On 28 June 2018 at 18:22, Daniel P. Berrangé <[email protected]> wrote: > On Wed, Jun 27, 2018 at 01:31:17PM +0100, Dr. David Alan Gilbert wrote: >> * Hongbo Zhang ([email protected]) wrote: >> > This patch introduces a new Arm machine type 'SBSA' with features: >> > - Based on legacy 'virt' machine type. > > The 'virt' machine type is absolutely *not* legacy. It is the preferred > modern, legacy-free machine type when running virtual machines. Since > aarch64 is greenfield, there is no compelling reason to emulate a > specific physical machine for VMs, hence the 'virt' machine type. > >> > - Newly designed memory map. >> > - EL2 and EL3 are enabled by default. >> > - AHCI controller attached to system bus, and then CDROM and hard disc >> > can be added to it. >> > - EHCI controller attached to system bus, with USB mouse and key board >> > installed by default. >> > - E1000 ethernet card on PCIE bus. > >> > - VGA display adaptor on PCIE bus. >> > - Default CPU type cortex-a57, 4 cores, and 1G bytes memory. >> > - No virtio functions enabled, since this is to emulate real hardware. >> >> I'm a bit confused; do you have real modern ARM hardware that has an >> e1000 on it? If I understand correctly, e1000 is the old PCI version >> and the e1000e is at least the more modern PCIe version which makes >> more sense if you're building on PCIe. > > Indeed, it makes little sense to default to e1000 if the goal is to make > it legacy-free > >> However, if you: >> a) Don't have real hardware with the e1000 on >> b) Do have PCIe >> >> then to my mind it makes sense to use virtio-net-pci rather than >> an e1000e. > > If it does down the virtio-* route though, I fail to see any point in > adding the new machine type at all - 'virt' machine type is intended > to be used for guests where everything is paravirtualized, ignoring > physical hardware constraints. > Your comment comes earlier than I replied to Laszlo Ersek:
I said "yes yes yes" to him due to he describes the purpose so well, even better than me. And the I had some misunderstanding of term 'legacy' too, as I explained in that reply. > Regards, > Daniel > -- > |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| > |: https://libvirt.org -o- https://fstop138.berrange.com :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
