| Message ID | 20171117185211.32593-4-jean-philippe.brucker@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On 17/11/17 19:52, Jean-Philippe Brucker wrote: > The event queue offers a way for the device to report access faults from > devices. end points? It is implemented on virtqueue #1, whenever the host needs to > signal a fault it fills one of the buffers offered by the guest and > interrupts it. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> > --- > drivers/iommu/virtio-iommu.c | 138 ++++++++++++++++++++++++++++++++++---- > include/uapi/linux/virtio_iommu.h | 18 +++++ > 2 files changed, 142 insertions(+), 14 deletions(-) > > diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c > index 79e0add94e05..fe0d449bf489 100644 > --- a/drivers/iommu/virtio-iommu.c > +++ b/drivers/iommu/virtio-iommu.c > @@ -30,6 +30,12 @@ > #define MSI_IOVA_BASE 0x8000000 > #define MSI_IOVA_LENGTH 0x100000 > > +enum viommu_vq_idx { > + VIOMMU_REQUEST_VQ = 0, > + VIOMMU_EVENT_VQ = 1, > + VIOMMU_NUM_VQS = 2, > +}; > + > struct viommu_dev { > struct iommu_device iommu; > struct device *dev; > @@ -37,7 +43,7 @@ struct viommu_dev { > > struct ida domain_ids; > > - struct virtqueue *vq; > + struct virtqueue *vqs[VIOMMU_NUM_VQS]; > /* Serialize anything touching the request queue */ > spinlock_t request_lock; > > @@ -84,6 +90,15 @@ struct viommu_request { > struct list_head list; > }; > > +#define VIOMMU_FAULT_RESV_MASK 0xffffff00 > + > +struct viommu_event { > + union { > + u32 head; > + struct virtio_iommu_fault fault; > + }; > +}; > + > #define to_viommu_domain(domain) container_of(domain, struct viommu_domain, domain) > > /* Virtio transport */ > @@ -160,12 +175,13 @@ static int viommu_receive_resp(struct viommu_dev *viommu, int nr_sent, > unsigned int len; > int nr_received = 0; > struct viommu_request *req, *pending; > + struct virtqueue *vq = viommu->vqs[VIOMMU_REQUEST_VQ]; > > 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) { > + while ((req = virtqueue_get_buf(vq, &len)) != NULL) { > if (req != pending) { > dev_warn(viommu->dev, "discarding stale request\n"); > continue; > @@ -202,6 +218,7 @@ static int _viommu_send_reqs_sync(struct viommu_dev *viommu, > * dies. > */ > unsigned long timeout_ms = 1000; > + struct virtqueue *vq = viommu->vqs[VIOMMU_REQUEST_VQ]; > > *nr_sent = 0; > > @@ -211,15 +228,14 @@ static int _viommu_send_reqs_sync(struct viommu_dev *viommu, > sg[0] = &req->top; > sg[1] = &req->bottom; > > - ret = virtqueue_add_sgs(viommu->vq, sg, 1, 1, req, > - GFP_ATOMIC); > + ret = virtqueue_add_sgs(vq, sg, 1, 1, req, GFP_ATOMIC); > if (ret) > break; > > list_add_tail(&req->list, &pending); > } > > - if (i && !virtqueue_kick(viommu->vq)) > + if (i && !virtqueue_kick(vq)) > return -EPIPE; > > timeout = ktime_add_ms(ktime_get(), timeout_ms * i); > @@ -554,6 +570,70 @@ static int viommu_probe_endpoint(struct viommu_dev *viommu, struct device *dev) > return 0; > } > > +static int viommu_fault_handler(struct