[PATCH v3 5/8] iommu/vt-d: Implement def_domain_type iommu ops entry

Lu Baolu
2019-04-29T02:09:22Z

It will be used by the iommu generic framework to check the
default domain types that Intel IOMMU driver supports for a
specific device. Return IOMMU_DOMAIN_DMA if device requires
a non-identity domain; Return IOMMU_DOMAIN_IDENTITY if the
device requires to use an identity domain. Otherwise return
IOMMU_DOMAIN_ANY which indicates that both domain types are
supported, hence the static default domain type defined in
iommu generic layer will be used.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
drivers/iommu/intel-iommu.c | 86 +++++++++++++------------------------
1 file changed, 29 insertions(+), 57 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 847e4a326d29..d2b51e045603 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -2858,9 +2858,6 @@ static int identity_mapping(struct device *dev)
{
struct device_domain_info *info;

- if (likely(!iommu_identity_mapping))
- return 0;
-
info = dev->archdata.iommu;
if (info && info != DUMMY_DEVICE_DOMAIN_INFO)
return (info->domain == si_domain);
@@ -2945,29 +2942,26 @@ static bool device_is_rmrr_locked(struct device *dev)
return true;
}

-static int iommu_should_identity_map(struct device *dev, int startup)
+static int intel_iommu_def_domain_type(struct device *dev)
{
if (dev_is_pci(dev)) {
struct pci_dev *pdev = to_pci_dev(dev);

if (device_is_rmrr_locked(dev))
- return 0;
+ return IOMMU_DOMAIN_DMA;

/*
* Prevent any device marked as untrusted from getting
* placed into the statically identity mapping domain.
*/
if (pdev->untrusted)
- return 0;
+ return IOMMU_DOMAIN_DMA;

if ((iommu_identity_mapping & IDENTMAP_AZALIA) && IS_AZALIA(pdev))
- return 1;
+ return IOMMU_DOMAIN_IDENTITY;

if ((iommu_identity_mapping & IDENTMAP_GFX) && IS_GFX_DEVICE(pdev))
- return 1;
-
- if (!(iommu_identity_mapping & IDENTMAP_ALL))
- return 0;
+ return IOMMU_DOMAIN_IDENTITY;

/*
* We want to start off with all devices in the 1:1 domain, and
@@ -2988,43 +2982,25 @@ static int iommu_should_identity_map(struct device *dev, int startup)
*/
if (!pci_is_pcie(pdev)) {
if (!pci_is_root_bus(pdev->bus))
- return 0;
+ return IOMMU_DOMAIN_DMA;
if (pdev->class >> 8 == PCI_CLASS_BRIDGE_PCI)
- return 0;
+ return IOMMU_DOMAIN_DMA;
} else if (pci_pcie_type(pdev) == PCI_EXP_TYPE_PCI_BRIDGE)
- return 0;
+ return IOMMU_DOMAIN_DMA;
} else {
if (device_has_rmrr(dev))
- return 0;
- }
-
- /*
- * At boot time, we don't yet know if devices will be 64-bit capable.
- * Assume that they will — if they turn out not to be, then we can
- * take them out of the 1:1 domain later.
- */
- if (!startup) {
- /*
- * If the device's dma_mask is less than the system's memory
- * size then this is not a candidate for identity mapping.
- */
- u64 dma_mask = *dev->dma_mask;
-
- if (dev->coherent_dma_mask &&
- dev->coherent_dma_mask < dma_mask)
- dma_mask = dev->coherent_dma_mask;
-
- return dma_mask >= dma_get_required_mask(dev);
+ return IOMMU_DOMAIN_DMA;
}

- return 1;
+ return (iommu_identity_mapping & IDENTMAP_ALL) ?
+ IOMMU_DOMAIN_IDENTITY : IOMMU_DOMAIN_ANY;
}

static int __init dev_prepare_static_identity_mapping(struct device *dev, int hw)
{
int ret;

- if (!iommu_should_identity_map(dev, 1))
+ if (intel_iommu_def_domain_type(dev) != IOMMU_DOMAIN_IDENTITY)
return 0;

ret = domain_add_dev_info(si_domain, dev);
@@ -3631,35 +3607,30 @@ static int iommu_no_mapping(struct device *dev)
if (iommu_dummy(dev))
return 1;

- if (!iommu_identity_mapping)
- return 0;
-
found = identity_mapping(dev);
if (found) {
- if (iommu_should_identity_map(dev, 0))
- return 1;
- else {
+ /*
+ * If the device's dma_mask is less than the system's memory
+ * size then this is not a candidate for identity mapping.
+ */
+ u64 dma_mask = *dev->dma_mask;
+
+ if (dev->coherent_dma_mask &&
+ dev->coherent_dma_mask < dma_mask)
+ dma_mask = dev->coherent_dma_mask;
+
+ if (dma_mask < dma_get_required_mask(dev)) {
/*
* 32 bit DMA is removed from si_domain and fall back
* to non-identity mapping.
*/
dmar_remove_one_dev_info(dev);
- dev_info(dev, "32bit DMA uses non-identity mapping\n");
+ dev_warn(dev, "32bit DMA uses non-identity mapping\n");
+
return 0;
}
- } else {
- /*
- * In case of a detached 64 bit DMA device from vm, the device
- * is put into si_domain for identity mapping.
- */
- if (iommu_should_identity_map(dev, 0)) {
- int ret;
- ret = domain_add_dev_info(si_domain, dev);
- if (!ret) {
- dev_info(dev, "64bit DMA uses identity mapping\n");
- return 1;
- }
- }
+
+ return 1;
}

return 0;
@@ -4605,7 +4576,7 @@ static int device_notifier(struct notifier_block *nb,
list_empty(&domain->devices))
domain_exit(domain);
} else if (action == BUS_NOTIFY_ADD_DEVICE) {
- if (iommu_should_identity_map(dev, 1))
+ if (intel_iommu_def_domain_type(dev) == IOMMU_DOMAIN_IDENTITY)
domain_add_dev_info(si_domain, dev);
}

@@ -5781,6 +5752,7 @@ const struct iommu_ops intel_iommu_ops = {
.dev_feat_enabled = intel_iommu_dev_feat_enabled,
.dev_enable_feat = intel_iommu_dev_enable_feat,
.dev_disable_feat = intel_iommu_dev_disable_feat,
+ .def_domain_type = intel_iommu_def_domain_type,
.pgsize_bitmap = INTEL_IOMMU_PGSIZES,
};

--
2.17.1