libvirt/examples/dominfo/info1.c

/**
 * section: Informations
 * synopsis: Extract information about Xen domain 0
 * purpose: Demonstrate the basic use of the library to connect to the
 *          hypervisor and extract domain information.
 * usage: info1
 * test: info1
 * copy: see Copyright for the status of this software.
 */

#include <stdio.h>
#include <libvirt/libvirt.h>

/**
 * getDomainInfo:
 * @id: the id of the domain
 *
 * extract the domain 0 information
 */
static void
getDomainInfo(int id)
{
    virConnectPtr conn = NULL; /* the hypervisor connection */
    virDomainPtr dom = NULL;   /* the domain being checked */
    virDomainInfo info;        /* the information being fetched */
    int ret;

    /* NULL means connect to local Xen hypervisor */
    conn = virConnectOpenReadOnly(NULL);
    if (conn == NULL) {
        fprintf(stderr, "Failed to connect to hypervisor\n");
        goto error;
    }

    /* Find the domain of the given id */
    dom = virDomainLookupByID(conn, id);
    if (dom == NULL) {
        fprintf(stderr, "Failed to find Domain %d\n", id);
        goto error;
    }

    /* Get the information */
    ret = virDomainGetInfo(dom, &info);
    if (ret < 0) {
        fprintf(stderr, "Failed to get information for Domain %d\n", id);
        goto error;
    }

    printf("Domains %d: %d CPUs\n", id, info.nrVirtCpu);

 error:
    if (dom != NULL)
        virDomainFree(dom);
    if (conn != NULL)
        virConnectClose(conn);
}

int main()
{
    getDomainInfo(0);

    return 0;
}