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[Xen-devel] New Hypercall Declaration

To: "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: [Xen-devel] New Hypercall Declaration
From: "Nimgaonkar, Satyajeet" <SatyajeetNimgaonkar@xxxxxxxxxx>
Date: Thu, 30 Sep 2010 22:02:39 +0000
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Thread-index: Actg6zLDmwctUSDVSuSguwfJ9sLYHA==
Thread-topic: New Hypercall Declaration
Hello Xen Developers,

 I am currently working on declaring a new hypercall in Xen.
For this i have declared my hypercall in xen.h -
#define __HYPERVISOR_jeet1                56

Then I modified the xcom_privcmd.c to accomodate my hypercall -
         case __HYPERVISOR_jeet1:
                 printk("Successfull Hypercall made to

I defined the structure for the Hypercall in xc_domain.c

int hypercall_test(int handle){
    int rc;
    /* Hypercall definitions */
    hypercall.op     = __HYPERVISOR_jeet1;
    rc = do_xen_hypercall(handle, &hypercall);
    hypercall.arg[0] = 0;
    hypercall.arg[1] = 1;
    //printf ("Hypercall Details: %d\n", rc);
    return rc;

And then I am calling this Hypercall through an user level program-
#include <xenctrl.h>
#include <stdio.h>

int main(){
     printf("Attempt to invoke the hypercall: __HYPERVISOR_jeet1\n");
     int handle, rc;
         /* Acquire Hypervisor Interface Handle.
            This handle goes as the first argument for the function do_xen_hypercall()
     handle = xc_interface_open();
     printf ("Acquired handle to Xen Hypervisor:%d\n",handle);
     rc = hypercall_test(handle);
     printf ("Hypercall Details: %d\n", rc);
     return 0;

The program compiles properly but gives me -1 error for rc. I have posted the same query and I got replies on it. But even after trying many things, I am still stuck with this problem. Can anyone please tell me what I am doing wrong here. Also please tell me where
should I view the output of printk in xen.

Thanks in advance.

Satyajeet Nimgaonkar
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