kfree(reqs); > + > + return ret; > +} > + > +/* IOMMU API */ > + > +static bool viommu_capable(enum iommu_cap cap) > +{ > + return false; /* :( */ > +} > + > +static struct iommu_domain *viommu_domain_alloc(unsigned type) > +{ > + struct viommu_domain *vdomain; > + > + if (type !=3D IOMMU_DOMAIN_UNMANAGED && type !=3D IOMMU_DOMAIN_DMA) > + return NULL; > + > + vdomain =3D kzalloc(sizeof(*vdomain), GFP_KERNEL); > + if (!vdomain) > + return NULL; > + > + mutex_init(&vdomain->mutex); > + spin_lock_init(&vdomain->mappings_lock); > + vdomain->mappings =3D RB_ROOT_CACHED; > + refcount_set(&vdomain->endpoints, 0); > + > + if (type =3D=3D IOMMU_DOMAIN_DMA && > + iommu_get_dma_cookie(&vdomain->domain)) { > + kfree(vdomain); > + return NULL; > + } > + > + return &vdomain->domain; > +} > + > +static int viommu_domain_finalise(struct viommu_dev *viommu, > + struct iommu_domain *domain) > +{ > + int ret; > + struct viommu_domain *vdomain =3D to_viommu_domain(domain); > + /* ida limits size to 31 bits. A value of 0 means "max" */ > + unsigned int max_domain =3D viommu->domain_bits >=3D 31 ? 0 : > + 1U << viommu->domain_bits; > + > + vdomain->viommu =3D viommu; > + > + domain->pgsize_bitmap =3D viommu->pgsize_bitmap; > + domain->geometry =3D viommu->geometry; > + > + ret =3D ida_simple_get(&viommu->domain_ids, 0, max_domain, GFP_KERNEL); > + if (ret >=3D 0) > + vdomain->id =3D (unsigned int)ret; > + > + return ret > 0 ? 0 : ret; > +} > + > +static void viommu_domain_free(struct iommu_domain *domain) > +{ > + struct viommu_domain *vdomain =3D to_viommu_domain(domain); > + > + iommu_put_dma_cookie(domain); > + > + /* Free all remaining mappings (size 2^64) */ > + viommu_del_mappings(vdomain, 0, 0, NULL); > + > + if (vdomain->viommu) > + ida_simple_remove(&vdomain->viommu->domain_ids, vdomain->id); > + > + kfree(vdomain); > +} > + > +static int viommu_attach_dev(struct iommu_domain *domain, struct device = *dev) > +{ > + int i; > + int ret =3D 0; > + struct virtio_iommu_req_attach *req; > + struct iommu_fwspec *fwspec =3D dev->iommu_fwspec; > + struct viommu_endpoint *vdev =3D fwspec->iommu_priv; > + struct viommu_domain *vdomain =3D to_viommu_domain(domain); > + > + mutex_lock(&vdomain->mutex); > + if (!vdomain->viommu) { > + /* > + * Initialize the domain proper now that we know which viommu > + * owns it. > + */ > + ret =3D viommu_domain_finalise(vdev->viommu, domain); > + } else if (vdomain->viommu !=3D vdev->viommu) { > + dev_err(dev, "cannot attach to foreign vIOMMU\n"); > + ret =3D -EXDEV; > + } > + mutex_unlock(&vdomain->mutex); > + > + if (ret) > + return ret; > + > + /* > + * When attaching the device to a new domain, it will be detached from > + * the old one and, if as as a result the old domain isn't attached to as as > + * any device, all mappings are removed from the old domain and it is > + * freed. (Note that we can't use get_domain_for_dev here, it returns > + * the default domain during initial attach.) I don't see where the old domain is freed. I see you descrement the endpoints ref count. Also if you replay the mapping, I guess the mappings were not destroyed? > + * > + * Take note of the device disappearing, so we can ignore unmap request > + * on stale domains (that is, between this