Hi, Am 21.06.24 um 14:05 schrieb Gerd Hoffmann: > On Wed, Jun 19, 2024 at 11:21:14AM GMT, John Levon wrote: >> Older 32-bit Linux VMs (including Ubuntu 16.10) have issues with the >> 64-bit pci io window, failing during boot with errors like: > > Well. Why people would use *that* ubuntu version is not clear to me. > It's *loooooong* out of support. Even the LTS version from that year > (16.04) is not supported any more. But it is at least available for > download still, so I gave it a spin. > > Turns out it apparently can't deal with PCI bars mapped above 16TB (aka > 44 phys-bits). Test patch below. > > take care, > Gerd > > diff --git a/src/fw/pciinit.c b/src/fw/pciinit.c > index bb44dc296047..a43876a931c9 100644 > --- a/src/fw/pciinit.c > +++ b/src/fw/pciinit.c > @@ -1189,11 +1189,16 @@ pci_setup(void) > > if (CPUPhysBits) { > pci_mem64_top = 1LL << CPUPhysBits; > - if (CPUPhysBits > 46) { > - // Old linux kernels have trouble dealing with more than 46 > - // phys-bits, so avoid that for now. Seems to be a bug in the > - // virtio-pci driver. Reported: centos-7, ubuntu-18.04 > - pci_mem64_top = 1LL << 46; > + if (CPUPhysBits > 44) { > + // Old linux kernels have trouble dealing with more than 44/46 > + // phys-bits. Seems to be a bug in the virtio-pci driver. > + // 46: centos-7, ubuntu-18.04 > + // 44: ubuntu-16.04 > + // Limit the used address space to mitigate the bug, except we > are > + // running in a guest with more than 1TB of memory installed. > + if (RamSizeOver4G < (1LL << 40)) { > + pci_mem64_top = 1LL << 44; > + } > } > } >
we've also had two reports about issues with 32-bit guests now[0][1] (both had '-m 4096' in the QEMU commandline), which I was able to reproduce with a 32-bit Debian 12.6 install, so nothing ancient ;) The QEMU commandline is below[2]. Unfortunately, it still fails to boot, even with the "limit address space used for pci devices, part two" patch applied on top of rel-1.16.3 (and using current QEMU master). It boots fine with '-m 3583', but not anymore with '-m 3584'. So is bumping the limit for the check necessary after all? Best Regards, Fiona [0]: https://forum.proxmox.com/threads/150217/ [1]: https://forum.proxmox.com/threads/149772/post-683562 [2]: > ./qemu-system-x86_64 \ > -accel 'kvm' \ > -cpu 'host' \ > -chardev > 'socket,id=qmp,path=/var/run/qemu-server/121.qmp,server=on,wait=off' \ > -mon 'chardev=qmp,mode=control' \ > -chardev 'socket,id=qmp-event,path=/var/run/qmeventd.sock,reconnect=5' \ > -mon 'chardev=qmp-event,mode=control' \ > -pidfile /var/run/qemu-server/121.pid \ > -smp '4,sockets=1,cores=4,maxcpus=4' \ > -nodefaults \ > -vnc 'unix:/var/run/qemu-server/121.vnc,password=on' \ > -m 4096 \ > -device 'pci-bridge,id=pci.3,chassis_nr=3,bus=pci.0,addr=0x5' \ > -device 'VGA,id=vga,bus=pci.0,addr=0x2' \ > -device 'virtio-scsi-pci,id=virtioscsi0,bus=pci.3,addr=0x1' \ > -drive > 'file=/dev/lvmthinbig/vm-121-disk-0,if=none,id=drive-scsi0,format=raw,cache=none,aio=io_uring,detect-zeroes=on' > \ > -device > 'scsi-hd,bus=virtioscsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0,id=scsi0,bootindex=100' > \ > -machine 'type=pc' _______________________________________________ SeaBIOS mailing list -- seabios@seabios.org To unsubscribe send an email to seabios-le...@seabios.org