Commit c0c76359 authored by Jean-Philippe Brucker's avatar Jean-Philippe Brucker Committed by Joerg Roedel
Browse files

iommu/virtio: Pass end address to viommu_add_mapping() 



To support identity mappings, the virtio-iommu driver must be able to
represent full 64-bit ranges internally. Pass (start, end) instead of
(start, size) to viommu_add/del_mapping().

Clean comments. The one about the returned size was never true: when
sweeping the whole address space the returned size will most certainly
be smaller than 2^64.

Reviewed-by: default avatarEric Auger <eric.auger@redhat.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Signed-off-by: default avatarJean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20211201173323.1045819-5-jean-philippe@linaro.org


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 56109794

drivers/iommu/virtio-iommu.c

+15 −16
Original line number Diff line number Diff line
@@ -311,8 +311,8 @@ static int viommu_send_req_sync(struct viommu_dev *viommu, void *buf, 
 *

 * On success, return the new mapping. Otherwise return NULL.

 */

static int viommu_add_mapping(struct viommu_domain *vdomain, unsigned long iova,

			      phys_addr_t paddr, size_t size, u32 flags)

static int viommu_add_mapping(struct viommu_domain *vdomain, u64 iova, u64 end,

			      phys_addr_t paddr, u32 flags)

{

	unsigned long irqflags;

	struct viommu_mapping *mapping;
@@ -323,7 +323,7 @@ static int viommu_add_mapping(struct viommu_domain *vdomain, unsigned long iova, 


	mapping->paddr		= paddr;

	mapping->iova.start	= iova;

	mapping->iova.last	= iova + size - 1;

	mapping->iova.last	= end;

	mapping->flags		= flags;



	spin_lock_irqsave(&vdomain->mappings_lock, irqflags);
@@ -338,26 +338,24 @@ static int viommu_add_mapping(struct viommu_domain *vdomain, unsigned long iova, 
 *

 * @vdomain: the domain

 * @iova: start of the range

 * @size: size of the range. A size of 0 corresponds to the entire address

 *	space.

 * @end: end of the range

 *

 * On success, returns the number of unmapped bytes (>= size)

 * On success, returns the number of unmapped bytes

 */

static size_t viommu_del_mappings(struct viommu_domain *vdomain,

				  unsigned long iova, size_t size)

				  u64 iova, u64 end)

{

	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);

	next = interval_tree_iter_first(&vdomain->mappings, iova, end);

	while (next) {

		node = next;

		mapping = container_of(node, struct viommu_mapping, iova);

		next = interval_tree_iter_next(node, iova, last);

		next = interval_tree_iter_next(node, iova, end);



		/* Trying to split a mapping? */

		if (mapping->iova.start < iova)
@@ -656,8 +654,8 @@ static void viommu_domain_free(struct iommu_domain *domain) 
{

	struct viommu_domain *vdomain = to_viommu_domain(domain);



	/* Free all remaining mappings (size 2^64) */

	viommu_del_mappings(vdomain, 0, 0);

	/* Free all remaining mappings */

	viommu_del_mappings(vdomain, 0, ULLONG_MAX);



	if (vdomain->viommu)

		ida_free(&vdomain->viommu->domain_ids, vdomain->id);
@@ -742,6 +740,7 @@ static int viommu_map(struct iommu_domain *domain, unsigned long iova, 
{

	int ret;

	u32 flags;

	u64 end = iova + size - 1;

	struct virtio_iommu_req_map map;

	struct viommu_domain *vdomain = to_viommu_domain(domain);
@@ -752,7 +751,7 @@ static int viommu_map(struct iommu_domain *domain, unsigned long iova, 
	if (flags & ~vdomain->map_flags)

		return -EINVAL;



	ret = viommu_add_mapping(vdomain, iova, paddr, size, flags);

	ret = viommu_add_mapping(vdomain, iova, end, paddr, flags);

	if (ret)

		return ret;
@@ -761,7 +760,7 @@ static int viommu_map(struct iommu_domain *domain, unsigned long iova, 
		.domain		= cpu_to_le32(vdomain->id),

		.virt_start	= cpu_to_le64(iova),

		.phys_start	= cpu_to_le64(paddr),

		.virt_end	= cpu_to_le64(iova + size - 1),

		.virt_end	= cpu_to_le64(end),

		.flags		= cpu_to_le32(flags),

	};
@@ -770,7 +769,7 @@ static int viommu_map(struct iommu_domain *domain, unsigned long iova, 


	ret = viommu_send_req_sync(vdomain->viommu, &map, sizeof(map));

	if (ret)

		viommu_del_mappings(vdomain, iova, size);

		viommu_del_mappings(vdomain, iova, end);



	return ret;

}
@@ -783,7 +782,7 @@ static size_t viommu_unmap(struct iommu_domain *domain, unsigned long iova, 
	struct virtio_iommu_req_unmap unmap;

	struct viommu_domain *vdomain = to_viommu_domain(domain);



	unmapped = viommu_del_mappings(vdomain, iova, size);

	unmapped = viommu_del_mappings(vdomain, iova, iova + size - 1);

	if (unmapped < size)

		return 0;