From: David Laight <David.Laight@ACULAB.COM>
To: 'Jim Mattson' <jmattson@google.com>, Paolo Bonzini <pbonzini@redhat.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
kvm list <kvm@vger.kernel.org>,
"Sean Christopherson" <sean.j.christopherson@intel.com>,
Joerg Roedel <joro@8bytes.org>,
"everdox@gmail.com" <everdox@gmail.com>
Subject: RE: [PATCH] KVM: x86: handle wrap around 32-bit address space
Date: Wed, 29 Apr 2020 08:50:21 +0000 [thread overview]
Message-ID: <c3ac5f4c9e3a412cb57ea02df19dd2d2@AcuMS.aculab.com> (raw)
In-Reply-To: <CALMp9eTBs=deSYu1=CMLwZcO8HTpGM2JsgDxvFR1Y220tdUQ3w@mail.gmail.com>
From: Jim Mattson
> Sent: 28 April 2020 01:29
> On Mon, Apr 27, 2020 at 9:59 AM Paolo Bonzini <pbonzini@redhat.com> wrote:
> >
> > KVM is not handling the case where EIP wraps around the 32-bit address
> > space (that is, outside long mode). This is needed both in vmx.c
> > and in emulate.c. SVM with NRIPS is okay, but it can still print
> > an error to dmesg due to integer overflow.
...
> > + if (unlikely(((rip ^ orig_rip) >> 31) == 3) && !is_64_bit_mode(vcpu))
Isn't the more obvious:
if (((rip ^ orig_rip) & 1ull << 32) ...
equivalent?
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2020-04-29 8:50 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-27 16:59 [PATCH] KVM: x86: handle wrap around 32-bit address space Paolo Bonzini
2020-04-28 0:28 ` Jim Mattson
2020-04-28 0:33 ` Sean Christopherson
2020-04-29 8:50 ` David Laight [this message]
2020-04-29 8:56 ` David Laight
2020-04-30 12:45 ` Paolo Bonzini
2020-04-30 13:18 ` David Laight
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=c3ac5f4c9e3a412cb57ea02df19dd2d2@AcuMS.aculab.com \
--to=david.laight@aculab.com \
--cc=everdox@gmail.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=sean.j.christopherson@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).