linux-kernel - Re: [PATCH 1/3] Implement emulator_write

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]

Date:	Mon, 27 Aug 2007 12:23:39 -0500
From:	Anthony Liguori <aliguori@...ibm.com>
To:	Avi Kivity <avi@...ranet.com>
Cc:	kvm-devel@...ts.sourceforge.net, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/3] Implement emulator_write_phys()


On Mon, 2007-08-27 at 18:45 +0300, Avi Kivity wrote:
> Anthony Liguori wrote:
> > Since a hypercall may span two pages and is a gva, we need a function to write
> > to a gva that may span multiple pages.  emulator_write_phys() seems like the
> > logical choice for this.
> >
> > @@ -962,8 +962,35 @@ static int emulator_write_std(unsigned long addr,
> >  			      unsigned int bytes,
> >  			      struct kvm_vcpu *vcpu
> 
> I think that emulator_write_emulated(), except for being awkwardly 
> named, should do the job.  We have enough APIs.
> 
> But!  We may not overwrite the hypercall instruction while a vcpu may be 
> executing, since there's no atomicity guarantee for code fetch.  We have 
> to to be out of guest mode while writing that insn.


Hrm, good catch.

How can we get out of guest mode given SMP guest support?

Regards,

Anthony Liguori

> 
> 

-
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/