Commit 20b23b13 authored by Eric Auger's avatar Eric Auger Committed by Zheng Zengkai
Browse files

vfio/pci: Add VFIO_REGION_TYPE_NESTED region type 

virt inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I401IF


CVE: NA

------------------------------

Add a new specific DMA_FAULT region aiming to exposed nested mode
translation faults. This region only is exposed if the device
is attached to a nested domain.

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: default avatarEric Auger <eric.auger@redhat.com>
Signed-off-by: default avatarKunkun <Jiang&lt;jiangkunkun@huawei.com>
Reviewed-by: default avatarKeqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent ac16d334

drivers/vfio/pci/vfio_pci.c

+79 −0
Original line number Diff line number Diff line
@@ -309,6 +309,81 @@ 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)

{

	kfree(vdev->fault_pages);

}



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_dma_fault_init(struct vfio_pci_device *vdev)

{

	struct vfio_region_dma_fault *header;

	struct iommu_domain *domain;

	size_t size;

	int nested;

	int ret;



	domain = iommu_get_domain_for_dev(&vdev->pdev->dev);

	if (!domain)

		return 0;



	ret = iommu_domain_get_attr(domain, DOMAIN_ATTR_NESTING, &nested);

	if (ret || !nested)

		return 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);

	vdev->fault_pages = NULL;

	return ret;

}



static int vfio_pci_enable(struct vfio_pci_device *vdev)

{

	struct pci_dev *pdev = vdev->pdev;
@@ -407,6 +482,10 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev) 
		}

	}



	ret = vfio_pci_dma_fault_init(vdev);

	if (ret)

		goto disable_exit;



	vfio_pci_probe_mmaps(vdev);



	return 0;

drivers/vfio/pci/vfio_pci_private.h

+6 −0
Original line number Diff line number Diff line
@@ -134,6 +134,8 @@ 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;
@@ -170,6 +172,10 @@ 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);



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);

drivers/vfio/pci/vfio_pci_rdwr.c

+44 −0
Original line number Diff line number Diff line
@@ -356,6 +356,50 @@ 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 void vfio_pci_ioeventfd_do_write(struct vfio_pci_ioeventfd *ioeventfd,

					bool test_mem)

{

include/uapi/linux/vfio.h

+35 −0
Original line number Diff line number Diff line
@@ -329,6 +329,7 @@ struct vfio_region_info_cap_type { 
#define VFIO_REGION_TYPE_GFX                    (1)

#define VFIO_REGION_TYPE_CCW			(2)

#define VFIO_REGION_TYPE_MIGRATION              (3)

#define VFIO_REGION_TYPE_NESTED			(4)



/* sub-types for VFIO_REGION_TYPE_PCI_* */
@@ -353,6 +354,9 @@ struct vfio_region_info_cap_type { 
/* sub-types for VFIO_REGION_TYPE_GFX */

#define VFIO_REGION_SUBTYPE_GFX_EDID            (1)



/* sub-types for VFIO_REGION_TYPE_NESTED */

#define VFIO_REGION_SUBTYPE_NESTED_DMA_FAULT	(1)



/**

 * struct vfio_region_gfx_edid - EDID region layout.

 *
@@ -998,6 +1002,37 @@ struct vfio_device_feature { 
 */

#define VFIO_DEVICE_FEATURE_PCI_VF_TOKEN	(0)



/*

 * 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 -------- */



/**