From: Paul Durrant <paul@xen.org>
To: xen-devel@lists.xenproject.org
Cc: "Andrew Cooper" <andrew.cooper3@citrix.com>,
"Paul Durrant" <pdurrant@amazon.com>, "Wei Liu" <wl@xen.org>,
"Jan Beulich" <jbeulich@suse.com>,
"Roger Pau Monné" <roger.pau@citrix.com>
Subject: [PATCH v4 2/2] x86/hvm: simplify 'mmio_direct' check in epte_get_entry_emt()
Date: Fri, 31 Jul 2020 15:41:12 +0100 [thread overview]
Message-ID: <20200731144112.12516-3-paul@xen.org> (raw)
In-Reply-To: <20200731144112.12516-1-paul@xen.org>
From: Paul Durrant <pdurrant@amazon.com>
Re-factor the code to take advantage of the fact that the APIC access page is
a 'special' page. The VMX code is left alone and hence the APIC access page is
still inserted into the P2M with type p2m_mmio_direct. This is left alone as it
is not obvious there is another suitable type to use, and the necessary
re-ordering in epte_get_entry_emt() is straightforward.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
---
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Wei Liu <wl@xen.org>
Cc: "Roger Pau Monné" <roger.pau@citrix.com>
v2:
- New in v2
v3:
- Re-base
- Expand commit comment
---
xen/arch/x86/hvm/mtrr.c | 15 ++++-----------
1 file changed, 4 insertions(+), 11 deletions(-)
diff --git a/xen/arch/x86/hvm/mtrr.c b/xen/arch/x86/hvm/mtrr.c
index 2bd64e8025..fb051d59c3 100644
--- a/xen/arch/x86/hvm/mtrr.c
+++ b/xen/arch/x86/hvm/mtrr.c
@@ -815,23 +815,13 @@ int epte_get_entry_emt(struct domain *d, unsigned long gfn, mfn_t mfn,
return -1;
}
- if ( direct_mmio )
- {
- if ( (mfn_x(mfn) ^ mfn_x(d->arch.hvm.vmx.apic_access_mfn)) >> order )
- return MTRR_TYPE_UNCACHABLE;
- if ( order )
- return -1;
- *ipat = 1;
- return MTRR_TYPE_WRBACK;
- }
-
if ( !mfn_valid(mfn) )
{
*ipat = 1;
return MTRR_TYPE_UNCACHABLE;
}
- if ( !is_iommu_enabled(d) && !cache_flush_permitted(d) )
+ if ( !direct_mmio && !is_iommu_enabled(d) && !cache_flush_permitted(d) )
{
*ipat = 1;
return MTRR_TYPE_WRBACK;
@@ -848,6 +838,9 @@ int epte_get_entry_emt(struct domain *d, unsigned long gfn, mfn_t mfn,
}
}
+ if ( direct_mmio )
+ return MTRR_TYPE_UNCACHABLE;
+
gmtrr_mtype = hvm_get_mem_pinned_cacheattr(d, _gfn(gfn), order);
if ( gmtrr_mtype >= 0 )
{
--
2.20.1
next prev parent reply other threads:[~2020-07-31 14:41 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-31 14:41 [PATCH v4 0/2] epte_get_entry_emt() modifications Paul Durrant
2020-07-31 14:41 ` [PATCH v4 1/2] x86/hvm: set 'ipat' in EPT for special pages Paul Durrant
2020-07-31 14:41 ` Paul Durrant [this message]
2020-07-31 14:50 ` [PATCH v4 0/2] epte_get_entry_emt() modifications Jan Beulich
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