From: "Jan Beulich" <JBeulich@suse.com>
To: xen-devel <xen-devel@lists.xenproject.org>
Cc: George Dunlap <George.Dunlap@eu.citrix.com>,
Andrew Cooper <andrew.cooper3@citrix.com>
Subject: [PATCH v5 04/14] x86emul: adjust_bnd() should check XCR0
Date: Thu, 15 Mar 2018 07:04:51 -0600 [thread overview]
Message-ID: <5AAA7D8302000078001B225F@prv-mh.provo.novell.com> (raw)
In-Reply-To: <5AAA7BAF02000078001B2242@prv-mh.provo.novell.com>
Experimentally MPX instructions have been confirmed to behave as NOPs
unless both related XCR0 bits are set to 1. By implication branches
then also don't clear BNDn.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
v4: Re-base over XSTATE_* renaming.
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -2154,12 +2154,16 @@ static bool umip_active(struct x86_emula
static void adjust_bnd(struct x86_emulate_ctxt *ctxt,
const struct x86_emulate_ops *ops, enum vex_pfx pfx)
{
- uint64_t bndcfg;
+ uint64_t xcr0, bndcfg;
int rc;
if ( pfx == vex_f2 || !cpu_has_mpx || !vcpu_has_mpx() )
return;
+ if ( !ops->read_xcr || ops->read_xcr(0, &xcr0, ctxt) != X86EMUL_OKAY ||
+ !(xcr0 & X86_XCR0_BNDREGS) || !(xcr0 & X86_XCR0_BNDCSR) )
+ return;
+
if ( !mode_ring0() )
bndcfg = read_bndcfgu();
else if ( !ops->read_msr ||
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next prev parent reply other threads:[~2018-03-15 13:04 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-15 12:57 [PATCH v5 00/14] x86: emulator enhancements Jan Beulich
2018-03-15 13:02 ` [PATCH v5 01/14] x86emul: support 3DNow! insns Jan Beulich
2018-03-15 13:24 ` Andrew Cooper
2018-03-15 13:03 ` [PATCH v5 02/14] x86emul: place test blobs in executable section Jan Beulich
2018-03-15 13:04 ` [PATCH v5 03/14] x86emul: abstract out XCRn accesses Jan Beulich
2018-03-15 13:35 ` Andrew Cooper
2018-03-15 13:44 ` Jan Beulich
2018-03-15 13:55 ` Andrew Cooper
2018-03-15 15:41 ` Andrew Cooper
2018-03-15 16:08 ` Jan Beulich
2018-03-19 13:56 ` Paul Durrant
2018-03-20 17:22 ` George Dunlap
2018-03-15 13:04 ` Jan Beulich [this message]
2018-03-15 13:06 ` [PATCH v5 05/14] x86/HVM: eliminate custom #MF/#XM handling Jan Beulich
2018-03-22 14:12 ` Roger Pau Monné
2018-03-22 14:38 ` Jan Beulich
2018-03-15 13:07 ` [PATCH v5 06/14] x86emul: tell cmpxchg hook whether LOCK is in effect Jan Beulich
2018-03-15 13:08 ` [PATCH v5 07/14] x86emul: correctly handle CMPXCHG* comparison failures Jan Beulich
2018-03-15 13:08 ` [PATCH v5 08/14] x86emul: add read-modify-write hook Jan Beulich
2018-03-15 14:19 ` Andrew Cooper
2018-03-15 14:46 ` Jan Beulich
2018-03-15 14:48 ` Andrew Cooper
2018-03-15 13:09 ` [PATCH v5 09/14] x86emul: also handle shifts through ->rmw() Jan Beulich
2018-03-15 14:23 ` Andrew Cooper
2018-03-15 13:10 ` [PATCH v5 10/14] x86/HVM: do actual CMPXCHG in hvmemul_cmpxchg() Jan Beulich
2018-03-15 15:28 ` Andrew Cooper
2018-03-15 13:10 ` [PATCH v5 11/14] x86/HVM: make use of new read-modify-write emulator hook Jan Beulich
2018-03-15 13:12 ` [PATCH v5 12/14] x86/HVM: use x86emul_write_xcr() Jan Beulich
2018-03-15 15:43 ` Andrew Cooper
2018-03-15 16:05 ` Boris Ostrovsky
2018-03-19 12:57 ` Tian, Kevin
2018-03-15 13:13 ` [PATCH v5 13/14] x86/shadow: fully move unmap-dest into common code Jan Beulich
2018-03-15 13:13 ` [PATCH v5 14/14] x86/shadow: fold sh_x86_emulate_{write, cmpxchg}() into their only callers Jan Beulich
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