From d001bd8483c805c45a42d9bd0468a96722e72875 Mon Sep 17 00:00:00 2001
From: Grissiom <chaos.proton@gmail.com>
Date: Thu, 1 Aug 2013 14:59:56 +0800
Subject: [PATCH 1/2] RTT-VMM: implement dual system running on realview-pb-a8

Signed-off-by: Grissiom <chaos.proton@gmail.com>
Signed-off-by: Bernard.Xiong <bernard.xiong@gmail.com>
---
 arch/arm/Kconfig                   |   1 +
 arch/arm/Makefile                  |   1 +
 arch/arm/common/gic.c              |  67 +++++++++++++-
 arch/arm/include/asm/assembler.h   |   8 +-
 arch/arm/include/asm/domain.h      |   7 ++
 arch/arm/include/asm/irqflags.h    |  84 ++++++++++++-----
 arch/arm/include/asm/mach/map.h    |   5 +
 arch/arm/include/vmm/vmm.h         |  35 +++++++
 arch/arm/include/vmm/vmm_config.h  |   7 ++
 arch/arm/kernel/entry-armv.S       |  30 +++++-
 arch/arm/kernel/entry-common.S     |   3 +
 arch/arm/kernel/entry-header.S     |  15 ++-
 arch/arm/mach-omap2/irq.c          |  12 +++
 arch/arm/mm/fault.c                |   9 ++
 arch/arm/mm/init.c                 |   8 ++
 arch/arm/mm/mmu.c                  |  44 +++++++++
 arch/arm/vmm/Kconfig               |  49 ++++++++++
 arch/arm/vmm/Makefile              |  10 ++
 arch/arm/vmm/README                |   1 +
 arch/arm/vmm/am33xx/intc.h         |  13 +++
 arch/arm/vmm/am33xx/softirq.c      |  14 +++
 arch/arm/vmm/am33xx/virq.c         |  48 ++++++++++
 arch/arm/vmm/realview_a8/softirq.c |  12 +++
 arch/arm/vmm/vmm.c                 |  32 +++++++
 arch/arm/vmm/vmm_traps.c           |  37 ++++++++
 arch/arm/vmm/vmm_virhw.h           |  59 ++++++++++++
 arch/arm/vmm/vmm_virq.c            | 183 +++++++++++++++++++++++++++++++++++++
 27 files changed, 767 insertions(+), 27 deletions(-)
 create mode 100644 arch/arm/include/vmm/vmm.h
 create mode 100644 arch/arm/include/vmm/vmm_config.h
 create mode 100644 arch/arm/vmm/Kconfig
 create mode 100644 arch/arm/vmm/Makefile
 create mode 100644 arch/arm/vmm/README
 create mode 100644 arch/arm/vmm/am33xx/intc.h
 create mode 100644 arch/arm/vmm/am33xx/softirq.c
 create mode 100644 arch/arm/vmm/am33xx/virq.c
 create mode 100644 arch/arm/vmm/realview_a8/softirq.c
 create mode 100644 arch/arm/vmm/vmm.c
 create mode 100644 arch/arm/vmm/vmm_traps.c
 create mode 100644 arch/arm/vmm/vmm_virhw.h
 create mode 100644 arch/arm/vmm/vmm_virq.c

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 67874b8..eb82cd6 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1164,6 +1164,7 @@ config ARM_TIMER_SP804
 	select HAVE_SCHED_CLOCK
 
 source arch/arm/mm/Kconfig
+source arch/arm/vmm/Kconfig
 
 config ARM_NR_BANKS
 	int
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 30c443c..262c8e2 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -252,6 +252,7 @@ core-$(CONFIG_FPE_NWFPE)	+= arch/arm/nwfpe/
 core-$(CONFIG_FPE_FASTFPE)	+= $(FASTFPE_OBJ)
 core-$(CONFIG_VFP)		+= arch/arm/vfp/
 core-$(CONFIG_XEN)		+= arch/arm/xen/
+core-$(CONFIG_ARM_VMM)		+= arch/arm/vmm/
 
 # If we have a machine-specific directory, then include it in the build.
 core-y				+= arch/arm/kernel/ arch/arm/mm/ arch/arm/common/
diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
index 87dfa90..a9d7357 100644
--- a/arch/arm/common/gic.c
+++ b/arch/arm/common/gic.c
@@ -45,6 +45,11 @@
 #include <asm/mach/irq.h>
 #include <asm/hardware/gic.h>
 
+#ifdef CONFIG_ARM_VMM
+#include <vmm/vmm.h>
+#include "../vmm/vmm_virhw.h"
+#endif
+
 union gic_base {
 	void __iomem *common_base;
 	void __percpu __iomem **percpu_base;
@@ -276,12 +281,72 @@ static int gic_set_wake(struct irq_data *d, unsigned int on)
 #define gic_set_wake	NULL
 #endif
 
