Messages in this thread | | | Subject | Re: [PATCH 3/5 v2] iommu/vt-d: Do deferred attachment in iommu_need_mapping() | From | Lu Baolu <> | Date | Tue, 18 Feb 2020 19:54:52 +0800 |
| |
Hi Joerg,
On 2020/2/18 17:28, 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. >
Looks good to me now. For all patches in this series,
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Best regards, baolu
> 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> > --- > 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 42cdcce1602e..723f615c6e84 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); > - > return find_domain(dev); > } > > @@ -3595,6 +3592,9 @@ 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; > @@ -3958,7 +3958,11 @@ 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; > >
| |