iommu/amd: Fix I/O page table memory leak

The current logic updates the I/O page table mode for the domain
before calling the logic to free memory used for the page table.
This results in IOMMU page table memory leak, and can be observed
when launching VM w/ pass-through devices.

Fix by freeing the memory used for page table before updating the mode.

Cc: Joerg Roedel <joro@8bytes.org>
Reported-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Tested-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Fixes: e42ba0633064 ("iommu/amd: Restructure code for freeing page table")
Link: https://lore.kernel.org/all/20220118194720.urjgi73b7c3tq2o6@oracle.com/
Link: https://lore.kernel.org/r/20220210154745.11524-1-suravee.suthikulpanit@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/amd/io_pgtable.c b/drivers/iommu/amd/io_pgtable.c
index b1bf4125b0f7e32c0a1f7f17efe1b5d4f45eb583..6608d171757445e3d90030bd04b5c55ec3d4fe1c 100644 (file)
--- a/drivers/iommu/amd/io_pgtable.c
+++ b/drivers/iommu/amd/io_pgtable.c
@@ -492,18 +492,18 @@ static void v1_free_pgtable(struct io_pgtable *iop)
 
        dom = container_of(pgtable, struct protection_domain, iop);
 
-       /* Update data structure */
-       amd_iommu_domain_clr_pt_root(dom);
-
-       /* Make changes visible to IOMMUs */
-       amd_iommu_domain_update(dom);
-
        /* Page-table is not visible to IOMMU anymore, so free it */
        BUG_ON(pgtable->mode < PAGE_MODE_NONE ||
               pgtable->mode > PAGE_MODE_6_LEVEL);
 
        free_sub_pt(pgtable->root, pgtable->mode, &freelist);
 
+       /* Update data structure */
+       amd_iommu_domain_clr_pt_root(dom);
+
+       /* Make changes visible to IOMMUs */
+       amd_iommu_domain_update(dom);
+
        put_pages_list(&freelist);
 }