detach and the upcoming > + * free.) > + * > + * vdev->vdomain is protected by group->mutex > + */ > + if (vdev->vdomain) > + refcount_dec(&vdev->vdomain->endpoints); > + > + /* DMA to the stack is forbidden, store request on the heap */ > + req =3D kzalloc(sizeof(*req), GFP_KERNEL); > + if (!req) > + return -ENOMEM; > + > + *req =3D (struct virtio_iommu_req_attach) { > + .head.type =3D VIRTIO_IOMMU_T_ATTACH, > + .domain =3D cpu_to_le32(vdomain->id), > + }; > + > + for (i =3D 0; i < fwspec->num_ids; i++) { > + req->endpoint =3D cpu_to_le32(fwspec->ids[i]); > + > + ret =3D viommu_send_req_sync(vdomain->viommu, req); > + if (ret) > + break; > + } > + > + kfree(req); > + > + if (ret) > + return ret; > + > + if (!refcount_read(&vdomain->endpoints)) { > + /* > + * This endpoint is the first to be attached to the domain. > + * Replay existing mappings if any. > + */ > + ret =3D viommu_replay_mappings(vdomain); > + if (ret) > + return ret; > + } > + > + refcount_inc(&vdomain->endpoints); This does not work for me as the ref counter is initialized to 0 and ref_count does not work if the counter is 0. It emits a WARN_ON and stays at 0. I worked around the issue by explicitly setting recount_set(&vdomain->endpoints, 1) if it was 0 and reffount_inc otherwise. > + vdev->vdomain =3D vdomain; > + > + return 0; > +} > + > +static int viommu_map(struct iommu_domain *domain, unsigned long iova, > + phys_addr_t paddr, size_t size, int prot) > +{ > + int ret; > + int flags; > + struct viommu_mapping *mapping; > + struct viommu_domain *vdomain =3D to_viommu_domain(domain); > + > + mapping =3D viommu_add_mapping(vdomain, iova, paddr, size); > + if (!mapping) > + return -ENOMEM; > + > + flags =3D (prot & IOMMU_READ ? VIRTIO_IOMMU_MAP_F_READ : 0) | > + (prot & IOMMU_WRITE ? VIRTIO_IOMMU_MAP_F_WRITE : 0); > + > + mapping->req.map =3D (struct virtio_iommu_req_map) { > + .head.type =3D VIRTIO_IOMMU_T_MAP, > + .domain =3D cpu_to_le32(vdomain->id), > + .virt_addr =3D cpu_to_le64(iova), > + .phys_addr =3D cpu_to_le64(paddr), > + .size =3D cpu_to_le64(size), > + .flags =3D cpu_to_le32(flags), > + }; > + > + if (!refcount_read(&vdomain->endpoints)) > + return 0; > + > + ret =3D viommu_send_req_sync(vdomain->viommu, &mapping->req); > + if (ret) > + viommu_del_mappings(vdomain, iova, size, NULL); > + > + return ret; > +} > + > +static size_t viommu_unmap(struct iommu_domain *domain, unsigned long io= va, > + size_t size) > +{ > + int ret =3D 0; > + size_t unmapped; > + struct viommu_mapping *mapping =3D NULL; > + struct viommu_domain *vdomain =3D to_viommu_domain(domain); > + > + unmapped =3D viommu_del_mappings(vdomain, iova, size, &mapping); > + if (unmapped < size) { > + ret =3D -EINVAL; > + goto out_free; > + } > + > + /* Device already removed all mappings after detach. */ > + if (!refcount_read(&vdomain->endpoints)) > + goto out_free; > + > + if (WARN_ON(!mapping)) > + return 0; > + > + mapping->req.unmap =3D (struct virtio_iommu_req_unmap) { > + .head.type =3D VIRTIO_IOMMU_T_UNMAP, > + .domain =3D cpu_to_le32(vdomain->id), > + .virt_addr =3D cpu_to_le64(iova), > + .size =3D cpu_to_le64(unmapped), > + }; > + > + ret =3D viommu_send_req_sync(vdomain->viommu, &mapping->req); > + > +out_free: > + if (mapping) > + kfree(mapping); > + > + return ret ? 