From: Jan Beulich Date: Tue, 3 Jun 2014 10:22:14 +0000 (+0200) Subject: AMD IOMMU: don't free page table prematurely X-Git-Tag: 4.2.5-rc1~6 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=f9d3462a8fe6768e8230f1ee21251dee9f165fc7;p=xen.git AMD IOMMU: don't free page table prematurely iommu_merge_pages() still wants to look at the next level page table, the TLB flush necessary before freeing too happens in that function, and if it fails no free should happen at all. Hence the freeing must be done after that function returned successfully, not before it's being called. Signed-off-by: Jan Beulich Reviewed-by: Andrew Cooper Reviewed-by: Suravee Suthikulpanit Tested-by: Suravee Suthikulpanit master commit: 6b4d71d028f445cba7426a144751fddc8bfdd67b master date: 2014-05-28 09:50:33 +0200 --- diff --git a/xen/drivers/passthrough/amd/iommu_map.c b/xen/drivers/passthrough/amd/iommu_map.c index 43bf5e53a2..f51db77a37 100644 --- a/xen/drivers/passthrough/amd/iommu_map.c +++ b/xen/drivers/passthrough/amd/iommu_map.c @@ -701,8 +701,6 @@ int amd_iommu_map_page(struct domain *d, unsigned long gfn, unsigned long mfn, if ( !iommu_update_pde_count(d, pt_mfn[merge_level], gfn, mfn, merge_level) ) break; - /* Deallocate lower level page table */ - free_amd_iommu_pgtable(mfn_to_page(pt_mfn[merge_level - 1])); if ( iommu_merge_pages(d, pt_mfn[merge_level], gfn, flags, merge_level) ) @@ -713,6 +711,9 @@ int amd_iommu_map_page(struct domain *d, unsigned long gfn, unsigned long mfn, domain_crash(d); return -EFAULT; } + + /* Deallocate lower level page table */ + free_amd_iommu_pgtable(mfn_to_page(pt_mfn[merge_level - 1])); } out: