From: Joerg Roedel jroedel@suse.de
commit a11bfde9c77df1fd350ea27169ab921f511bf5d0 upstream.
The attachment of deferred devices needs to happen before the check whether the device is identity mapped or not. Otherwise the check will return wrong results, cause warnings boot failures in kdump kernels, like
WARNING: CPU: 0 PID: 318 at ../drivers/iommu/intel-iommu.c:592 domain_get_iommu+0x61/0x70
[...]
Call Trace: __intel_map_single+0x55/0x190 intel_alloc_coherent+0xac/0x110 dmam_alloc_attrs+0x50/0xa0 ahci_port_start+0xfb/0x1f0 [libahci] ata_host_start.part.39+0x104/0x1e0 [libata]
With the earlier check the kdump boot succeeds and a crashdump is written.
Fixes: 1ee0186b9a12 ("iommu/vt-d: Refactor find_domain() helper") Cc: stable@vger.kernel.org # v5.5 Reviewed-by: Jerry Snitselaar jsnitsel@redhat.com Acked-by: Lu Baolu baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/iommu/intel-iommu.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
--- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -2452,9 +2452,6 @@ static void do_deferred_attach(struct de
static struct dmar_domain *deferred_attach_domain(struct device *dev) { - if (unlikely(attach_deferred(dev))) - do_deferred_attach(dev); - return find_domain(dev); }
@@ -3478,6 +3475,9 @@ static bool iommu_need_mapping(struct de if (iommu_dummy(dev)) return false;
+ if (unlikely(attach_deferred(dev))) + do_deferred_attach(dev); + ret = identity_mapping(dev); if (ret) { u64 dma_mask = *dev->dma_mask; @@ -3841,7 +3841,11 @@ bounce_map_single(struct device *dev, ph int prot = 0; int ret;
+ if (unlikely(attach_deferred(dev))) + do_deferred_attach(dev); + domain = deferred_attach_domain(dev); + if (WARN_ON(dir == DMA_NONE || !domain)) return DMA_MAPPING_ERROR;