From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH v2] kvm: Disable MSI/MSI-X in assigned device reset path Date: Mon, 16 Apr 2012 20:47:10 +0200 Message-ID: <4F8C692E.80802@siemens.com> References: <20120405033450.25661.68810.stgit@bling.home> <1334584997.3112.8.camel@bling.home> <20120416150640.GB13713@redhat.com> <4F8C364F.6090901@siemens.com> <20120416160823.GA18914@redhat.com> <4F8C450F.9030706@siemens.com> <20120416163624.GD18914@redhat.com> <4F8C4AFE.8010309@siemens.com> <20120416171235.GA19517@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Alex Williamson , "kvm@vger.kernel.org" , Avi Kivity , Marcelo Tosatti , "jbaron@redhat.com" To: "Michael S. Tsirkin" Return-path: Received: from david.siemens.de ([192.35.17.14]:32568 "EHLO david.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752038Ab2DPSrO (ORCPT ); Mon, 16 Apr 2012 14:47:14 -0400 In-Reply-To: <20120416171235.GA19517@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 2012-04-16 19:12, Michael S. Tsirkin wrote: > On Mon, Apr 16, 2012 at 06:38:22PM +0200, Jan Kiszka wrote: >> On 2012-04-16 18:36, Michael S. Tsirkin wrote: >>> On Mon, Apr 16, 2012 at 06:13:03PM +0200, Jan Kiszka wrote: >>>> On 2012-04-16 18:08, Michael S. Tsirkin wrote: >>>>> On Mon, Apr 16, 2012 at 05:10:07PM +0200, Jan Kiszka wrote: >>>>>> On 2012-04-16 17:06, Michael S. Tsirkin wrote: >>>>>>> On Mon, Apr 16, 2012 at 08:03:17AM -0600, Alex Williamson wrote: >>>>>>>> The discussion on this patch seems to have fizzled, with no clear short >>>>>>>> term solution. >>>>>>> >>>>>>> I think we are in concensus, it's just that there are >>>>>>> multiple bugs still left to fix. >>>>>>> >>>>>>> First, we need to prevent guest from touching command >>>>>>> register except for the bus master bit. Something like >>>>>> >>>>>> INTx is harmless as well. Denying access breaks masking for the guest. >>>>> >>>>> We currently mark intx as emulated, no? >>>> >>>> If we use the mask also in the kernel for IRQ sharing, we *monitor* it. >>>> >>>>> Anyway - care fixing it properly? >>>> >>>> There is nothing to fix. >>>> >>>> Jan >>> >>> Guest access to command register is a bug. >>> E.g. it has no business enabling SERR as SERR crashes >>> host when triggered. >> >> Maybe a misunderstanding. I agree that other bits are not guest >> business. But INTx should be excluded from this filtering and handled as >> is, i.e. passed through. >> >> Jan > > Ah, I see what you mean. > So let's add > pci_dev->emulate_config_write[PCI_COMMAND + 1] &= ~(PCI_COMMAND_INTX_DISABLE >> 8); > on top? Looks good. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux