Messages in this thread | | | From | "Sironi, Filippo" <> | Subject | Re: [PATCH 4/5] iommu/amd: Hold the domain lock when calling iommu_map_page | Date | Fri, 20 Sep 2019 18:05:37 +0000 |
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> On 10. Sep 2019, at 19:49, Filippo Sironi <sironi@amazon.de> wrote: > > iommu_map_page calls into __domain_flush_pages, which requires the > domain lock since it traverses the device list, which the lock protects. > > Signed-off-by: Filippo Sironi <sironi@amazon.de> > --- > drivers/iommu/amd_iommu.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c > index d4f25767622e..3714ae5ded31 100644 > --- a/drivers/iommu/amd_iommu.c > +++ b/drivers/iommu/amd_iommu.c > @@ -2562,6 +2562,7 @@ static int map_sg(struct device *dev, struct scatterlist *sglist, > unsigned long address; > u64 dma_mask; > int ret; > + unsigned long flags; > > domain = get_domain(dev); > if (IS_ERR(domain)) > @@ -2587,7 +2588,9 @@ static int map_sg(struct device *dev, struct scatterlist *sglist, > > bus_addr = address + s->dma_address + (j << PAGE_SHIFT); > phys_addr = (sg_phys(s) & PAGE_MASK) + (j << PAGE_SHIFT); > + spin_lock_irqsave(&domain->lock, flags); > ret = iommu_map_page(domain, bus_addr, phys_addr, PAGE_SIZE, prot, GFP_ATOMIC); > + spin_unlock_irqrestore(&domain->lock, flags); > if (ret) > goto out_unmap; > > @@ -3095,7 +3098,9 @@ static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova, > prot |= IOMMU_PROT_IW; > > mutex_lock(&domain->api_lock); > + spin_lock(&domain->lock); > ret = iommu_map_page(domain, iova, paddr, page_size, prot, GFP_KERNEL); > + spin_unlock(&domain->lock); > mutex_unlock(&domain->api_lock);
The spin_lock/spin_unlock aren't the correct choice. These should be spin_lock_irqsave and spin_unlock_irqrestore. Of course, with the variant Joerg suggested, this isn't a problem anymore.
> domain_flush_np_cache(domain, iova, page_size); > -- > 2.7.4 >
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