Re: Crash on kvm_iommu_map_pages

["Roedel, Joerg" <Joerg.Roedel@amd.com>]

The registers rax and rbx contain non-canonical addresses (if
interpreted as pointers). The instruction where this happens is a mov so
I guess that the #GP is because of an non-canonical address.
Can you find out the code-line where this happens and the exact
assembler instruction? (haven't managed to decode the registers used).

	Joerg

On Mon, Nov 01, 2010 at 08:57:42AM -0400, Jan Kiszka wrote:
> [ Forgot to CC LKML - maybe it's not KVM-specific.
>   BTW, is anyone actually using current KVM device assigment on
>   Intel? I'm starting to believe that can only very few lucky people...
> ]
> 
> Am 01.11.2010 13:51, Jan Kiszka wrote:
> > Hi again,
> > 
> > OK, I swapped those two lines in intel_iommu_attach_device [1], fixed
> > another warning in the wbinvd emulation, but now I'm about to give up.
> > This is freaky MMU stuff:
> > 
> > 
> > general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
> > last sysfs file: /sys/devices/pci0000:00/0000:00:1a.0/device
> > CPU 1 
> > Modules linked in: kvm_intel kvm bluetooth snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device edd ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_raw xt_NOTRACK ipt_REJECT xt_state iptable_raw iptable_filter ip6table_mangle nf_conntrack_netbios_ns nf_conntrack_ipv4 nf_conntrack nf_defrag_ipv4 ip_tables ip6table_filter ip6_tables x_tables ipv6 fuse loop mac80211 snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec ath9k_common ath9k_hw snd_hwdep snd_pcm snd_timer snd ath pcmcia cfg80211 sdhci_pci tpm_infineon sdhci yenta_socket firewire_ohci tpm_tis mmc_core soundcore e1000e sg pcmcia_rsrc tpm firewire_core iTCO_wdt video snd_page_alloc pcmcia_core i2c_i801 rfkill tpm_bios intel_agp output fujitsu_laptop iTCO_vendor_support i2c_core serio_raw pcspkr led_class joydev crc_itu_t button battery intel_gtt ac ext4 mbcache jbd2 crc16 sha256_generic aes_x86_64 aes_generic cbc dm_crypt linear sd_mod crc_t10dif dm_snapshot dm_mod fan processor ahci libahci ata_gene
> ri
> > c liba
> > ta scsi_mod thermal thermal_sys hwmon
> > Nov  1 13:19:11 mchn199C kernel:
> > Pid: 2248, comm: qemu-system-x86 Not tainted 2.6.36+ #12 FJNB211W/CELSIUS H700
> > RIP: 0010:[<ffffffff8121de8c>]  [<ffffffff8121de8c>] pfn_to_dma_pte+0x73/0x190
> > RSP: 0018:ffff8800bd4bdb68  EFLAGS: 00010202
> > RAX: ffff1000bd4fe000 RBX: ffff1000bd4fec00 RCX: 0000000000000009
> > RDX: 0000000000000180 RSI: ffff88012a940938 RDI: 0000000000000202
> > RBP: ffff8800bd4bdba8 R08: ffffea00025ac2a0 R09: 0000000000000004
> > R10: 0000000000000001 R11: 0000000000000000 R12: ffff880128dfee00
> > R13: 0000000000000002 R14: 00000000000f0000 R15: 0000000000000009
> > FS:  00007f4990d33710(0000) GS:ffff8800be680000(0000) knlGS:0000000000000000
> > CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
> > CR2: 0000000001408000 CR3: 00000000bd7db000 CR4: 00000000000026e0
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> > Process qemu-system-x86 (pid: 2248, threadinfo ffff8800bd4bc000, task ffff88012a940000)
> > Stack:
> > ffff8800bd4bdb88 ffff8800ac378000 00000000000000d2 00000000000f0000
> > <0> ffff8800bd4bdce8 ffff8800ac2fc000 0000000000000003 00000000000f0001
> > <0> ffff8800bd4bdbb8 ffffffff8121dfbe ffff8800bd4bdbc8 ffffffff812a9573
> > Call Trace:
> > [<ffffffff8121dfbe>] intel_iommu_iova_to_phys+0x15/0x2a
> > [<ffffffff812a9573>] iommu_iova_to_phys+0x13/0x15
> > [<ffffffffa04e91d0>] kvm_iommu_map_pages+0x77/0x194 [kvm]
> > [<ffffffff8111404d>] ? __vmalloc_node+0x86/0x9b
> > [<ffffffffa04e30e2>] __kvm_set_memory_region+0x4e5/0x787 [kvm]
> > [<ffffffff81081ee8>] ? mark_held_locks+0x50/0x72
> > [<ffffffff8137c983>] ? mutex_lock_nested+0x325/0x34d
> > [<ffffffffa04e33bb>] kvm_set_memory_region+0x37/0x50 [kvm]
> > [<ffffffffa04e4c15>] kvm_vm_ioctl_set_memory_region+0x18/0x1a [kvm]
> > [<ffffffffa04e4e44>] kvm_vm_ioctl+0x22d/0x3b1 [kvm]
> > [<ffffffff811355aa>] ? fget_light+0x17b/0x31f
> > [<ffffffff81143bd7>] do_vfs_ioctl+0x4c6/0x507
> > [<ffffffff81135732>] ? fget_light+0x303/0x31f
> > [<ffffffff811355aa>] ? fget_light+0x17b/0x31f
> > [<ffffffff8137ebb9>] ? retint_swapgs+0x13/0x1b
> > [<ffffffff81143c6e>] sys_ioctl+0x56/0x7c
> > [<ffffffff81002df2>] system_call_fastpath+0x16/0x1b
> > Code: c7 31 db 47 8d 3c ff e9 1d 01 00 00 0f 0b 4c 89 f2 44 88 f9 48 d3 ea 81 e2 ff 01 00 00 41 83 fd 01 48 8d 1c d0 0f 84 0b 01 00 00 <f6> 03 03 0f 85 d8 00 00 00 41 8b 44 24 04 85 c0 79 08 65 8b 04 
> > RIP  [<ffffffff8121de8c>] pfn_to_dma_pte+0x73/0x190
> > RSP <ffff8800bd4bdb68>
> > 
> > 
> > Can anyone parse this? Is it Intel-specific or a generic issue? The
> > kernel is current kvm.git + unrelated patch + [1].
> > 
> > Jan
> > 
> > [1] http://thread.gmane.org/gmane.comp.emulators.kvm.devel/61923
> > 
> 



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