This patch add support for guest debugging with qemu gdbstub.
Now hardware breakpoint and watchpoint can be set/unset. This
patch also support for software beakpoint.
Signed-off-by: Bharat Bhushan <bharat.bhushan@xxxxxxxxxxxxx>
---
hw/ppc/e500.c | 3 +
target-ppc/kvm.c | 242 ++++++++++++++++++++++++++++++++++++++++++++++++++
target-ppc/kvm_ppc.h | 1 +
3 files changed, 246 insertions(+), 0 deletions(-)
diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c
index f07be08..83a2972 100644
--- a/hw/ppc/e500.c
+++ b/hw/ppc/e500.c
@@ -588,5 +588,8 @@ void ppce500_init(PPCE500Params *params)
if (kvm_enabled()) {
kvmppc_init();
+#ifdef KVM_CAP_SET_GUEST_DEBUG
+ kvmppc_e500_hw_breakpoint_init();
+#endif
}
}
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index f70e7a6..f980700 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -33,6 +33,7 @@
#include "hw/sysbus.h"
#include "hw/spapr.h"
#include "hw/watchdog.h"
+#include "gdbstub.h"
#include "hw/sysbus.h"
#include "hw/spapr.h"
@@ -805,6 +806,236 @@ static int kvmppc_handle_dcr_write(CPUPPCState *env, uint32_t dcrn, uint32_t dat
return 0;
}
+#ifdef KVM_CAP_SET_GUEST_DEBUG
+int kvm_arch_insert_sw_breakpoint(CPUPPCState *env,
+ struct kvm_sw_breakpoint *bp)
+{
+ uint32_t sc = tswap32(KVM_INST_GUESTGDB);
+
+ 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;
+ }
+
+ return 0;
+}
+
+int kvm_arch_remove_sw_breakpoint(CPUPPCState *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 HWBreakpoint {
+ target_ulong addr;
+ int type;
+} hw_breakpoint[6];
+
+static int nb_hw_breakpoint;
+static int nb_hw_watchpoint;
+static int max_hw_breakpoint = 4;
+static int max_hw_watchpoint = 2;
+
+void kvmppc_e500_hw_breakpoint_init(void)
+{
+ max_hw_breakpoint = 2;
+ max_hw_watchpoint = 2;
+}
+
+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;
+}
+
+static int find_hw_watchpoint(target_ulong addr, int *flag)
+{
+ int n;
+
+ n = find_hw_breakpoint(addr, GDB_WATCHPOINT_ACCESS);
+ if (n >= 0) {
+ *flag = BP_MEM_ACCESS;
+ return n;
+ }
+
+ n = find_hw_breakpoint(addr, KVMPPC_DEBUG_WATCH_WRITE);
+ if (n >= 0) {
+ *flag = BP_MEM_WRITE;
+ return n;
+ }
+
+ n = find_hw_breakpoint(addr, KVMPPC_DEBUG_WATCH_READ);
+ if (n >= 0) {
+ *flag = BP_MEM_READ;
+ 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_READ:
+ 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_READ:
+ 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;
+
+
+static int kvm_handle_debug(struct kvm_debug_exit_arch *arch_info)
+{
+ int handle = 0;
+ int n;
+ int flag = 0;
+
+ 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_READ |
+ KVMPPC_DEBUG_WATCH_WRITE)) {
+ n = find_hw_watchpoint(arch_info->pc, &flag);
+ if (n >= 0) {
+ handle = 1;
+ cpu_single_env->watchpoint_hit = &hw_watchpoint;
+ hw_watchpoint.vaddr = hw_breakpoint[n].addr;
+ hw_watchpoint.flags = flag;
+ }
+ }
+ } else if (kvm_find_sw_breakpoint(cpu_single_env, arch_info->pc)) {
+ handle = 1;
+ }
+
+ /* XXX inject guest debug exception */
+ if (!handle) {
+ fprintf(stderr, "Unhandled debug exception!\n");
+ }
+
+ return handle;
+}
+
+void kvm_arch_update_guest_debug(CPUPPCState *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_WRITE:
+ dbg->arch.bp[n].type = KVMPPC_DEBUG_WATCH_WRITE;
+ break;
+ case GDB_WATCHPOINT_READ:
+ dbg->arch.bp[n].type = KVMPPC_DEBUG_WATCH_READ;
+ break;
+ case GDB_WATCHPOINT_ACCESS:
+ dbg->arch.bp[n].type = KVMPPC_DEBUG_WATCH_WRITE |
+ KVMPPC_DEBUG_WATCH_READ;
+ break;
+ default:
+ cpu_abort(env, "Unsupported breakpoint type\n");
+ }
+ dbg->arch.bp[n].addr = hw_breakpoint[n].addr;
+ }
+ }
+}
+#endif /* KVM_CAP_SET_GUEST_DEBUG */
+
int kvm_arch_handle_exit(CPUPPCState *env, struct kvm_run *run)
{
int ret;
@@ -838,6 +1069,17 @@ int kvm_arch_handle_exit(CPUPPCState *env, struct kvm_run *run)
ret = 0;
break;
#endif
+#ifdef KVM_CAP_SET_GUEST_DEBUG
+ case KVM_EXIT_DEBUG:
+ dprintf("kvm_exit_debug\n");
+ if (kvm_handle_debug(&run->debug.arch)) {
+ ret = EXCP_DEBUG;
+ break;
+ }
+ /* re-enter, this exception was guest-internal */
+ ret = 0;
+ break;
+#endif
default:
fprintf(stderr, "KVM: unknown exit reason %d\n", run->exit_reason);
ret = -1;
diff --git a/target-ppc/kvm_ppc.h b/target-ppc/kvm_ppc.h
index e2f8703..6e34cf3 100644
--- a/target-ppc/kvm_ppc.h
+++ b/target-ppc/kvm_ppc.h
@@ -30,6 +30,7 @@ int kvmppc_remove_spapr_tce(void *table, int pfd, uint32_t window_size);
#endif /* !CONFIG_USER_ONLY */
const ppc_def_t *kvmppc_host_cpu_def(void);
int kvmppc_fixup_cpu(CPUPPCState *env);
+void kvmppc_e500_hw_breakpoint_init(void);
#else
--
1.7.0.4
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