+#ifdef CONFIG_ARM_VMM
+void vmm_irq_handle(struct gic_chip_data *gic, struct pt_regs *regs)
+{
+	unsigned long flags;
+	struct vmm_context* _vmm_context;
+
+	_vmm_context = vmm_context_get();
+
+	while (_vmm_context->virq_pended) {
+		int index;
+
+		flags = vmm_irq_save();
+		_vmm_context->virq_pended = 0;
+		vmm_irq_restore(flags);
+
+		/* get the pending interrupt */
+		for (index = 0; index < IRQS_NR_32; index++) {
+			int pdbit;
+
+			for (pdbit = __builtin_ffs(_vmm_context->virq_pending[index]);
+			     pdbit != 0;
+			     pdbit = __builtin_ffs(_vmm_context->virq_pending[index])) {
+				unsigned long inner_flag;
+				int irqnr, oirqnr;
+
+				pdbit--;
+
+				inner_flag = vmm_irq_save();
+				_vmm_context->virq_pending[index] &= ~(1 << pdbit);
+				vmm_irq_restore(inner_flag);
+
+				oirqnr = pdbit + index * 32;
+				if (likely(oirqnr > 15 && oirqnr < 1021)) {
+					irqnr = irq_find_mapping(gic->domain, oirqnr);
+					handle_IRQ(irqnr, regs);
+				} else if (oirqnr < 16) {
+					/* soft IRQs are EOIed by the host. */
+#ifdef CONFIG_SMP
+					handle_IPI(oirqnr, regs);
+#endif
+				}
+				/* umask interrupt */
+				/* FIXME: maybe we don't need this */
+				writel_relaxed(1 << (oirqnr % 32),
+					       gic_data_dist_base(gic)
+					       + GIC_DIST_ENABLE_SET
+					       + (oirqnr / 32) * 4);
+
+			}
+		}
+	}
+}
+#endif
+
 asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs)
 {
 	u32 irqstat, irqnr;
 	struct gic_chip_data *gic = &gic_data[0];
 	void __iomem *cpu_base = gic_data_cpu_base(gic);
 
+#ifdef CONFIG_ARM_VMM
+	if (vmm_get_status()) {
+		vmm_irq_handle(gic, regs);
+		return;
+	}
+#endif
 	do {
 		irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK);
 		irqnr = irqstat & ~0x1c00;
@@ -777,7 +842,7 @@ void __cpuinit gic_secondary_init(unsigned int gic_nr)
 	gic_cpu_init(&gic_data[gic_nr]);
 }
 
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) || defined(CONFIG_ARM_VMM)
 void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
 {
 	int cpu;
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index eb87200..b646fa7 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -82,11 +82,15 @@
  */
 #if __LINUX_ARM_ARCH__ >= 6
 	.macro	disable_irq_notrace
-	cpsid	i
+	stmdb   sp!, {r0-r3, ip, lr}
+	bl	irq_disable_asm
+	ldmia	sp!, {r0-r3, ip, lr}
 	.endm
 
 	.macro	enable_irq_notrace
-	cpsie	i
+	stmdb   sp!, {r0-r3, ip, lr}
+	bl	irq_enable_asm
+	ldmia	sp!, {r0-r3, ip, lr}
 	.endm
 #else
 	.macro	disable_irq_notrace
diff --git a/arch/arm/include/asm/domain.h b/arch/arm/include/asm/domain.h
index 6ddbe44..bbc4470 100644
--- a/arch/arm/include/asm/domain.h
+++ b/arch/arm/include/asm/domain.h
@@ -44,6 +44,13 @@
 #define DOMAIN_IO	0
 #endif
 
+#ifdef CONFIG_ARM_VMM
+/* RT-Thread VMM memory space */
+#define DOMAIN_RTVMM      3
+/* shared memory with VMM and Linux */
+#define DOMAIN_RTVMM_SHR  4
+#endif
+
 /*
  * Domain types
  */
diff --git a/arch/arm/include/asm/irqflags.h b/arch/arm/include/asm/irqflags.h
index 1e6cca5..bfaedff 100644
--- a/arch/arm/include/asm/irqflags.h
+++ b/arch/arm/include/asm/irqflags.h
@@ -9,34 +9,56 @@
  * CPU interrupt mask handling.
  */
 #if __LINUX_ARM_ARCH__ >= 6
+#include <vmm/vmm.h> /* VMM only support ARMv7 right now */
 
 static inline unsigned long arch_local_irq_save(void)
 {
 	unsigned long flags;
 
-	asm volatile(
-		"	mrs	%0, cpsr	@ arch_local_irq_save\n"
-		"	cpsid	i"
-		: "=r" (flags) : : "memory", "cc");
+	if (vmm_status)
+	{
+		flags = vmm_save_virq();
+	}
+	else
+	{
+		asm volatile(
+			"	mrs	%0, cpsr	@ arch_local_irq_save\n"
+			"	cpsid	i"
+			: "=r" (flags) : : "memory", "cc");
+	}
 	return flags;
 }
 
 static inline void arch_local_irq_enable(void)
 {
-	asm volatile(
-		"	cpsie i			@ arch_local_irq_enable"
-		:
-		:
-		: "memory", "cc");
+	if (vmm_status)
+	{
+		vmm_enable_virq();
+	}
+	else
+	{
+		asm volatile(
+			"	cpsie i			@ arch_local_irq_enable"
+			:
+			:
+			: "memory", "cc");
+	}
 }
 
 static inline void arch_local_irq_disable(void)
 {
-	asm volatile(
-		"	cpsid i			@ arch_local_irq_disable"
-		:
-		:
-		: "memory", "cc");
+	if (vmm_status)
+	{
+		vmm_disable_virq();
+	}
+	else
+	{
+		asm volatile(
+			"	cpsid i			@ arch_local_irq_disable"
+			:
+			:
+			: "memory", "cc");
+	}
 }
 
