[PATCH v7 09/19] iommu/vt-d: Implement reserved region get/put callbacks

Eric Auger
2017-01-09T13:50:04Z

This patch registers the [FEE0_0000h - FEF0_000h] 1MB MSI
range as a reserved region and RMRR regions as direct regions.

This will allow to report those reserved regions in the
iommu-group sysfs.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---
v6 -> v7:
- report RMRR regions as direct regions
- Due to the usage of rcu_read_lock, the rmrr reserved region
allocation is done on rmrr allocation.
- use IOMMU_RESV_RESERVED

RFCv2 -> RFCv3:
- use get/put_resv_region callbacks.

RFC v1 -> RFC v2:
- fix intel_iommu_add_reserved_regions name
- use IOAPIC_RANGE_START and IOAPIC_RANGE_END defines
- return if the MSI region is already registered;
---
drivers/iommu/intel-iommu.c | 92 ++++++++++++++++++++++++++++++++++++---------
1 file changed, 74 insertions(+), 18 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 8a18525..bce59a5 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -440,6 +440,7 @@ 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 {
@@ -4246,27 +4247,40 @@ 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;

rmrru = kzalloc(sizeof(*rmrru), GFP_KERNEL);
if (!rmrru)
- return -ENOMEM;
+ goto out;

rmrru->hdr = header;
rmrr = (struct acpi_dmar_reserved_memory *)header;
rmrru->base_address = rmrr->base_address;
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) {
- kfree(rmrru);
- return -ENOMEM;
- }
+ if (rmrru->devices_cnt && rmrru->devices == NULL)
+ goto free_all;

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

return 0;
+free_all:
+ kfree(rmrru->resv);
+free_rmrru:
+ kfree(rmrru);
+out:
+ return -ENOMEM;
}

static struct dmar_atsr_unit *dmar_find_atsr(struct acpi_dmar_atsr *atsr)
@@ -4480,6 +4494,7 @@ 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);
}

@@ -5203,6 +5218,45 @@ static void intel_iommu_remove_device(struct device *dev)
iommu_device_unlink(iommu->iommu_dev, dev);
}

+static void intel_iommu_get_resv_regions(struct device *device,
+ struct list_head *head)
+{
+ struct iommu_resv_region *reg;
+ struct dmar_rmrr_unit *rmrr;
+ struct device *i_dev;
+ int i;
+
+ rcu_read_lock();
+ for_each_rmrr_units(rmrr) {
+ for_each_active_dev_scope(rmrr->devices, rmrr->devices_cnt,
+ i, i_dev) {
+ if (i_dev != device)
+ continue;
+
+ list_add_tail(&rmrr->resv->list, head);
+ }
+ }
+ rcu_read_unlock();
+
+ reg = iommu_alloc_resv_region(IOAPIC_RANGE_START,
+ IOAPIC_RANGE_END - IOAPIC_RANGE_START + 1,
+ 0, IOMMU_RESV_RESERVED);
+ if (!reg)
+ return;
+ list_add_tail(&reg->list, head);
+}
+
+static void intel_iommu_put_resv_regions(struct device *dev,
+ struct list_head *head)
+{
+ struct iommu_resv_region *entry, *next;
+
+ list_for_each_entry_safe(entry, next, head, list) {
+ if (entry->type == IOMMU_RESV_RESERVED)
+ kfree(entry);
+ }
+}
+
#ifdef CONFIG_INTEL_IOMMU_SVM
#define MAX_NR_PASID_BITS (20)
static inline unsigned long intel_iommu_get_pts(struct intel_iommu *iommu)
@@ -5333,19 +5387,21 @@ struct intel_iommu *intel_svm_device_to_iommu(struct device *dev)
#endif /* CONFIG_INTEL_IOMMU_SVM */

static const struct iommu_ops intel_iommu_ops = {
- .capable = intel_iommu_capable,
- .domain_alloc = intel_iommu_domain_alloc,
- .domain_free = intel_iommu_domain_free,
- .attach_dev = intel_iommu_attach_device,
- .detach_dev = intel_iommu_detach_device,
- .map = intel_iommu_map,
- .unmap = intel_iommu_unmap,
- .map_sg = default_iommu_map_sg,
- .iova_to_phys = intel_iommu_iova_to_phys,
- .add_device = intel_iommu_add_device,
- .remove_device = intel_iommu_remove_device,
- .device_group = pci_device_group,
- .pgsize_bitmap = INTEL_IOMMU_PGSIZES,
+ .capable = intel_iommu_capable,
+ .domain_alloc = intel_iommu_domain_alloc,
+ .domain_free = intel_iommu_domain_free,
+ .attach_dev = intel_iommu_attach_device,
+ .detach_dev = intel_iommu_detach_device,
+ .map = intel_iommu_map,
+ .unmap = intel_iommu_unmap,
+ .map_sg = default_iommu_map_sg,
+ .iova_to_phys = intel_iommu_iova_to_phys,
+ .add_device = intel_iommu_add_device,
+ .remove_device = intel_iommu_remove_device,
+ .get_resv_regions = intel_iommu_get_resv_regions,
+ .put_resv_regions = intel_iommu_put_resv_regions,
+ .device_group = pci_device_group,
+ .pgsize_bitmap = INTEL_IOMMU_PGSIZES,
};

static void quirk_iommu_g4x_gfx(struct pci_dev *dev)
--
1.9.1