Hi Eric, Just curious about your plan on this patch, I just heard my colleague would like to reference the functions from this patch in his dsa driver work.
Regards, Yi Liu > From: Eric Auger <[email protected]> > Sent: Saturday, March 21, 2020 12:19 AM > To: [email protected]; [email protected]; [email protected] > foundation.org; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; Liu, Yi L <[email protected]>; jean- > [email protected]; [email protected]; [email protected] > Cc: [email protected]; [email protected]; [email protected] > Subject: [PATCH v10 04/11] vfio/pci: Add VFIO_REGION_TYPE_NESTED region type > > Add a new specific DMA_FAULT region aiming to exposed nested mode > translation faults. > > The region has a ring buffer that contains the actual fault > records plus a header allowing to handle it (tail/head indices, > max capacity, entry size). At the moment the region is dimensionned > for 512 fault records. > > Signed-off-by: Eric Auger <[email protected]> > > --- > > v8 -> v9: > - Use a single region instead of a prod/cons region > > v4 -> v5 > - check cons is not null in vfio_pci_check_cons_fault > > v3 -> v4: > - use 2 separate regions, respectively in read and write modes > - add the version capability > --- > drivers/vfio/pci/vfio_pci.c | 68 +++++++++++++++++++++++++++++ > drivers/vfio/pci/vfio_pci_private.h | 10 +++++ > drivers/vfio/pci/vfio_pci_rdwr.c | 45 +++++++++++++++++++ > include/uapi/linux/vfio.h | 35 +++++++++++++++ > 4 files changed, 158 insertions(+) > > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c > index 379a02c36e37..586b89debed5 100644 > --- a/drivers/vfio/pci/vfio_pci.c > +++ b/drivers/vfio/pci/vfio_pci.c > @@ -260,6 +260,69 @@ int vfio_pci_set_power_state(struct vfio_pci_device > *vdev, > pci_power_t state) > return ret; > } > > +static void vfio_pci_dma_fault_release(struct vfio_pci_device *vdev, > + struct vfio_pci_region *region) > +{ > +} > + > +static int vfio_pci_dma_fault_add_capability(struct vfio_pci_device *vdev, > + struct vfio_pci_region *region, > + struct vfio_info_cap *caps) > +{ > + struct vfio_region_info_cap_fault cap = { > + .header.id = VFIO_REGION_INFO_CAP_DMA_FAULT, > + .header.version = 1, > + .version = 1, > + }; > + return vfio_info_add_capability(caps, &cap.header, sizeof(cap)); > +} > + > +static const struct vfio_pci_regops vfio_pci_dma_fault_regops = { > + .rw = vfio_pci_dma_fault_rw, > + .release = vfio_pci_dma_fault_release, > + .add_capability = vfio_pci_dma_fault_add_capability, > +}; > + > +#define DMA_FAULT_RING_LENGTH 512 > + > +static int vfio_pci_init_dma_fault_region(struct vfio_pci_device *vdev) > +{ > + struct vfio_region_dma_fault *header; > + size_t size; > + int ret; > + > + mutex_init(&vdev->fault_queue_lock); > + > + /* > + * We provision 1 page for the header and space for > + * DMA_FAULT_RING_LENGTH fault records in the ring buffer. > + */ > + size = ALIGN(sizeof(struct iommu_fault) * > + DMA_FAULT_RING_LENGTH, PAGE_SIZE) + PAGE_SIZE; > + > + vdev->fault_pages = kzalloc(size, GFP_KERNEL); > + if (!vdev->fault_pages) > + return -ENOMEM; > + > + ret = vfio_pci_register_dev_region(vdev, > + VFIO_REGION_TYPE_NESTED, > + VFIO_REGION_SUBTYPE_NESTED_DMA_FAULT, > + &vfio_pci_dma_fault_regops, size, > + VFIO_REGION_INFO_FLAG_READ | > VFIO_REGION_INFO_FLAG_WRITE, > + vdev->fault_pages); > + if (ret) > + goto out; > + > + header = (struct vfio_region_dma_fault *)vdev->fault_pages; > + header->entry_size = sizeof(struct iommu_fault); > + header->nb_entries = DMA_FAULT_RING_LENGTH; > + header->offset = sizeof(struct vfio_region_dma_fault); > + return 0; > +out: > + kfree(vdev->fault_pages); > + return ret; > +} > + > static int vfio_pci_enable(struct vfio_pci_device *vdev) > { > struct pci_dev *pdev = vdev->pdev; > @@ -358,6 +421,10 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev) > } > } > > + ret = vfio_pci_init_dma_fault_region(vdev); > + if (ret) > + goto disable_exit; > + > vfio_pci_probe_mmaps(vdev); > > return 0; > @@ -1383,6 +1450,7 @@ static void vfio_pci_remove(struct pci_dev *pdev) > > vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev); > kfree(vdev->region); > + kfree(vdev->fault_pages); > mutex_destroy(&vdev->ioeventfds_lock); > > if (!disable_idle_d3) > diff --git a/drivers/vfio/pci/vfio_pci_private.h > b/drivers/vfio/pci/vfio_pci_private.h > index 8a2c7607d513..a392f50e3a99 100644 > --- a/drivers/vfio/pci/vfio_pci_private.h > +++ b/drivers/vfio/pci/vfio_pci_private.h > @@ -119,6 +119,8 @@ struct vfio_pci_device { > int ioeventfds_nr; > struct eventfd_ctx *err_trigger; > struct eventfd_ctx *req_trigger; > + u8 *fault_pages; > + struct mutex fault_queue_lock; > struct list_head dummy_resources_list; > struct mutex ioeventfds_lock; > struct list_head ioeventfds_list; > @@ -150,6 +152,14 @@ extern ssize_t vfio_pci_vga_rw(struct vfio_pci_device > *vdev, char __user *buf, > extern long vfio_pci_ioeventfd(struct vfio_pci_device *vdev, loff_t offset, > uint64_t data, int count, int fd); > > +struct vfio_pci_fault_abi { > + u32 entry_size; > +}; > + > +extern size_t vfio_pci_dma_fault_rw(struct vfio_pci_device *vdev, > + char __user *buf, size_t count, > + loff_t *ppos, bool iswrite); > + > extern int vfio_pci_init_perm_bits(void); > extern void vfio_pci_uninit_perm_bits(void); > > diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c > b/drivers/vfio/pci/vfio_pci_rdwr.c > index a87992892a9f..4004ab8cad0e 100644 > --- a/drivers/vfio/pci/vfio_pci_rdwr.c > +++ b/drivers/vfio/pci/vfio_pci_rdwr.c > @@ -274,6 +274,51 @@ ssize_t vfio_pci_vga_rw(struct vfio_pci_device *vdev, > char > __user *buf, > return done; > } > > +size_t vfio_pci_dma_fault_rw(struct vfio_pci_device *vdev, char __user *buf, > + size_t count, loff_t *ppos, bool iswrite) > +{ > + unsigned int i = VFIO_PCI_OFFSET_TO_INDEX(*ppos) - > VFIO_PCI_NUM_REGIONS; > + loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK; > + void *base = vdev->region[i].data; > + int ret = -EFAULT; > + > + if (pos >= vdev->region[i].size) > + return -EINVAL; > + > + count = min(count, (size_t)(vdev->region[i].size - pos)); > + > + mutex_lock(&vdev->fault_queue_lock); > + > + if (iswrite) { > + struct vfio_region_dma_fault *header = > + (struct vfio_region_dma_fault *)base; > + u32 new_tail; > + > + if (pos != 0 || count != 4) { > + ret = -EINVAL; > + goto unlock; > + } > + > + if (copy_from_user((void *)&new_tail, buf, count)) > + goto unlock; > + > + if (new_tail > header->nb_entries) { > + ret = -EINVAL; > + goto unlock; > + } > + header->tail = new_tail; > + } else { > + if (copy_to_user(buf, base + pos, count)) > + goto unlock; > + } > + *ppos += count; > + ret = count; > +unlock: > + mutex_unlock(&vdev->fault_queue_lock); > + return ret; > +} > + > + > static int vfio_pci_ioeventfd_handler(void *opaque, void *unused) > { > struct vfio_pci_ioeventfd *ioeventfd = opaque; > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h > index 9f2429eb1958..40d770f80e3d 100644 > --- a/include/uapi/linux/vfio.h > +++ b/include/uapi/linux/vfio.h > @@ -330,6 +330,9 @@ struct vfio_region_info_cap_type { > /* sub-types for VFIO_REGION_TYPE_GFX */ > #define VFIO_REGION_SUBTYPE_GFX_EDID (1) > > +#define VFIO_REGION_TYPE_NESTED (2) > +#define VFIO_REGION_SUBTYPE_NESTED_DMA_FAULT (1) > + > /** > * struct vfio_region_gfx_edid - EDID region layout. > * > @@ -708,6 +711,38 @@ struct vfio_device_ioeventfd { > > #define VFIO_DEVICE_IOEVENTFD _IO(VFIO_TYPE, VFIO_BASE + 16) > > + > +/* > + * Capability exposed by the DMA fault region > + * @version: ABI version > + */ > +#define VFIO_REGION_INFO_CAP_DMA_FAULT 6 > + > +struct vfio_region_info_cap_fault { > + struct vfio_info_cap_header header; > + __u32 version; > +}; > + > +/* > + * DMA Fault Region Layout > + * @tail: index relative to the start of the ring buffer at which the > + * consumer finds the next item in the buffer > + * @entry_size: fault ring buffer entry size in bytes > + * @nb_entries: max capacity of the fault ring buffer > + * @offset: ring buffer offset relative to the start of the region > + * @head: index relative to the start of the ring buffer at which the > + * producer (kernel) inserts items into the buffers > + */ > +struct vfio_region_dma_fault { > + /* Write-Only */ > + __u32 tail; > + /* Read-Only */ > + __u32 entry_size; > + __u32 nb_entries; > + __u32 offset; > + __u32 head; > +}; > + > /* -------- API for Type1 VFIO IOMMU -------- */ > > /** > -- > 2.20.1 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
