KVM/MIPS32: KVM Guest kernel support.
Both Guest kernel and Guest Userspace execute in UM. The memory map is as follows:
Guest User address space: 0x00000000 -> 0x40000000
Guest Kernel Unmapped: 0x40000000 -> 0x60000000
Guest Kernel Mapped: 0x60000000 -> 0x80000000
- Guest Usermode virtual memory is limited to 1GB.
Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/mach-generic/spaces.h b/arch/mips/include/asm/mach-generic/spaces.h
index 73d717a..5b2f2e6 100644
--- a/arch/mips/include/asm/mach-generic/spaces.h
+++ b/arch/mips/include/asm/mach-generic/spaces.h
@@ -20,14 +20,21 @@
#endif
#ifdef CONFIG_32BIT
-
+#ifdef CONFIG_KVM_GUEST
+#define CAC_BASE _AC(0x40000000, UL)
+#else
#define CAC_BASE _AC(0x80000000, UL)
+#endif
#define IO_BASE _AC(0xa0000000, UL)
#define UNCAC_BASE _AC(0xa0000000, UL)
#ifndef MAP_BASE
+#ifdef CONFIG_KVM_GUEST
+#define MAP_BASE _AC(0x60000000, UL)
+#else
#define MAP_BASE _AC(0xc0000000, UL)
#endif
+#endif
/*
* Memory above this physical address will be considered highmem.
diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h
index 2a5fa7a..71686c8 100644
--- a/arch/mips/include/asm/processor.h
+++ b/arch/mips/include/asm/processor.h
@@ -44,11 +44,16 @@
#define SPECIAL_PAGES_SIZE PAGE_SIZE
#ifdef CONFIG_32BIT
+#ifdef CONFIG_KVM_GUEST
+/* User space process size is limited to 1GB in KVM Guest Mode */
+#define TASK_SIZE 0x3fff8000UL
+#else
/*
* User space process size: 2GB. This is hardcoded into a few places,
* so don't change it unless you know what you are doing.
*/
#define TASK_SIZE 0x7fff8000UL
+#endif
#ifdef __KERNEL__
#define STACK_TOP_MAX TASK_SIZE
diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h
index bd87e36..b46caab 100644
--- a/arch/mips/include/asm/uaccess.h
+++ b/arch/mips/include/asm/uaccess.h
@@ -23,7 +23,11 @@
*/
#ifdef CONFIG_32BIT
-#define __UA_LIMIT 0x80000000UL
+#ifdef CONFIG_KVM_GUEST
+#define __UA_LIMIT 0x40000000UL
+#else
+#define __UA_LIMIT 0x80000000UL
+#endif
#define __UA_ADDR ".word"
#define __UA_LA "la"
@@ -55,8 +59,13 @@
* address in this range it's the process's problem, not ours :-)
*/
+#ifdef CONFIG_KVM_GUEST
+#define KERNEL_DS ((mm_segment_t) { 0x80000000UL })
+#define USER_DS ((mm_segment_t) { 0xC0000000UL })
+#else
#define KERNEL_DS ((mm_segment_t) { 0UL })
#define USER_DS ((mm_segment_t) { __UA_LIMIT })
+#endif
#define VERIFY_READ 0
#define VERIFY_WRITE 1