0 : unmapped; > +} > + > +static phys_addr_t viommu_iova_to_phys(struct iommu_domain *domain, > + dma_addr_t iova) > +{ > + u64 paddr =3D 0; > + unsigned long flags; > + struct viommu_mapping *mapping; > + struct interval_tree_node *node; > + struct viommu_domain *vdomain =3D to_viommu_domain(domain); > + > + spin_lock_irqsave(&vdomain->mappings_lock, flags); > + node =3D interval_tree_iter_first(&vdomain->mappings, iova, iova); > + if (node) { > + mapping =3D container_of(node, struct viommu_mapping, iova); > + paddr =3D mapping->paddr + (iova - mapping->iova.start); > + } > + spin_unlock_irqrestore(&vdomain->mappings_lock, flags); > + > + return paddr; > +} > + > +static struct iommu_ops viommu_ops; > +static struct virtio_driver virtio_iommu_drv; > + > +static int viommu_match_node(struct device *dev, void *data) > +{ > + return dev->parent->fwnode =3D=3D data; > +} > + > +static struct viommu_dev *viommu_get_by_fwnode(struct fwnode_handle *fwn= ode) > +{ > + struct device *dev =3D driver_find_device(&virtio_iommu_drv.driver, NUL= L, > + fwnode, viommu_match_node); > + put_device(dev); > + > + return dev ? dev_to_virtio(dev)->priv : NULL; > +} > + > +static int viommu_add_device(struct device *dev) > +{ > + struct iommu_group *group; > + struct viommu_endpoint *vdev; > + struct viommu_dev *viommu =3D NULL; > + struct iommu_fwspec *fwspec =3D dev->iommu_fwspec; > + > + if (!fwspec || fwspec->ops !=3D &viommu_ops) > + return -ENODEV; > + > + viommu =3D viommu_get_by_fwnode(fwspec->iommu_fwnode); > + if (!viommu) > + return -ENODEV; > + > + vdev =3D kzalloc(sizeof(*vdev), GFP_KERNEL); > + if (!vdev) > + return -ENOMEM; > + > + vdev->viommu =3D viommu; > + fwspec->iommu_priv =3D vdev; > + > + /* > + * Last step creates a default domain and attaches to it. Everything > + * must be ready. > + */ > + group =3D iommu_group_get_for_dev(dev); > + if (!IS_ERR(group)) > + iommu_group_put(group); > + > + return PTR_ERR_OR_ZERO(group); > +} > + > +static void viommu_remove_device(struct device *dev) > +{ > + kfree(dev->iommu_fwspec->iommu_priv); > +} > + > +static struct iommu_group *viommu_device_group(struct device *dev) > +{ > + if (dev_is_pci(dev)) > + return pci_device_group(dev); > + else > + return generic_device_group(dev); > +} > + > +static int viommu_of_xlate(struct device *dev, struct of_phandle_args *a= rgs) > +{ > + return iommu_fwspec_add_ids(dev, args->args, 1); > +} > + > +static void viommu_get_resv_regions(struct device *dev, struct list_head= *head) > +{ > + struct iommu_resv_region *region; > + int prot =3D IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO; > + > + region =3D iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH, prot, > + IOMMU_RESV_SW_MSI); > + if (!region) > + return; > + > + list_add_tail(®ion->list, head); > +} > + > +static void viommu_put_resv_regions(struct device *dev, struct list_head= *head) > +{ > + struct iommu_resv_region *entry, *next; > + > + list_for_each_entry_safe(entry, next, head, list) > + kfree(entry); > +} > + > +static struct iommu_ops viommu_ops =3D { > + .capable =3D viommu_capable, > + .domain_alloc =3D viommu_domain_alloc, > + .domain_free =3D viommu_domain_free, > + .attach_dev =3D viommu_attach_dev, > + .map =3D viommu_map, > + .unmap =3D viommu_unmap, > + .map_sg =3D default_iommu_map_sg, > + .iova_to_phys =3D viommu_iova_to_phys, > + .add_device =3D viommu_add_device, > + .remove_device =3D viommu_remove_device, > + .device_group =3D viommu_device_group, > + .of_xlate =3D viommu_of_xlate, > + .get_resv_regions =3D viommu_get_resv_regions, > + .put_resv_regions =3D viommu_put_resv_regions, > +}; > + > +static int viommu_init_vq(struct viommu_dev *viommu) > +{ > + struct virtio_device *vdev =3D dev_to_virtio(viommu->dev); > + const char *name =3D "request"; > + void *ret; > + > + ret =3D virtio_find_single_vq(vdev, NULL, name); > + if (IS_ERR(ret)) { > + dev_err(viommu->dev, "cannot find VQ\n"); > + return PTR_ERR(ret); > + } > + > + viommu->vq =3D ret; > + > + return 0; > +} > + > +static int viommu_probe(struct virtio_device *vdev) > +{ > + struct device *parent_dev =3D vdev->dev.parent; > + struct viommu_dev *viommu =3D NULL; > + struct device *dev =3D &vdev->dev; > + u64 input_start =3D 0; > + u64 input_end =3D -1UL; > + int ret; > + > + viommu =3D kzalloc(sizeof(*viommu), GFP_KERNEL); > + if (!viommu) > + return -ENOMEM; > + > + spin_lock_init(&viommu->request_lock); > + ida_init(&viommu->domain_ids); > + viommu->dev =3D dev; > + viommu->vdev =3D vdev; > + > + ret =3D viommu_init_vq(viommu); > + if (ret) > + goto err_free_viommu; > + > + virtio_cread(vdev, struct virtio_iommu_config, page_size_mask, > + &viommu->pgsize_bitmap); > + > + if (!viommu->pgsize_bitmap) { > + ret =3D -EINVAL; > + goto err_free_viommu; > + } > + > + viommu->domain_bits =3D 32; > + > + /* Optional features */ > + virtio_cread_feature(vdev, VIRTIO_IOMMU_F_INPUT_RANGE, > + struct virtio_iommu_config, input_range.start, > + &input_start); > + > + virtio_cread_feature(vdev, VIRTIO_IOMMU_F_INPUT_RANGE, > + struct virtio_iommu_config, input_range.end, > + &input_end); > + > + virtio_cread_feature(vdev, VIRTIO_IOMMU_F_DOMAIN_BITS, > + struct virtio_iommu_config, domain_bits, > + &viommu->domain_bits); > + > + viommu->geometry =3D (struct iommu_domain_geometry) { > + .aperture_start =3D input_start, > + .aperture_end =3D input_end, > + .force_aperture =3D true, > + }; > + > + viommu_ops.pgsize_bitmap =3D viommu->pgsize_bitmap; > + > + virtio_device_ready(vdev); > + > + ret =3D iommu_device_sysfs_add(&viommu->iommu, dev, NULL, "%s", > + virtio_bus_name(vdev)); > + if (ret) > + goto err_free_viommu; > + > + iommu_device_set_ops(&viommu->iommu, &viommu_ops); > + iommu_device_set_fwnode(&viommu->iommu, parent_dev->fwnode); > + > + iommu_device_register(&viommu->iommu); > + > +#ifdef CONFIG_PCI > + if (pci_bus_type.iommu_ops !=3D &viommu_ops) { > + pci_request_acs(); > + ret =3D bus_set_iommu(&pci_bus_type, &viommu_ops); > + if (ret) > + goto err_unregister; > + } > +#endif > +#ifdef CONFIG_ARM_AMBA > + if (amba_bustype.iommu_ops !=3D &viommu_ops) { > + ret =3D bus_set_iommu(&amba_bustype, &viommu_ops); > + if (ret) > + goto err_unregister; > + } > +#endif > + if (platform_bus_type.iommu_ops !