WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-users

Re: [Xen-users] PCI Passthrough without VT-d

On Fri, Mar 05, 2010 at 02:01:28PM -0300, Sergio Charpinel Jr. wrote:
>    Hi,
>    I created a PV guest, and did a passthrough on my PCI USB Controller, to
>    use the webcam.
>    But, I'm receiving a kernel panic message on my domU afte boot.
>    I'm using CentOS 5.4 and Xen 3.4.2
>    Password: Fatal DMA error! Please use 'swiotlb=force'

Did you try that 'swiotlb=force' option for the guest kernel? 
Also, does the same problem happen if you run the official EL5 Xen (3.1.2)
instead of 3.4.2 ?

-- Pasi

>    ----------- [cut here ] --------- [please bite here ] ---------
>    Kernel BUG at arch/x86_64/kernel/../../i386/kernel/pci-dma-xen.c:394
>    invalid opcode: 0000 [1] SMPÂ
>    last sysfs file:
>    
> /devices/xen/pci-0/pci0000:00/0000:00:00.3/usb1/1-1/1-1:1.0/usbdev1.2_ep82/dev
>    CPU 0Â
>    Modules linked in: autofs4 hidp rfcomm l2cap bluetooth lockd sunrpc
>    ip_conntrack_netbios_ns ipt_MASQUERADE xt_mark iptable_nat ip_nat xt_MARK
>    iptable_mangle ipt_REJECT xt_state ip_conntrack nfnetlink iptable_filter
>    ip_tables ip6t_REJECT xt_tcpudp ip6table_filter ip6_tables x_tables ipv6
>    xfrm_nalgo crypto_api dm_mirror dm_multipath scsi_dh scsi_mod parport_pc
>    lp parport stv680 compat_ioctl32 videodev v4l1_compat pcspkr v4l2_common
>    xennet dm_raid45 dm_message dm_region_hash dm_log dm_mod dm_mem_cache
>    xenblk ext3 jbd uhci_hcd ohci_hcd ehci_hcd
>    Pid: 1752, comm: zmc Not tainted 2.6.18-164.11.1.el5xen #1
>    RIP: e030:[<ffffffff8027217b>] Â [<ffffffff8027217b>]
>    dma_map_single+0x12d/0x17d
>    RSP: e02b:ffff88000cfb1c78 Â EFLAGS: 00010282
>    RAX: 000000000000002f RBX: ffff88000e860000 RCX: ffffffff804f3ba8
>    RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
>    RBP: 0000000035032000 R08: ffffffff804f3ba8 R09: 0000000000000000
>    R10: 000000000000002d R11: ffff88001f4230c0 R12: 0000000000019610
>    R13: ffff88001fdef870 R14: ffff88001fb5f980 R15: ffff880010296ad4
>    FS: Â 00002b8745423c10(0000) GS:ffffffff805ca000(0000)
>    knlGS:0000000000000000
>    CS: Â e033 DS: 0000 ES: 0000
>    Process zmc (pid: 1752, threadinfo ffff88000cfb0000, task
>    ffff88000f4530c0)
>    Stack: Â ffff88000f4530c0 Â ffff880010296ac0 Â 00000000ffffffff
>    Â ffff880010296ac0Â
>    Â ffff88001ff7d400 Â ffffffff803e4200 Â 0000000000000000
>    Â 000000d0802572b0Â
>     fffffffffff7ffff  ffffffff802c2e18Â
>    Call Trace:
>    Â [<ffffffff803e4200>] hcd_submit_urb+0x693/0x748
>    Â [<ffffffff802c2e18>] mod_zone_page_state+0x27/0x3d
>    Â [<ffffffff8020b242>] kmem_cache_alloc+0x62/0x6d
>    Â [<ffffffff8025e6e3>] cache_alloc_refill+0x13c/0x4e5
>    Â [<ffffffff802cfc34>] __kmalloc+0x8f/0x9f
>    Â [<ffffffff881377e0>] :stv680:stv680_start_stream+0x18b/0x1c5
>    Â [<ffffffff881397a0>] :stv680:stv680_do_ioctl+0x4e1/0x57b
>    Â [<ffffffff8811ddda>] :videodev:video_usercopy+0x1a1/0x265
>    Â [<ffffffff881392bf>] :stv680:stv680_do_ioctl+0x0/0x57b
>    Â [<ffffffff8031a360>] inode_has_perm+0x56/0x63
>    Â [<ffffffff80222789>] __up_read+0x19/0x7f
>    Â [<ffffffff802676cd>] do_page_fault+0xfae/0x12e0