 #define local_fiq_enable()  __asm__("cpsie f	@ __stf" : : : "memory", "cc")
@@ -128,9 +150,17 @@ static inline void arch_local_irq_disable(void)
 static inline unsigned long arch_local_save_flags(void)
 {
 	unsigned long flags;
-	asm volatile(
-		"	mrs	%0, cpsr	@ local_save_flags"
-		: "=r" (flags) : : "memory", "cc");
+
+	if (vmm_status)
+	{
+		flags = vmm_return_virq();
+	}
+	else
+	{
+		asm volatile(
+			"	mrs	%0, cpsr	@ local_save_flags"
+			: "=r" (flags) : : "memory", "cc");
+	}
 	return flags;
 }
 
@@ -139,15 +169,25 @@ static inline unsigned long arch_local_save_flags(void)
  */
 static inline void arch_local_irq_restore(unsigned long flags)
 {
-	asm volatile(
-		"	msr	cpsr_c, %0	@ local_irq_restore"
-		:
-		: "r" (flags)
-		: "memory", "cc");
+	if (vmm_status)
+	{
+		vmm_restore_virq(flags);
+	}
+	else
+	{
+		asm volatile(
+			"	msr	cpsr_c, %0	@ local_irq_restore"
+			:
+			: "r" (flags)
+			: "memory", "cc");
+	}
 }
 
 static inline int arch_irqs_disabled_flags(unsigned long flags)
 {
+	if (vmm_status)
+		return (flags == 0x01);
+
 	return flags & PSR_I_BIT;
 }
 
diff --git a/arch/arm/include/asm/mach/map.h b/arch/arm/include/asm/mach/map.h
index 2fe141f..502b341 100644
--- a/arch/arm/include/asm/mach/map.h
+++ b/arch/arm/include/asm/mach/map.h
@@ -35,6 +35,11 @@ struct map_desc {
 #define MT_MEMORY_SO		14
 #define MT_MEMORY_DMA_READY	15
 
+#ifdef CONFIG_ARM_VMM
+#define MT_RTVMM                16
+#define MT_RTVMM_SHARE          17
+#endif
+
 #ifdef CONFIG_MMU
 extern void iotable_init(struct map_desc *, int);
 extern void vm_reserve_area_early(unsigned long addr, unsigned long size,
diff --git a/arch/arm/include/vmm/vmm.h b/arch/arm/include/vmm/vmm.h
new file mode 100644
index 0000000..3ff3f31
--- /dev/null
+++ b/arch/arm/include/vmm/vmm.h
@@ -0,0 +1,35 @@
+#ifndef __LINUX_VMM_H__
+#define __LINUX_VMM_H__
+
+#include <linux/compiler.h>
+
+#include "vmm_config.h"
+
+struct irq_domain;
+struct pt_regs;
+
+extern int vmm_status;
+extern struct vmm_context *_vmm_context;
+
+/* VMM context routines */
+void vmm_context_init(void* context);
+struct vmm_context* vmm_context_get(void);
+
+void vmm_set_status(int status);
+int vmm_get_status(void);
+
+void vmm_mem_init(void);
+void vmm_raise_softirq(int irq);
+
+/* VMM vIRQ routines */
+unsigned long vmm_save_virq(void);
+unsigned long vmm_return_virq(void);
+
+void vmm_restore_virq(unsigned long flags);
+void vmm_enable_virq(void);
+void vmm_disable_virq(void);
+void vmm_enter_hw_noirq(void);
+
+void vmm_raise_softirq(int irq);
+
+#endif
diff --git a/arch/arm/include/vmm/vmm_config.h b/arch/arm/include/vmm/vmm_config.h
new file mode 100644
index 0000000..cce5e8a
--- /dev/null
+++ b/arch/arm/include/vmm/vmm_config.h
@@ -0,0 +1,7 @@
+#ifndef __LINUX_VMM_CONFIG_H__
+#define __LINUX_VMM_CONFIG_H__
+
+#define HOST_VMM_ADDR_END 		CONFIG_HOST_VMM_ADDR_END
+#define HOST_VMM_ADDR_BEGIN 	(CONFIG_HOST_VMM_ADDR_END - CONFIG_HOST_VMM_SIZE)
+
+#endif
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 0f82098..80f1681 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -182,6 +182,15 @@ ENDPROC(__und_invalid)
 	@
 	stmia	r7, {r2 - r6}
 
+	stmdb   sp!, {r0-r3, ip, lr}
+	mov     r0, r5
+	add     r1, sp, #4*6
+	bl      vmm_save_virq_spsr_asm
+	mov     r5, r0
+	bl      vmm_switch_nohwirq_to_novirq
+	ldmia   sp!, {r0-r3, ip, lr}
+	str     r5, [sp, #S_PSR]              @ fix the pushed SPSR
+
 #ifdef CONFIG_TRACE_IRQFLAGS
 	bl	trace_hardirqs_off
 #endif
@@ -208,6 +217,23 @@ __dabt_svc:
  UNWIND(.fnend		)
 ENDPROC(__dabt_svc)
 
