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Violators will be prosecuted for from ; Fri, 18 Jan 2019 14:08:26 -0000 From: Fabiano Rosas Date: Fri, 18 Jan 2019 12:07:57 -0200 In-Reply-To: <20190118140758.829-1-farosas@linux.ibm.com> References: <20190118140758.829-1-farosas@linux.ibm.com> Message-Id: <20190118140758.829-7-farosas@linux.ibm.com> Subject: [Qemu-devel] [RFC PATCH v3 6/7] target/ppc: Refactor kvm_handle_debug List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-ppc@nongnu.org, philmd@redhat.com, pbonzini@redhat.com, crosthwaite.peter@gmail.com, rth@twiddle.net, david@gibson.dropbear.id.au, cohuck@redhat.com, aik@ozlabs.ru There are four scenarios being handled in this function: - single stepping - hardware breakpoints - software breakpoints - fallback (no debug supported) A future patch will add code to handle specific single step and software breakpoints cases so let's split each scenario into its own function now to avoid hurting readability. Signed-off-by: Fabiano Rosas --- target/ppc/kvm.c | 86 ++++++++++++++++++++++++++++-------------------- 1 file changed, 50 insertions(+), 36 deletions(-) diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c index 96a5895792..c27190d7fb 100644 --- a/target/ppc/kvm.c +++ b/target/ppc/kvm.c @@ -1621,52 +1621,66 @@ static int kvm_handle_hw_breakpoint(CPUState *cs, return handle; } +static int kvm_handle_singlestep(void) +{ + return 1; +} + +static int kvm_handle_sw_breakpoint(void) +{ + return 1; +} + 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 (cs->singlestep_enabled) { - handle = 1; - } else if (arch_info->status) { - handle = kvm_handle_hw_breakpoint(cs, arch_info); - } else 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 !! - * When QEMU is using debug resources then debug exception must - * be always set. To achieve this we set MSR_DE and also set - * MSRP_DEP so guest cannot change MSR_DE. - * When emulating debug resource for guest we want guest - * to control MSR_DE (enable/disable debug interrupt on need). - * Supporting both configurations are NOT possible. - * So the result is that we cannot share debug resources - * between QEMU and Guest on BOOKE architecture. - * In the current design QEMU gets the priority over guest, - * this means that if QEMU is using debug resources then guest - * cannot use them; - * For software breakpoint QEMU uses a privileged instruction; - * So there cannot be any reason that we are here for guest - * set debug exception, only possibility is guest executed a - * privileged / illegal instruction and that's why we are - * injecting a program interrupt. - */ + return kvm_handle_singlestep(); + } + + if (arch_info->status) { + return kvm_handle_hw_breakpoint(cs, arch_info); + } - 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); + if (kvm_find_sw_breakpoint(cs, arch_info->address)) { + return kvm_handle_sw_breakpoint(); } - return handle; + /* + * QEMU is not able to handle debug exception, so inject + * program exception to guest; + * Yes program exception NOT debug exception !! + * When QEMU is using debug resources then debug exception must + * be always set. To achieve this we set MSR_DE and also set + * MSRP_DEP so guest cannot change MSR_DE. + * When emulating debug resource for guest we want guest + * to control MSR_DE (enable/disable debug interrupt on need). + * Supporting both configurations are NOT possible. + * So the result is that we cannot share debug resources + * between QEMU and Guest on BOOKE architecture. + * In the current design QEMU gets the priority over guest, + * this means that if QEMU is using debug resources then guest + * cannot use them; + * For software breakpoint QEMU uses a privileged instruction; + * So there cannot be any reason that we are here for guest + * set debug exception, only possibility is guest executed a + * privileged / illegal instruction and that's why we are + * injecting a program interrupt. + */ + 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 0; } int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run) -- 2.17.1