Subject: Re: [Xen-devel] [PATCH v2] xen: get rid of paravirt op
 adjust_exception_frame
To: Andy Lutomirski <luto@amacapital.net>,
        Andrew Cooper <andrew.cooper3@citrix.com>
Cc: X86 ML <x86@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
        "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Thomas Gleixner <tglx@linutronix.de>
References: <20170801103954.23904-1-jgross@suse.com>
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 <5c14a9a9-7b13-50d0-2338-2bccac7b7ac3@citrix.com>
 <CALCETrW4s-mGKoTSBqXV4J4agX2uRVoQkTUwGrzo43USsKd+qg@mail.gmail.com>
From: Juergen Gross <jgross@suse.com>
Message-ID: <c6b4dd49-b18b-6674-7c3c-6799d62a8904@suse.com>
Date: Thu, 3 Aug 2017 16:13:13 +0200
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On 02/08/17 01:52, Andy Lutomirski wrote:
> On Tue, Aug 1, 2017 at 4:38 PM, Andrew Cooper <andrew.cooper3@citrix.com> wrote:
>> On 01/08/2017 20:45, Andy Lutomirski wrote:
>>> Also, IMO it would be nice to fully finish the job.  Remaining steps are:
>>>
>>> 1. Unsuck the SYSCALL entries on Xen PV.
>>> 2. Unsuck the SYENTER entry on Xen PV.
>>> 3. Make a xen_nmi that's actually correct (should be trivial)
>>>
>>> #1 is here:
>>>
>>> https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git/commit/?h=x86/entry_syscall&id=14fee348e3e86c994400d68085217d1232a637d6
>>
>> If the
>>
>> /* Zero-extending 32-bit regs, do not remove */
>> movl    %eax, %eax
>>
>> comments are to be believed, then the entry logic needs reordering
>> slightly to:
>>
>> GLOBAL(entry_*_compat_after_hwframe)
>>     movl    %eax, %eax    /* Zero-extending 32-bit regs, do not remove */
>>     pushq    %rax                /* pt_regs->orig_ax */
> 
> D'oh, right.  Juergen, want to make that change?

Hmm, I'd prefer you sending an update which I could test and ack then.


Juergen