From: Sai Praneeth Prakhya <sai.praneeth.prak...@intel.com>
Presently, the default domain of an iommu group is allocated during boot
time and it cannot be changed later. So, the device would typically be
either in identity (also known as pass_through) mode or the device would be
in DMA mode as long as the machine is up and running. There is no way to
change the default domain type dynamically i.e. after booting, a device
cannot switch between identity mode and DMA mode.
But, assume a use case wherein the user trusts the device and believes that
the OS is secure enough and hence wants *only* this device to bypass IOMMU
(so that it could be high performing) whereas all the other devices to go
through IOMMU (so that the system is protected). Presently, this use case
is not supported. It will be helpful if there is some way to change the
default domain of an iommu group dynamically. Hence, add such support.
A privileged user could request the kernel to change the default domain
type of a iommu group by writing to
"/sys/kernel/iommu_groups/<grp_id>/type" file. Presently, only three values
are supported
1. identity: all the DMA transactions from the device in this group are
*not* translated by the iommu
2. DMA: all the DMA transactions from the device in this group are
translated by the iommu
3. auto: change to the type the device was booted with
Note:
1. Default domain of an iommu group with two or more devices cannot be
changed.
2. The device in the iommu group shouldn't be bound to any driver.
3. The device shouldn't be assigned to user for direct access.
4. The change request will fail if any device in the group has a mandatory
default domain type and the requested one conflicts with that.
Please see "Documentation/ABI/testing/sysfs-kernel-iommu_groups" for more
information.
NOTE: This back-port does not support using the /sys interface on GRR.
It simply adds macros for GRR (8086:0dbd), GRR_QAT_PF (8086:578a)
and GRR_QAT_VF (8086:578b).
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prak...@intel.com>
Signed-off-by: Lu Baolu <baolu...@linux.intel.com>
Cc: Christoph Hellwig <h...@lst.de>
Cc: Joerg Roedel <j...@8bytes.org>
Cc: Ashok Raj <ashok....@intel.com>
Cc: Will Deacon <will.dea...@arm.com>
Cc: Sohil Mehta <sohil.me...@intel.com>
Cc: Robin Murphy <robin.mur...@arm.com>
Cc: Jacob Pan <jacob.jun....@linux.intel.com>
Cc: Magnus Hjohlman <magnus.hjohl...@ericsson.com>
Link:
https://lore.kernel.org/r/20201124130604.2912899-3-baolu...@linux.intel.com
Signed-off-by: Will Deacon <w...@kernel.org>
Back-ported-by: John Jacques <john.jacq...@intel.com>
[YL: Original patch from
https://github.com/intel-collab/networking.wireless.transport.rdk.board-support.meta-intel-axxia.git.]
Signed-off-by: Yongxin Liu <yongxin....@windriver.com>
---
drivers/iommu/intel/iommu.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 744e4e6b8d72..ae6b343912c3 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -39,6 +39,11 @@
#define IS_USB_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_SERIAL_USB)
#define IS_ISA_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA)
#define IS_AZALIA(pdev) ((pdev)->vendor == 0x8086 && (pdev)->device == 0x3a3e)
+#define IS_GRR(pdev) ((pdev)->vendor == 0x8086 && (pdev)->device == 0x0dbd)
+#define IS_GRR_QAT_PF(pdev) \
+ ((pdev)->vendor == 0x8086 && (pdev)->device == 0x578a)
+#define IS_GRR_QAT_VF(pdev) \
+ ((pdev)->vendor == 0x8086 && (pdev)->device == 0x578b)
#define IOAPIC_RANGE_START (0xfee00000)
#define IOAPIC_RANGE_END (0xfeefffff)
@@ -2545,6 +2550,15 @@ static int device_def_domain_type(struct device *dev)
if ((iommu_identity_mapping & IDENTMAP_GFX) &&
IS_GFX_DEVICE(pdev))
return IOMMU_DOMAIN_IDENTITY;
+
+ if (IS_GRR(pdev))
+ return IOMMU_DOMAIN_IDENTITY;
+
+ if (IS_GRR_QAT_PF(pdev))
+ return IOMMU_DOMAIN_IDENTITY;
+
+ if (IS_GRR_QAT_VF(pdev))
+ return IOMMU_DOMAIN_IDENTITY;
}
return 0;
--
2.45.0
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