viommu_dev *viommu, > + struct virtio_iommu_fault *fault) > +{ > + char *reason_str; > + > + u8 reason = fault->reason; > + u32 flags = le32_to_cpu(fault->flags); > + u32 endpoint = le32_to_cpu(fault->endpoint); > + u64 address = le64_to_cpu(fault->address); > + > + switch (reason) { > + case VIRTIO_IOMMU_FAULT_R_DOMAIN: > + reason_str = "domain"; > + break; > + case VIRTIO_IOMMU_FAULT_R_MAPPING: > + reason_str = "page"; > + break; > + case VIRTIO_IOMMU_FAULT_R_UNKNOWN: > + default: > + reason_str = "unknown"; > + break; > + } > + > + /* TODO: find EP by ID and report_iommu_fault */ > + if (flags & VIRTIO_IOMMU_FAULT_F_ADDRESS) > + dev_err_ratelimited(viommu->dev, "%s fault from EP %u at %#llx [%s%s%s]\n", > + reason_str, endpoint, address, > + flags & VIRTIO_IOMMU_FAULT_F_READ ? "R" : "", > + flags & VIRTIO_IOMMU_FAULT_F_WRITE ? "W" : "", > + flags & VIRTIO_IOMMU_FAULT_F_EXEC ? "X" : ""); > + else > + dev_err_ratelimited(viommu->dev, "%s fault from EP %u\n", > + reason_str, endpoint); > + > + return 0; > +} > + > +static void viommu_event_handler(struct virtqueue *vq) > +{ > + int ret; > + unsigned int len; > + struct scatterlist sg[1]; > + struct viommu_event *evt; > + struct viommu_dev *viommu = vq->vdev->priv; > + > + while ((evt = virtqueue_get_buf(vq, &len)) != NULL) { > + if (len > sizeof(*evt)) { > + dev_err(viommu->dev, > + "invalid event buffer (len %u != %zu)\n", > + len, sizeof(*evt)); > + } else if (!(evt->head & VIOMMU_FAULT_RESV_MASK)) { > + viommu_fault_handler(viommu, &evt->fault); > + } > + > + sg_init_one(sg, evt, sizeof(*evt)); in case of above error case, ie. len > sizeof(*evt), is it safe to push evt again? > + ret = virtqueue_add_inbuf(vq, sg, 1, evt, GFP_ATOMIC); > + if (ret) > + dev_err(viommu->dev, "could not add event buffer\n"); > + } > + > + if (!virtqueue_kick(vq)) > + dev_err(viommu->dev, "kick failed\n"); > +} > + > /* IOMMU API */ > > static bool viommu_capable(enum iommu_cap cap) > @@ -938,19 +1018,44 @@ static struct iommu_ops viommu_ops = { > .put_resv_regions = viommu_put_resv_regions, > }; > > -static int viommu_init_vq(struct viommu_dev *viommu) > +static int viommu_init_vqs(struct viommu_dev *viommu) > { > struct virtio_device *vdev = dev_to_virtio(viommu->dev); > - const char *name = "request"; > - void *ret; > + const char *names[] = { "request", "event" }; > + vq_callback_t *callbacks[] = { > + NULL, /* No async requests */ > + viommu_event_handler, > + }; > + > + return virtio_find_vqs(vdev, VIOMMU_NUM_VQS, viommu->vqs, callbacks, > + names, NULL); > +} > > - ret = virtio_find_single_vq(vdev, NULL, name); > - if (IS_ERR(ret)) { > - dev_err(viommu->dev, "cannot find VQ\n"); > - return PTR_ERR(ret); > +static int viommu_fill_evtq(struct viommu_dev *viommu) > +{ > + int i, ret; > + struct scatterlist sg[1]; > + struct viommu_event *evts; > + struct virtqueue *vq = viommu->vqs[VIOMMU_EVENT_VQ]; > + size_t nr_evts = min_t(size_t, PAGE_SIZE / sizeof(struct