+	.macro	svc_exit_irq, rpsr
+	cpsid   i
+	msr	spsr_cxsf, \rpsr
+	mov     r0, \rpsr
+	bl      vmm_on_svc_exit_irq
+#if defined(CONFIG_CPU_V6)
+	ldr	r0, [sp]
+	strex	r1, r2, [sp]			@ clear the exclusive monitor
+	ldmib	sp, {r1 - pc}^			@ load r1 - pc, cpsr
+#elif defined(CONFIG_CPU_32v6K)
+	clrex					@ clear the exclusive monitor
+	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr
+#else
+	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr
+#endif
+	.endm
+
 	.align	5
 __irq_svc:
 	svc_entry
@@ -228,7 +254,7 @@ __irq_svc:
 	@ the first place, so there's no point checking the PSR I bit.
 	bl	trace_hardirqs_on
 #endif
-	svc_exit r5				@ return from exception
+	svc_exit_irq r5				@ return from exception
  UNWIND(.fnend		)
 ENDPROC(__irq_svc)
 
@@ -393,6 +419,8 @@ ENDPROC(__pabt_svc)
 	@
 	zero_fp
 
+	bl      vmm_switch_nohwirq_to_novirq
+
 #ifdef CONFIG_IRQSOFF_TRACER
 	bl	trace_hardirqs_off
 #endif
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index a6c301e..325a26e 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -349,6 +349,9 @@ ENTRY(vector_swi)
 	str	lr, [sp, #S_PC]			@ Save calling PC
 	str	r8, [sp, #S_PSR]		@ Save CPSR
 	str	r0, [sp, #S_OLD_R0]		@ Save OLD_R0
+	stmdb   sp!, {r0-r3, ip, lr}
+	bl	vmm_switch_nohwirq_to_novirq
+	ldmia	sp!, {r0-r3, ip, lr}
 	zero_fp
 
 	/*
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 9a8531e..9e438dc 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -75,7 +75,11 @@
 
 #ifndef CONFIG_THUMB2_KERNEL
 	.macro	svc_exit, rpsr
-	msr	spsr_cxsf, \rpsr
+	cpsid   i
+	mov     r0, \rpsr
+	bl      vmm_restore_virq_asm            @ restore the IRQ to emulate
+	                                        @ the behavior of ldmia {}^
+	msr	spsr_cxsf, r0
 #if defined(CONFIG_CPU_V6)
 	ldr	r0, [sp]
 	strex	r1, r2, [sp]			@ clear the exclusive monitor
@@ -90,6 +94,10 @@
 
 	.macro	restore_user_regs, fast = 0, offset = 0
 	ldr	r1, [sp, #\offset + S_PSR]	@ get calling cpsr
+	@ protect the spsr *and* stack we push the registers into this stack
+	@ and if the sp is not point to the bottom of the stack, IRQ should be
+	@ disabled.
+	cpsid   i
 	ldr	lr, [sp, #\offset + S_PC]!	@ get pc
 	msr	spsr_cxsf, r1			@ save in spsr_svc
 #if defined(CONFIG_CPU_V6)
@@ -105,6 +113,11 @@
 	mov	r0, r0				@ ARMv5T and earlier require a nop
 						@ after ldm {}^
 	add	sp, sp, #S_FRAME_SIZE - S_PC
+	@ TODO: in some conditions the call to vmm_on_ret_to_usr is useless.
+	stmdb   sp!, {r0-r3, ip, lr}
+	mrs     r0, spsr                        @ debug code
+	bl      vmm_on_ret_to_usr
+	ldmia	sp!, {r0-r3, ip, lr}
 	movs	pc, lr				@ return & move spsr_svc into cpsr
 	.endm
 
diff --git a/arch/arm/mach-omap2/irq.c b/arch/arm/mach-omap2/irq.c
index 3926f37..252577f 100644
--- a/arch/arm/mach-omap2/irq.c
+++ b/arch/arm/mach-omap2/irq.c
@@ -23,6 +23,10 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 
+#ifdef CONFIG_ARM_VMM
+#include <vmm/vmm.h>
+#endif
+
 #include "soc.h"
 #include "iomap.h"
 #include "common.h"
@@ -223,6 +227,14 @@ static inline void omap_intc_handle_irq(void __iomem *base_addr, struct pt_regs
 {
 	u32 irqnr;
 
+#ifdef CONFIG_ARM_VMM
+	if (vmm_get_status())
+	{
+		vmm_irq_handle(base_addr, domain, regs);
+		return;
+	}
+#endif
+
 	do {
 		irqnr = readl_relaxed(base_addr + 0x98);
 		if (irqnr)
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 5dbf13f..e76ba74 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -255,6 +255,10 @@ out:
 	return fault;
 }
 
+#ifdef CONFIG_ARM_VMM
+#include <vmm/vmm.h>
+#endif
+
 static int __kprobes
 do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 {
@@ -268,6 +272,11 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	if (notify_page_fault(regs, fsr))
 		return 0;
 
+#ifdef CONFIG_ARM_VMMX
+	WARN(HOST_VMM_ADDR_BEGIN < regs->ARM_pc &&
+	       regs->ARM_pc < HOST_VMM_ADDR_END);
+#endif
+
 	tsk = current;
 	mm  = tsk->mm;
 
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index ad722f1..ebb4e7f 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -34,6 +34,10 @@
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
 
+#ifdef CONFIG_ARM_VMM
+#include <vmm/vmm.h>
+#endif
+
 #include "mm.h"
 
 static unsigned long phys_initrd_start __initdata = 0;
@@ -338,6 +342,10 @@ void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc)
 	for (i = 0; i < mi->nr_banks; i++)
 		memblock_add(mi->bank[i].start, mi->bank[i].size);
 
