monitoring guest sidt execution

[matteo <signorinimatteo@gmail.com>]

Hi to all,

 I'm trying to intercept the guest "sidt" instruction execution from the
host

i've added the bit to the control structure:


 control->intercept = | (1ULL << INTERCEPT_STORE_IDTR);

 then I have defined the sidt handler to manage the STORE_IDTR action:


 [SVM_EXIT_IDTR_READ]                    = idtr_write_interception,

 So, in the idtr_write_interception handler there is the invocation of
 the "emulate_instruction(&svm->
vcpu, kvm_run, 0, 0, 0);" function.
 Following the execution flow i found that the emulation failed in the

 x86_emulate.c source file and precisely in the "if (c->d == 0) "
 conditional statement but i really don't know why it happens and how to
 fix it.

could you please give me some hints with respect to this issue?

thanks in advance,

Matteo