[Qemu-devel] [PATCH 3/5] Add guest debug support for kvmppc

[Liu Yu <yu.liu@freescale.com>]

Signed-off-by: Liu Yu <yu.liu@freescale.com>
---
 target-ppc/kvm.c |  197 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 197 insertions(+), 0 deletions(-)

diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index b53d6e9..d8dbdb4 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -8,6 +8,9 @@
  *  Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
  *  Hollis Blanchard <hollisb@us.ibm.com>
  *
+ * Copyright (C) 2009 Freescale Semiconductor, Inc. All rights reserved.
+ *  Yu Liu <yu.liu@freescale.com>
+ *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
  *
@@ -18,6 +21,7 @@
 #include <sys/mman.h>
 
 #include <linux/kvm.h>
+#include <asm/kvm_asm.h>
 
 #include "qemu-common.h"
 #include "qemu-timer.h"
@@ -26,6 +30,7 @@
 #include "kvm_ppc.h"
 #include "cpu.h"
 #include "device_tree.h"
+#include "gdbstub.h"
 
 //#define DEBUG_KVM
 
@@ -216,3 +221,195 @@ int kvm_arch_handle_exit(CPUState *env, struct kvm_run *run)
     return ret;
 }
 
+#ifdef KVM_CAP_SET_GUEST_DEBUG
+int kvm_arch_insert_sw_breakpoint(CPUState *env, struct kvm_sw_breakpoint *bp)
+{
+    uint32_t sc = tswap32(KVM_INST_GUESTGDB);
+    uint32_t tmp;
+
+    if (cpu_memory_rw_debug(env, bp->pc, (uint8_t *)&bp->saved_insn, 4, 0) ||
+        cpu_memory_rw_debug(env, bp->pc, (uint8_t *)&sc, 4, 1))
+        return -EINVAL;
+    cpu_memory_rw_debug(env, bp->pc, (uint8_t *)&tmp, 4, 0);
+    return 0;
+}
+
+int kvm_arch_remove_sw_breakpoint(CPUState *env, struct kvm_sw_breakpoint *bp)
+{
+    uint32_t sc;
+
+    if (cpu_memory_rw_debug(env, bp->pc, (uint8_t *)&sc, 4, 0) ||
+        sc != tswap32(KVM_INST_GUESTGDB) ||
+        cpu_memory_rw_debug(env, bp->pc, (uint8_t *)&bp->saved_insn, 4, 1))
+        return -EINVAL;
+    return 0;
+}
+
+static struct {
+    target_ulong addr;
+    int type;
+} hw_breakpoint[6];
+
+static int nb_hw_breakpoint;
+static int nb_hw_watchpoint;
+static int max_hw_breakpoint;
+static int max_hw_watchpoint;
+
+void kvmppc_debug_init(int max_hw_bp, int max_hw_wp)
+{
+    max_hw_breakpoint = max_hw_bp > 4? 4 : max_hw_bp;
+    max_hw_watchpoint = max_hw_wp > 2? 2 : max_hw_wp;
+}
+
+static int find_hw_breakpoint(target_ulong addr, int type)
+{
+    int n;
+
+    for (n = 0; n < nb_hw_breakpoint + nb_hw_watchpoint; n++)
+        if (hw_breakpoint[n].addr == addr && hw_breakpoint[n].type == type)
+            return n;
+    return -1;
+}
+
+int kvm_arch_insert_hw_breakpoint(target_ulong addr,
+                                  target_ulong len, int type)
+{
+    hw_breakpoint[nb_hw_breakpoint + nb_hw_watchpoint].addr = addr;
+    hw_breakpoint[nb_hw_breakpoint + nb_hw_watchpoint].type = type;
+
+    switch (type) {
+    case GDB_BREAKPOINT_HW:
+        if (nb_hw_breakpoint >= max_hw_breakpoint)
+            return -ENOBUFS;
+
+        if (find_hw_breakpoint(addr, type) >= 0)
+            return -EEXIST;
+
+        nb_hw_breakpoint++;
+        break;
+
+    case GDB_WATCHPOINT_WRITE:
+    case GDB_WATCHPOINT_ACCESS:
+        if (nb_hw_watchpoint >= max_hw_watchpoint)
+            return -ENOBUFS;
+
+        if (find_hw_breakpoint(addr, type) >= 0)
+            return -EEXIST;
+
+        nb_hw_watchpoint++;
+        break;
+
+    default:
+        return -ENOSYS;