viommu_event), > + viommu->vqs[VIOMMU_EVENT_VQ]->num_free); > + > + evts = devm_kmalloc_array(viommu->dev, nr_evts, sizeof(*evts), > + GFP_KERNEL); > + if (!evts) > + return -ENOMEM; > + > + for (i = 0; i < nr_evts; i++) { > + sg_init_one(sg, &evts[i], sizeof(*evts)); > + ret = virtqueue_add_inbuf(vq, sg, 1, &evts[i], GFP_KERNEL); who does the deallocation of evts? Thanks Eric > + if (ret) > + return ret; > } > > - viommu->vq = ret; > + if (!virtqueue_kick(vq)) > + return -EPIPE; > + > + dev_info(viommu->dev, "%zu event buffers\n", nr_evts); > > return 0; > } > @@ -973,7 +1078,7 @@ static int viommu_probe(struct virtio_device *vdev) > viommu->dev = dev; > viommu->vdev = vdev; > > - ret = viommu_init_vq(viommu); > + ret = viommu_init_vqs(viommu); > if (ret) > goto err_free_viommu; > > @@ -1014,6 +1119,11 @@ static int viommu_probe(struct virtio_device *vdev) > > virtio_device_ready(vdev); > > + /* Populate the event queue with buffers */ > + ret = viommu_fill_evtq(viommu); > + if (ret) > + goto err_free_viommu; > + > ret = iommu_device_sysfs_add(&viommu->iommu, dev, NULL, "%s", > virtio_bus_name(vdev)); > if (ret) > diff --git a/include/uapi/linux/virtio_iommu.h b/include/uapi/linux/virtio_iommu.h > index eec90a2ab547..b57543b4145b 100644 > --- a/include/uapi/linux/virtio_iommu.h > +++ b/include/uapi/linux/virtio_iommu.h > @@ -174,4 +174,22 @@ union virtio_iommu_req { > struct virtio_iommu_req_probe probe; > }; > > +/* Fault types */ > +#define VIRTIO_IOMMU_FAULT_R_UNKNOWN 0 > +#define VIRTIO_IOMMU_FAULT_R_DOMAIN 1 > +#define VIRTIO_IOMMU_FAULT_R_MAPPING 2 > + > +#define VIRTIO_IOMMU_FAULT_F_READ (1 << 0) > +#define VIRTIO_IOMMU_FAULT_F_WRITE (1 << 1) > +#define VIRTIO_IOMMU_FAULT_F_EXEC (1 << 2) > +#define VIRTIO_IOMMU_FAULT_F_ADDRESS (1 << 8) > + > +struct virtio_iommu_fault { > + __u8 reason; > + __u8 padding[3]; > + __le32 flags; > + __le32 endpoint; > + __le64 address; > +} __packed; > + > #endif >
On 16/01/18 10:10, Auger Eric wrote: > Hi, > > On 17/11/17 19:52, Jean-Philippe Brucker wrote: >> The event queue offers a way for the device to report access faults from >> devices. > end points? Yes [...] >> +static void viommu_event_handler(struct virtqueue *vq) >> +{ >> + int ret; >> + unsigned int len; >> + struct scatterlist sg[1]; >> + struct viommu_event *evt; >> + struct viommu_dev *viommu = vq->vdev->priv; >> + >> + while ((evt = virtqueue_get_buf(vq, &len)) != NULL) { >> + if (len > sizeof(*evt)) { >> + dev_err(viommu->dev, >> + "invalid event buffer (len %u != %zu)\n", >> + len, sizeof(*evt)); >> + } else if (!