Re: Nested KVM

[Alexander Graf <agraf@suse.de>]

On 23.12.2008, at 03:55, "Todd Deshane" <deshantm@gmail.com> wrote:

> I have successfully built the latest kvm, kvm-userspace from git.
>
> I loaded the kvm_amd module with the nested=1 option.
>
> The kvm guest that I am working with has an older version
> of kvm (Ubuntu 8.10 + kvm package) and during boot I get:
>
> [   23.673107] Modules linked in: kvm_amd(+) kvm ppdev cpufreq_stats
> cpufreq_powersave cpufreq_userspace cpufreq_conservative
> cpufreq_ondemand freq_table container pci_slot wmi video output sbs
> sbshc battery
> ipv6 iptable_filter ip_tables x_tables ac lp virtio_balloon
> virtio_net serio_raw psmouse pcspkr evdev joydev i2c_piix4 i2c_core
> parport_pc parport button ext3 jbd mbcache usbhid hid sr_mod cdrom sg
> virtio_b
> lk pata_acpi ata_piix ata_generic uhci_hcd virtio_pci virtio_ring
> virtio usbcore libata scsi_mod dock thermal processor fan fbcon
> tileblit font bitblit softcursor fuse
> [   23.673107] Pid: 4278, comm: modprobe Tainted: G S         
> 2.6.27-7-generic #1
> [   23.673107] RIP: 0010:[<ffffffff8022d35a>]  [<ffffffff8022d35a>]
> native_write_msr_safe+0xa/0x10
> [   23.673107] RSP: 0018:ffff880018dc3dd8  EFLAGS: 00010002
> [   23.673107] RAX: 0000000000001d01 RBX: ffff880018dc3e04 RCX:  
> 00000000c0000080
> [   23.673107] RDX: 0000000000000000 RSI: 0000000000001d01 RDI:  
> 00000000c0000080
> [   23.673107] RBP: ffff880018dc3dd8 R08: 0000000000000000 R09:  
> ffffffff806e1e20
> [   23.673107] R10: ffff880018dc3dfc R11: ffff880018dc3df8 R12:  
> ffff880018c096c0
> [   23.673107] R13: ffffffffa02b25e0 R14: ffffffffa02e1c80 R15:  
> 00000000c0000080
> [   23.673107] FS:  00007f2f14f946e0(0000) GS:ffffffff806e1a80(0000)
> knlGS:0000000000000000
> [   23.673107] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [   23.673107] CR2: 00007f2f14fa8000 CR3: 0000000018d4f000 CR4:  
> 00000000000006e0
> [   23.673107] DR0: 0000000000000000 DR1: 0000000000000000 DR2:  
> 0000000000000000
> [   23.673107] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7:  
> 0000000000000400
> [   23.673107] Process modprobe (pid: 4278, threadinfo
> ffff880018dc2000, task ffff8800190f1670)
> [   23.673107] Stack:  ffff880018dc3e38 ffffffffa02db196
> 88000100b000007f 000000000000ffff
> [   23.673107]  0000000000000000 0000000000000010 0000000000000000
> 0000000000000000
> [   23.673107]  0000000000000000 ffffffffa02b25e0 ffffffffa02e1c80
> 00007f2f14f9a000
> [   23.673107] Call Trace:
> [   23.673107]  [<ffffffffa02db196>] svm_hardware_enable+0xd6/0x140  
> [kvm_amd]
> [   23.673107]  [<ffffffffa02b25e0>] ? hardware_enable+0x0/0x40 [kvm]
> [   23.673107]  [<ffffffffa02b4693>] kvm_arch_hardware_enable 
> +0x13/0x20 [kvm]
> [   23.673107]  [<ffffffffa02b260f>] hardware_enable+0x2f/0x40 [kvm]
> [   23.673107]  [<ffffffff80254a44>] on_each_cpu+0x34/0x50
> [   23.673107]  [<ffffffffa02b0c85>] kvm_init+0x165/0x280 [kvm]
> [   23.673107]  [<ffffffffa00b3000>] ? svm_init+0x0/0x23 [kvm_amd]
> [   23.673107]  [<ffffffffa00b3021>] svm_init+0x21/0x23 [kvm_amd]
> [   23.673107]  [<ffffffff8020a041>] do_one_initcall+0x41/0x170
> [   23.673107]  [<ffffffff8026c261>] ? __blocking_notifier_call_chain 
> +0x21/0x90
> [   23.673107]  [<ffffffff8027d085>] sys_init_module+0xb5/0x1f0
> [   23.673107]  [<ffffffff8021285a>] system_call_fastpath+0x16/0x1b
> [   23.673107]
> [   23.673107]
> [   23.673107] Code: 00 55 89 f9 48 89 e5 0f 32 31 c9 89 c7 48 89 d0
> 89 0e 48 c1 e0 20 89 fa 48 09 d0 c9 c3 0f 1f 40 00 55 89 f9 89 f0 48
> 89 e5 0f 30 <31> c0 c9 c3 66 90 55 89 f9 48 89 e5 0f 33 89 c1 48 89 d0
> 48 c1
> [   23.673107] RIP  [<ffffffff8022d35a>] native_write_msr_safe+0xa/ 
> 0x10
> [   23.673107]  RSP <ffff880018dc3dd8>
> [   23.673107] ---[ end trace 0dc989f1cf9a296e ]---
>
> Maybe it is just that a newer version of KVM is needed?
>
> I will also try to build a newer version of KVM and test.
>
> Thanks for any comments.

Your guest is writing to an MSR that is unknown to the kvm msr  
emulation. What does dmesg on the host say?

Alex

>
>
> Cheers,
> Todd
>
> -- 
> Todd Deshane
> http://todddeshane.net
> http://runningxen.com
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html