Intercept system call trap on Xen,

Intercept system call trap on Xen,

[Hui Kang]

[-- Attachment #1.1: Type: text/plain, Size: 846 bytes --]

Hi,
I have a question regarding intercepting the system call from a guest kernel on hypervisor. I am using xen-4.0.1 with a PV-guest.
To disable the fast system call which bypasses the hypervisor, I first comment out this lines in the file
Xen/arch/x86/traps.c
      If (cur.vector == 0x80)
       {
    /* init_int80_direct_trap(curr); */
}
To verify this, when I boot the kernel, I add printk and see that init_int80_direct_trap is not executed.

Then in the function in the same file as above, do_guest_trap, I add a printk to trap the system call from guest kernel

Static void do_guest_trap…
{
If (trapnr == 0x80)
printk("System call from guest");
}

However, when I run some program in the guest kernel to issue some system call, the hypervisor does not print out the message. Can anyone help on this? Thanks.

- Hui


[-- Attachment #1.2: Type: text/html, Size: 2275 bytes --]

[-- Attachment #2: Type: text/plain, Size: 138 bytes --]

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