[Xen-changelog] [xen staging] x86/iommu: avoid mapping the interrupt address range for hwdom

[patchbot@xxxxxxx]

commit 991b9c6ff7be20a02be146b99a711a5c94664ab1
Author:     Roger Pau Monné <roger.pau@xxxxxxxxxx>
AuthorDate: Thu Jul 25 12:17:34 2019 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Jul 25 12:17:34 2019 +0200

    x86/iommu: avoid mapping the interrupt address range for hwdom
    
    Current code only prevent mapping the lapic page into the guest
    physical memory map. Expand the range to be 0xFEEx_xxxx as described
    in the Intel VTd specification section 3.13 "Handling Requests to
    Interrupt Address Range".
    
    AMD also lists this address range in the AMD SR5690 Databook, section
    2.4.4 "MSI Interrupt Handling and MSI to HT Interrupt Conversion".
    
    Requested-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/drivers/passthrough/x86/iommu.c | 16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/xen/drivers/passthrough/x86/iommu.c 
b/xen/drivers/passthrough/x86/iommu.c
index a7438c9c25..fd05075bb5 100644
--- a/xen/drivers/passthrough/x86/iommu.c
+++ b/xen/drivers/passthrough/x86/iommu.c
@@ -232,19 +232,9 @@ static bool __hwdom_init hwdom_iommu_map(const struct 
domain *d,
             return false;
     }
 
-    /*
-     * Check that it doesn't overlap with the LAPIC
-     * TODO: if the guest relocates the MMIO area of the LAPIC Xen should make
-     * sure there's nothing in the new address that would prevent trapping.
-     */
-    if ( has_vlapic(d) )
-    {
-        const struct vcpu *v;
-
-        for_each_vcpu(d, v)
-            if ( pfn == PFN_DOWN(vlapic_base_address(vcpu_vlapic(v))) )
-                return false;
-    }
+    /* Check that it doesn't overlap with the Interrupt Address Range. */
+    if ( pfn >= 0xfee00 && pfn <= 0xfeeff )
+        return false;
     /* ... or the IO-APIC */
     for ( i = 0; has_vioapic(d) && i < d->arch.hvm.nr_vioapics; i++ )
         if ( pfn == PFN_DOWN(domain_vioapic(d, i)->base_address) )
--
generated by git-patchbot for /home/xen/git/xen.git#staging

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