=3D &viommu_ops) { > + ret =3D bus_set_iommu(&platform_bus_type, &viommu_ops); > + if (ret) > + goto err_unregister; > + } > + > + vdev->priv =3D viommu; > + > + dev_info(dev, "input address: %u bits\n", > + order_base_2(viommu->geometry.aperture_end)); > + dev_info(dev, "page mask: %#llx\n", viommu->pgsize_bitmap); > + > + return 0; > + > +err_unregister: > + iommu_device_unregister(&viommu->iommu); > + > +err_free_viommu: > + kfree(viommu); > + > + return ret; > +} > + > +static void viommu_remove(struct virtio_device *vdev) > +{ > + struct viommu_dev *viommu =3D vdev->priv; > + > + iommu_device_unregister(&viommu->iommu); > + kfree(viommu); > + > + dev_info(&vdev->dev, "device removed\n"); > +} > + > +static void viommu_config_changed(struct virtio_device *vdev) > +{ > + dev_warn(&vdev->dev, "config changed\n"); > +} > + > +static unsigned int features[] =3D { > + VIRTIO_IOMMU_F_MAP_UNMAP, > + VIRTIO_IOMMU_F_DOMAIN_BITS, > + VIRTIO_IOMMU_F_INPUT_RANGE, > +}; > + > +static struct virtio_device_id id_table[] =3D { > + { VIRTIO_ID_IOMMU, VIRTIO_DEV_ANY_ID }, > + { 0 }, > +}; > + > +static struct virtio_driver virtio_iommu_drv =3D { > + .driver.name =3D KBUILD_MODNAME, > + .driver.owner =3D THIS_MODULE, > + .id_table =3D id_table, > + .feature_table =3D features, > + .feature_table_size =3D ARRAY_SIZE(features), > + .probe =3D viommu_probe, > + .remove =3D viommu_remove, > + .config_changed =3D viommu_config_changed, > +}; > + > +module_virtio_driver(virtio_iommu_drv); > + > +IOMMU_OF_DECLARE(viommu, "virtio,mmio", NULL); > + > +MODULE_DESCRIPTION("Virtio IOMMU driver"); > +MODULE_AUTHOR("Jean-Philippe Brucker "); > +MODULE_LICENSE("GPL v2"); > diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_= ids.h > index 6d5c3b2d4f4d..934ed3d3cd3f 100644 > --- a/include/uapi/linux/virtio_ids.h > +++ b/include/uapi/linux/virtio_ids.h > @@ -43,5 +43,6 @@ > #define VIRTIO_ID_INPUT 18 /* virtio input */ > #define VIRTIO_ID_VSOCK 19 /* virtio vsock transport */ > #define VIRTIO_ID_CRYPTO 20 /* virtio crypto */ > +#define VIRTIO_ID_IOMMU 61216 /* virtio IOMMU (temporary) */ > =20 > #endif /* _LINUX_VIRTIO_IDS_H */ > diff --git a/include/uapi/linux/virtio_iommu.h b/include/uapi/linux/virti= o_iommu.h > new file mode 100644 > index 000000000000..2b4cd2042897 > --- /dev/null > +++ b/include/uapi/linux/virtio_iommu.h > @@ -0,0 +1,140 @@ > +/* > + * Virtio-iommu definition v0.5 > + * > + * Copyright (C) 2017 ARM Ltd. > + * > + * This header is BSD licensed so anyone can use the definitions > + * to implement compatible drivers/servers: > + * > + * Redistribution and use in source and binary forms, with or without > + * modification, are permitted provided that the following conditions > + * are met: > + * 1. Redistributions of source code must retain the above copyright > + * notice, this list of conditions and the following disclaimer. > + * 2. Redistributions in binary form must reproduce the above copyright > + * notice, this list of conditions and the following disclaimer in the > + * documentation and/or other materials provided with the distributio= n. > + * 3. Neither the name of ARM Ltd. nor the names of its contributors > + * may be used to endorse or promote products derived from this softw= are > + * without specific prior written permission. > + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS > + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT > + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS > + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL IBM OR > + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, > + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT > + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF > + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND > + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, > + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT > + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF > + * SUCH DAMAGE. > + */ > +#ifndef _UAPI_LINUX_VIRTIO_IOMMU_H > +#define _UAPI_LINUX_VIRTIO_IOMMU_H > + > +/* Feature bits */ > +#define VIRTIO_IOMMU_F_INPUT_RANGE 0 > +#define VIRTIO_IOMMU_F_DOMAIN_BITS 1 > +#define VIRTIO_IOMMU_F_MAP_UNMAP 2 > +#define VIRTIO_IOMMU_F_BYPASS 3 > + > +struct virtio_iommu_config { > + /* Supported page sizes */ > + __u64 page_size_mask; Get a warning ./usr/include/linux/virtio_iommu.h:45: found __[us]{8,16,32,64} type without #include > + /* Supported IOVA range */ > + struct virtio_iommu_range { > + __u64 start; > + __u64 end; > + } input_range; > + /* Max domain ID size */ > + __u8 domain_bits; > +} __packed; > + > +/* Request types */ > +#define VIRTIO_IOMMU_T_ATTACH 0x01 > +#define VIRTIO_IOMMU_T_DETACH 0x02 > +#define VIRTIO_IOMMU_T_MAP 0x03 > +#define VIRTIO_IOMMU_T_UNMAP 0x04 > + > +/* Status types */ > +#define VIRTIO_IOMMU_S_OK 0x00 > +#define VIRTIO_IOMMU_S_IOERR 0x01 > +#define VIRTIO_IOMMU_S_UNSUPP 0x02 > +#define VIRTIO_IOMMU_S_DEVERR 0x03 > +#define VIRTIO_IOMMU_S_INVAL 0x04 > +#define VIRTIO_IOMMU_S_RANGE 0x05 > +#define VIRTIO_IOMMU_S_NOENT 0x06 > +#define VIRTIO_IOMMU_S_FAULT 0x07 > + > +struct virtio_iommu_req_head { > + __u8 type; > + __u8 reserved[3]; > +} __packed; > + > +struct virtio_iommu_req_tail { > + __u8 status; > + __u8 reserved[3]; > +} __packed; > + > +struct virtio_iommu_req_attach { > + struct virtio_iommu_req_head head; > + > + __le32 domain; > + __le32 endpoint; > + __le32 reserved; > + > + struct virtio_iommu_req_tail tail; > +} __packed; > + > +struct virtio_iommu_req_detach { > + struct virtio_iommu_req_head head; > + > + __le32 endpoint; > + __le32 reserved; > + > + struct virtio_iommu_req_tail tail; > +} __packed; > + > +#define VIRTIO_IOMMU_MAP_F_READ (1 << 0) > +#define VIRTIO_IOMMU_MAP_F_WRITE (1 << 1) > +#define VIRTIO_IOMMU_MAP_F_EXEC (1 << 2) > + > +#define VIRTIO_IOMMU_MAP_F_MASK (VIRTIO_IOMMU_MAP_F_READ | \ > + VIRTIO_IOMMU_MAP_F_WRITE | \ > + VIRTIO_IOMMU_MAP_F_EXEC) > + > +struct virtio_iommu_req_map { > + struct virtio_iommu_req_head head; > + > + __le32 domain; > + __le64 virt_addr; > + __le64 phys_addr; > + __le64 size; > + __le32 flags; > + > + struct virtio_iommu_req_tail tail; > +} __packed; > + > +__packed > +struct virtio_iommu_req_unmap { > + struct virtio_iommu_req_head head; > + > + __le32 domain; > + __le64 virt_addr; > + __le64 size; > + __le32 reserved; > + > + struct virtio_iommu_req_tail tail; > +} __packed; > + > +union virtio_iommu_req { > + struct virtio_iommu_req_head head; > + > + struct virtio_iommu_req_attach attach; > + struct virtio_iommu_req_detach detach; > + struct virtio_iommu_req_map map; > + struct virtio_iommu_req_unmap unmap; > +}; > + > +#endif >=20 Thanks Eric --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org