rt-thread-official/components/vmm/vmm_context.c

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2014-03-29 12:14:24 +08:00
/*
* guest context on VMM
*
* COPYRIGHT (C) 2013-2014, Shanghai Real-Thread Technology Co., Ltd
*
* This file is part of RT-Thread (http://www.rt-thread.org)
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Change Logs:
* Date Author Notes
* 2013-11-04 Grissiom add comment
*/
#include <rthw.h>
#include <rtthread.h>
#include <interrupt.h>
#include <log_trace.h>
#include <vmm.h>
#include "vmm_context.h"
struct rt_vmm_share_layout rt_vmm_share SECTION(".vmm.share");
volatile struct vmm_context *_vmm_context = RT_NULL;
void vmm_context_init(void *context_addr)
{
_vmm_context = (struct vmm_context *)context_addr;
rt_memset((void *)_vmm_context, 0x00, sizeof(struct vmm_context));
/* When loading RT-Thread, the IRQ on the guest should be disabled. */
_vmm_context->virq_status = 1;
}
#ifdef RT_VMM_USING_DOMAIN
unsigned long guest_domain_val SECTION(".bss.share");
unsigned long vmm_domain_val SECTION(".bss.share");
/* some RT-Thread code need to be called in the guest
* context(rt_thread_idle_excute for example). To simplify the code, we need a
* "super" domain mode to have access of both side. The code executed in super
* domain mode is restricted and should be harmless. */
unsigned long super_domain_val SECTION(".bss.share");
void vmm_context_init_domain(struct vmm_domain *domain)
{
asm volatile ("mrc p15, 0, %0, c3, c0\n" : "=r" (guest_domain_val));
rt_kprintf("Linux domain: kernel: %d, user: %d, io: %d\n"
"VMM domain: vmm: %d, share: %d\n",
domain->kernel, domain->user, domain->io,
domain->vmm, domain->vmm_share);
if (domain->kernel == domain->vmm ||
domain->io == domain->vmm)
{
rt_kprintf("VMM and the guest share the same domain\n");
super_domain_val = vmm_domain_val = guest_domain_val;
return;
}
vmm_domain_val = guest_domain_val;
/* become client to our own territory */
vmm_domain_val |= (1 << (domain->vmm * 2)) | (1 << (domain->vmm_share * 2));
super_domain_val = vmm_domain_val;
/* super domain has access to both side */
super_domain_val |= (1 << (domain->kernel * 2)) | (1 << (domain->user * 2));
rt_kprintf("Original DAC: 0x%08x\n", guest_domain_val);
}
unsigned long vmm_context_enter_domain(unsigned long domain_val)
{
unsigned long old_domain;
asm volatile ("mrc p15, 0, %0, c3, c0\n" : "=r" (old_domain));
asm volatile ("mcr p15, 0, %0, c3, c0\n" : :"r" (domain_val) : "memory");
return old_domain;
}
void vmm_context_restore_domain(unsigned long domain_val)
{
asm volatile ("mcr p15, 0, %0, c3, c0\n" : :"r" (domain_val) : "memory");
}
#endif
void vmm_virq_pending(int irq)
{
/* when running this piece of code, the guest is already suspended. So it's
* safe to set the bits without locks. */
_vmm_context->virq_pending[irq / 32] |= (1 << (irq % 32));
_vmm_context->virq_pended = 1;
/* mask this IRQ in host */
rt_hw_interrupt_mask(irq);
}
void vmm_virq_update(void)
{
if ((!_vmm_context->virq_status) &&
( _vmm_context->virq_pended))
{
rt_hw_interrupt_trigger(RT_VMM_VIRQ_TRIGGER);
}
}
/** check the guest IRQ status
*
* @return 0 on guest should handle IRQ, -1 on should restore the guest context
* normally.
