On 02/15/2016 09:58 AM, Thomas Lamprecht wrote: > Hi all, > > > I'm wondering if there is a possibility to pass through a big GPU like > the NVIDIA Tesla K80 (with 24 GB ram). > AFAIK, there is a problem with mapping that lot of memory which would > need 64 bit MMIO > (or "above 4G mapping" feature, like some firmware are calling it). > > So after some searching on the web I came to no clear answer and > though simply asking here would be the best. > I only found a post from about 2010 on the qemu-devel list [1] which > stated that there isn't 64-bit MMIO support (yet), > but also that it'd be useful. Was there any progress on this matter? > If yes how could someone enable it (with OVMF?). > > How is the support for passing through such Hardware, or in other word > has anybody achieved this? > Maybe I should also note that smaller GPUs pass-through just fine. > > best regards, > Thomas > > [1] > https://lists.nongnu.org/archive/html/qemu-devel/2010-02/msg01106.html > > > >
For anyone wondering, or if someone stumbles upon this post, as he run into problems when passing through a Tesla or similar graphic card in the future, qemu is fully to do this. The limitation here comes from OVMF as Laszlo Ersek told me on a GitHub issue I opened (thanks again). Here's the quote [1]: > QEMU definitely supports 64-bit MMIO for the x86_64 target. > > The PCI host bridge / root bridge driver that OVMF uses at the moment > lacks support for 64-bit PCI MMIO however. This is a known limitation, > and it should be resolved after OVMF is ported to the new, central PCI > host bridge / root bridge driver in edk2. (It won't happen > automatically with the port, but when the port is complete, it > shouldn't take much work on top.) > > I started to work on that port recently, but ran into some issues with > the central driver that OVMF should use. We've been discussing those > topics recently on the mailing list, with @marcel-apf and @niruiyu . > > Please refer to these (sub)threads in the list archive: > * http://thread.gmane.org/gmane.comp.bios.edk2.devel/6526/focus=6910 > * http://thread.gmane.org/gmane.comp.bios.edk2.devel/7382 > * http://thread.gmane.org/gmane.comp.bios.edk2.devel/7967 > * http://thread.gmane.org/gmane.comp.bios.edk2.devel/7969 cheers, Thomas [1] https://github.com/tianocore/edk2/issues/59#issuecomment-187226312
