Commit 5f64ce54 authored by Eric Auger's avatar Eric Auger Committed by Joerg Roedel
Browse files

iommu/vt-d: Duplicate iommu_resv_region objects per device list 



intel_iommu_get_resv_regions() aims to return the list of
reserved regions accessible by a given @device. However several
devices can access the same reserved memory region and when
building the list it is not safe to use a single iommu_resv_region
object, whose container is the RMRR. This iommu_resv_region must
be duplicated per device reserved region list.

Let's remove the struct iommu_resv_region from the RMRR unit
and allocate the iommu_resv_region directly in
intel_iommu_get_resv_regions(). We hold the dmar_global_lock instead
of the rcu-lock to allow sleeping.

Fixes: 0659b8dc ("iommu/vt-d: Implement reserved region get/put callbacks")
Signed-off-by: default avatarEric Auger <eric.auger@redhat.com>
Reviewed-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent ad0834de

drivers/iommu/intel-iommu.c

+17 −17
Original line number Diff line number Diff line
@@ -324,7 +324,6 @@ struct dmar_rmrr_unit { 
	u64	end_address;		/* reserved end address */

	struct dmar_dev_scope *devices;	/* target devices */

	int	devices_cnt;		/* target device count */

	struct iommu_resv_region *resv; /* reserved region handle */

};



struct dmar_atsr_unit {
@@ -4050,7 +4049,6 @@ static inline void init_iommu_pm_ops(void) {} 
int __init dmar_parse_one_rmrr(struct acpi_dmar_header *header, void *arg)

{

	struct acpi_dmar_reserved_memory *rmrr;

	int prot = DMA_PTE_READ|DMA_PTE_WRITE;

	struct dmar_rmrr_unit *rmrru;

	size_t length;
@@ -4064,22 +4062,16 @@ int __init dmar_parse_one_rmrr(struct acpi_dmar_header *header, void *arg) 
	rmrru->end_address = rmrr->end_address;



	length = rmrr->end_address - rmrr->base_address + 1;

	rmrru->resv = iommu_alloc_resv_region(rmrr->base_address, length, prot,

					      IOMMU_RESV_DIRECT);

	if (!rmrru->resv)

		goto free_rmrru;



	rmrru->devices = dmar_alloc_dev_scope((void *)(rmrr + 1),

				((void *)rmrr) + rmrr->header.length,

				&rmrru->devices_cnt);

	if (rmrru->devices_cnt && rmrru->devices == NULL)

		goto free_all;

		goto free_rmrru;



	list_add(&rmrru->list, &dmar_rmrr_units);



	return 0;

free_all:

	kfree(rmrru->resv);

free_rmrru:

	kfree(rmrru);

out:
@@ -4297,7 +4289,6 @@ static void intel_iommu_free_dmars(void) 
	list_for_each_entry_safe(rmrru, rmrr_n, &dmar_rmrr_units, list) {

		list_del(&rmrru->list);

		dmar_free_dev_scope(&rmrru->devices, &rmrru->devices_cnt);

		kfree(rmrru->resv);

		kfree(rmrru);

	}
@@ -5400,22 +5391,33 @@ static void intel_iommu_remove_device(struct device *dev) 
static void intel_iommu_get_resv_regions(struct device *device,

					 struct list_head *head)

{

	int prot = DMA_PTE_READ | DMA_PTE_WRITE;

	struct iommu_resv_region *reg;

	struct dmar_rmrr_unit *rmrr;

	struct device *i_dev;

	int i;



	rcu_read_lock();

	down_read(&dmar_global_lock);

	for_each_rmrr_units(rmrr) {

		for_each_active_dev_scope(rmrr->devices, rmrr->devices_cnt,

					  i, i_dev) {

			struct iommu_resv_region *resv;

			size_t length;



			if (i_dev != device)

				continue;



			list_add_tail(&rmrr->resv->list, head);

			length = rmrr->end_address - rmrr->base_address + 1;

			resv = iommu_alloc_resv_region(rmrr->base_address,

						       length, prot,

						       IOMMU_RESV_DIRECT);

			if (!resv)

				break;



			list_add_tail(&resv->list, head);

		}

	}

	rcu_read_unlock();

	up_read(&dmar_global_lock);



#ifdef CONFIG_INTEL_IOMMU_FLOPPY_WA

	if (dev_is_pci(device)) {
@@ -5443,11 +5445,9 @@ static void intel_iommu_put_resv_regions(struct device *dev, 
{

	struct iommu_resv_region *entry, *next;



	list_for_each_entry_safe(entry, next, head, list) {

		if (entry->type == IOMMU_RESV_MSI)

	list_for_each_entry_safe(entry, next, head, list)

		kfree(entry);

}

}



int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct device *dev)

{

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