unsigned long xc_make_page_below_4G(
xc_interface *xch, uint32_t domid, unsigned long mfn)
{
xen_pfn_t old_mfn = mfn;
xen_pfn_t new_mfn;
if ( xc_domain_decrease_reservation_exact(
xch, domid, 1, 0, &old_mfn) != 0 )
{
DPRINTF("xc_make_page_below_4G decrease failed. mfn=%lx\n",mfn);
return 0;
}
if ( xc_domain_increase_reservation_exact(
xch, domid, 1, 0, XENMEMF_address_bits(32), &new_mfn) != 0 )
{
DPRINTF("xc_make_page_below_4G increase failed. mfn=%lx\n",mfn);
return 0;
}
return new_mfn;
}
void *xc_vm_event_enable(xc_interface *xch, domid_t domain_id, int param,
uint32_t *port)
{
void *ring_page = NULL;
uint64_t pfn;
xen_pfn_t ring_pfn, mmap_pfn;
unsigned int op, mode;
int rc1, rc2, saved_errno;
if ( !port )
{
errno = EINVAL;
return NULL;
}
/* Pause the domain for ring page setup */
rc1 = xc_domain_pause(xch, domain_id);
if ( rc1 != 0 )
{
PERROR("Unable to pause domain\n");
return NULL;
}
/* Get the pfn of the ring page */
rc1 = xc_hvm_param_get(xch, domain_id, param, &pfn);
if ( rc1 != 0 )
{
PERROR("Failed to get pfn of ring page\n");
goto out;
}
ring_pfn = pfn;
mmap_pfn = pfn;
rc1 = xc_get_pfn_type_batch(xch, domain_id, 1, &mmap_pfn);
if ( rc1 || mmap_pfn & XEN_DOMCTL_PFINFO_XTAB )
{
/* Page not in the physmap, try to populate it */
rc1 = xc_domain_populate_physmap_exact(xch, domain_id, 1, 0, 0,
&ring_pfn);
if ( rc1 != 0 )
{
PERROR("Failed to populate ring pfn\n");
goto out;
}
}
mmap_pfn = ring_pfn;
ring_page = xc_map_foreign_pages(xch, domain_id, PROT_READ | PROT_WRITE,
&mmap_pfn, 1);
if ( !ring_page )
{
PERROR("Could not map the ring page\n");
goto out;
}
switch ( param )
{
case HVM_PARAM_PAGING_RING_PFN:
op = XEN_VM_EVENT_ENABLE;
mode = XEN_DOMCTL_VM_EVENT_OP_PAGING;
break;
case HVM_PARAM_MONITOR_RING_PFN:
op = XEN_VM_EVENT_ENABLE;
mode = XEN_DOMCTL_VM_EVENT_OP_MONITOR;
break;
case HVM_PARAM_SHARING_RING_PFN:
op = XEN_VM_EVENT_ENABLE;
mode = XEN_DOMCTL_VM_EVENT_OP_SHARING;
break;
/*
* This is for the outside chance that the HVM_PARAM is valid but is invalid
* as far as vm_event goes.
*/
default:
errno = EINVAL;
rc1 = -1;
goto out;
}
rc1 = xc_vm_event_control(xch, domain_id, op, mode, port);
if ( rc1 != 0 )
{
PERROR("Failed to enable vm_event\n");
goto out;
}
/* Remove the ring_pfn from the guest's physmap */
rc1 = xc_domain_decrease_reservation_exact(xch, domain_id, 1, 0, &ring_pfn);
if ( rc1 != 0 )
PERROR("Failed to remove ring page from guest physmap");
out:
saved_errno = errno;
rc2 = xc_domain_unpause(xch, domain_id);
if ( rc1 != 0 || rc2 != 0 )
{
if ( rc2 != 0 )
{
if ( rc1 == 0 )
saved_errno = errno;
PERROR("Unable to unpause domain");
}
if ( ring_page )
xenforeignmemory_unmap(xch->fmem, ring_page, 1);
ring_page = NULL;
errno = saved_errno;
}
return ring_page;
}