*/
int vmm_virq_check(void)
{
if ((!_vmm_context->virq_status) &&
( _vmm_context->virq_pended))
{
return 0;
}
return -1;
}
/* 10 = len("%08x, ") */
static char _vmbuf[10*ARRAY_SIZE(_vmm_context->virq_pending)];
void vmm_dump_virq(void)
{
int i, s;
vmm_info("---- virtual IRQ ----\n");
vmm_info(" status: %08x, pended: %08x, pending:\n",
_vmm_context->virq_status, _vmm_context->virq_pended);
for (s = 0, i = 0; i < ARRAY_SIZE(_vmm_context->virq_pending); i++)
{
s += rt_snprintf(_vmbuf+s, sizeof(_vmbuf)-s,
"%08x, ", _vmm_context->virq_pending[i]);
}
vmm_info("%.*s\n", sizeof(_vmbuf), _vmbuf);
vmm_info("---- virtual IRQ ----\n");
}
int vmm_virq_coherence_ok(void)
{
int i, res;
int should_pend = 0;
for (i = 0; i < ARRAY_SIZE(_vmm_context->virq_pending); i++)
{
should_pend |= _vmm_context->virq_pending[i];
}
res = (_vmm_context->virq_pended == !!should_pend);
if (!res)
{
vmm_info("--- %x %x, %x\n",
_vmm_context->virq_pended, should_pend, !!should_pend);
}
return res;
}
extern struct rt_thread vmm_thread;
void vmm_show_guest_reg(void)
{
struct rt_hw_stack *sp = vmm_thread.sp;
#ifdef RT_VMM_USING_DOMAIN
unsigned long old_domain;
old_domain = vmm_context_enter_domain(super_domain_val);
#endif
vmm_info("CPSR: %08x, PC: %08x, LR: %08x, SP: %08x\n",
sp->cpsr, sp->pc, sp->lr, sp+1);
#ifdef RT_VMM_USING_DOMAIN
vmm_context_restore_domain(old_domain);
#endif
}
void vmm_dump_domain(void)
{
unsigned long dac;
asm volatile ("mrc p15, 0, %0, c3, c0\n" : "=r" (dac));
vmm_info("current DAC: %08x\n", dac);
#ifdef RT_VMM_USING_DOMAIN
vmm_info("guest DAC: %08x, RTT DAC: %08x, super DAC: %08x\n",
guest_domain_val, vmm_domain_val, super_domain_val);
#endif
}
void vmm_show_guest(void)
{
vmm_show_guest_reg();
vmm_dump_virq();
vmm_dump_domain();
}
#ifdef RT_USING_FINSH
#include <finsh.h>
FINSH_FUNCTION_EXPORT_ALIAS(vmm_show_guest, vmm, show vmm status);
#endif
static int _bad_cpsr(unsigned long cpsr)
{
int bad = 1;
switch (cpsr & MODEMASK)
{
case USERMODE:
case FIQMODE:
case IRQMODE:
case SVCMODE:
#ifdef CPU_HAS_MONITOR_MODE
case MONITORMODE:
#endif
case ABORTMODE:
#ifdef CPU_HAS_HYP_MODE
case HYPMODE:
#endif
case UNDEFMODE:
case MODEMASK:
bad = 0;
break;
};
return bad;
}
void vmm_verify_guest_status(struct rt_hw_stack *sp)
{
int dump_vmm = 0;
unsigned long cpsr;
#ifdef RT_VMM_USING_DOMAIN
unsigned long old_domain;
old_domain = vmm_context_enter_domain(super_domain_val);
#endif
cpsr = sp->cpsr;
if (_bad_cpsr(cpsr))
{
vmm_info("=================================\n");
vmm_info("VMM WARING: bad CPSR in guest\n");
dump_vmm = 1;
}
else
{
if (cpsr & A_Bit && 0)
{
vmm_info("=================================\n");
vmm_info("VMM WARING: A bit is set in guest\n");
dump_vmm = 1;
}
if ((cpsr & I_Bit) && (sp->pc <= VMM_BEGIN))
{
vmm_info("=================================\n");
vmm_info("VMM WARING: IRQ disabled in guest\n");
dump_vmm = 1;
}
if (cpsr & F_Bit)
{
vmm_info("=================================\n");
vmm_info("VMM WARING: FIQ disabled in guest\n");
dump_vmm = 1;
}
if ((cpsr & MODEMASK) == USERMODE)
{
if (_vmm_context->virq_status & 1)
{
vmm_info("=================================\n");
vmm_info("VMM WARING: VIRQ disabled in user mode\n");
dump_vmm = 1;
}
if ((sp->pc > 0xbf000000) && (sp->pc < 0xffff0000))
{
vmm_info("=================================\n");
vmm_info("VMM WARING: executing kernel code in usr mode\n");
dump_vmm = 1;
}
/* FIXME: when the guest is suspended in user mode and its
* interrupts come, this can be misleading. */
#if 0
if (_vmm_context->virq_pended)
{
vmm_info("=================================\n");
vmm_info("VMM WARING: VIRQ pended in user mode\n");
dump_vmm = 1;
}
#endif
}
else if ((cpsr & MODEMASK) == SVCMODE && sp->pc < 0xbf000000)
{
vmm_info("=================================\n");
vmm_info("VMM WARING: executing usr code in svc mode\n");
dump_vmm = 1;
}
}
#if 0
if (!vmm_virq_coherence_ok())
{
vmm_info("=================================\n");
vmm_info("VMM WARING: bad VIRQ status\n");
dump_vmm = 1;
}
#endif
if (dump_vmm)
{
vmm_show_guest();
vmm_info("=================================\n");
}
#ifdef RT_VMM_USING_DOMAIN
vmm_context_restore_domain(old_domain);
#endif
}