[v2] x86/p2m: fix non-translated handling of iommu mappings

[Xen-devel] [PATCH v2] x86/p2m: fix non-translated handling of iommu mappings

Posted by Roger Pau Monne 4 years, 9 months ago

The current usage of need_iommu_pt_sync in p2m for non-translated
guests is wrong because it doesn't correctly handle a relaxed PV
hardware domain, that has need_sync set to false, but still need
entries to be added from calls to {set/clear}_identity_p2m_entry.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
---
Cc: George Dunlap <george.dunlap@eu.citrix.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Wei Liu <wl@xen.org>
Cc: Paul Durrant <Paul.Durrant@citrix.com>
---
Changes since v1:
 - Drop the guest_physmap_add_page modification.
---
 xen/arch/x86/mm/p2m.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index fef97c82f6..3605614aaf 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -1341,7 +1341,7 @@ int set_identity_p2m_entry(struct domain *d, unsigned long gfn_l,
 
     if ( !paging_mode_translate(p2m->domain) )
     {
-        if ( !need_iommu_pt_sync(d) )
+        if ( !has_iommu_pt(d) )
             return 0;
         return iommu_legacy_map(d, _dfn(gfn_l), _mfn(gfn_l), PAGE_ORDER_4K,
                                 IOMMUF_readable | IOMMUF_writable);
@@ -1432,7 +1432,7 @@ int clear_identity_p2m_entry(struct domain *d, unsigned long gfn_l)
 
     if ( !paging_mode_translate(d) )
     {
-        if ( !need_iommu_pt_sync(d) )
+        if ( !has_iommu_pt(d) )
             return 0;
         return iommu_legacy_unmap(d, _dfn(gfn_l), PAGE_ORDER_4K);
     }
-- 
2.20.1 (Apple Git-117)


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Re: [Xen-devel] [PATCH v2] x86/p2m: fix non-translated handling of iommu mappings

Posted by Jan Beulich 4 years, 9 months ago

On 23.07.2019 14:43, Roger Pau Monne wrote:
> The current usage of need_iommu_pt_sync in p2m for non-translated
> guests is wrong because it doesn't correctly handle a relaxed PV
> hardware domain, that has need_sync set to false, but still need
> entries to be added from calls to {set/clear}_identity_p2m_entry.
> 
> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
> Reviewed-by: Paul Durrant <paul.durrant@citrix.com>

Reviewed-by: Jan Beulich <jbeulich@suse.com>
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Re: [Xen-devel] [PATCH v2] x86/p2m: fix non-translated handling of iommu mappings

Posted by George Dunlap 4 years, 8 months ago

On 7/23/19 1:43 PM, Roger Pau Monne wrote:
> The current usage of need_iommu_pt_sync in p2m for non-translated
> guests is wrong because it doesn't correctly handle a relaxed PV
> hardware domain, that has need_sync set to false, but still need
> entries to be added from calls to {set/clear}_identity_p2m_entry.
> 
> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
> Reviewed-by: Paul Durrant <paul.durrant@citrix.com>

Acked-by: George Dunlap <george.dunlap@citrix.com>

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