diff mbox series

[01/18] memory: Adjust event ranges to fit within notifier boundaries

Message ID 20250414020253.443831-2-alejandro.j.jimenez@oracle.com (mailing list archive)
State New
Headers show
Series AMD vIOMMU: DMA remapping support for VFIO devices | expand

Commit Message

Alejandro Jimenez April 14, 2025, 2:02 a.m. UTC 
Invalidating the entire address space (i.e. range of [0, ~0ULL]) is a
valid and required operation by vIOMMU implementations. However, such
invalidations currently trigger an assertion unless they originate from
device IOTLB invalidations.

Although in recent Linux guests this case is not exercised by the VTD
implementation due to various optimizations, the assertion will be hit
by upcoming AMD vIOMMU changes to support DMA address translation. More
specifically, when running a Linux guest with VFIO passthrough device,
and a kernel that does not contain commmit 3f2571fed2fa ("iommu/amd:
Remove redundant domain flush from attach_device()").

Remove the assertion altogether and adjust the range to ensure it does
not cross notifier boundaries.

Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
---
 system/memory.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/system/memory.c b/system/memory.c
index 4c829793a0ad..7d120e25abe8 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -2030,13 +2030,9 @@  void memory_region_notify_iommu_one(IOMMUNotifier *notifier,
         return;
     }
 
-    if (notifier->notifier_flags & IOMMU_NOTIFIER_DEVIOTLB_UNMAP) {
-        /* Crop (iova, addr_mask) to range */
-        tmp.iova = MAX(tmp.iova, notifier->start);
-        tmp.addr_mask = MIN(entry_end, notifier->end) - tmp.iova;
-    } else {
-        assert(entry->iova >= notifier->start && entry_end <= notifier->end);
-    }
+    /* Crop (iova, addr_mask) to range */
+    tmp.iova = MAX(tmp.iova, notifier->start);
+    tmp.addr_mask = MIN(entry_end, notifier->end) - tmp.iova;
 
     if (event->type & notifier->notifier_flags) {
         notifier->notify(notifier, &tmp);