linux-kernel - Re: [PATCH 0/3] KVM: Introduce VCPU-wide notion of guest-mode V2

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]

Message-ID: <20101201132020.GA11986@amd.com>
Date:	Wed, 1 Dec 2010 14:20:20 +0100
From:	"Roedel, Joerg" <Joerg.Roedel@....com>
To:	Nadav Har'El <nyh@...h.technion.ac.il>
CC:	Avi Kivity <avi@...hat.com>, Marcelo Tosatti <mtosatti@...hat.com>,
	"kvm@...r.kernel.org" <kvm@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 0/3] KVM: Introduce VCPU-wide notion of guest-mode V2

On Wed, Dec 01, 2010 at 06:38:30AM -0500, Nadav Har'El wrote:

> Can you please say a few words why you'd want to move this nested-exit
> request bit to x86.c?

I don't want to move the actual exit-code itself into generic code. This
code is different between svm and vmx. I think we could implement a
call-back in kvm_x86_ops which is called when a vmexit is requested.
The benefit is that we have a single and well-defined place where we
emulate a vmexit.
SVM already as a similar mechanism internally because nested_svm_vmexit
may sleep and can't be called from certain places. Another reason is
that emulating a vmexit at a wrong plase may have side-effects (for
example when called from within the instruction emulator).
With a generic request-bit I can remove the SVM internal implementation
and nested vmx could use it too. I am certain you will need something
similar in nested-vmx too. 

> Do you want to move some of the exit logic to x86.c - e.g., for the
> injection logic?

Thats another and probably more complex topic. I need a better
understanding of (nested-)vmx before we discuss how this can be done.
But a vmexit-callback may be helpful there as well.

	Joerg

-- 
AMD Operating System Research Center

Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach
General Managers: Alberto Bozzo, Andrew Bowd
Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632

--
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/