[PATCH v5 05/12] target-mips: get_physical_address: Add KVM awareness

James Hogan
2014-06-17T22:14:13Z

MIPS KVM trap & emulate mode (which is currently the only supported
mode) has to add an extra kseg0/kseg1 at 0x40000000 and an extra
kseg2/kseg3 at 0x60000000. Take this into account in
get_physical_address() so that debug memory access works.

This is done by translating the address to a standard kseg0 or kseg2
address before doing the normal address translation. The real virtual
address is still used for TLB lookups.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
---
target-mips/helper.c | 33 ++++++++++++++++++++++++++-------
1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/target-mips/helper.c b/target-mips/helper.c
index caacd762fd90..8a997e44e5ac 100644
--- a/target-mips/helper.c
+++ b/target-mips/helper.c
@@ -24,6 +24,7 @@
#include <signal.h>

#include "cpu.h"
+#include "sysemu/kvm.h"

enum {
TLBRET_DIRTY = -4,
@@ -100,7 +101,7 @@ int r4k_map_address (CPUMIPSState *env, hwaddr *physical, int *prot,
}

static int get_physical_address (CPUMIPSState *env, hwaddr *physical,
- int *prot, target_ulong address,
+ int *prot, target_ulong real_address,
int rw, int access_type)
{
/* User mode can only access useg/xuseg */
@@ -113,6 +114,8 @@ static int get_physical_address (CPUMIPSState *env, hwaddr *physical,
int KX = (env->CP0_Status & (1 << CP0St_KX)) != 0;
#endif
int ret = TLBRET_MATCH;
+ /* effective address (modified for KVM T&E kernel segments) */
+ target_ulong address = real_address;

#if 0
qemu_log("user mode %d h %08x\n", user_mode, env->hflags);
@@ -124,19 +127,35 @@ static int get_physical_address (CPUMIPSState *env, hwaddr *physical,
#define KSEG2_BASE 0xC0000000UL
#define KSEG3_BASE 0xE0000000UL

+#define KVM_KSEG0_BASE 0x40000000UL
+#define KVM_KSEG2_BASE 0x60000000UL
+
+ if (kvm_enabled()) {
+ /* KVM T&E adds guest kernel segments in useg */
+ if (real_address >= KVM_KSEG0_BASE) {
+ if (real_address < KVM_KSEG2_BASE) {
+ /* kseg0 */
+ address += KSEG0_BASE - KVM_KSEG0_BASE;
+ } else if (real_address <= USEG_LIMIT) {
+ /* kseg2/3 */
+ address += KSEG2_BASE - KVM_KSEG2_BASE;
+ }
+ }
+ }
+
if (address <= USEG_LIMIT) {
/* useg */
if (env->CP0_Status & (1 << CP0St_ERL)) {
*physical = address & 0xFFFFFFFF;
*prot = PAGE_READ | PAGE_WRITE;
} else {
- ret = env->tlb->map_address(env, physical, prot, address, rw, access_type);
+ ret = env->tlb->map_address(env, physical, prot, real_address, rw, access_type);
}
#if defined(TARGET_MIPS64)
} else if (address < 0x4000000000000000ULL) {
/* xuseg */
if (UX && address <= (0x3FFFFFFFFFFFFFFFULL & env->SEGMask)) {
- ret = env->tlb->map_address(env, physical, prot, address, rw, access_type);
+ ret = env->tlb->map_address(env, physical, prot, real_address, rw, access_type);
} else {
ret = TLBRET_BADADDR;
}
@@ -144,7 +163,7 @@ static int get_physical_address (CPUMIPSState *env, hwaddr *physical,
/* xsseg */
if ((supervisor_mode || kernel_mode) &&
SX && address <= (0x7FFFFFFFFFFFFFFFULL & env->SEGMask)) {
- ret = env->tlb->map_address(env, physical, prot, address, rw, access_type);
+ ret = env->tlb->map_address(env, physical, prot, real_address, rw, access_type);
} else {
ret = TLBRET_BADADDR;
}
@@ -161,7 +180,7 @@ static int get_physical_address (CPUMIPSState *env, hwaddr *physical,
/* xkseg */
if (kernel_mode && KX &&
address <= (0xFFFFFFFF7FFFFFFFULL & env->SEGMask)) {
- ret = env->tlb->map_address(env, physical, prot, address, rw, access_type);
+ ret = env->tlb->map_address(env, physical, prot, real_address, rw, access_type);
} else {
ret = TLBRET_BADADDR;
}
@@ -185,7 +204,7 @@ static int get_physical_address (CPUMIPSState *env, hwaddr *physical,
} else if (address < (int32_t)KSEG3_BASE) {
/* sseg (kseg2) */
if (supervisor_mode || kernel_mode) {
- ret = env->tlb->map_address(env, physical, prot, address, rw, access_type);
+ ret = env->tlb->map_address(env, physical, prot, real_address, rw, access_type);
} else {
ret = TLBRET_BADADDR;
}
@@ -193,7 +212,7 @@ static int get_physical_address (CPUMIPSState *env, hwaddr *physical,
/* kseg3 */
/* XXX: debug segment is not emulated */
if (kernel_mode) {
- ret = env->tlb->map_address(env, physical, prot, address, rw, access_type);
+ ret = env->tlb->map_address(env, physical, prot, real_address, rw, access_type);
} else {
ret = TLBRET_BADADDR;
}
--
1.9.3