sys/kern/sys_vmm.c

   1 /*
   2  * Copyright (c) 2003-2013 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Mihai Carabas <mihai.carabas@gmail.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/systm.h>
  37 #include <sys/sysproto.h>
  38 #include <sys/proc.h>
  39 #include <sys/user.h>
  40 #include <sys/wait.h>
  41 #include <sys/vmm.h>
  42
  43 #include <sys/thread2.h>
  44 #include <sys/spinlock2.h>
  45
  46 #include <machine/cpu.h>
  47 #include <machine/vmm.h>
  48
  49 /*
  50  * vmm guest system call:
  51  * - init the calling thread structure
  52  * - prepare for running in non-root mode
  53  */
  54 int
  55 sys_vmm_guest_ctl(struct vmm_guest_ctl_args *uap)
  56 {
  57         int error = 0;
  58         struct vmm_guest_options options;
  59         struct trapframe *tf = uap->sysmsg_frame;
  60         unsigned long stack_limit = USRSTACK;
  61         unsigned char stack_page[PAGE_SIZE];
  62
  63         clear_quickret();
  64
  65         switch (uap->op) {
  66                 case VMM_GUEST_RUN:
  67                         error = copyin(uap->options, &options, sizeof(struct vmm_guest_options));
  68                         if (error) {
  69                                 kprintf("sys_vmm_guest: error copyin vmm_guest_options\n");
  70                                 goto out;
  71                         }
  72
  73                         while(stack_limit > tf->tf_sp) {
  74                                 stack_limit -= PAGE_SIZE;
  75                                 options.new_stack -= PAGE_SIZE;
  76
  77                                 error = copyin((const void *)stack_limit, (void *)stack_page, PAGE_SIZE);
  78                                 if (error) {
  79                                         kprintf("sys_vmm_guest: error copyin stack\n");
  80                                         goto out;
  81                                 }
  82
  83                                 error = copyout((const void *)stack_page, (void *)options.new_stack, PAGE_SIZE);
  84                                 if (error) {
  85                                         kprintf("sys_vmm_guest: error copyout stack\n");
  86                                         goto out;
  87                                 }
  88                         }
  89
  90                         bcopy(tf, &options.tf, sizeof(struct trapframe));
  91
  92                         error = vmm_vminit(&options);
  93                         if (error) {
  94                                 if (error == ENODEV) {
  95                                         kprintf("sys_vmm_guest: vmm_vminit failed -"
  96                                             "no VMM available \n");
  97                                         goto out;
  98                                 } else {
  99                                         kprintf("sys_vmm_guest: vmm_vminit failed\n");
 100                                         goto out_exit;
 101                                 }
 102                         }
 103
 104                         generic_lwp_return(curthread->td_lwp, tf);
 105
 106                         error = vmm_vmrun();
 107
 108                         break;
 109                 default:
 110                         kprintf("sys_vmm_guest: INVALID op\n");
 111                         error = EINVAL;
 112                         goto out;
 113         }
 114 out_exit:
 115         exit1(W_EXITCODE(error, 0));
 116 out:
 117         return (error);
 118 }
 119
 120 static
 121 void
 122 vmm_exit_vmm(void *dummy __unused)
 123 {
 124 }
 125
 126 int
 127 sys_vmm_guest_sync_addr(struct vmm_guest_sync_addr_args *uap)
 128 {
 129         int error = 0;
 130         cpulock_t olock;
 131         cpulock_t nlock;
 132         cpumask_t mask;
 133         long val;
 134         struct proc *p = curproc;
 135
 136         if (p->p_vmm == NULL)
 137                 return ENOSYS;
 138
 139         crit_enter_id("vmm_inval");
 140
 141         /*
 142          * Acquire CPULOCK_EXCL, spin while we wait.
 143          */
 144         KKASSERT(CPUMASK_TESTMASK(p->p_vmm_cpumask, mycpu->gd_cpumask) == 0);
 145         for (;;) {
 146                 olock = p->p_vmm_cpulock & ~CPULOCK_EXCL;
 147                 cpu_ccfence();
 148                 nlock = olock | CPULOCK_EXCL;
 149                 if (atomic_cmpset_int(&p->p_vmm_cpulock, olock, nlock))
 150                         break;
 151                 lwkt_process_ipiq();
 152                 cpu_pause();
 153         }
 154
 155         /*
 156          * Wait for other cpu's to exit VMM mode (for this vkernel).  No
 157          * new cpus will enter VMM mode while we hold the lock.  New waiters
 158          * may turn-up though so the wakeup() later on has to be
 159          * unconditional.
 160          *
 161          * We must test on p_vmm_cpulock's counter, not the mask, because
 162          * VMM entries will set the mask bit unconditionally first
 163          * (interlocking our IPI below) and then conditionally bump the
 164          * counter.
 165          */
 166         if (olock & CPULOCK_CNTMASK) {
 167                 mask = p->p_vmm_cpumask;
 168                 CPUMASK_ANDMASK(mask, mycpu->gd_other_cpus);
 169                 lwkt_send_ipiq_mask(mask, vmm_exit_vmm, NULL);
 170                 while (p->p_vmm_cpulock & CPULOCK_CNTMASK) {
 171                         lwkt_process_ipiq();
 172                         cpu_pause();
 173                 }
 174         }
 175
 176         /*
 177          * Make the requested modification, wakeup any waiters.
 178          */
 179         copyin(uap->srcaddr, &val, sizeof(long));
 180         copyout(&val, uap->dstaddr, sizeof(long));
 181
 182         atomic_clear_int(&p->p_vmm_cpulock, CPULOCK_EXCL);
 183         wakeup(&p->p_vmm_cpulock);
 184
 185         crit_exit_id("vmm_inval");
 186
 187         return error;
 188 }