From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: Re: [PULL] virtio and lguest Date: Fri, 13 Jan 2012 12:59:19 +1030 Message-ID: <87fwfkjpxc.fsf@rustcorp.com.au> References: <87lipd4hqx.fsf@rustcorp.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Linus Torvalds Cc: Stratos Psomadakis , "Michael S. Tsirkin" , lkml - Kernel Mailing List , virtualization@lists.linux-foundation.org, Sasha Levin , Amit Shah , Jacek Galowicz , Christoph Hellwig , Davidlohr Bueso List-Id: virtualization@lists.linuxfoundation.org T24gVGh1LCAxMiBKYW4gMjAxMiAxNjoyOToxNCAtMDgwMCwgTGludXMgVG9ydmFsZHMgPHRvcnZh bGRzQGxpbnV4LWZvdW5kYXRpb24ub3JnPiB3cm90ZToKPiBPbiBXZWQsIEphbiAxMSwgMjAxMiBh dCA5OjIyIFBNLCBSdXN0eSBSdXNzZWxsIDxydXN0eUBydXN0Y29ycC5jb20uYXU+IHdyb3RlOgo+ ID4KPiA+IEFtaXQgU2hhaCAoMTIpOgo+ID4gwqAgwqAgwqB2aXJ0aW86IHBjaTogc3dpdGNoIHRv IG5ldyBQTSBBUEkKPiAKPiBIbW0uIEFmYWlrLCB0aGlzIGlzIGJyb2tlbiwgb3IgYXQgbGVhc3Qg bm90IGNvbXBsZXRlLgo+IAo+IFN1cmUsIGl0IHN3aXRjaGVzIHRvIHRoZSBuZXcgUE0gQVBJLCBi dXQgaXQgc3RpbGwgZG9lcyB0aGUgUENJIG9wcyBpdHNlbGYuCj4gCj4gSXQgc2hvdWxkIG5vdCBu ZWVkIHRvIC0gdGhlIFBDSSBsYXllciB3aWxsIGRvIHRoZSBwb3dlciBzdGF0ZSBhbmQKPiBzdGFu ZGFyZCBQQ0kgZGV2aWNlIHN0YXRlIHNhdmluZy4gQW5kIHNldHRpbmcgdGhlIFBDSV9EM2hvdCBz dGF0ZSB3aGVuCj4gc2hhcmVkIGludGVycnVwdHMgY2FuIHN0aWxsIGhhcHBlbiBhdCBzdXNwZW5k IHRpbWUgaXMganVzdCBhIGJhZCBpZGVhLgo+IAo+IFNvIEkgdGhpbmsgeW91J3JlIGRvaW5nIGV4 dHJhIHdvcmsgYW5kIGludHJvZHVjaW5nIGJ1Z3MgYnkgZG9pbmcgc28gLQo+IHRoZSBkZWZhdWx0 IFBDSSBidXMgb3BlcmF0aW9ucyBzaG91bGQgYWxyZWFkeSBkbyBhbGwgeW91IGRvLCBqdXN0IGRv Cj4gaXQgYmV0dGVyLiBBbmQgdGhlbiB5b3UgY2FuIHVzZSB0aGUgU0lNUExFX0RFVl9QTV9PUFMo KSB0byBidWlsZCB0aGUKPiBkZXZfcG1fb3BzIHN0cnVjdHVyZSBhbmQgZ2V0IGFsbCB0aGUgbm9y bWFsIGNhc2VzIHJpZ2h0IGF1dG9tYXRpY2FsbHkuCj4gCj4gSSBkb24ndCBrbm93IGlmIHRoZXJl IGlzIGFueSBwYXJ0aWN1bGFybHkgZ29vZCBleGFtcGxlIG9mIHRoaXMsIGJ1dAo+IHlvdSBjYW4g c2VlIHNvbWUgb2YgdGhlIG5ldHdvcmsgZHJpdmVycyBmb3IgZXhhbXBsZXMgb2YgdGhpcy4gTm90 aWNlCj4gaG93IHRoZXkgZG9uJ3QgbmVlZCB0byB3b3JyeSBhYm91dCBQQ0kgcG93ZXIgc3RhdGVz IGV0YyBhdCBhbGwsIHRoZXkKPiBqdXN0IG5lZWQgdG8gd29ycnkgYWJvdXQgdGhlIGFjdHVhbCBj aGlwIHN1c3BlbmQvcmVzdW1lIChhbmQgZm9yIGEKPiBuZXR3b3JrIGRyaXZlciwgeW91J2QgZG8g dGhlIG5ldGlmX2RldmljZV9kZXRhY2gvbmV0aWZfZGV2aWNlX2F0dGFjaAo+IGV0YykKCk9rLCBJ J2xsIGNvbmZlc3MgY29tcGxldGUgaWdub3JhbmNlLCBhbmQgd2FpdCBmb3IgQW1pdCB0byByZXNw b25kLiAgSQptdXN0IGFkbWl0IHRoYXQgUE0gZm9yIHZpcnR1YWwgZGV2aWNlcyBpcyBub3QgYSBw