Hi:
Recently I try to intercept a given kernel address-syscall address,for example-
of the guest windows 7 to the hypervisor, I set the exception flag in the
EXCEPTION_BITMAP as follows:
vmcs.c
void vmx_do_resume(vcpu * v)
{
......
unsigned long intercepts = __vmread(EXCEPTION_BITMAP);
unsigned long mask = (1UL << TRAP_debug);
intercepts |= mask;
__vmwrite(EXCEPTION_BITMAP, intercepts)
v->arch.guest_context.debugreg[0] = [Address of a syscall];
v->arch.guest_context.debugreg[7] |= 2;
......
}
I do reveive the VMexit in the vmx_vmexit_handler in vmx.c then I want to let
the guest os keep going as usual without concerning about the debug breakpoint
so I set some flags as follows:
case TRAP_debug:
......
regs->eflags |= X86_EFLAGS_RF;
exit_qualification = __vmread(EXIT_QUALIFICATION);
write_debug(6, exit_qualification | 0xffff0ff0);
......
The problem is the guest os seems trapped into an infinite loop and take the
full vcpu capacity, I find the RIP in the VCPU stay the same, EFLAGS value of
the VCPU is 0x2 and the guest os can''t respond to any movement of mouse
or keyboard,.
Do I missed some flag when restoring the guest context?Or there are some other
reasons that lead to this issue?Could you give me any suggestions?
Jone
......
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel