Message ID | 1405329338-10206-5-git-send-email-Bharat.Bhushan@freescale.com |
---|---|
State | New |
Headers | show |
On Monday 14 July 2014 02:45 PM, Bharat Bhushan wrote: > This patch allow insert/remove software breakpoint. > > When QEMU is not able to handle debug exception then we inject > program exception to guest because for software breakpoint QEMU > uses a ehpriv-1 instruction; > So there cannot be any reason that we are in qemu with exit reason > KVM_EXIT_DEBUG for guest set debug exception, only possibility is > guest executed ehpriv-1 privilege instruction and that's why we are > injecting program exception. > > Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com> > --- > v7->v8 > - Decrement nip by 4 before calling ppc_cpu_do_interrupt() > as pointed by "Madhavan Srinivasan" Just a minor change. We increment the nip. > - Also added missing cpu_sync() > > target-ppc/kvm.c | 93 +++++++++++++++++++++++++++++++++++++++++++++++--------- > 1 file changed, 79 insertions(+), 14 deletions(-) > > diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c > index e00a20f..0f2e8e4 100644 > --- a/target-ppc/kvm.c > +++ b/target-ppc/kvm.c > @@ -1275,6 +1275,75 @@ 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, > + sizeof(sc), 0) || > + cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, sizeof(sc), 1)) { > + 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, sizeof(sc), 0) || > + sc != debug_inst_opcode || > + cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, > + sizeof(sc), 1)) { > + return -EINVAL; > + } > + > + 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); > + CPUPPCState *env = &cpu->env; > + struct kvm_debug_exit_arch *arch_info = &run->debug.arch; > + int handle = 0; > + > + if (kvm_find_sw_breakpoint(cs, arch_info->address)) { > + handle = 1; > + } else { > + /* QEMU is not able to handle debug exception, so inject > + * program exception to guest; > + * Yes program exception NOT debug exception !! > + * For software breakpoint QEMU uses a ehpriv-1 instruction; Instead, can you say "QEMU uses a SW breakpoint instruction". In server side, we use illegal instruction to trap to hypervisor ("0x00dddd00") > + * So there cannot be any reason that we are here for guest > + * set debug exception, only possibility is guest executed a > + * privilege instruction and that's why we are injecting ^^^^privilege or illegal instruction My Bad. I should have read just last time. But just minor and I am ok as is. Reviewed By: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> > + * program exception. > + */ > + > + cpu_synchronize_state(cs); > + /* env->nip is PC, so increment this by 4 to use > + * ppc_cpu_do_interrupt(), which set srr0 = env->nip - 4. > + */ > + env->nip += 4; > + cs->exception_index = POWERPC_EXCP_PROGRAM; > + env->error_code = POWERPC_EXCP_INVAL; > + ppc_cpu_do_interrupt(cs); > + } > + > + return handle; > +} > + > int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run) > { > PowerPCCPU *cpu = POWERPC_CPU(cs); > @@ -1315,6 +1384,16 @@ 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 */ > + ret = 0; > + break; > + > default: > fprintf(stderr, "KVM: unknown exit reason %d\n", run->exit_reason); > ret = -1; > @@ -2003,16 +2082,6 @@ void kvm_arch_init_irq_routing(KVMState *s) > { > } > > -int kvm_arch_insert_sw_breakpoint(CPUState *cpu, struct kvm_sw_breakpoint *bp) > -{ > - return -EINVAL; > -} > - > -int kvm_arch_remove_sw_breakpoint(CPUState *cpu, struct kvm_sw_breakpoint *bp) > -{ > - return -EINVAL; > -} > - > int kvm_arch_insert_hw_breakpoint(target_ulong addr, target_ulong len, int type) > { > return -EINVAL; > @@ -2027,10 +2096,6 @@ void kvm_arch_remove_all_hw_breakpoints(void) > { > } > > -void kvm_arch_update_guest_debug(CPUState *cpu, struct kvm_guest_debug *dbg) > -{ > -} > - > struct kvm_get_htab_buf { > struct kvm_get_htab_header header; > /* >
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c index e00a20f..0f2e8e4 100644 --- a/target-ppc/kvm.c +++ b/target-ppc/kvm.c @@ -1275,6 +1275,75 @@ 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, + sizeof(sc), 0) || + cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, sizeof(sc), 1)) { + 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, sizeof(sc), 0) || + sc != debug_inst_opcode || + cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, + sizeof(sc), 1)) { + return -EINVAL; + } + + 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); + CPUPPCState *env = &cpu->env; + struct kvm_debug_exit_arch *arch_info = &run->debug.arch; + int handle = 0; + + if (kvm_find_sw_breakpoint(cs, arch_info->address)) { + handle = 1; + } else { + /* QEMU is not able to handle debug exception, so inject + * program exception to guest; + * Yes program exception NOT debug exception !! + * For software breakpoint QEMU uses a ehpriv-1 instruction; + * So there cannot be any reason that we are here for guest + * set debug exception, only possibility is guest executed a + * privilege instruction and that's why we are injecting + * program exception. + */ + + cpu_synchronize_state(cs); + /* env->nip is PC, so increment this by 4 to use + * ppc_cpu_do_interrupt(), which set srr0 = env->nip - 4. + */ + env->nip += 4; + cs->exception_index = POWERPC_EXCP_PROGRAM; + env->error_code = POWERPC_EXCP_INVAL; + ppc_cpu_do_interrupt(cs); + } + + return handle; +} + int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run) { PowerPCCPU *cpu = POWERPC_CPU(cs); @@ -1315,6 +1384,16 @@ 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 */ + ret = 0; + break; + default: fprintf(stderr, "KVM: unknown exit reason %d\n", run->exit_reason); ret = -1; @@ -2003,16 +2082,6 @@ void kvm_arch_init_irq_routing(KVMState *s) { } -int kvm_arch_insert_sw_breakpoint(CPUState *cpu, struct kvm_sw_breakpoint *bp) -{ - return -EINVAL; -} - -int kvm_arch_remove_sw_breakpoint(CPUState *cpu, struct kvm_sw_breakpoint *bp) -{ - return -EINVAL; -} - int kvm_arch_insert_hw_breakpoint(target_ulong addr, target_ulong len, int type) { return -EINVAL; @@ -2027,10 +2096,6 @@ void kvm_arch_remove_all_hw_breakpoints(void) { } -void kvm_arch_update_guest_debug(CPUState *cpu, struct kvm_guest_debug *dbg) -{ -} - struct kvm_get_htab_buf { struct kvm_get_htab_header header; /*
This patch allow insert/remove software breakpoint. When QEMU is not able to handle debug exception then we inject program exception to guest because for software breakpoint QEMU uses a ehpriv-1 instruction; So there cannot be any reason that we are in qemu with exit reason KVM_EXIT_DEBUG for guest set debug exception, only possibility is guest executed ehpriv-1 privilege instruction and that's why we are injecting program exception. Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com> --- v7->v8 - Decrement nip by 4 before calling ppc_cpu_do_interrupt() as pointed by "Madhavan Srinivasan" - Also added missing cpu_sync() target-ppc/kvm.c | 93 +++++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 79 insertions(+), 14 deletions(-)