Compute Engine now supports custom OSes [1], so I've been working on getting OpenBSD working on it. I thought I'd share a status update.
[1] http://googlecloudplatform.blogspot.com/2013/12/google-compute-engine-is-now-generally-available.html ** virtio-scsi Compute Engine exposes disks as virtio-scsi devices, whereas OpenBSD currently only supports virtio-blk disks. I've got a mostly working virtio-scsi driver (WIP: https://codereview.appspot.com/33540044), but I still need to polish it a bit. One complication is Compute Engine advertises excessively large virtio queues: e.g., 32k CCBs for virtio-scsi and 16k deep tx and rx queues for virtio-net. This seems to push the limit of how many dmamaps we can pre-allocate, so for now I'm still pre-allocating DMA memory for all the virtio-scsi CCBs but lazily allocating dmamaps as needed. This allows things to work, but it seems fragile. ** networking The network environment is a bit goofy: the DHCP server will assign an IP and netmask like 10.240.93.65/255.255.255.255, and then specify the default gateway as 10.240.0.1. On Linux, ISC's DHCP client special cases the netmask==255.255.255.255 case by adding a direct route like "route add 10.240.0.1 dev eth0" before running "route add default 10.240.0.1". However, I can't seem to reproduce this behavior on OpenBSD. I'd expect something like "route add 10.240.0.1 -iface 10.240.93.65" to work, but the network stack never ARP resolves 10.240.0.1 so packets just drop instead. My current workaround is to instead override the netmask as 255.255.0.0 so the network stack realizes it can directly contact 10.240.0.1, and then I add additional routes so that other 10.240/16 addresses (e.g., other VM instances) are still routed via 10.240.0.1. So with those two hacky workarounds in place, I've successfully started OpenBSD on Compute Engine (dmesg below) and been able to SSH into it. OpenBSD 5.4-current (GENERIC.MP) #43: Wed Nov 27 22:36:26 PST 2013 matt...@bento.dempsky.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP real mem = 4009746432 (3823MB) avail mem = 3894853632 (3714MB) mainbus0 at root bios0 at mainbus0: SMBIOS rev. 2.4 @ 0xfd990 (12 entries) bios0: vendor Google version "Google" date 01/01/2011 bios0: Google Google acpi0 at bios0: rev 0 acpi0: sleep states S3 S4 S5 acpi0: tables DSDT FACP SSDT APIC acpi0: wakeup devices acpitimer0 at acpi0: 3579545 Hz, 24 bits acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat acpiprt0 at acpi0: bus 0 (PCI0) mpbios0 at bios0: Intel MP Specification 1.4 cpu0 at mainbus0: apid 0 (boot processor) cpu0: Intel(R) Xeon(R) CPU @ 2.60GHz, 2600.35 MHz cpu0: FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,MMX,FXSR,SSE,SSE2,SS,SSE3,PCLMUL,SSSE3,CX16,SSE4.1,SSE4.2,x2APIC,POPCNT,AES,NXE,LONG,LAHF cpu0: smt 0, core 0, package 0 cpu0: apic clock running at 1000MHz mpbios0: bus 0 is type PCI mpbios0: bus 1 is type ISA ioapic0 at mainbus0: apid 0 pa 0xfec00000, version 11, 24 pins pci0 at mainbus0 bus 0 pcib0 at pci0 dev 1 function 0 "Intel 82371AB PIIX4 ISA" rev 0x03 piixpm0 at pci0 dev 1 function 3 "Intel 82371AB Power" rev 0x03: SMBus disabled virtio0 at pci0 dev 3 function 0 "Qumranet Virtio SCSI" rev 0x00: Virtio SCSI host Device vioscsi0 at virtio0: qsize 32768 scsibus0 at vioscsi0: 253 targets sd0 at scsibus0 targ 1 lun 0: <Google, PersistentDisk, > SCSI4 0/direct fixed sd0(vioscsi0:1:0): Check Condition (error 0x70) on opcode 0x1b SENSE KEY: No Additional Sense sd0: 10240MB, 512 bytes/sector, 20971520 sectors sd0(vioscsi0:1:0): Check Condition (error 0x70) on opcode 0xa0 SENSE KEY: No Additional Sense virtio0: apic 0 int 11 virtio1 at pci0 dev 4 function 0 "Qumranet Virtio Network" rev 0x00: Virtio Network Device vio0 at virtio1: address 42:01:0a:f0:5d:41 virtio1: apic 0 int 11 isa0 at pcib0 isadma0 at isa0 com0 at isa0 port 0x3f8/8 irq 4: ns16550a, 16 byte fifo com0: console com1 at isa0 port 0x2f8/8 irq 3: ns16550a, 16 byte fifo pcppi0 at isa0 port 0x61 spkr0 at pcppi0 nvram: invalid checksum mtrr: Pentium Pro MTRR support, 8 var ranges, 88 fixed ranges vscsi0 at root scsibus1 at vscsi0: 256 targets softraid0 at root scsibus2 at softraid0: 256 targets sd0(vioscsi0:1:0): Check Condition (error 0x70) on opcode 0x1b SENSE KEY: No Additional Sense root on sd0a (bd2b1320d2a54646.a) swap on sd0b dump on sd0b sd0(vioscsi0:1:0): Check Condition (error 0x70) on opcode 0x1b SENSE KEY: No Additional Sense sd0(vioscsi0:1:0): Check Condition (error 0x70) on opcode 0x1b SENSE KEY: No Additional Sense sd0(vioscsi0:1:0): Check Condition (error 0x70) on opcode 0x1b SENSE KEY: No Additional Sense clock: unknown CMOS layout