(evt->head & VIOMMU_FAULT_RESV_MASK)) { >> + viommu_fault_handler(viommu, &evt->fault); >> + } >> + >> + sg_init_one(sg, evt, sizeof(*evt)); > in case of above error case, ie. len > sizeof(*evt), is it safe to push > evt again? I think it is, len is just what the device reports as written. The above error would be a device bug, very unlikely and not worth a special treatment (freeing the buffer), maybe not even worth the dev_err() actually. >> + ret = virtqueue_add_inbuf(vq, sg, 1, evt, GFP_ATOMIC); >> + if (ret) >> + dev_err(viommu->dev, "could not add event buffer\n"); >> + } >> + >> + if (!virtqueue_kick(vq)) >> + dev_err(viommu->dev, "kick failed\n"); >> +} >> + >> /* IOMMU API */ >> >> static bool viommu_capable(enum iommu_cap cap) >> @@ -938,19 +1018,44 @@ static struct iommu_ops viommu_ops = { >> .put_resv_regions = viommu_put_resv_regions, >> }; >> >> -static int viommu_init_vq(struct viommu_dev *viommu) >> +static int viommu_init_vqs(struct viommu_dev *viommu) >> { >> struct virtio_device *vdev = dev_to_virtio(viommu->dev); >> - const char *name = "request"; >> - void *ret; >> + const char *names[] = { "request", "event" }; >> + vq_callback_t *callbacks[] = { >> + NULL, /* No async requests */ >> + viommu_event_handler, >> + }; >> + >> + return virtio_find_vqs(vdev, VIOMMU_NUM_VQS, viommu->vqs, callbacks, >> + names, NULL); >> +} >> >> - ret = virtio_find_single_vq(vdev, NULL, name); >> - if (IS_ERR(ret)) { >> - dev_err(viommu->dev, "cannot find VQ\n"); >> - return PTR_ERR(ret); >> +static int viommu_fill_evtq(struct viommu_dev *viommu) >> +{ >> + int i, ret; >> + struct scatterlist sg[1]; >> + struct viommu_event *evts; >> + struct virtqueue *vq = viommu->vqs[VIOMMU_EVENT_VQ]; >> + size_t nr_evts = min_t(size_t, PAGE_SIZE / sizeof(struct viommu_event), >> + viommu->vqs[VIOMMU_EVENT_VQ]->num_free); >> + >> + evts = devm_kmalloc_array(viommu->dev, nr_evts, sizeof(*evts), >> + GFP_KERNEL); >> + if (!evts) >> + return -ENOMEM; >> + >> + for (i = 0; i < nr_evts; i++) { >> + sg_init_one(sg, &evts[i], sizeof(*evts)); >> + ret = virtqueue_add_inbuf(vq, sg, 1, &evts[i], GFP_KERNEL); > who does the deallocation of evts? I think it should be viommu_remove, which should also remove the virtqueues. I'll add this. Thanks, Jean
diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c index 79e0add94e05..fe0d449bf489 100644 --- a/drivers/iommu/virtio-iommu.c +++ b/drivers/iommu/virtio-iommu.c @@ -30,6 +30,12 @@ #define MSI_IOVA_BASE 0x8000000 #define MSI_IOVA_LENGTH 0x100000 +enum viommu_vq_idx { + VIOMMU_REQUEST_VQ = 0, + VIOMMU_EVENT_VQ = 1, + VIOMMU_NUM_VQS = 2, +}; + struct viommu_dev { struct iommu_device iommu; struct device *dev; @@ -37,7 +43,7 @@ struct viommu_dev { struct ida domain_ids; - struct virtqueue *vq; + struct virtqueue *vqs[VIOMMU_NUM_VQS]; /* Serialize anything touching the request queue */ spinlock_t request_lock; @@ -84,6 +90,15 @@ struct viommu_request { struct list_head list; }; +#define VIOMMU_FAULT_RESV_MASK 0xffffff00 + +struct viommu_event { + union { + u32 head; + struct virtio_iommu_fault fault; + }; +}; + #define to_viommu_domain(domain) container_of(domain, struct viommu_domain, domain) /* Virtio transport */ @@ -160,12 +175,13 @@ static int viommu_receive_resp(struct viommu_dev *viommu, int nr_sent, unsigned int len; int nr_received = 0; struct viommu_request *req, *pending; + struct