+#ifdef CONFIG_ARM_VMM
+	memblock_reserve(__pa(HOST_VMM_ADDR_BEGIN), HOST_VMM_ADDR_END - HOST_VMM_ADDR_BEGIN);
+#endif
+
 	/* Register the kernel text, kernel data and initrd with memblock. */
 #ifdef CONFIG_XIP_KERNEL
 	memblock_reserve(__pa(_sdata), _end - _sdata);
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index ce328c7..7e7d0ca 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -294,6 +294,20 @@ static struct mem_type mem_types[] = {
 		.prot_l1   = PMD_TYPE_TABLE,
 		.domain    = DOMAIN_KERNEL,
 	},
+#ifdef CONFIG_ARM_VMM
+	[MT_RTVMM] = {
+		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
+		.prot_l1   = PMD_TYPE_TABLE,
+		.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
+		.domain    = DOMAIN_RTVMM,
+	},
+	[MT_RTVMM_SHARE] = {
+		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
+		.prot_l1   = PMD_TYPE_TABLE,
+		.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
+		.domain    = DOMAIN_RTVMM_SHR,
+	},
+#endif
 };
 
 const struct mem_type *get_mem_type(unsigned int type)
@@ -450,6 +464,9 @@ static void __init build_mem_type_table(void)
 			mem_types[MT_DEVICE_CACHED].prot_pte |= L_PTE_SHARED;
 			mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
 			mem_types[MT_MEMORY].prot_pte |= L_PTE_SHARED;
+#ifdef CONFIG_ARM_VMM
+			/* FIXME */
+#endif
 			mem_types[MT_MEMORY_DMA_READY].prot_pte |= L_PTE_SHARED;
 			mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_S;
 			mem_types[MT_MEMORY_NONCACHED].prot_pte |= L_PTE_SHARED;
@@ -503,6 +520,12 @@ static void __init build_mem_type_table(void)
 	mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask;
 	mem_types[MT_MEMORY].prot_sect |= ecc_mask | cp->pmd;
 	mem_types[MT_MEMORY].prot_pte |= kern_pgprot;
+#ifdef CONFIG_ARM_VMM
+	mem_types[MT_RTVMM].prot_sect |= ecc_mask | cp->pmd;
+	mem_types[MT_RTVMM].prot_pte |= kern_pgprot;
+	mem_types[MT_RTVMM_SHARE].prot_sect |= ecc_mask | cp->pmd;
+	mem_types[MT_RTVMM_SHARE].prot_pte |= kern_pgprot;
+#endif
 	mem_types[MT_MEMORY_DMA_READY].prot_pte |= kern_pgprot;
 	mem_types[MT_MEMORY_NONCACHED].prot_sect |= ecc_mask;
 	mem_types[MT_ROM].prot_sect |= cp->pmd;
@@ -1152,6 +1175,27 @@ static void __init devicemaps_init(struct machine_desc *mdesc)
 #endif
 
