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/******************************************************************************
* multicall.c
*/
#include <xen/config.h>
#include <xen/types.h>
#include <xen/lib.h>
#include <xen/mm.h>
#include <xen/sched.h>
#include <xen/event.h>
#include <xen/multicall.h>
#include <xen/guest_access.h>
#include <asm/current.h>
#include <asm/hardirq.h>
DEFINE_PER_CPU(struct mc_state, mc_state);
long
do_multicall(
XEN_GUEST_HANDLE(multicall_entry_t) call_list, unsigned int nr_calls)
{
struct mc_state *mcs = &this_cpu(mc_state);
unsigned int i;
if ( unlikely(__test_and_set_bit(_MCSF_in_multicall, &mcs->flags)) )
{
gdprintk(XENLOG_INFO, "Multicall reentry is disallowed.\n");
return -EINVAL;
}
if ( unlikely(!guest_handle_okay(call_list, nr_calls)) )
goto fault;
for ( i = 0; i < nr_calls; i++ )
{
if ( hypercall_preempt_check() )
goto preempted;
if ( unlikely(__copy_from_guest(&mcs->call, call_list, 1)) )
goto fault;
do_multicall_call(&mcs->call);
#ifndef NDEBUG
{
/*
* Deliberately corrupt the contents of the multicall structure.
* The caller must depend only on the 'result' field on return.
*/
struct multicall_entry corrupt;
memset(&corrupt, 0xAA, sizeof(corrupt));
(void)__copy_to_guest(call_list, &corrupt, 1);
}
#endif
if ( unlikely(__copy_field_to_guest(call_list, &mcs->call, result)) )
goto fault;
if ( test_bit(_MCSF_call_preempted, &mcs->flags) )
{
/* Copy the sub-call continuation. */
(void)__copy_to_guest(call_list, &mcs->call, 1);
goto preempted;
}
guest_handle_add_offset(call_list, 1);
}
mcs->flags = 0;
return 0;
fault:
mcs->flags = 0;
return -EFAULT;
preempted:
mcs->flags = 0;
return hypercall_create_continuation(
__HYPERVISOR_multicall, "hi", call_list, nr_calls-i);
}
/*
* Local variables:
* mode: C
* c-set-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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