kernel/system/do_vmctl.c

   1 /* The kernel call implemented in this file:
   2  *   m_type:    SYS_VMCTL
   3  *
   4  * The parameters for this kernel call are:
   5  *      SVMCTL_WHO      which process
   6  *      SVMCTL_PARAM    set this setting (VMCTL_*)
   7  *      SVMCTL_VALUE    to this value
   8  */
   9
  10 #include "../system.h"
  11 #include "../vm.h"
  12 #include "../debug.h"
  13 #include <minix/type.h>
  14 #include <minix/config.h>
  15
  16 /*===========================================================================*
  17  *                              do_vmctl                                     *
  18  *===========================================================================*/
  19 PUBLIC int do_vmctl(m_ptr)
  20 register message *m_ptr;        /* pointer to request message */
  21 {
  22   int proc_nr, i;
  23   endpoint_t ep = m_ptr->SVMCTL_WHO;
  24   struct proc *p, *rp;
  25
  26   if(ep == SELF) { ep = m_ptr->m_source; }
  27
  28   vm_init();
  29
  30   if(!isokendpt(ep, &proc_nr)) {
  31         kprintf("do_vmctl: unexpected endpoint %d from VM\n", ep);
  32         return EINVAL;
  33   }
  34
  35   p = proc_addr(proc_nr);
  36
  37   switch(m_ptr->SVMCTL_PARAM) {
  38         case VMCTL_CLEAR_PAGEFAULT:
  39                 RTS_LOCK_UNSET(p, PAGEFAULT);
  40                 return OK;
  41         case VMCTL_MEMREQ_GET:
  42                 /* Send VM the information about the memory request.  */
  43                 if(!(rp = vmrequest))
  44                         return ESRCH;
  45                 if(!RTS_ISSET(rp, VMREQUEST))
  46                         minix_panic("do_vmctl: no VMREQUEST set", NO_NUM);
  47
  48                 /* Reply with request fields. */
  49                 m_ptr->SVMCTL_MRG_ADDR = (char *) rp->p_vmrequest.start;
  50                 m_ptr->SVMCTL_MRG_LEN = rp->p_vmrequest.length;
  51                 m_ptr->SVMCTL_MRG_WRITE = rp->p_vmrequest.writeflag;
  52                 m_ptr->SVMCTL_MRG_EP = rp->p_vmrequest.who;
  53                 rp->p_vmrequest.vmresult = VMSUSPEND;
  54
  55                 /* Remove from request chain. */
  56                 vmrequest = vmrequest->p_vmrequest.nextrequestor;
  57
  58                 return OK;
  59         case VMCTL_MEMREQ_REPLY:
  60                 if(!(rp = p->p_vmrequest.requestor))
  61                         minix_panic("do_vmctl: no requestor set", ep);
  62                 p->p_vmrequest.requestor = NULL;
  63                 if(!RTS_ISSET(rp, VMREQUEST))
  64                         minix_panic("do_vmctl: no VMREQUEST set", ep);
  65                 if(rp->p_vmrequest.vmresult != VMSUSPEND)
  66                         minix_panic("do_vmctl: result not VMSUSPEND set",
  67                                 rp->p_vmrequest.vmresult);
  68                 rp->p_vmrequest.vmresult = m_ptr->SVMCTL_VALUE;
  69                 if(rp->p_vmrequest.vmresult == VMSUSPEND)
  70                         minix_panic("VM returned VMSUSPEND?", NO_NUM);
  71                 if(rp->p_vmrequest.vmresult != OK)
  72                         kprintf("SYSTEM: VM replied %d to mem request\n",
  73                                 rp->p_vmrequest.vmresult);
  74
  75                 /* Put on restart chain. */
  76                 rp->p_vmrequest.nextrestart = vmrestart;
  77                 vmrestart = rp;
  78
  79 #if DEBUG_VMASSERT
  80                 /* Sanity check. */
  81                 if(rp->p_vmrequest.vmresult == OK) {
  82                         if(CHECKRANGE(p,
  83                                 rp->p_vmrequest.start,
  84                                 rp->p_vmrequest.length,
  85                                 rp->p_vmrequest.writeflag) != OK) {
  86 kprintf("SYSTEM: request %d:0x%lx-0x%lx, wrflag %d, failed\n",
  87         rp->p_endpoint,
  88         rp->p_vmrequest.start,  rp->p_vmrequest.start + rp->p_vmrequest.length,
  89         rp->p_vmrequest.writeflag);
  90
  91                                 minix_panic("SYSTEM: fail but VM said OK", NO_NUM);
  92                         }
  93                 }
  94 #endif
  95                 return OK;
  96 #if VM_KERN_NOPAGEZERO
  97         case VMCTL_NOPAGEZERO:
  98                 return OK;
  99 #endif
 100   }
 101
 102   /* Try architecture-specific vmctls. */
 103   return arch_do_vmctl(m_ptr, p);
 104 }