Messages in this thread | | | Date | Tue, 18 Feb 2020 08:53:11 -0700 | From | Jerry Snitselaar <> | Subject | Re: [PATCH 3/5 v2] iommu/vt-d: Do deferred attachment in iommu_need_mapping() |
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On Tue Feb 18 20, Joerg Roedel wrote: >Hi Baolu, > >On Tue, Feb 18, 2020 at 10:38:14AM +0800, Lu Baolu wrote: >> > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c >> > index 42cdcce1602e..32f43695a22b 100644 >> > --- a/drivers/iommu/intel-iommu.c >> > +++ b/drivers/iommu/intel-iommu.c >> > @@ -2541,9 +2541,6 @@ 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); >> > - >> >> This should also be moved to the call place of deferred_attach_domain() >> in bounce_map_single(). >> >> bounce_map_single() assumes that devices always use DMA domain, so it >> doesn't call iommu_need_mapping(). We could do_deferred_attach() there >> manually. > >Good point, thanks for your review. Updated patch below. > >From 3a5b8a66d288d86ac1fd45092e7d96f842d0cccf Mon Sep 17 00:00:00 2001 >From: Joerg Roedel <jroedel@suse.de> >Date: Mon, 17 Feb 2020 17:20:59 +0100 >Subject: [PATCH 3/5] iommu/vt-d: Do deferred attachment in > iommu_need_mapping() > >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. > >Signed-off-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
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