virtqueue *vq = viommu->vqs[VIOMMU_REQUEST_VQ]; 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) { + while ((req = virtqueue_get_buf(vq, &len)) != NULL) { if (req != pending) { dev_warn(viommu->dev, "discarding stale request\n"); continue; @@ -202,6 +218,7 @@ static int _viommu_send_reqs_sync(struct viommu_dev *viommu, * dies. */ unsigned long timeout_ms = 1000; + struct virtqueue *vq = viommu->vqs[VIOMMU_REQUEST_VQ]; *nr_sent = 0; @@ -211,15 +228,14 @@ static int _viommu_send_reqs_sync(struct viommu_dev *viommu, sg[0] = &req->top; sg[1] = &req->bottom; - ret = virtqueue_add_sgs(viommu->vq, sg, 1, 1, req, - GFP_ATOMIC); + ret = virtqueue_add_sgs(vq, sg, 1, 1, req, GFP_ATOMIC); if (ret) break; list_add_tail(&req->list, &pending); } - if (i && !virtqueue_kick(viommu->vq)) + if (i && !virtqueue_kick(vq)) return -EPIPE; timeout = ktime_add_ms(ktime_get(), timeout_ms * i); @@ -554,6 +570,70 @@ static int viommu_probe_endpoint(struct viommu_dev *viommu, struct device *dev) return 0; } +static int viommu_fault_handler(struct viommu_dev *viommu, + struct virtio_iommu_fault *fault) +{ + char *reason_str; + + u8 reason = fault->reason; + u32 flags = le32_to_cpu(fault->flags); + u32 endpoint = le32_to_cpu(fault->endpoint); + u64 address = le64_to_cpu(fault->address); + + switch (reason) { + case VIRTIO_IOMMU_FAULT_R_DOMAIN: + reason_str = "domain"; + break; + case VIRTIO_IOMMU_FAULT_R_MAPPING: + reason_str = "page"; + break; + case VIRTIO_IOMMU_FAULT_R_UNKNOWN: + default: + reason_str = "unknown"; + break; + } + + /* TODO: find EP by ID and report_iommu_fault */ + if (flags & VIRTIO_IOMMU_FAULT_F_ADDRESS) + dev_err_ratelimited(viommu->dev, "%s fault from EP %u at %#llx [%s%s%s]\n", + reason_str, endpoint, address, + flags & VIRTIO_IOMMU_FAULT_F_READ ? "R" : "", + flags & VIRTIO_IOMMU_FAULT_F_WRITE ? "W" : "", + flags & VIRTIO_IOMMU_FAULT_F_EXEC ? "X" : ""); + else + dev_err_ratelimited(viommu->dev, "%s fault from EP %u\n", + reason_str, endpoint); + + return 0; +} + +static void viommu_event_handler(struct virtqueue *vq) +{ + int ret; + unsigned int len; + struct scatterlist sg[1]; + struct viommu_event *evt; + struct viommu_dev *viommu = vq->vdev->priv; + + while ((evt = virtqueue_get_buf(vq, &len)) != NULL) { + if (len > sizeof(*evt)) { + dev_err(viommu->dev, + "invalid event buffer (len %u != %zu)\n", + len, sizeof(*evt)); + } else if (!(evt->head & VIOMMU_FAULT_RESV_MASK)) { + viommu_fault_handler(viommu, &evt->fault); + } + + sg_init_one(sg, evt, sizeof(*evt)); + ret = virtqueue_add_inbuf(vq, sg, 1, evt, GFP_ATOMIC); + if (ret) + dev_err(viommu->dev, "could not add event buffer\n"); + } + + if (!virtqueue_kick(vq)) + dev_err(viommu->dev, "kick failed\n"); +} + /* IOMMU API */ static bool viommu_capable(enum iommu_cap cap) @@ -938,19 +1018,44 @@ static struct iommu_ops viommu_ops = { .put_resv_regions = viommu_put_resv_regions, }; -static int viommu_init_vq(struct viommu_dev *viommu) +static int