Commit fa77b023eb80 for kernel
commit fa77b023eb80cdb297ff32f6b13786e483a81ca8
Author: Kevin Mitchell <kevmitch@arista.com>
Date: Thu Nov 5 16:32:18 2026 +0000
iommu/amd: remove obsolete domain pointer warning on release
A warning is triggered in amd_iommu_release_device() on removal of a
device with an IOMMU_RESV_DIRECT region. The warning is based on the
false assumption that correct attachment to the release_domain will
always result in a NULL dev_data->domain pointer. For devices with
IOMMU_RESV_DIRECT (and consequently dev->iommu->require_direct), the
release domain is the permanent identity_domain which sets
itself to dev_data->domain on attach.
This behaviour was added in commit e94160488e65 ("iommu: Generic support
for RMRs during device release"). Commit c21b34762e2f ("iommu/amd: Set
release_domain to blocked_domain") caused it to take effect for AMD
IOMMU.
Remove the warning as it is no longer strictly an error to have a non-NULL
domain pointer. As this leaves amd_iommu_release_device() empty, remove it.
The warning was observed for a device with direct mapped region:
/sys/bus/pci/devices/0000:04:00.0/iommu_group/reserved_regions:
0x00000000fee00000 0x00000000feefffff msi
0x000000fd00000000 0x000000ffffffffff reserved
0x0000fffd00000000 0x0000ffffffffffff direct
Upon hotunplug:
[ 28.715475] pcieport 0000:00:03.1: pciehp: Slot(0-3): Link Down
[ 28.715482] pcieport 0000:00:03.1: pciehp: Slot(0-3): Card not present
[ 28.715601] ------------[ cut here ]------------
[ 28.715603] WARNING: drivers/iommu/amd/iommu.c:2521 at amd_iommu_release_device+0x5d/0x70, CPU#4: irq/29-pciehp/99
[ 28.715657] RIP: 0010:amd_iommu_release_device+0x5d/0x70
[ 28.715687] Call Trace:
[ 28.715689] <TASK>
[ 28.715694] iommu_deinit_device+0x84/0x110
[ 28.715699] __iommu_group_remove_device+0xa8/0xd0
[ 28.715703] iommu_bus_notifier+0x48/0x70
[ 28.715707] notifier_call_chain+0x48/0xe0
[ 28.715712] blocking_notifier_call_chain+0x45/0x60
[ 28.715716] bus_notify+0x3b/0x60
[ 28.715720] device_del+0x259/0x3b0
[ 28.715730] pci_remove_bus_device+0x85/0x100
[ 28.715735] pciehp_unconfigure_device+0x9d/0x180
[ 28.715743] __pciehp_disable_slot+0x47/0xe0
[ 28.715747] pciehp_handle_presence_or_link_change+0x80/0x5e0
[ 28.715753] pciehp_ist+0x162/0x290
Fixes: c21b34762e2f ("iommu/amd: Set release_domain to blocked_domain")
Cc: stable@vger.kernel.org
Signed-off-by: Kevin Mitchell <kevmitch@arista.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 54465e041155..91981c8a9614 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -488,6 +488,10 @@ static void setup_aliases(struct amd_iommu *iommu, struct device *dev)
clone_aliases(iommu, dev);
}
+/*
+ * We keep dev_data around for unplugged devices and reuse it when the
+ * device is re-plugged - not doing so would introduce a ton of races.
+ */
static struct iommu_dev_data *find_dev_data(struct amd_iommu *iommu, u16 devid)
{
struct iommu_dev_data *dev_data;
@@ -2551,18 +2555,6 @@ static struct iommu_device *amd_iommu_probe_device(struct device *dev)
return iommu_dev;
}
-static void amd_iommu_release_device(struct device *dev)
-{
- struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
-
- WARN_ON(dev_data->domain);
-
- /*
- * We keep dev_data around for unplugged devices and reuse it when the
- * device is re-plugged - not doing so would introduce a ton of races.
- */
-}
-
static struct iommu_group *amd_iommu_device_group(struct device *dev)
{
if (dev_is_pci(dev))
@@ -3266,7 +3258,6 @@ const struct iommu_ops amd_iommu_ops = {
.domain_alloc_paging_flags = amd_iommu_domain_alloc_paging_flags,
.domain_alloc_sva = amd_iommu_domain_alloc_sva,
.probe_device = amd_iommu_probe_device,
- .release_device = amd_iommu_release_device,
.device_group = amd_iommu_device_group,
.get_resv_regions = amd_iommu_get_resv_regions,
.is_attach_deferred = amd_iommu_is_attach_deferred,