linux-kernel - Re: [PATCH 1/3] x86/xen: Avoid fast syscall path for Xen PV guests

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 18 Nov 2015 17:05:23 -0500
From:	Boris Ostrovsky <boris.ostrovsky@...cle.com>
To:	Andy Lutomirski <luto@...capital.net>,
	Brian Gerst <brgerst@...il.com>
Cc:	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	David Vrabel <david.vrabel@...rix.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	Andrew Lutomirski <luto@...nel.org>,
	Borislav Petkov <bp@...e.de>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"xen-devel@...ts.xenproject.org" <xen-devel@...ts.xenproject.org>,
	Linux Virtualization <virtualization@...ts.linux-foundation.org>
Subject: Re: [PATCH 1/3] x86/xen: Avoid fast syscall path for Xen PV guests

On 11/18/2015 03:58 PM, Andy Lutomirski wrote:
> On Wed, Nov 18, 2015 at 12:50 PM, Brian Gerst <brgerst@...il.com> wrote:
>>
>> Can you just add !xen_pv_domain() to the opportunistic SYSRET check
>> instead?  Bury the alternatives in that macro, ie.
>> static_cpu_has(X86_FEATURE_XENPV).  That would likely benefit other
>> code as well.
> We could, but that won't help the 64-bit case where we want to keep
> the full asm path.

I don't think I understand what you mean here. Which full asm path?

-boris


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/