From 271b0526cb62fa6ba7d4a3771742bef46baad3f3 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Mon, 17 Feb 2020 17:20:59 +0100 Subject: [PATCH] iommu/vt-d: Do deferred attachment in iommu_need_mapping() 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 Acked-by: Lu Baolu Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/intel-iommu.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 03d268cbfa7e..cf0602760525 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -2452,9 +2452,6 @@ static void do_deferred_attach(struct device *dev) 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 device *dev) 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, phys_addr_t paddr, size_t size, 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;