This patch registers a fault handler which records faults in a circular buffer and then signals an eventfd. This buffer is exposed within the fault region. Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx> --- v3 -> v4: - move iommu_unregister_device_fault_handler to vfio_pci_release --- drivers/vfio/pci/vfio_pci.c | 49 +++++++++++++++++++++++++++++ drivers/vfio/pci/vfio_pci_private.h | 1 + 2 files changed, 50 insertions(+) diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 01b1b4cb8349..cf12204486c3 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -29,6 +29,7 @@ #include <linux/vfio.h> #include <linux/vgaarb.h> #include <linux/nospec.h> +#include <linux/circ_buf.h> #include "vfio_pci_private.h" @@ -295,6 +296,46 @@ static const struct vfio_pci_regops vfio_pci_fault_prod_regops = { .add_capability = vfio_pci_fault_prod_add_capability, }; +int vfio_pci_iommu_dev_fault_handler(struct iommu_fault_event *evt, void *data) +{ + struct vfio_pci_device *vdev = (struct vfio_pci_device *) data; + struct vfio_region_fault_prod *prod_region = + (struct vfio_region_fault_prod *)vdev->fault_pages; + struct vfio_region_fault_cons *cons_region = + (struct vfio_region_fault_cons *)(vdev->fault_pages + 2 * PAGE_SIZE); + struct iommu_fault *new = + (struct iommu_fault *)(vdev->fault_pages + prod_region->offset + + prod_region->prod * prod_region->entry_size); + int prod, cons, size; + + mutex_lock(&vdev->fault_queue_lock); + + if (!vdev->fault_abi) + goto unlock; + + prod = prod_region->prod; + cons = cons_region->cons; + size = prod_region->nb_entries; + + if (CIRC_SPACE(prod, cons, size) < 1) + goto unlock; + + *new = evt->fault; + prod = (prod + 1) % size; + prod_region->prod = prod; + mutex_unlock(&vdev->fault_queue_lock); + + mutex_lock(&vdev->igate); + if (vdev->dma_fault_trigger) + eventfd_signal(vdev->dma_fault_trigger, 1); + mutex_unlock(&vdev->igate); + return 0; + +unlock: + mutex_unlock(&vdev->fault_queue_lock); + return -EINVAL; +} + static int vfio_pci_init_fault_region(struct vfio_pci_device *vdev) { struct vfio_region_fault_prod *header; @@ -327,6 +368,13 @@ static int vfio_pci_init_fault_region(struct vfio_pci_device *vdev) header = (struct vfio_region_fault_prod *)vdev->fault_pages; header->version = -1; header->offset = PAGE_SIZE; + + ret = iommu_register_device_fault_handler(&vdev->pdev->dev, + vfio_pci_iommu_dev_fault_handler, + vdev); + if (ret) + goto out; + return 0; out: kfree(vdev->fault_pages); @@ -574,6 +622,7 @@ static void vfio_pci_release(void *device_data) if (!(--vdev->refcnt)) { vfio_spapr_pci_eeh_release(vdev->pdev); vfio_pci_disable(vdev); + iommu_unregister_device_fault_handler(&vdev->pdev->dev); } mutex_unlock(&vdev->reflck->lock); diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h index 8e0a55682d3f..a9276926f008 100644 --- a/drivers/vfio/pci/vfio_pci_private.h +++ b/drivers/vfio/pci/vfio_pci_private.h @@ -122,6 +122,7 @@ struct vfio_pci_device { int ioeventfds_nr; struct eventfd_ctx *err_trigger; struct eventfd_ctx *req_trigger; + struct eventfd_ctx *dma_fault_trigger; struct mutex fault_queue_lock; int fault_abi; struct list_head dummy_resources_list; -- 2.20.1 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm