From: Jan Beulich <jbeulich@suse.com>
Date: Fri, 2 May 2014 08:50:04 +0000 (+0200)
Subject: x86/EPT: refine direct MMIO checking when determining EMT
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~5123
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success//%22http:/www.example.com/cgi/success/?a=commitdiff_plain;h=c5004d34693341e2b368467fad1860e53cb5a5d8;p=xen.git

x86/EPT: refine direct MMIO checking when determining EMT

With need_iommu() only ever true when iommu_enabled is also true, and
with the former getting set when a PCI device gets added to a guest,
the checks can be consolidated. The range set check are left in place
just in case raw MMIO or I/O port ranges get passed to a guest.

At once drop open-coding of cache_flush_permitted().

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Tim Deegan <tim@xen.org>
---

diff --git a/xen/arch/x86/hvm/mtrr.c b/xen/arch/x86/hvm/mtrr.c
index 894de5f54c..34215f4467 100644
--- a/xen/arch/x86/hvm/mtrr.c
+++ b/xen/arch/x86/hvm/mtrr.c
@@ -20,6 +20,7 @@
 #include <public/hvm/e820.h>
 #include <xen/types.h>
 #include <asm/e820.h>
+#include <asm/iocap.h>
 #include <asm/mm.h>
 #include <asm/paging.h>
 #include <asm/p2m.h>
@@ -810,10 +811,7 @@ int epte_get_entry_emt(struct domain *d, unsigned long gfn, mfn_t mfn,
         return -1;
     }
 
-    if ( !iommu_enabled ||
-         (rangeset_is_empty(d->iomem_caps) &&
-          rangeset_is_empty(d->arch.ioport_caps) &&
-          !has_arch_pdevs(d)) )
+    if ( !need_iommu(d) && !cache_flush_permitted(d) )
     {
         ASSERT(!direct_mmio ||
                !((mfn_x(mfn) ^ d->arch.hvm_domain.vmx.apic_access_mfn) >>