 	/*
+	 * Create mappings for RT-Thread VMM and it's shared memory with Linux
+	 */
+#ifdef CONFIG_ARM_VMM
+	/* the TEXCB attribute is not right yet */
+	/* shared memory region comes first */
+	map.pfn = __phys_to_pfn(virt_to_phys((void*)HOST_VMM_ADDR_BEGIN));
+	map.virtual = HOST_VMM_ADDR_BEGIN;
+	map.length = CONFIG_RTVMM_SHARED_SIZE;
+	map.type = MT_RTVMM_SHARE;
+	create_mapping(&map);
+
+	/* vmm private region comes next */
+	map.pfn = __phys_to_pfn(virt_to_phys((void*)HOST_VMM_ADDR_BEGIN
+					     + CONFIG_RTVMM_SHARED_SIZE));
+	map.virtual = HOST_VMM_ADDR_BEGIN + CONFIG_RTVMM_SHARED_SIZE;
+	map.length = CONFIG_HOST_VMM_SIZE - CONFIG_RTVMM_SHARED_SIZE;
+	map.type = MT_RTVMM;
+	create_mapping(&map);
+#endif
+
+	/*
 	 * Create a mapping for the machine vectors at the high-vectors
 	 * location (0xffff0000).  If we aren't using high-vectors, also
 	 * create a mapping at the low-vectors virtual address.
diff --git a/arch/arm/vmm/Kconfig b/arch/arm/vmm/Kconfig
new file mode 100644
index 0000000..d852056
--- /dev/null
+++ b/arch/arm/vmm/Kconfig
@@ -0,0 +1,49 @@
+menu "RT-Thread VMM Features"
+
+# ARM-VMM
+config ARM_VMM
+	bool "Support RT-Thread VMM on ARM Cortex-A8"
+	depends on MACH_REALVIEW_PBA8
+	help
+	  RT-Thread VMM implementation on ARM Cortex-A8
+
+	  Say Y if you want support for the RT-Thread VMM.
+	  Otherwise, say N.
+
+if SOC_AM33XX
+config HOST_VMM_ADDR_END
+	hex "End address of VMM"
+	depends on ARM_VMM
+	default 0xE0000000
+	help
+	  The end address of VMM space. Normally, it's the
+	  end address of DDR memory.
+endif
+
+if MACH_REALVIEW_PBA8
+config HOST_VMM_ADDR_END
+	hex "End address of VMM"
+	depends on ARM_VMM
+	default 0xE0000000
+	help
+	  The end address of VMM space. Normally, it's the
+	  end address of DDR memory.
+endif
+
+config HOST_VMM_SIZE
+	hex "Size of VMM space"
+	depends on ARM_VMM
+	default 0x400000
+	help
+	  The size of VMM space.
+
+config RTVMM_SHARED_SIZE
+	hex "Size of shared memory space between rt-vmm and Linux"
+	depends on ARM_VMM
+	default 0x100000
+	help
+	  The size of shared memory space between rt-vmm and Linux. This shared
+	  space is within the total size of the HOST_VMM_SIZE. So it is should
+	  be smaller than HOST_VMM_SIZE.
+
+endmenu
diff --git a/arch/arm/vmm/Makefile b/arch/arm/vmm/Makefile
new file mode 100644
index 0000000..127e43a
--- /dev/null
+++ b/arch/arm/vmm/Makefile
@@ -0,0 +1,10 @@
+#
+# Makefile for the linux arm-vmm
+#
+
+obj-$(CONFIG_ARM_VMM) += vmm.o vmm_traps.o vmm_virq.o
+
+ifeq ($(CONFIG_ARM_VMM),y)
+obj-$(CONFIG_SOC_AM33XX)		 += am33xx/softirq.o am33xx/virq.o
+obj-$(CONFIG_MACH_REALVIEW_PBA8) += realview_a8/softirq.o
+endif
diff --git a/arch/arm/vmm/README b/arch/arm/vmm/README
new file mode 100644
index 0000000..24f1b42
--- /dev/null
+++ b/arch/arm/vmm/README
@@ -0,0 +1 @@
+Linux VMM kernel routines
diff --git a/arch/arm/vmm/am33xx/intc.h b/arch/arm/vmm/am33xx/intc.h
new file mode 100644
index 0000000..6c24f8d
--- /dev/null
+++ b/arch/arm/vmm/am33xx/intc.h
@@ -0,0 +1,13 @@
+#ifndef __INTC_H__
+#define __INTC_H__
+
+#define OMAP34XX_IC_BASE	0x48200000
+
+#define INTC_SIR_SET0		0x0090
+#define INTC_MIR_CLEAR0		0x0088
+
+#define OMAP2_L4_IO_OFFSET	0xb2000000
+#define OMAP2_L4_IO_ADDRESS(pa)	IOMEM((pa) + OMAP2_L4_IO_OFFSET) /* L4 */
+#define OMAP3_IRQ_BASE		OMAP2_L4_IO_ADDRESS(OMAP34XX_IC_BASE)
+
+#endif
diff --git a/arch/arm/vmm/am33xx/softirq.c b/arch/arm/vmm/am33xx/softirq.c
new file mode 100644
index 0000000..5648496
--- /dev/null
+++ b/arch/arm/vmm/am33xx/softirq.c
@@ -0,0 +1,14 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/io.h>
+
+#include <vmm/vmm.h>
+#include "../vmm_virhw.h"
+#include "intc.h"
+
+void vmm_raise_softirq(int irq)
+{
+	writel_relaxed(1 << (irq % 32),
+		OMAP3_IRQ_BASE + INTC_SIR_SET0 + (irq / 32) * 4);
+}
+EXPORT_SYMBOL(vmm_raise_softirq);
diff --git a/arch/arm/vmm/am33xx/virq.c b/arch/arm/vmm/am33xx/virq.c
new file mode 100644
index 0000000..4ef7671
--- /dev/null
+++ b/arch/arm/vmm/am33xx/virq.c
@@ -0,0 +1,48 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/irqdomain.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+
+#include <vmm/vmm.h>
+#include "../vmm_virhw.h"
+#include "intc.h"
+
+void vmm_irq_handle(void __iomem *base_addr, struct irq_domain *domain,
+				 struct pt_regs *regs)
