On 2024/5/10 21:38, Jason Gunthorpe wrote:
On Fri, May 10, 2024 at 11:14:20AM +0800, Baolu Lu wrote:
On 5/8/24 8:04 AM, Jason Gunthorpe wrote:
On Tue, Apr 30, 2024 at 10:57:04PM +0800, Lu Baolu wrote:
@@ -206,8 +197,11 @@ void iommu_report_device_fault(struct device *dev, struct iopf_fault *evt)
if (group == &abort_group)
goto err_abort;
- group->domain = get_domain_for_iopf(dev, fault);
- if (!group->domain)
+ if (!(fault->prm.flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID) ||
+ get_attach_handle_for_iopf(dev, fault->prm.pasid, group))
+ get_attach_handle_for_iopf(dev, IOMMU_NO_PASID, group);
That seems a bit weird looking?
Agreed.
get_attach_handle_for_iopf(dev,
(fault->prm.flags &
IOMMU_FAULT_PAGE_REQUEST_PASID_VALID) ? fault->prm.pasid : IOMMU_NO_PASID,
group);
The logic here is that it tries the PASID domain and if it doesn't
exist, then tries the RID domain as well. I explained this in the commit
message:
"
... if the pasid table of a device is wholly managed by user space,
there is no domain attached to the PASID of the device ...
"
Okay, it needs a comment in the code, and the RID fallback should be
based aroudn checking for a NESTING domain type which includes the
PASID table. (ie ARM and AMD not Intel)
It appears that Intel is just special. ARM, AMD, and RISC-V all support
a NESTING domain which includes the PASID table. So, how about defining
a special NESTING domain type for Intel? Like this,
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 35ae9a6f73d3..09b4e671dcee 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -173,6 +173,8 @@ struct iommu_domain_geometry {
#define __IOMMU_DOMAIN_NESTED (1U << 6) /* User-managed address
space nested
on a stage-2 translation
*/
+#define __IOMMU_DOMAIN_PASID (1U << 7) /* User-managed domain for a
+ specific PASID*/
#define IOMMU_DOMAIN_ALLOC_FLAGS ~__IOMMU_DOMAIN_DMA_FQ
/*
@@ -204,6 +206,9 @@ struct iommu_domain_geometry {
#define IOMMU_DOMAIN_SVA (__IOMMU_DOMAIN_SVA)
#define IOMMU_DOMAIN_PLATFORM (__IOMMU_DOMAIN_PLATFORM)
#define IOMMU_DOMAIN_NESTED (__IOMMU_DOMAIN_NESTED)
+#define IOMMU_DOMAIN_NESTED_PASID \
+ (__IOMMU_DOMAIN_NESTED | \
+ __IOMMU_DOMAIN_PASID)
And current IOMMU_DOMAIN_NESTED domain type is just for a nesting domain
with PASID table.
The Intel IOMMU driver will convert to use IOMMU_DOMAIN_NESTED_PASID in
the PASID interface series.
We shouldn't just elevate a random PASID to the RID if it isn't
approprite..
If above propose looks good to you, then I just need to add a domain
type check before RID fallback.
Best regards,
baolu
