Yes, I get it, thanks. Any way to find out if a given hardware supports VFIO?
regards, Lars On Wed, Apr 10, 2019, 20:56 Jakob Bohm <jb-gnumli...@wisemo.com> wrote: > As I wrote, qemu can pass disks (and disk partitions) through without > passing the disk controller through. To qemu, a physical disk is just > another virtual disk storage format. > > But if you want to pass through an entire PCI disk controller (with all > its disks) for faster I/O, then VFIO is needed. > > On 10/04/2019 20:40, Lars Bonnesen wrote: > > I want to pass local disks to a VM in order to run freenas or similar. > > > > Regards, Lars. > > > > On Wed, Apr 10, 2019, 20:20 Jakob Bohm <jb-gnumli...@wisemo.com > > <mailto:jb-gnumli...@wisemo.com>> wrote: > > > > If you pass through the disk access to your SAN partitions as disk > > accesses to block devices (such as SAN client drivers) in the host > > machine, you don't need VFIO for that. This can handle nearly > > unlimited number of virtual machines without running out of PCI > > slots in the host machine. This is the equivalent of "passing > > through a SAN disk" in VMWare, but isn't artificially limited to > > SAN disks (for example, you can layer the Linux multipath drivers > > and/or the Linux disk encryption drivers between the virtual > > machine and the actual SAN). > > > > If you pass through the network access to your (iSCSI or NBD) SAN > > as network traffic via the general qemu/kvm network features, you > > don't need VFIO for that. This can handle nearly unlimited number > > of virtual machines without running out of PCI slots in the host > > machine. This is equivalent to using a "VMWare virtual switch". > > > > If you dedicate a physical SAN adapter (iSCSI, NBD, SAS or fibre > > channel) to each virtual machine and pass it through to that > > virtual machine, you need VFIO for that. As on VMWare, this will > > limit you to one virtual machine for each PCI slot in the > > motherboard. > > > > If you dedicate a physical network adapter (NIC) to each individual > > virtual machine and pass it through to PCI drivers in that virtual > > machine, you need VFIO for that. This too will limit you to one > > virtual machine for each PCI slot in the motherboard. > > > > As for passing through raw SCSI devices or busses, I don't know > > if the latest qemu versions have the ability to do this at a > > hardware-independent level like VMWare does (VM sends standard > > SCSI requests to qemu virtual SCSI adapter, qemu sends those > > same SCSI requests to real SCSI hardware via something like the > > Linux "SCSI generic" driver, optionally mapping at most the > > SCSI-level bus address). > > > > On 10/04/2019 19:42, Lars Bonnesen wrote: > > > But for sure I want passthru - for running virtualized SAN and > such > > > > > > Any unofficial list? > > > > > > Regards, Lars. > > > > > > On Wed, Apr 10, 2019, 18:58 Friedrich Oslage > > <friedrich+qemu-u...@oslage.de <mailto: > friedrich%2bqemu-u...@oslage.de>> > > > wrote: > > > > > >> As long as it's VT-x capable and can run Linux, you're good to > go. > > >> > > >> It only gets tricky once you start using VFIO (direct > passthrough of > > >> host PCI devices to a VM, such as GPUs, NICs or NVMes for > > instance). You > > >> need VT-d support for that and both the CPU and mainboard have to > > >> support it. And not only do they have to support it, they have to > > >> support in a usable way with decent iommu group isolation and > > without > > >> weird bugs. There are no (official) compatibility lists for > > this, it's > > >> still mostly trial and error... > > >> > > >> Regards > > >> Friedrich > > >> > > >> On 4/10/19 2:26 PM, Lars Bonnesen wrote: > > >>> So I am coming from the VMware world (with comprehensive > > compatibillity > > >>> lists) but about to start a project with KVM/Qemu and I would > > like to > > >> setup > > >>> an inexpensive test setup for this purpose. > > >>> > > >>> I am thinking of buying one of SuperMicros IoT-servers like > > >>> > > >> > > > https://www.supermicro.com/products/system/Mini-ITX/SYS-E300-9D-4CN8TP.cfm > > >>> Will this be a nice pick for Qemu? Or any VT-supportet system > > will work > > >>> fine? > > >>> > > >>> Regards, Lars. > > > > > Enjoy > > Jakob > -- > Jakob Bohm, CIO, Partner, WiseMo A/S. https://www.wisemo.com > Transformervej 29, 2860 Søborg, Denmark. Direct +45 31 13 16 10 > This public discussion message is non-binding and may contain errors. > WiseMo - Remote Service Management for PCs, Phones and Embedded > >