Il giorno lunedì 18 dicembre 2017 17:13:41 UTC+1, Henning Schild ha scritto:
> Am Mon, 18 Dec 2017 07:41:34 -0800
> schrieb Luca Cuomo <[email protected]>:
> 
> > Il giorno lunedì 18 dicembre 2017 16:22:37 UTC+1, Henning Schild ha
> > scritto:
> > > Am Mon, 18 Dec 2017 05:58:11 -0800
> > > schrieb Luca Cuomo <[email protected]>:
> > >   
> > > > > > Hi,
> > > > > > 
> > > > > > I can now confirm that the patch 87fbf1f works and interrupts
> > > > > > are received correctly, /dev/uiox is accessible and works as
> > > > > > expected. Without it, I got a: "FATAL: forbidden access
> > > > > > (exception class 0x24)" but I don't remember if this was
> > > > > > triggered by Jailhouse or Linux.    
> > > > > 
> > > > > Thanks, applied to "jailhouse" and removed "jailhouse-next".
> > > > > 
> > > > > Henning
> > > > >     
> > > > > > Best Regards,
> > > > > > Constantin
> > > > > >    
> > > > 
> > > > Hi all,
> > > > 
> > > > i've got a strange situation. I'm using the latest jailhouse
> > > > branch on x86 with a linux root cell and a Bare Metal cell
> > > > connected via 2 pci device (bdf e.00 and f.00).
> > > > 
> > > > Two Ivshmem device are correctly mapped to /dev/uio0
> > > > and /dev/uio1. But if on /dev/uio0 i can correctly map registers
> > > > ( offset 0, size 0x1000) and shmem  (offset 0x1000, size 0x1000),
> > > > for /dev/uio1 the first mapping fails with the ENODEV errno set
> > > > (shmem mapping is done correctly). Parameters of mapping are the
> > > > same for uio0 and uio1.
> > > > 
> > > > Here i list a dmesg snippet of the root cell kernel:
> > > > 
> > > > [  302.092280] pci 0000:00:0e.0: [1af4:1110] type 00 class
> > > > 0xff0000 [  302.092622] pci 0000:00:0e.0: reg 0x10: [mem
> > > > 0x00000000-0x000000ff 64bit] [  302.092776]
> > > > hpet_rtc_timer_reinit: 39 callbacks suppressed [  302.092777]
> > > > hpet1: lost 62 rtc interrupts [  302.093025] pci 0000:00:0e.0:
> > > > reg 0x20: [mem 0x00000000-0x0000001f 64bit] [  302.093634] pci
> > > > 0000:00:0e.0: BAR 0: assigned [mem 0xc0000000-0xc00000ff 64bit]
> > > > [  302.093765] pci 0000:00:0e.0: BAR 4: assigned [mem
> > > > 0xc0000100-0xc000011f 64bit] [  302.093982] virtio-pci
> > > > 0000:00:0e.0: enabling device (0000 -> 0002) [  302.094169]
> > > > uio_ivshmem 0000:00:0e.0: using jailhouse mode [  302.094625]
> > > > uio_ivshmem 0000:00:0e.0: MSI-X enabled [  302.094918] pci
> > > > 0000:00:0f.0: [1af4:1110] type 00 class 0xff0000 [  302.095259]
> > > > pci 0000:00:0f.0: reg 0x10: [mem 0x00000000-0x000000ff 64bit]
> > > > [  302.095725] pci 0000:00:0f.0: reg 0x20: [mem
> > > > 0x00000000-0x0000001f 64bit] [  302.096468] pci 0000:00:0f.0: BAR
> > > > 0: assigned [mem 0xc0000200-0xc00002ff 64bit] [  302.096667] pci
> > > > 0000:00:0f.0: BAR 4: assigned [mem 0xc0000120-0xc000013f 64bit]
> > > > [  302.096962] virtio-pci 0000:00:0f.0: enabling device (0000 ->
> > > > 0002) [  302.097139] uio_ivshmem 0000:00:0f.0: using jailhouse
> > > > mode [  302.097568] uio_ivshmem 0000:00:0f.0: MSI-X enabled  
> > > 
> > > I do not remember whether i tested the uio-driver with multiple
> > > devices, i can not rule out a hidden bug in there. The output looks
> > > pretty much the same for both instances and does not seem too
> > > useful. 
> >  
> > Even the /sys/class/uio/uiox ... directories seem to be ok.
> > 
> > > What would be interesting is which call fails and where it fails in
> > > the kernel? Could you "unbind" the two devices from the driver and
> > > "bind" them the other way around, does that make the "second" work
> > > and the "first" fail?  
> > 
> > This could be a good idea but how do you suggest to unbind them?
> 
> # echo 0000:00:0f.0 > /sys/bus/pci/drivers/uio_ivshmem/unbind
> # echo 0000:00:0e.0 > /sys/bus/pci/drivers/uio_ivshmem/unbind
> 
> # echo 0000:00:0f.0 > /sys/bus/pci/drivers/uio_ivshmem/bind
> 
> Now 0f should be your uio0.

I've tried and now the problem in on /dev/uio0. So the problem in on the same 
device (the one that previously was /dev/uio1.

> 
> > > What test-code are you using, if anyone wanted to reproduce the
> > > setup for further assistance.  
> > 
> > The same result using both the uio_send test which is in the repo and
> > a self made test which basically does:
> > 
> > int firstFd = open(/dev/uio0, O_RDWR) //ok
> > mmap( NULL, 4096, PROT_READ | PROT_WRITE, MAP_SHARED, firstFd,
> > 0) //regs ok mmap( NULL, 4096, PROT_READ | PROT_WRITE, MAP_SHARED,
> > firstFd, 4096) //shmem ok
> > 
> > int secondFd = open(/dev/uio1, O_RDWR) //ok
> > mmap( NULL, 4096, PROT_READ | PROT_WRITE, MAP_SHARED, secondFd,
> > 0) //regs FAIL mmap( NULL, 4096, PROT_READ | PROT_WRITE, MAP_SHARED,
> > secondFd, 4096) //shmem ok
> 
> Ok, let us see where this is coming from with ftrace.
> 
> Could you try something like this, best on an otherwise idle system:
> 
> trace-cmd record -p function -l '*mmap*' yourtest
> trace-cmd report
> 
> Maybe check out the documentation of ftrace to get closer to the root
> cause of the error. The mmap itself is not even implemented in the
> driver, i am guessing a parameter like size or location might be wrong.
> But if you can mmap it from /dev/mem i might also be an alignment issue.
> We basically have to trace that mmap-call to the condition in the
> kernel returning the error.

This will take me some time, so when i'll setup the environment i will post the 
results.

> 
> > The way i can overcome the problem for the second device is reading
> > the address from /sys/class/uio/uio1/maps/map0/addr and then mmapping
> > from /dev/mem with the proper offset
> > (/sys/class/uio/uio1/maps/map0/offset)
> 
> Well from a security point of view, i would not suggest that. Rather
> have your uios in a group via udev ...
> For now a good workaround but i would like to understand and fix it, if
> it is something in the uio-driver.

I will try this on arm too.

> 
> Henning
> 
> > > Henning
> > >   
> > > > What i'm doing wrong? I do exactly the same things on /dev/uio0
> > > > and /dev/uio1  
> >  
 Thanks,
  
 --Luca
 


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