[PATCH] iommu/amd: Reserve exclusion range in iova-domain

From: Joerg Roedel
Date: Thu Mar 28 2019 - 06:45:06 EST


From: Joerg Roedel <jroedel@xxxxxxx>

If a device has an exclusion range specified in the IVRS
table, this region needs to be reserved in the iova-domain
of that device. This hasn't happened until now and can cause
data corruption on data transfered with these devices.

Treat exclusion ranges as reserved regions in the iommu-core
to fix the problem.

Fixes: be2a022c0dd0 ('x86, AMD IOMMU: add functions to parse IOMMU memory mapping requirements for devices')
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
drivers/iommu/amd_iommu.c | 9 ++++++---
drivers/iommu/amd_iommu_init.c | 7 ++++---
2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 21cb088d6687..2a8d2806d5b9 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3169,21 +3169,24 @@ static void amd_iommu_get_resv_regions(struct device *dev,
return;

list_for_each_entry(entry, &amd_iommu_unity_map, list) {
+ int type, prot = 0;
size_t length;
- int prot = 0;

if (devid < entry->devid_start || devid > entry->devid_end)
continue;

+ type = IOMMU_RESV_DIRECT;
length = entry->address_end - entry->address_start;
if (entry->prot & IOMMU_PROT_IR)
prot |= IOMMU_READ;
if (entry->prot & IOMMU_PROT_IW)
prot |= IOMMU_WRITE;
+ if (entry->prot & (1 << 2))
+ /* Exclusion range */
+ type = IOMMU_RESV_RESERVED;

region = iommu_alloc_resv_region(entry->address_start,
- length, prot,
- IOMMU_RESV_DIRECT);
+ length, prot, type);
if (!region) {
dev_err(dev, "Out of memory allocating dm-regions\n");
return;
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index f773792d77fd..1b1378619fc9 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -2013,6 +2013,9 @@ static int __init init_unity_map_range(struct ivmd_header *m)
if (e == NULL)
return -ENOMEM;

+ if (m->flags & IVMD_FLAG_EXCL_RANGE)
+ init_exclusion_range(m);
+
switch (m->type) {
default:
kfree(e);
@@ -2059,9 +2062,7 @@ static int __init init_memory_definitions(struct acpi_table_header *table)

while (p < end) {
m = (struct ivmd_header *)p;
- if (m->flags & IVMD_FLAG_EXCL_RANGE)
- init_exclusion_range(m);
- else if (m->flags & IVMD_FLAG_UNITY_MAP)
+ if (m->flags & (IVMD_FLAG_UNITY_MAP | IVMD_FLAG_EXCL_RANGE))
init_unity_map_range(m);

p += m->length;
--
2.16.4