Re: [virtio-dev] I can read/write in virtio BLK Device, but I can't run a hello world program in it

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Jul 07, 2015 at 11:06:46AM +0900, Ganis Zulfa Santoso wrote:
> Hi Virtio-Dev Mailing List Members,
> 
> I am trying to develop a driver for virtio blk device in guest. I can safely
> mount the virtual blk device with: mount /dev/vda /mnt/
> in /mnt/ I can read & write the device. But when I run a simple hello world
> program in /mnt/root/, this error happens:

You got the wrong list. You want whoever implemented your device - QEMU?
This list is for virtio spec related discussions.


> root@linux_guest:/mnt/root# ./helloworld_static 
> [   23.003459] CPU: 0 PID: 491 Comm: helloworld_stat Not tainted 3.19.1+ #101
> [   23.007030] Hardware name: ARM-Versatile Express
> [   23.010102] task: 970f2400 ti: 9184e000 task.ti: 9184e000
> [   23.011645] PC is at 0x11d6a
> [   23.012801] LR is at 0x89b3
> [   23.013627] pc : [<00011d6a>]    lr : [<000089b3>]    psr: 80000030
> [   23.013627] sp : 7e932c10  ip : 00008e45  fp : 00000000
> [   23.017108] r10: 00000000  r9 : 00000000  r8 : 00000000
> [   23.023165] r7 : 00000000  r6 : 00053794  r5 : 7e932dd4  r4 : 0006a9b4
> [   23.026854] r3 : 0000022c  r2 : 00000000  r1 : ffffffd0  r0 : 00000021
> [   23.031814] Flags: Nzcv  IRQs on  FIQs on  Mode USER_32  ISA Thumb  Segment
> user
> [   23.036225] Control: 10c5387d  Table: 916f4059  DAC: 00000015
> [   23.040885] CPU: 0 PID: 491 Comm: helloworld_stat Not tainted 3.19.1+ #101
> [   23.043224] Hardware name: ARM-Versatile Express
> [   23.045168] [<80012c68>] (unwind_backtrace) from [<80010dc8>]
> (show_stack+0x10/0x14)
> [   23.050392] [<80010dc8>] (show_stack) from [<8030c9d0>]
> (__do_user_fault.isra.10+0x98/0xa8)
> [   23.052687] [<8030c9d0>] (__do_user_fault.isra.10) from [<80017c6c>]
> (do_page_fault+0x35c/0x3b8)
> [   23.055358] [<80017c6c>] (do_page_fault) from [<80008488>]
> (do_DataAbort+0x34/0x98)
> [   23.057510] [<80008488>] (do_DataAbort) from [<80011a5c>] (__dabt_usr+0x3c/
> 0x40)
> [   23.065243] Exception stack(0x9184ffb0 to 0x9184fff8)
> [   23.069425] ffa0:                                     00000021 ffffffd0
> 00000000 0000022c
> [   23.073779] ffc0: 0006a9b4 7e932dd4 00053794 00000000 00000000 00000000
> 00000000 00000000
> [   23.079985] ffe0: 00008e45 7e932c10 000089b3 00011d6a 80000030 ffffffff
> 
> Can you tell me what I could probably miss? Thank you very much, I forever in
> debt for your time and effort to read this. I am writing the BLK Device based
> on Lguest's code.
> 
> some information that may help:
> 
> root@linux_guest:/mnt/root# file helloworld_static 
> helloworld_static: ELF 32-bit LSB executable, ARM, version 1 (SYSV), statically
> linked, for GNU/Linux 2.6.31, BuildID[sha1]=
> 0xc63622efd65f635f2b93c05caa8a1302d60a8caa, not stripped
> 
> root@linux_guest:/mnt/root# uname -a
> Linux linux_guest 3.19.1+ #101 Tue Jul 7 09:35:23 KST 2015 armv7l GNU/Linux
> 
> root@linux_guest:/mnt/root# ls -l helloworld_static
> -rwxr-xr-x    1 root     root        456218 Jul  7  2015 helloworld_static
> 
> during booting:
> 
> [    0.202185] brd: module loaded
> [    0.262288] loop: module loaded
> [    0.304868]  vda: unknown partition table
> AtLFprofile: no performance counters
> [    0.399451] oprofile: using timer interrupt.
> CP: cubic registered
> [    0.403361] NET: Registered protocol family 17
> [    0.405039] Registering SWP/SWPB emulation handler
> [    0.409375] RAMDISK: gzip image found at block 0
> [    0.572643] EXT2-fs (ram0): warning: mounting unchecked fs, running e2fsck
> is recommended
> [    0.620201] VFS: Mounted root (ext2 filesystem) on device 1:0.
> [    0.622113] devtmpfs: mounted
> [    0.623328] Freeing unused kernel memory: 172K (80417000 - 80442000)
> 
> Starting logging: OK
> Initializing random number generator... 
> [    0.691483] random: dd urandom read with 0 bits of entropy available
> done.
> Starting network...
> Starting dropbear sshd: OK
> 
> linux_guest login: