q35 is the newer one with better support for more CPUs, PCI-E vs PCI, integrated SATA vs integrated IDE emulation, IOMMU emulation, and I *think* it is needed for hotplugging CPUs/memory.
I thought we were supposed to use it because of the PCI-E part, specifically. On 12/27/18 3:18 PM, Brett Foster wrote: > Why use q35? I always thought that wasn't recommended. At least a couple > years ago, that was my impression. > > > Sent from my BlackBerry - the most secure mobile device > > Original Message > From: erra...@yourstruly.sx > Sent: December 27, 2018 12:12 PM > To: fost...@edgeandvertex.org; b...@spamcop.net > Cc: vfio-users@redhat.com > Subject: Re: [vfio-users] Installing Catalyst prevents VM from booting. > > > BTW I think the specific reason you want to separate your pcie endpoints on > q35 from the root complex using a switch or up/downstream ports is due to the > fact that the root complex has direct access to memory. I can't find anything > more specific regarding why that might be problematic but I know that pcie > addressing is different for devices downstream as opposed to being connected > directly to the root complex. I arrived at the conclusion that the amd driver > works now with q35 because changed the topology as per the advice I read > somewhere regarding how it should be done. I'd like to know for sure but I > don't really understand PCIe well enough and I think as far as the driver is > concerned its up to a guess as to why one configuration works and the other > doesn't (unless you have better luck getting the windows remote kernel > debugging to work than I have.) > ________________________________________ > From: vfio-users-boun...@redhat.com <vfio-users-boun...@redhat.com> on behalf > of Brett Foster <fost...@edgeandvertex.org> > Sent: Wednesday, December 26, 2018 11:24:48 AM > To: Bronek Kozicki > Cc: vfio-users > Subject: Re: [vfio-users] Installing Catalyst prevents VM from booting. > > I have been using AMD via i440fx for like 5 years or so (across different > hardware and graphics cards). The drivers that work are the ones that come > via Windows Update. The drivers distributed by AMD do not. Not sure why since > presumably they come from the same place. lol. > > On Tue, Dec 25, 2018 at 9:51 AM Bronek Kozicki > <b...@spamcop.net<mailto:b...@spamcop.net>> wrote: > On Tue, 25 Dec 2018, at 4:21 PM, Paige Thompson wrote: >> Hey, >> >> From what I understand in general connecting devices straight to the >> root complex is problematic and they should be connected to a bridge. I >> was kind of wondering if anybody had any knowledge of this. I find the >> configuration really confusing. I still cant really tell how the >> topology works. > > Hope Alex will shed some light on it when he's back from the holiday break. > > > -- > Bronek Kozicki > b...@spamcop.net<mailto:b...@spamcop.net> > > _______________________________________________ > vfio-users mailing list > vfio-users@redhat.com<mailto:vfio-users@redhat.com> > https://www.redhat.com/mailman/listinfo/vfio-users > > _______________________________________________ > vfio-users mailing list > vfio-users@redhat.com > https://www.redhat.com/mailman/listinfo/vfio-users _______________________________________________ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
