linux-kernel - Re: [PATCH] ARM: KVM: Handle IPA unmapping on memory region deletion

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] [day] [month] [year] [list]

Message-ID: <CAMJs5B-YP8dsiapL=wpue5zhH1DruKENvAPtzNnvvRbCvqU-HQ@mail.gmail.com>
Date:	Thu, 3 Apr 2014 10:07:30 -0700
From:	Christoffer Dall <christoffer.dall@...aro.org>
To:	Marc Zyngier <marc.zyngier@....com>
Cc:	Eric Auger <eric.auger@...aro.org>,
	"eric.auger@...com" <eric.auger@...com>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"kvmarm@...ts.cs.columbia.edu" <kvmarm@...ts.cs.columbia.edu>,
	"kvm@...r.kernel.org" <kvm@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"patches@...aro.org" <patches@...aro.org>,
	"christophe.barnichon@...com" <christophe.barnichon@...com>
Subject: Re: [PATCH] ARM: KVM: Handle IPA unmapping on memory region deletion

On 3 April 2014 08:26, Marc Zyngier <marc.zyngier@....com> wrote:
> Hi Eric,
>
> On 03/04/14 16:17, Eric Auger wrote:
>> Currently when a KVM region is removed using
>> kvm_vm_ioctl_set_memory_region (with memory region size equal to 0), the
>> corresponding intermediate physical memory is not unmapped.
>>
>> This patch unmaps the region's IPA range in
>> kvm_arch_commit_memory_region using unmap_stage2_range.
>>
>> The patch was tested on QEMU VFIO based use case where RAM memory region
>> creation/deletion frequently happens for IRQ handling.
>>
>> Notes:
>> - the KVM_MR_MOVE case shall request some similar addition but I cannot test
>>   this currently
>
> I think you should try to handle it anyway. I'm sure you could hack QEMU
> to do this test it, but even if you don't, better plug that hole right now.
>
I don't think we want untested code in the kernel if we can avoid it,
so I would say, either test it somehow (kvm-unit-tests ?) or print a
warning...?

-Christoffer
--
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/