On 24.06.14 19:59, Madhavan Srinivasan wrote:
On Tuesday 24 June 2014 10:36 PM, bharat.bhus...@freescale.com wrote:
-----Original Message-----
From: Madhavan Srinivasan [mailto:ma...@linux.vnet.ibm.com]
Sent: Tuesday, June 24, 2014 8:59 PM
To: Bhushan Bharat-R65777; ag...@suse.de
Cc: qemu-...@nongnu.org; qemu-devel@nongnu.org
Subject: Re: [PATCH 4/5 v3][RESEND] ppc: Add software breakpoint support
On Tuesday 24 June 2014 05:40 PM, Bharat Bhushan wrote:
This patch allow insert/remove software breakpoint
Signed-off-by: Bharat Bhushan <bharat.bhus...@freescale.com>
---
target-ppc/kvm.c | 71
+++++++++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 57 insertions(+), 14 deletions(-)
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c index
5238de7..8e2dbb3 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -1317,6 +1317,53 @@ static int kvmppc_handle_dcr_write(CPUPPCState *env,
uint32_t dcrn, uint32_t dat
return 0;
}
+int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct
+kvm_sw_breakpoint *bp) {
+ /* Mixed endian case is not handled */
+ uint32_t sc = debug_inst_opcode;
+
+ if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 0) ||
+ cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, 4, 1)) {
Instead of hard coding, can we use sizeof ()?
Yes
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct
+kvm_sw_breakpoint *bp) {
+ uint32_t sc;
+
+ if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, 4, 0) ||
+ sc != debug_inst_opcode ||
+ cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 1)) {
+ return -EINVAL;
+ }
+
Same. Can we use sizeof?
Yes
+ return 0;
+}
+
+void kvm_arch_update_guest_debug(CPUState *cs, struct kvm_guest_debug
+*dbg) {
+ /* Software Breakpoint updates */
+ if (kvm_sw_breakpoints_active(cs)) {
+ dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
+ }
+}
+
+static int kvm_handle_debug(PowerPCCPU *cpu, struct kvm_run *run) {
+ CPUState *cs = CPU(cpu);
+ struct kvm_debug_exit_arch *arch_info = &run->debug.arch;
+ int handle = 0;
+
+ if (kvm_find_sw_breakpoint(cs, arch_info->address)) {
+ handle = 1;
+ }
+
+ return handle;
+}
+
int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run) {
PowerPCCPU *cpu = POWERPC_CPU(cs); @@ -1357,6 +1404,16 @@ int
kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
ret = 0;
break;
+ case KVM_EXIT_DEBUG:
+ DPRINTF("handle debug exception\n");
+ if (kvm_handle_debug(cpu, run)) {
+ ret = EXCP_DEBUG;
+ break;
+ }
+ /* re-enter, this exception was guest-internal */
Kindly can you explain when this will happen?
If the debug interrupt condition (breakpoint/watchpoint etc) is not set by
qemu, i.e that is set by guest.
OK. This is my understanding. Kindly correct if it is wrong.
If we are here without any breakpoint from qemu, are we not suppose to
pass it on to guest with an interrupt inject?
Yes. If the guest issued that instruction itself we need to pass in the
interrupt that the guest would have received. I think in the book3s case
this would be a PROGRAM interrupt rather than a DEBUG interrupt.
Alex