+{
+	unsigned long flags;
+	struct vmm_context* _vmm_context;
+
+	_vmm_context = vmm_context_get();
+
+	while (_vmm_context->virq_pended) {
+		int index;
+
+		flags = vmm_irq_save();
+		_vmm_context->virq_pended = 0;
+		vmm_irq_restore(flags);
+
+		/* get the pending interrupt */
+		for (index = 0; index < IRQS_NR_32; index++) {
+			int pdbit;
+
+			for (pdbit = __builtin_ffs(_vmm_context->virq_pending[index]);
+			     pdbit != 0;
+			     pdbit = __builtin_ffs(_vmm_context->virq_pending[index])) {
+				unsigned long inner_flag;
+				int irqnr;
+
+				pdbit--;
+
+				inner_flag = vmm_irq_save();
+				_vmm_context->virq_pending[index] &= ~(1 << pdbit);
+				vmm_irq_restore(inner_flag);
+
+				irqnr = irq_find_mapping(domain, pdbit + index * 32);
+				handle_IRQ(irqnr, regs);
+			}
+		}
+	}
+}
diff --git a/arch/arm/vmm/realview_a8/softirq.c b/arch/arm/vmm/realview_a8/softirq.c
new file mode 100644
index 0000000..a52b79c7
--- /dev/null
+++ b/arch/arm/vmm/realview_a8/softirq.c
@@ -0,0 +1,12 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/io.h>
+#include <asm/hardware/gic.h>
+
+#include <vmm/vmm.h>
+
+void vmm_raise_softirq(int irq)
+{
+	gic_raise_softirq(cpumask_of(0),  irq);
+}
+EXPORT_SYMBOL(vmm_raise_softirq);
diff --git a/arch/arm/vmm/vmm.c b/arch/arm/vmm/vmm.c
new file mode 100644
index 0000000..3b1d202
--- /dev/null
+++ b/arch/arm/vmm/vmm.c
@@ -0,0 +1,32 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <vmm/vmm.h>
+
+struct vmm_context* _vmm_context = NULL;
+int vmm_status = 0;
+EXPORT_SYMBOL(vmm_status);
+
+void vmm_set_status(int status)
+{
+	vmm_status = status;
+}
+EXPORT_SYMBOL(vmm_set_status);
+
+int vmm_get_status(void)
+{
+	return vmm_status;
+}
+EXPORT_SYMBOL(vmm_get_status);
+
+void vmm_context_init(void* context_addr)
+{
+	_vmm_context = (struct vmm_context*)context_addr;
+}
+EXPORT_SYMBOL(vmm_context_init);
+
+struct vmm_context* vmm_context_get(void)
+{
+	return _vmm_context;
+}
+EXPORT_SYMBOL(vmm_context_get);
diff --git a/arch/arm/vmm/vmm_traps.c b/arch/arm/vmm/vmm_traps.c
new file mode 100644
index 0000000..def0d90
--- /dev/null
+++ b/arch/arm/vmm/vmm_traps.c
@@ -0,0 +1,37 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/traps.h>
+#include <asm/cp15.h>
+#include <asm/cacheflush.h>
+
+void trap_set_vector(void *start, unsigned int length)
+{
+	unsigned char *ptr;
+	unsigned char *vector;
+
+	ptr = start;
+	vector = (unsigned char*)vectors_page;
+
+	/* only set IRQ and FIQ */
+#if defined(CONFIG_CPU_USE_DOMAINS)
+	/* IRQ */
+	memcpy((void *)0xffff0018, (void*)(ptr + 0x18), 4);
+	memcpy((void *)(0xffff0018 + 0x20), (void*)(ptr + 0x18 + 0x20), 4);
+
+	/* FIQ */
+	memcpy((void *)0xffff001C, (void*)(ptr + 0x1C), 4);
+	memcpy((void *)(0xffff001C + 0x20), (void*)(ptr + 0x1C + 0x20), 4);
+#else
+	/* IRQ */
+	memcpy(vector + 0x18, (void*)(ptr + 0x18), 4);
+	memcpy(vector + 0x18 + 0x20, (void*)(ptr + 0x18 + 0x20), 4);
+
+	/* FIQ */
+	memcpy(vector + 0x1C, (void*)(ptr + 0x1C), 4);
+	memcpy(vector + 0x1C + 0x20, (void*)(ptr + 0x1C + 0x20), 4);
+#endif
+	flush_icache_range(0xffff0000, 0xffff0000 + length);
+	if (!vectors_high())
+		flush_icache_range(0x00, 0x00 + length);
+}
+EXPORT_SYMBOL(trap_set_vector);
diff --git a/arch/arm/vmm/vmm_virhw.h b/arch/arm/vmm/vmm_virhw.h
new file mode 100644
index 0000000..363cc6e
--- /dev/null
+++ b/arch/arm/vmm/vmm_virhw.h
@@ -0,0 +1,59 @@
+#ifndef __VMM_VIRTHWH__
+#define __VMM_VIRTHWH__
+
+#define REALVIEW_NR_IRQS        96
+#define IRQS_NR_32              ((REALVIEW_NR_IRQS + 31)/32)
+#define RTT_VMM_IRQ_TRIGGER     10
+
+struct vmm_context
+{
+	/* the status of vGuest irq */
+	volatile unsigned long virq_status;
+
+	/* has interrupt pended on vGuest OS IRQ */
+	volatile unsigned long virq_pended;
+
+	/* pending interrupt for vGuest OS */
+	volatile unsigned long virq_pending[IRQS_NR_32];
+};
+
+/* IRQ operation under VMM */
+static inline unsigned long vmm_irq_save(void)
+{
+	unsigned long flags;
+
+	asm volatile(
+		"	mrs	%0, cpsr	@ arch_local_irq_save\n"
+		"	cpsid	i"
+		: "=r" (flags) : : "memory", "cc");
+	return flags;
+}
+
+static inline void vmm_irq_restore(unsigned long flags)
+{
+	asm volatile(
+		"	msr	cpsr_c, %0	@ local_irq_restore"
+		:
+		: "r" (flags)
+		: "memory", "cc");
+}
+
+static inline void vmm_irq_enable(void)
+{
+	asm volatile(
