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

BugLink: https://bugs.launchpad.net/bugs/1964361
[ Upstream commit 6b0b2d9a6a308bcd9300c2d83000a82812c56cea ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/drivers/iommu/amd/io_pgtable.c b/drivers/iommu/amd/io_pgtable.c
index 182c93a43efd85a825faf6f6c548715998afe016..1eddf557636d77c20733288dc55a660fd463af32 100644 (file)
--- a/drivers/iommu/amd/io_pgtable.c
+++ b/drivers/iommu/amd/io_pgtable.c
@@ -519,12 +519,6 @@ 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);
@@ -532,6 +526,12 @@ static void v1_free_pgtable(struct io_pgtable *iop)
        root = (unsigned long)pgtable->root;
        freelist = free_sub_pt(root, pgtable->mode, freelist);
 
+       /* Update data structure */
+       amd_iommu_domain_clr_pt_root(dom);
+
+       /* Make changes visible to IOMMUs */
+       amd_iommu_domain_update(dom);
+
        free_page_list(freelist);
 }