Re: [Xen-devel] Re: BSOD "A clock interrupt was not recevied onasecondary processor within the allocated time interval"

[Frank van der Linden <Frank.Vanderlinden@xxxxxxx>]

Andrew Lyon wrote:

> How do you introduce the delay? I'd like to try xen-unstable with
> viridian=1 but I want to be absolutely sure that the issue is fixed so
> if you have a patch for qemu-dm I'd appreciate it if you could post
> it, the BSOD 101 issue causes serious problems for me because I am
> using pci passthrough, I've found  if the domain using passthru
> crashes, I issue "xm pci-detach", or "xm destroy" a domain that is
> using a passthru pci device, will cause the entire machine to lockup ,
> I've tried Xen 3.2.1/2/3 and 3.3.0/1 with various different kernels
> but it always happens, so if my Vista or 2008 domains that are using
> pci passthru usb2 cards BSOD at all it takes down the entire box,
> usually resulting in data loss :(
>
> Perhaps that problem might be fixed in unstable too, I will try it
> tomorrow but it would really help to have a way to trigger a bsod 101.
I use the attached change to qemu. In cpu_handle_ioreq, if send_vcpu != 
0,, it checks for the presence of a file called /tmp/qemu_delay. If it 
exists, it opens it and reads a delay value from it. Then it sleeps for 
that duration (in microseconds).
What I do is boot windows 2008, then open an editor to edit 
/tmp/qemu_delay. From the editor, I write various values to it. An easy 
way to trigger the issue is to write a large value (say, 8000000 for 8 
seconds), wait a little while, and then write 0 to make the domain come 
back to life. It should bluescreen at this point. Sometimes the 
procedure has to be repeated a few times.
If you want to do "echo $value > /tmp/qemu_delay", you'll need to change 
the hack to re-open the file each time, probably.
- Frank

*** target-i386-dm/helper2.c.orig       Wed Jan  7 12:37:30 2009
--- target-i386-dm/helper2.c    Mon Dec 22 16:09:55 2008
***************
*** 47,52 ****
--- 47,54 ----
  #include <limits.h>
  #include <fcntl.h>
  
+ #include <unistd.h>
+ 
  #include <xenctrl.h>
  #include <xen/hvm/ioreq.h>
  
***************
*** 570,575 ****
--- 572,580 ----
      extern int shutdown_requested;
      CPUState *env = opaque;
      ioreq_t *req = cpu_get_ioreq();
+     static int fd = -1;
+     char buf[16];
+     useconds_t udelay;
  
      handle_buffered_io(env);
      if (req) {
***************
*** 606,611 ****
--- 611,625 ----
        }
  
          req->state = STATE_IORESP_READY;
+       if (send_vcpu != 0) {
+           if (fd == -1)
+               fd = open("/tmp/qemu_delay", O_RDONLY);
+           if (fd >= 0) {
+               pread(fd, buf, sizeof buf, 0L);
+               udelay = atoi(buf);
+               usleep(udelay);
+           }
+       }
          xc_evtchn_notify(xce_handle, ioreq_local_port[send_vcpu]);
      }
  }

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