+		"	cpsie i			@ arch_local_irq_enable"
+		:
+		:
+		: "memory", "cc");
+}
+
+static inline void vmm_irq_disable(void)
+{
+	asm volatile(
+		"	cpsid i			@ arch_local_irq_disable"
+		:
+		:
+		: "memory", "cc");
+}
+
+#endif
diff --git a/arch/arm/vmm/vmm_virq.c b/arch/arm/vmm/vmm_virq.c
new file mode 100644
index 0000000..85886a2
--- /dev/null
+++ b/arch/arm/vmm/vmm_virq.c
@@ -0,0 +1,183 @@
+#include <linux/bug.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/unwind.h>
+
+#include <vmm/vmm.h>
+
+#include "vmm_virhw.h"
+
+/* VMM use the I bit in SPSR to save the virq status in the isr entry. So warn
+ * on the I bit set would gave some false negative result. */
+//#define VMM_WARN_ON_I_BIT
+
+extern struct vmm_context* _vmm_context;
+
+void vmm_disable_virq(void)
+{
+	unsigned long flags = vmm_irq_save();
+	_vmm_context->virq_status = 0x01;
+	vmm_irq_restore(flags);
+}
+EXPORT_SYMBOL(vmm_disable_virq);
+
+static void _vmm_raise_on_pended(void)
+{
+	/* check any interrupt pended in vIRQ */
+	if (_vmm_context->virq_pended) {
+		/* trigger an soft interrupt */
+		vmm_raise_softirq(RTT_VMM_IRQ_TRIGGER);
+		return;
+	}
+
+#if 0
+	int i;
+	for (i = 0; i < ARRAY_SIZE(_vmm_context->virq_pending); i++) {
+		if (_vmm_context->virq_pending[i]) {
+			_vmm_context->virq_pended = 1;
+			pr_info("\n");
+			vmm_raise_softirq(RTT_VMM_IRQ_TRIGGER);
+			return;
+		}
+	}
+#endif
+}
+
+void vmm_enable_virq(void)
+{
+	unsigned long flags = vmm_irq_save();
+	_vmm_context->virq_status = 0x00;
+	_vmm_raise_on_pended();
+	vmm_irq_restore(flags);
+}
+EXPORT_SYMBOL(vmm_enable_virq);
+
+unsigned long vmm_return_virq(void)
+{
+	unsigned long flags;
+	unsigned long level;
+
+	level =  vmm_irq_save();
+	flags = _vmm_context->virq_status;
+	vmm_irq_restore(level);
+
+	return flags;
+}
+EXPORT_SYMBOL(vmm_return_virq);
+
+unsigned long vmm_save_virq(void)
+{
+	int status;
+	unsigned long flags = vmm_irq_save();
+
+	status = _vmm_context->virq_status;
+	_vmm_context->virq_status = 0x01;
+	vmm_irq_restore(flags);
+
+	return status;
+}
+EXPORT_SYMBOL(vmm_save_virq);
+
+void vmm_restore_virq(unsigned long flags)
+{
+	unsigned long level;
+
+	level =  vmm_irq_save();
+	_vmm_context->virq_status = flags;
+	if (_vmm_context->virq_status == 0)
+	{
+		_vmm_raise_on_pended();
+	}
+	vmm_irq_restore(level);
+}
+EXPORT_SYMBOL(vmm_restore_virq);
+
+unsigned long vmm_save_virq_spsr_asm(unsigned long spsr, struct pt_regs *regs)
+{
+	if (vmm_status) {
+		if (_vmm_context->virq_status)
+			return spsr | PSR_I_BIT;
+	}
+	return spsr;
+}
+
+void irq_enable_asm(void)
+{
+	if (vmm_status) {
+		vmm_enable_virq();
+	} else {
+		asm volatile("cpsie i" : : : "memory", "cc");
+	}
+}
+
+void irq_disable_asm(void)
+{
+	if (vmm_status) {
+		vmm_disable_virq();
+	} else {
+		asm volatile("cpsid i" : : : "memory", "cc");
+	}
+}
+
+/* should be called when the guest entering the state that the IRQ is disabled
+ * by hardware, for example, entering SVC, PABT, DABT mode.
+ *
+ * It will the open the hardware IRQ, virtual IRQ remain unchanged.
+ */
+void vmm_switch_nohwirq_to_novirq(void)
+{
+	if (vmm_status) {
+		vmm_disable_virq();
+		asm volatile("cpsie i" : : : "memory", "cc");
+	}
+}
+
+unsigned long vmm_restore_virq_asm(unsigned long spsr)
+{
+	if (vmm_status) {
+#ifdef VMM_WARN_ON_I_BIT
+		WARN(spsr & PSR_I_BIT, "return to svc mode with I in SPSR set\n");
+#endif
+		vmm_restore_virq(!!(spsr & PSR_I_BIT));
+		return spsr & ~PSR_I_BIT;
+	} else {
+		return spsr;
+	}
+}
+
+void vmm_on_ret_to_usr(unsigned long spsr)
+{
+	if (vmm_status) {
+#ifdef VMM_WARN_ON_I_BIT
+		WARN(spsr & PSR_I_BIT, "return to user mode with I in SPSR set\n");
+#endif
+		vmm_enable_virq();
+	}
+}
+
+void vmm_on_svc_exit_irq(unsigned long spsr)
+{
+	if (vmm_status) {
+#ifdef VMM_WARN_ON_I_BIT
+		WARN(spsr & PSR_I_BIT, "exit IRQ with I in SPSR set\n");
+#endif
+		vmm_enable_virq();
+	}
+}
+
+void vmm_dump_irq(void)
+{
+	int i;
+	unsigned long cpsr;
+
+	asm volatile ("mrs %0, cpsr": "=r"(cpsr));
+
+	printk("status: %08lx, pended: %08lx, cpsr: %08lx\n",
+	       _vmm_context->virq_status, _vmm_context->virq_pended, cpsr);
+	printk("pending: ");
+	for (i = 0; i < ARRAY_SIZE(_vmm_context->virq_pending); i++) {
+		printk("%08lx, ", _vmm_context->virq_pending[i]);
+	}
+	printk("\n");
+}
+
-- 
1.8.4