From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Xen-devel <xen-devel@lists.xenproject.org>
Cc: "Andrew Cooper" <andrew.cooper3@citrix.com>,
"Wei Liu" <wl@xen.org>, "Jan Beulich" <JBeulich@suse.com>,
"Roger Pau Monné" <roger.pau@citrix.com>
Subject: [Xen-devel] [PATCH 10/10] x86/hvm: Do not enable MPX by default
Date: Wed, 26 Feb 2020 20:22:21 +0000 [thread overview]
Message-ID: <20200226202221.6555-11-andrew.cooper3@citrix.com> (raw)
In-Reply-To: <20200226202221.6555-1-andrew.cooper3@citrix.com>
Memory Protection eXtension support has been dropped from GCC and Linux, and
will be dropped from future Intel CPUs.
With all other default/max pieces in place, move MPX from default to max.
This means that VMs won't be offered it by default, but can explicitly opt
into using it via cpuid="host,mpx=1" in their vm.cfg file.
The difference as visible to the guest is:
diff --git a/default b/mpx
index 0e91765d6b..c8c33cd584 100644
--- a/default
+++ b/mpx
@@ -13,15 +13,17 @@ Native cpuid:
00000004:00000004 -> 00000000:00000000:00000000:00000000
00000005:ffffffff -> 00000000:00000000:00000000:00000000
00000006:ffffffff -> 00000000:00000000:00000000:00000000
- 00000007:00000000 -> 00000000:009c2fbb:00000000:9c000400
+ 00000007:00000000 -> 00000000:009c6fbb:00000000:9c000400
00000008:ffffffff -> 00000000:00000000:00000000:00000000
00000009:ffffffff -> 00000000:00000000:00000000:00000000
0000000a:ffffffff -> 00000000:00000000:00000000:00000000
0000000b:ffffffff -> 00000000:00000000:00000000:00000000
0000000c:ffffffff -> 00000000:00000000:00000000:00000000
- 0000000d:00000000 -> 00000007:00000240:00000340:00000000
+ 0000000d:00000000 -> 0000001f:00000240:00000440:00000000
0000000d:00000001 -> 0000000f:00000240:00000000:00000000
0000000d:00000002 -> 00000100:00000240:00000000:00000000
+ 0000000d:00000003 -> 00000040:000003c0:00000000:00000000
+ 0000000d:00000004 -> 00000040:00000400:00000000:00000000
40000000:ffffffff -> 40000005:566e6558:65584d4d:4d4d566e
40000001:ffffffff -> 0004000e:00000000:00000000:00000000
40000002:ffffffff -> 00000001:40000000:00000000:00000000
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Wei Liu <wl@xen.org>
CC: Roger Pau Monné <roger.pau@citrix.com>
XXX - One moving piece (the migration series) is still in review on xen-devel.
I won't commit this change until that is sorted, and I can double check the
backwards compatibility for VMs from previous versions of Xen.
The main purpose of posting this patch now is to illustrate the effects of the
previous patches in the series.
---
xen/include/public/arch-x86/cpufeatureset.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/xen/include/public/arch-x86/cpufeatureset.h b/xen/include/public/arch-x86/cpufeatureset.h
index d79a53befe..81e4c2950f 100644
--- a/xen/include/public/arch-x86/cpufeatureset.h
+++ b/xen/include/public/arch-x86/cpufeatureset.h
@@ -207,7 +207,7 @@ XEN_CPUFEATURE(INVPCID, 5*32+10) /*H Invalidate Process Context ID */
XEN_CPUFEATURE(RTM, 5*32+11) /*A Restricted Transactional Memory */
XEN_CPUFEATURE(PQM, 5*32+12) /* Platform QoS Monitoring */
XEN_CPUFEATURE(NO_FPU_SEL, 5*32+13) /*! FPU CS/DS stored as zero */
-XEN_CPUFEATURE(MPX, 5*32+14) /*S Memory Protection Extensions */
+XEN_CPUFEATURE(MPX, 5*32+14) /*s Memory Protection Extensions */
XEN_CPUFEATURE(PQE, 5*32+15) /* Platform QoS Enforcement */
XEN_CPUFEATURE(AVX512F, 5*32+16) /*A AVX-512 Foundation Instructions */
XEN_CPUFEATURE(AVX512DQ, 5*32+17) /*A AVX-512 Doubleword & Quadword Instrs */
--
2.11.0
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next prev parent reply other threads:[~2020-02-26 20:41 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-26 20:22 [Xen-devel] [PATCH 00/10] x86: Default vs Max policies Andrew Cooper
2020-02-26 20:22 ` [Xen-devel] [PATCH 01/10] x86/sysctl: Don't return cpu policy data for compiled-out support (2) Andrew Cooper
2020-02-27 7:38 ` Jan Beulich
2020-02-27 9:33 ` Andrew Cooper
2020-02-27 9:40 ` Jan Beulich
2020-02-27 16:24 ` Andrew Cooper
2020-02-26 20:22 ` [Xen-devel] [PATCH 02/10] tools/libxc: Simplify xc_get_static_cpu_featuremask() Andrew Cooper
2020-02-27 7:47 ` Jan Beulich
2020-02-27 9:55 ` Andrew Cooper
2020-02-27 16:27 ` Andrew Cooper
2020-02-26 20:22 ` [Xen-devel] [PATCH 03/10] x86/gen-cpuid: Rework internal logic to ease future changes Andrew Cooper
2020-02-27 7:57 ` Jan Beulich
2020-02-27 10:08 ` Andrew Cooper
2020-02-26 20:22 ` [Xen-devel] [PATCH 04/10] x86/gen-cpuid: Create max and default variations of INIT_*_FEATURES Andrew Cooper
2020-02-27 8:02 ` Jan Beulich
2020-02-27 10:29 ` Andrew Cooper
2020-02-27 10:34 ` Jan Beulich
2020-02-26 20:22 ` [Xen-devel] [PATCH 05/10] x86/msr: Compile out unused logic/objects Andrew Cooper
2020-02-27 8:07 ` Jan Beulich
2020-02-27 10:37 ` Andrew Cooper
2020-02-27 11:24 ` Jan Beulich
2020-02-26 20:22 ` [Xen-devel] [PATCH 06/10] x86/msr: Introduce and use default MSR policies Andrew Cooper
2020-02-27 8:11 ` Jan Beulich
2020-02-26 20:22 ` [Xen-devel] [PATCH 07/10] x86/cpuid: Compile out unused logic/objects Andrew Cooper
2020-02-27 8:12 ` Jan Beulich
2020-02-26 20:22 ` [Xen-devel] [PATCH 08/10] x86/cpuid: Introduce and use default CPUID policies Andrew Cooper
2020-02-27 8:19 ` Jan Beulich
2020-02-27 10:55 ` Andrew Cooper
2020-02-27 11:29 ` Jan Beulich
2020-02-26 20:22 ` [Xen-devel] [PATCH 09/10] x86/gen-cpuid: Distinguish default vs max in feature annotations Andrew Cooper
2020-02-27 8:21 ` Jan Beulich
2020-02-26 20:22 ` Andrew Cooper [this message]
2020-02-27 8:23 ` [Xen-devel] [PATCH 10/10] x86/hvm: Do not enable MPX by default Jan Beulich
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