kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Avi Kivity <avi@redhat.com>
To: Sasha Levin <levinsasha928@gmail.com>
Cc: Carsten Otte <cotte@de.ibm.com>,
	Marcelo Tossati <mtosatti@redhat.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>,
	Cornelia Huck <cornelia.huck@de.ibm.com>,
	KVM <kvm@vger.kernel.org>,
	Joachim von Buttlar <joachim_von_buttlar@de.ibm.com>,
	Jens Freimann <jfrei@de.ibm.com>,
	Constantin Werner <constantin.werner@de.ibm.com>,
	Alexander Graf <agraf@suse.de>,
	Xiantao Zhang <xiantao.zhang@intel.com>
Subject: Re: [patch 01/12] [PATCH] kvm-s390: ioctl to switch to user controlled virtual machines
Date: Thu, 08 Dec 2011 11:59:39 +0200	[thread overview]
Message-ID: <4EE08A8B.8080502@redhat.com> (raw)
In-Reply-To: <1323338029.3904.15.camel@lappy>

On 12/08/2011 11:53 AM, Sasha Levin wrote:
> On Thu, 2011-12-08 at 11:45 +0200, Avi Kivity wrote:
> > On 12/08/2011 11:25 AM, Sasha Levin wrote:
> > > On Thu, 2011-12-08 at 10:12 +0100, Carsten Otte wrote:
> > > > plain text document attachment (enable-ucontrol.patch)
> > > > This patch introduces a new config option for user controlled kernel
> > > > virtual machines. It introduces an optional parameter to
> > > > KVM_CREATE_VM in order to create a user controlled virtual machine.
> > > > The parameter is passed to kvm_arch_init_vm for all architectures.
> > > > Valid values for the new parameter are KVM_VM_REGULAR (defined to 0
> > > > for backward compatibility to old KVM_CREATE_VM) and
> > > > KVM_VM_S390_UCONTROL for s390 only.
> > >
> > > Why is it s390 specific? why isn't it KVM_VM_UCONTROL which is currently
> > > only implemented on s390?
> > 
> > It's not possible (or at least very difficult) to implement ucontrol on
> > x86.  For example, to update VMCSs you need privileged instructions.  It
> > might be doable on svm, but there's no point, really.
>
> Might not work for x86, but maybe on arm? ppc? or some other random arch
> that will be added in the future?
>
> No point in limiting it to s390 from day one.

Agree.

> It also makes code a bit cleaner (kvm_main.c shouldn't have arch names
> in the code).

That doesn't bother me.

-- 
error compiling committee.c: too many arguments to function


  reply	other threads:[~2011-12-08  9:59 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-08  9:12 [patch 00/12] Ucontrol patchset V2 Carsten Otte
2011-12-08  9:12 ` [patch 01/12] [PATCH] kvm-s390: ioctl to switch to user controlled virtual machines Carsten Otte
2011-12-08  9:25   ` Sasha Levin
2011-12-08  9:27     ` Carsten Otte
2011-12-08  9:45     ` Avi Kivity
2011-12-08  9:53       ` Sasha Levin
2011-12-08  9:59         ` Avi Kivity [this message]
2011-12-08 10:18           ` Alexander Graf
2011-12-08 11:48             ` Carsten Otte
2011-12-08 13:16               ` Alexander Graf
2011-12-08  9:12 ` [patch 02/12] [PATCH] kvm-s390-ucontrol: per vcpu address spaces Carsten Otte
2011-12-08  9:12 ` [patch 03/12] [PATCH] kvm-s390-ucontrol: export page faults to user Carsten Otte
2011-12-08  9:12 ` [patch 04/12] [PATCH] kvm-s390-ucontrol: export SIE control block " Carsten Otte
2011-12-08  9:12 ` [patch 05/12] [PATCH] kvm-s390-ucontrol: disable in-kernel handling of SIE intercepts Carsten Otte
2011-12-08  9:12 ` [patch 06/12] [PATCH] kvm-s390-ucontrol: disable in-kernel irq stack Carsten Otte
2011-12-08  9:12 ` [patch 07/12] [PATCH] kvm-s390-ucontrol: interface to inject faults on a vcpu page table Carsten Otte
2011-12-08  9:12 ` [patch 08/12] [PATCH] kvm-s390-ucontrol: disable sca Carsten Otte
2011-12-08  9:12 ` [patch 09/12] [PATCH] kvm-s390: fix assumption for KVM_MAX_VCPUS Carsten Otte
2011-12-08  9:12 ` [patch 10/12] [PATCH] kvm-s390: storage key interface Carsten Otte
2011-12-08  9:12 ` [patch 11/12] [PATCH] kvm-s390-ucontrol: announce capability for user controlled vms Carsten Otte
2011-12-08  9:12 ` [patch 12/12] [PATCH] kvm-s390: Fix return code for unknown ioctl numbers Carsten Otte
  -- strict thread matches above, loose matches on Subject: below --
2011-12-01 12:57 [patch 00/12] User controlled virtual machines Carsten Otte
2011-12-01 12:57 ` [patch 01/12] [PATCH] kvm-s390: ioctl to switch to user " Carsten Otte
2011-12-01 13:15   ` Avi Kivity
2011-12-01 13:31     ` Avi Kivity
2011-12-01 14:20     ` Martin Schwidefsky

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4EE08A8B.8080502@redhat.com \
    --to=avi@redhat.com \
    --cc=agraf@suse.de \
    --cc=borntraeger@de.ibm.com \
    --cc=constantin.werner@de.ibm.com \
    --cc=cornelia.huck@de.ibm.com \
    --cc=cotte@de.ibm.com \
    --cc=heiko.carstens@de.ibm.com \
    --cc=jfrei@de.ibm.com \
    --cc=joachim_von_buttlar@de.ibm.com \
    --cc=kvm@vger.kernel.org \
    --cc=levinsasha928@gmail.com \
    --cc=mtosatti@redhat.com \
    --cc=schwidefsky@de.ibm.com \
    --cc=xiantao.zhang@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).