From: Joerg Roedel <joro@8bytes.org>
To: Alex Williamson <alex.williamson@redhat.com>,
Joerg Roedel <joro@8bytes.org>
Cc: iommu@lists.linux-foundation.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, jroedel@suse.de
Subject: [PATCH 4/7] iommu/amd: Allow downgrading page-sizes in alloc_pte()
Date: Fri, 9 Nov 2018 12:07:09 +0100 [thread overview]
Message-ID: <20181109110712.12469-5-joro@8bytes.org> (raw)
In-Reply-To: <20181109110712.12469-1-joro@8bytes.org>
From: Joerg Roedel <jroedel@suse.de>
Before this patch it was not possible the downgrade a
mapping established with page-mode 7 to a mapping using
smaller page-sizes, because the pte_level != level check
prevented that.
Treat page-mode 7 like a non-present mapping and allow to
overwrite it in alloc_pte().
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/amd_iommu.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 49b5d3115e56..6a88ba9321d1 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1460,10 +1460,13 @@ static u64 *alloc_pte(struct protection_domain *domain,
while (level > end_lvl) {
u64 __pte, __npte;
+ int pte_level;
- __pte = *pte;
+ __pte = *pte;
+ pte_level = PM_PTE_LEVEL(__pte);
- if (!IOMMU_PTE_PRESENT(__pte)) {
+ if (!IOMMU_PTE_PRESENT(__pte) ||
+ pte_level == PAGE_MODE_7_LEVEL) {
page = (u64 *)get_zeroed_page(gfp);
if (!page)
return NULL;
@@ -1475,10 +1478,13 @@ static u64 *alloc_pte(struct protection_domain *domain,
free_page((unsigned long)page);
continue;
}
+
+ if (pte_level == PAGE_MODE_7_LEVEL)
+ domain->updated = true;
}
/* No level skipping support yet */
- if (PM_PTE_LEVEL(*pte) != level)
+ if (pte_level != level)
return NULL;
level -= 1;
--
2.17.1
next prev parent reply other threads:[~2018-11-09 11:08 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-09 11:07 [PATCH 0/7] iommu/amd: Always allow to map huge pages Joerg Roedel
2018-11-09 11:07 ` [PATCH 1/7] iommu/amd: Collect page-table pages in freelist Joerg Roedel
2018-11-09 11:07 ` [PATCH 2/7] iommu/amd: Introduce free_sub_pt() function Joerg Roedel
2018-11-09 11:07 ` [PATCH 3/7] iommu/amd: Ignore page-mode 7 in free_sub_pt() Joerg Roedel
2018-11-09 11:07 ` Joerg Roedel [this message]
2018-11-09 11:07 ` [PATCH 5/7] iommu/amd: Restart loop if cmpxchg64 succeeded in alloc_pte() Joerg Roedel
2018-11-09 11:07 ` [PATCH 6/7] iommu/amd: Allow to upgrade page-size Joerg Roedel
2018-11-09 11:07 ` [PATCH 7/7] vfio/type1: Remove map_try_harder() code path Joerg Roedel
2018-11-09 16:23 ` Alex Williamson
2018-11-15 15:55 ` Joerg Roedel
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