ZXJzb25hbCBwcmlvcml0eS4uLgoKVGhhbmtzLApSdXN0eS4KX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX18KVmlydHVhbGl6YXRpb24gbWFpbGluZyBsaXN0ClZp cnR1YWxpemF0aW9uQGxpc3RzLmxpbnV4LWZvdW5kYXRpb24ub3JnCmh0dHBzOi8vbGlzdHMubGlu dXhmb3VuZGF0aW9uLm9yZy9tYWlsbWFuL2xpc3RpbmZvL3ZpcnR1YWxpemF0aW9u From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755866Ab2AMDZN (ORCPT ); Thu, 12 Jan 2012 22:25:13 -0500 Received: from ozlabs.org ([203.10.76.45]:33111 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750901Ab2AMDZK convert rfc822-to-8bit (ORCPT ); Thu, 12 Jan 2012 22:25:10 -0500 From: Rusty Russell To: Linus Torvalds Cc: lkml - Kernel Mailing List , Amit Shah , Christoph Hellwig , Davidlohr Bueso , Jacek Galowicz , "Michael S. Tsirkin" , Sasha Levin , Stratos Psomadakis , virtualization@lists.linux-foundation.org Subject: Re: [PULL] virtio and lguest In-Reply-To: References: <87lipd4hqx.fsf@rustcorp.com.au> User-Agent: Notmuch/0.6.1-1 (http://notmuchmail.org) Emacs/23.3.1 (i686-pc-linux-gnu) Date: Fri, 13 Jan 2012 12:59:19 +1030 Message-ID: <87fwfkjpxc.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 12 Jan 2012 16:29:14 -0800, Linus Torvalds wrote: > On Wed, Jan 11, 2012 at 9:22 PM, Rusty Russell wrote: > > > > Amit Shah (12): > >      virtio: pci: switch to new PM API > > Hmm. Afaik, this is broken, or at least not complete. > > Sure, it switches to the new PM API, but it still does the PCI ops itself. > > It should not need to - the PCI layer will do the power state and > standard PCI device state saving. And setting the PCI_D3hot state when > shared interrupts can still happen at suspend time is just a bad idea. > > So I think you're doing extra work and introducing bugs by doing so - > the default PCI bus operations should already do all you do, just do > it better. And then you can use the SIMPLE_DEV_PM_OPS() to build the > dev_pm_ops structure and get all the normal cases right automatically. > > I don't know if there is any particularly good example of this, but > you can see some of the network drivers for examples of this. Notice > how they don't need to worry about PCI power states etc at all, they > just need to worry about the actual chip suspend/resume (and for a > network driver, you'd do the netif_device_detach/netif_device_attach > etc) Ok, I'll confess complete ignorance, and wait for Amit to respond. I must admit that PM for virtual devices is not a personal priority... Thanks, Rusty.