viommu_init_vqs(struct viommu_dev *viommu) { struct virtio_device *vdev = dev_to_virtio(viommu->dev); - const char *name = "request"; - void *ret; + const char *names[] = { "request", "event" }; + vq_callback_t *callbacks[] = { + NULL, /* No async requests */ + viommu_event_handler, + }; + + return virtio_find_vqs(vdev, VIOMMU_NUM_VQS, viommu->vqs, callbacks, + names, NULL); +} - ret = virtio_find_single_vq(vdev, NULL, name); - if (IS_ERR(ret)) { - dev_err(viommu->dev, "cannot find VQ\n"); - return PTR_ERR(ret); +static int viommu_fill_evtq(struct viommu_dev *viommu) +{ + int i, ret; + struct scatterlist sg[1]; + struct viommu_event *evts; + struct virtqueue *vq = viommu->vqs[VIOMMU_EVENT_VQ]; + size_t nr_evts = min_t(size_t, PAGE_SIZE / sizeof(struct viommu_event), + viommu->vqs[VIOMMU_EVENT_VQ]->num_free); + + evts = devm_kmalloc_array(viommu->dev, nr_evts, sizeof(*evts), + GFP_KERNEL); + if (!evts) + return -ENOMEM; + + for (i = 0; i < nr_evts; i++) { + sg_init_one(sg, &evts[i], sizeof(*evts)); + ret = virtqueue_add_inbuf(vq, sg, 1, &evts[i], GFP_KERNEL); + if (ret) + return ret; } - viommu->vq = ret; + if (!virtqueue_kick(vq)) + return -EPIPE; + + dev_info(viommu->dev, "%zu event buffers\n", nr_evts); return 0; } @@ -973,7 +1078,7 @@ static int viommu_probe(struct virtio_device *vdev) viommu->dev = dev; viommu->vdev = vdev; - ret = viommu_init_vq(viommu); + ret = viommu_init_vqs(viommu); if (ret) goto err_free_viommu; @@ -1014,6 +1119,11 @@ static int viommu_probe(struct virtio_device *vdev) virtio_device_ready(vdev); + /* Populate the event queue with buffers */ + ret = viommu_fill_evtq(viommu); + if (ret) + goto err_free_viommu; + ret = iommu_device_sysfs_add(&viommu->iommu, dev, NULL, "%s", virtio_bus_name(vdev)); if (ret) diff --git a/include/uapi/linux/virtio_iommu.h b/include/uapi/linux/virtio_iommu.h index eec90a2ab547..b57543b4145b 100644 --- a/include/uapi/linux/virtio_iommu.h +++ b/include/uapi/linux/virtio_iommu.h @@ -174,4 +174,22 @@ union virtio_iommu_req { struct virtio_iommu_req_probe probe; }; +/* Fault types */ +#define VIRTIO_IOMMU_FAULT_R_UNKNOWN 0 +#define VIRTIO_IOMMU_FAULT_R_DOMAIN 1 +#define VIRTIO_IOMMU_FAULT_R_MAPPING 2 + +#define VIRTIO_IOMMU_FAULT_F_READ (1 << 0) +#define VIRTIO_IOMMU_FAULT_F_WRITE (1 << 1) +#define VIRTIO_IOMMU_FAULT_F_EXEC (1 << 2) +#define VIRTIO_IOMMU_FAULT_F_ADDRESS (1 << 8) + +struct virtio_iommu_fault { + __u8 reason; + __u8 padding[3]; + __le32 flags; + __le32 endpoint; + __le64 address; +} __packed; + #endif
The event queue offers a way for the device to report access faults from devices. It is implemented on virtqueue #1, whenever the host needs to signal a fault it fills one of the buffers offered by the guest and interrupts it. Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> --- drivers/iommu/virtio-iommu.c | 138 ++++++++++++++++++++++++++++++++++---- include/uapi/linux/virtio_iommu.h | 18 +++++ 2 files changed, 142 insertions(+), 14 deletions(-)