+    }
+
+    return 0;
+}
+
+int kvm_arch_remove_hw_breakpoint(target_ulong addr,
+                                  target_ulong len, int type)
+{
+    int n;
+
+    n = find_hw_breakpoint(addr, type);
+    if (n < 0)
+        return -ENOENT;
+
+    switch (type) {
+    case GDB_BREAKPOINT_HW:
+        nb_hw_breakpoint--;
+        break;
+
+    case GDB_WATCHPOINT_WRITE:
+    case GDB_WATCHPOINT_ACCESS:
+        nb_hw_watchpoint--;
+        break;
+
+    default:
+        return -ENOSYS;
+    }
+    hw_breakpoint[n] = hw_breakpoint[nb_hw_breakpoint + nb_hw_watchpoint];
+
+    return 0;
+}
+
+void kvm_arch_remove_all_hw_breakpoints(void)
+{
+    nb_hw_breakpoint = nb_hw_watchpoint = 0;
+}
+
+static CPUWatchpoint hw_watchpoint;
+
+int kvm_arch_debug(struct kvm_debug_exit_arch *arch_info)
+{
+    int handle = 0;
+    int n;
+
+    if (cpu_single_env->singlestep_enabled) {
+        handle = 1;
+
+    } else if (arch_info->status) {
+        if (arch_info->status == KVMPPC_DEBUG_BREAKPOINT) {
+            n = find_hw_breakpoint(arch_info->pc, GDB_BREAKPOINT_HW);
+            if (n >= 0)
+                handle = 1;
+
+        } else if (arch_info->status == KVMPPC_DEBUG_WATCH_ACCESS) {
+            n = find_hw_breakpoint(arch_info->pc, GDB_WATCHPOINT_ACCESS);
+            if (n >= 0) {
+                handle = 1;
+                cpu_single_env->watchpoint_hit = &hw_watchpoint;
+                hw_watchpoint.vaddr = hw_breakpoint[n].addr;
+                hw_watchpoint.flags = BP_MEM_ACCESS;
+            }
+
+        } else if (arch_info->status == KVMPPC_DEBUG_WATCH_WRITE) {
+            n = find_hw_breakpoint(arch_info->pc, GDB_WATCHPOINT_WRITE);
+            if (n >= 0) {
+                handle = 1;
+                cpu_single_env->watchpoint_hit = &hw_watchpoint;
+                hw_watchpoint.vaddr = hw_breakpoint[n].addr;
+                hw_watchpoint.flags = BP_MEM_WRITE;
+            }
+        }
+
+    } else if (kvm_find_sw_breakpoint(cpu_single_env, arch_info->pc))
+        handle = 1;
+
+    /* XXX inject guest debug exception */
+    if (!handle)
+        printf("Unhandled debug exception!\n");
+
+    return handle;
+}
+
+void kvm_arch_update_guest_debug(CPUState *env, struct kvm_guest_debug *dbg)
+{
+    if (kvm_sw_breakpoints_active(env))
+        dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
+
+    if (nb_hw_breakpoint + nb_hw_watchpoint > 0) {
+        int n;
+
+        dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP;
+        memset(dbg->arch.bp, 0, sizeof(dbg->arch.bp));
+        for (n = 0; n < nb_hw_breakpoint + nb_hw_watchpoint; n++) {
+            switch (hw_breakpoint[n].type) {
+            case GDB_BREAKPOINT_HW:
+                dbg->arch.bp[n].type = KVMPPC_DEBUG_BREAKPOINT;
+                break;
+            case GDB_WATCHPOINT_ACCESS:
+                dbg->arch.bp[n].type = KVMPPC_DEBUG_WATCH_ACCESS;
+                break;
+            case GDB_WATCHPOINT_WRITE:
+                dbg->arch.bp[n].type = KVMPPC_DEBUG_WATCH_WRITE;
+                break;
+            default:
+                printf("Unsupported breakpoint type\n");
+                exit(-1);
+            }
+            dbg->arch.bp[n].addr = hw_breakpoint[n].addr;
+        }
+    }
+}
+#endif /* KVM_CAP_SET_GUEST_DEBUG */
-- 
1.5.4