From: Borislav Petkov <bp@suse.de>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Linux Virtualization <virtualization@lists.linux-foundation.org>,
Ingo Molnar <mingo@redhat.com>,
David Vrabel <david.vrabel@citrix.com>,
Andrew Lutomirski <luto@kernel.org>,
"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>
Subject: Re: [PATCH 1/3] x86/xen: Avoid fast syscall path for Xen PV guests
Date: Thu, 19 Nov 2015 13:08:09 +0100 [thread overview]
Message-ID: <20151119120809.GC5953@pd.tnic> (raw)
In-Reply-To: <CALCETrVUpqQy_EZMe8T5iRkA0FzS0Oz1Kuicr9yz3SwtdF1=9g@mail.gmail.com>
On Wed, Nov 18, 2015 at 12:21:56PM -0800, Andy Lutomirski wrote:
> Could we make this a little less subtle:
>
> ALTERNATIVE "testl %eax, %eax; lz .Lsyscall_32_done", "jmp
> .Lsyscasll_32_done", X86_FEATURE_XENPV
>
> Borislav, what do you think?
I don't mind either.
I would've said your version doesn't touch %eax so the result in there
might be useful for callers but all paths do overwrite it, AFAICT.
--
Regards/Gruss,
Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
WARNING: multiple messages have this Message-ID (diff)
From: Borislav Petkov <bp@suse.de>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
David Vrabel <david.vrabel@citrix.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Andrew Lutomirski <luto@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
Linux Virtualization <virtualization@lists.linux-foundation.org>
Subject: Re: [PATCH 1/3] x86/xen: Avoid fast syscall path for Xen PV guests
Date: Thu, 19 Nov 2015 13:08:09 +0100 [thread overview]
Message-ID: <20151119120809.GC5953@pd.tnic> (raw)
In-Reply-To: <CALCETrVUpqQy_EZMe8T5iRkA0FzS0Oz1Kuicr9yz3SwtdF1=9g@mail.gmail.com>
On Wed, Nov 18, 2015 at 12:21:56PM -0800, Andy Lutomirski wrote:
> Could we make this a little less subtle:
>
> ALTERNATIVE "testl %eax, %eax; lz .Lsyscall_32_done", "jmp
> .Lsyscasll_32_done", X86_FEATURE_XENPV
>
> Borislav, what do you think?
I don't mind either.
I would've said your version doesn't touch %eax so the result in there
might be useful for callers but all paths do overwrite it, AFAICT.
--
Regards/Gruss,
Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--
next prev parent reply other threads:[~2015-11-19 12:08 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-18 20:06 [PATCH 0/3] Fix and cleanup for 32-bit PV sysexit Boris Ostrovsky
2015-11-18 20:06 ` [PATCH 1/3] x86/xen: Avoid fast syscall path for Xen PV guests Boris Ostrovsky
2015-11-18 20:06 ` Boris Ostrovsky
2015-11-18 20:21 ` Andy Lutomirski
2015-11-18 20:21 ` Andy Lutomirski
2015-11-18 20:47 ` Borislav Petkov
2015-11-18 20:47 ` Borislav Petkov
2015-11-18 20:47 ` Borislav Petkov
2015-11-18 20:50 ` Brian Gerst
2015-11-18 20:50 ` Brian Gerst
2015-11-18 20:58 ` Andy Lutomirski
2015-11-18 20:58 ` Andy Lutomirski
2015-11-18 20:58 ` Andy Lutomirski
2015-11-18 22:05 ` Boris Ostrovsky
2015-11-18 22:05 ` Boris Ostrovsky
2015-11-18 22:05 ` Boris Ostrovsky
2015-11-18 20:50 ` Brian Gerst
2015-11-19 12:08 ` Borislav Petkov [this message]
2015-11-19 12:08 ` Borislav Petkov
2015-11-19 12:08 ` Borislav Petkov
2015-11-18 20:21 ` Andy Lutomirski
2015-11-18 20:06 ` Boris Ostrovsky
2015-11-18 20:06 ` [PATCH 2/3] x86: irq_enable_sysexit pv op is no longer needed Boris Ostrovsky
2015-11-18 20:06 ` Boris Ostrovsky
2015-11-18 20:06 ` Boris Ostrovsky
2015-11-18 20:11 ` Konrad Rzeszutek Wilk
2015-11-18 20:34 ` Boris Ostrovsky
2015-11-18 20:34 ` Boris Ostrovsky
2015-11-18 20:34 ` Boris Ostrovsky
2015-11-18 21:16 ` Konrad Rzeszutek Wilk
2015-11-18 20:23 ` Andy Lutomirski
2015-11-18 20:23 ` Andy Lutomirski
2015-11-18 20:23 ` Andy Lutomirski
2015-11-18 20:06 ` [PATCH 3/3] x86: usergs_sysret32 " Boris Ostrovsky
2015-11-18 20:06 ` Boris Ostrovsky
2015-11-18 20:26 ` Andy Lutomirski
2015-11-18 20:26 ` Andy Lutomirski
2015-11-18 20:26 ` Andy Lutomirski
2015-11-18 20:06 ` Boris Ostrovsky
2015-11-19 12:10 ` [PATCH 0/3] Fix and cleanup for 32-bit PV sysexit Borislav Petkov
2015-11-19 12:10 ` Borislav Petkov
2015-11-19 12:10 ` Borislav Petkov
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