>    Â [<ffffffff8026ef47>] monotonic_clock+0x35/0x7b
>    Â [<ffffffff80243f5c>] do_ioctl+0x55/0x6b
>    Â [<ffffffff802316b5>] vfs_ioctl+0x457/0x4b9
>    Â [<ffffffff8024e68e>] sys_ioctl+0x59/0x78
>    Â [<ffffffff802602f9>] tracesys+0xab/0xb6
>    Code: 0f 0b 68 3a 2b 49 80 c2 8a 01 4d 85 ed 74 11 49 8b 85 18 02Â
>    RIP Â [<ffffffff8027217b>] dma_map_single+0x12d/0x17d
>    Â RSP <ffff88000cfb1c78>
>    Â <0>Kernel panic - not syncing: Fatal exception
>    2010/3/2 Jan Ä*eÅ¡Ä*ut <[1]Jan.Cescut@xxxxxx>
> 
>      Thanks for thorough explanation.
> 
>      Have a nice day,
>      Jan
>      -----Original Message-----
>      From: Pasi KÀrkkÀinen [mailto:[2]pasik@xxxxxx]
>      Sent: 27. februar 2010 14:04
>      To: Jan Ä*eÅ¡Ä*ut
>      Cc: [3]xen-users@xxxxxxxxxxxxxxxxxxx
>      Subject: Re: [Xen-users] PCI Passthrough without VT-d
> 
>      On Fri, Feb 26, 2010 at 11:29:22PM +0100, Jan ?eš?ut wrote:
>      > Â  Â As I read XEN supports assigning a pci device to an unprivileged
>      domain
>      > Â  Â without hardware supporting it. Has anyone already tried it? Are
>      there any
>      > Â  Â security risks? If I understand correctly how PCI passthrough
>      works the
>      > Â  Â performance should be the same as using the pci device in native
>      mode. Is
>      > Â  Â it so? I have a PCI video card which would like to use inside a
>      VM running
>      > Â  Â Windows XP.
>      >
> 
>      Xen supports PCI passthrough to _PV_ (paravirtual) guests without VT-d,
>      and has actually supported that for years. There are some potential
>      security
>      risks in this, since the PV guest gets full DMA control of the PCI
>      device
>      and could use it for malicious purposes.
> 
>      Xen PCI passthrough to HVM guests (=Windows) requires VT-d hardware
>      support.
> 
>      Also, PCI passthrough of a VGA/video card is not as simple as PCI
>      passthrough
>      of other cards (nic, disk controller, usb controller).
> 
>      VGA has lots of legacy stuff related to it, some memory ranges, IO
>      ports, VGA BIOS,
>      etc that have to be 'passed through' aswell, and emulated.
> 
>      Xen 4.0.0 will have PCI passthrough support of primary VGA adapters, but
>      it requires
>      VT-d support as stated already earlier.
> 
>      -- Pasi
> 
>      ps. There is actually a hack/patch available that allows PCI passthrough
>      to HVM guest
>      without VT-d, but that only works for the _first_ started HVM guest, and
>      it's experimental
>      and not supported in any way. iirc the patch is available in xen-devel
>      archives.
> 
>      _______________________________________________
>      Xen-users mailing list
>      [4]Xen-users@xxxxxxxxxxxxxxxxxxx
>      [5]http://lists.xensource.com/xen-users
> 
>    --
>    Sergio Roberto Charpinel Jr.
> 
> References
> 
>    Visible links
>    1. mailto:Jan.Cescut@xxxxxx
>    2. mailto:pasik@xxxxxx
>    3. mailto:xen-users@xxxxxxxxxxxxxxxxxxx
>    4. mailto:Xen-users@xxxxxxxxxxxxxxxxxxx
>    5. http://lists.xensource.com/xen-users

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users

<Prev in Thread] Current Thread [Next in Thread>