linux-kernel - Re: [PATCH gmem FIXUP] kvm: guestmem: do not use a file system

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: <c46606c8-fb6d-4e81-843c-47a0443bebc1@redhat.com>
Date:   Mon, 16 Oct 2023 17:19:56 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Sean Christopherson <seanjc@...gle.com>
Cc:     Al Viro <viro@...iv.linux.org.uk>, linux-kernel@...r.kernel.org,
        kvm@...r.kernel.org
Subject: Re: [PATCH gmem FIXUP] kvm: guestmem: do not use a file system

On 10/13/23 18:55, Sean Christopherson wrote:
> On Wed, Oct 11, 2023, Paolo Bonzini wrote:
>> Your patch 2 looks good, but perhaps instead of setting the owner we could
>> stash the struct module* in a global, and try_get/put it from open and
>> release respectively?  That is, .owner keeps the kvm module alive and the
>> kvm module keeps kvm-intel/kvm-amd alive.  That would subsume patches 1 and 3.
> 
> I don't think that would be a net positive.  We'd have to implement .open() for
> several file types just to get a reference to the sub-module.  At that point, the
> odds of forgetting to implement .open() are about the same as forgetting to set
> .owner when adding a new file type, e.g. guest_memfd.

Fair enough, it's true that many fops don't have a .open callback already.

Paolo