KVM won’t boot Ubuntu with module installed (on Intel)
Sunday, March 16th, 2008So, I’m planning on using KVM to virtualize my new server, but when I try to boot any of the install ISO images, I get a message like this:
# kvm -no-acpi -vnc :1 -m 2000 -cdrom ./ubuntu-7.10-jeos-i386.iso ../test.img -boot d
exception 6 (0)
rax 0000000000000469 rbx 0000000000800001 rcx 0000000000004300 rdx 0000000000000000
rsi 000000000005961d rdi 000000000005961c rsp 00000000fffaa9cc rbp 000000000000200c
r8 0000000000000000 r9 0000000000000000 r10 0000000000000000 r11 0000000000000000
r12 0000000000000000 r13 0000000000000000 r14 0000000000000000 r15 0000000000000000
rip 000000000000b04b rflags 00033006
cs 4143 (00041430/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
ds 4004 (00040040/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
es 4004 (00040040/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
ss 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
fs 3002 (00030020/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
gs 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
tr 0000 (7d850000/00002088 p 1 dpl 0 db 0 s 0 type b l 0 g 0 avl 0)
ldt 0000 (00000000/0000ffff p 1 dpl 0 db 0 s 0 type 2 l 0 g 0 avl 0)
gdt 40920/47
idt 0/ffff
cr0 60000010 cr2 0 cr3 0 cr4 0 cr8 0 efer 0
code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Aborted
And, if I
# rmmod kvm kvm_intel
Then it can boot, but without the KVM kernel modules, the performance is horrible. The KVM pages say that these exceptions are due to the fact that some Intel processors doesn’t emulate some 8088 instructions. Well, if that means that I can’t boot my install media, then its pretty pointless, isn’t it? BTW, would it be that hard to emulate these unfrequently used instructions properly?
I’m going to see if I can get through the install process without the kernel module (under full emulation), and then boot the resultant image with the module installed, but I don’t have much hope that it’ll work very well.
In the mean time, I’m reading up on Xen, which I think is a bit more mature than KVM is…
