[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20200602133309.xyet6tndjadwafnb@box>
Date: Tue, 2 Jun 2020 16:33:09 +0300
From: "Kirill A. Shutemov" <kirill@...temov.name>
To: Paolo Bonzini <pbonzini@...hat.com>
Cc: Vitaly Kuznetsov <vkuznets@...hat.com>,
David Rientjes <rientjes@...gle.com>,
Andrea Arcangeli <aarcange@...hat.com>,
Kees Cook <keescook@...omium.org>,
Will Drewry <wad@...omium.org>,
"Edgecombe, Rick P" <rick.p.edgecombe@...el.com>,
"Kleen, Andi" <andi.kleen@...el.com>, x86@...nel.org,
kvm@...r.kernel.org, linux-mm@...ck.org,
linux-kernel@...r.kernel.org,
"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
Dave Hansen <dave.hansen@...ux.intel.com>,
Andy Lutomirski <luto@...nel.org>,
Peter Zijlstra <peterz@...radead.org>,
Sean Christopherson <sean.j.christopherson@...el.com>,
Wanpeng Li <wanpengli@...cent.com>,
Jim Mattson <jmattson@...gle.com>,
Joerg Roedel <joro@...tes.org>
Subject: Re: [RFC 06/16] KVM: Use GUP instead of copy_from/to_user() to
access guest memory
On Mon, Jun 01, 2020 at 06:35:22PM +0200, Paolo Bonzini wrote:
> On 25/05/20 17:17, Kirill A. Shutemov wrote:
> >> Personally, I would've just added 'struct kvm' pointer to 'struct
> >> kvm_memory_slot' to be able to extract 'mem_protected' info when
> >> needed. This will make the patch much smaller.
> > Okay, can do.
> >
> > Other thing I tried is to have per-slot flag to indicate that it's
> > protected. But Sean pointed that it's all-or-nothing feature and having
> > the flag in the slot would be misleading.
> >
>
> Perhaps it would be misleading, but it's an optimization. Saving a
> pointer dereference can be worth it, also because there are some places
> where we just pass around a memslot and we don't have the struct kvm*.
Vitaly proposed to add struct kvm pointer into memslot. Do you object
against it?
--
Kirill A. Shutemov
Powered by blists - more mailing lists