linux-kernel - Re: [PATCH v3 00/15] KVM: MMU: fast zap all shadow pages

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: <20130421152751.GB28437@amt.cnet>
Date:	Sun, 21 Apr 2013 12:27:51 -0300
From:	Marcelo Tosatti <mtosatti@...hat.com>
To:	Gleb Natapov <gleb@...hat.com>
Cc:	Xiao Guangrong <xiaoguangrong@...ux.vnet.ibm.com>,
	avi.kivity@...il.com, linux-kernel@...r.kernel.org,
	kvm@...r.kernel.org
Subject: Re: [PATCH v3 00/15] KVM: MMU: fast zap all shadow pages

On Sun, Apr 21, 2013 at 04:03:46PM +0300, Gleb Natapov wrote:
> On Tue, Apr 16, 2013 at 02:32:38PM +0800, Xiao Guangrong wrote:
> > This patchset is based on my previous two patchset:
> > [PATCH 0/2] KVM: x86: avoid potential soft lockup and unneeded mmu reload
> > (https://lkml.org/lkml/2013/4/1/2)
> > 
> > [PATCH v2 0/6] KVM: MMU: fast invalid all mmio sptes
> > (https://lkml.org/lkml/2013/4/1/134)
> > 
> > Changlog:
> > V3:
> >   completely redesign the algorithm, please see below.
> > 
> This looks pretty complicated. Is it still needed in order to avoid soft
> lockups after "avoid potential soft lockup and unneeded mmu reload" patch?

Do not want kvm_set_memory (cases: DELETE/MOVE/CREATES) to be
suspectible to:

vcpu 1    		|	kvm_set_memory
create shadow page 		
				nuke shadow page
create shadow page
				nuke shadow page

Which is guest triggerable behavior with spinlock preemption algorithm.

--
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/