| Message ID | 20170629071129.29362-3-bobby.prani@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Pranith Kumar <bobby.prani@gmail.com> writes: > In mttcg, calling pause_all_vcpus() during execution from the > generated TBs causes a deadlock if some vCPU is waiting for exclusive > execution in start_exclusive(). Fix this by using the aync_safe_* > framework instead of pausing vcpus for patching instructions. It looks like this needs to be re-based. Can you spin a new version and then I'll pull it into my tree while I look at fixing: https://lists.gnu.org/archive/html/qemu-devel/2017-07/msg01061.html > > CC: Paolo Bonzini <pbonzini@redhat.com> > CC: Peter Maydell <peter.maydell@linaro.org> > Reviewed-by: Richard Henderson <rth@twiddle.net> > Reviewed-by: Alex Bennée <alex.bennee@linaro.org> > Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> > --- > hw/i386/kvmvapic.c | 73 +++++++++++++++++++++++++++++++----------------------- > 1 file changed, 42 insertions(+), 31 deletions(-) > > diff --git a/hw/i386/kvmvapic.c b/hw/i386/kvmvapic.c > index 82a49556af..5e0c8219b0 100644 > --- a/hw/i386/kvmvapic.c > +++ b/hw/i386/kvmvapic.c > @@ -383,8 +383,7 @@ static void patch_byte(X86CPU *cpu, target_ulong addr, uint8_t byte) > cpu_memory_rw_debug(CPU(cpu), addr, &byte, 1, 1); > } > > -static void patch_call(VAPICROMState *s, X86CPU *cpu, target_ulong ip, > - uint32_t target) > +static void patch_call(X86CPU *cpu, target_ulong ip, uint32_t target) > { > uint32_t offset; > > @@ -393,23 +392,24 @@ static void patch_call(VAPICROMState *s, X86CPU *cpu, target_ulong ip, > cpu_memory_rw_debug(CPU(cpu), ip + 1, (void *)&offset, sizeof(offset), 1); > } > > -static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip) > +struct PatchInfo { > + VAPICHandlers *handler; > + target_ulong ip; > +}; > + > +static void do_patch_instruction(CPUState *cs, run_on_cpu_data data) > { > - CPUState *cs = CPU(cpu); > - CPUX86State *env = &cpu->env; > - VAPICHandlers *handlers; > + X86CPU *x86_cpu = X86_CPU(cs); > + CPUX86State *env = &x86_cpu->env; > + struct PatchInfo *info = (struct PatchInfo *) data.host_ptr; > + VAPICHandlers *handlers = info->handler; > + target_ulong ip = info->ip; > uint8_t opcode[2]; > uint32_t imm32 = 0; > target_ulong current_pc = 0; > target_ulong current_cs_base = 0; > uint32_t current_flags = 0; > > - if (smp_cpus == 1) { > - handlers = &s->rom_state.up; > - } else { > - handlers = &s->rom_state.mp; > - } > - > if (!kvm_enabled()) { > cpu_get_tb_cpu_state(env, ¤t_pc, ¤t_cs_base, > ¤t_flags); > @@ -421,48 +421,59 @@ static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip) > } > } > > - pause_all_vcpus(); > - > cpu_memory_rw_debug(cs, ip, opcode, sizeof(opcode), 0); > > switch (opcode[0]) { > case 0x89: /* mov r32 to r/m32 */ > - patch_byte(cpu, ip, 0x50 + modrm_reg(opcode[1])); /* push reg */ > - patch_call(s, cpu, ip + 1, handlers->set_tpr); > + patch_byte(x86_cpu, ip, 0x50 + modrm_reg(opcode[1])); /* push reg */ > + patch_call(x86_cpu, ip + 1, handlers->set_tpr); > break; > case 0x8b: /* mov r/m32 to r32 */ > - patch_byte(cpu, ip, 0x90); > - patch_call(s, cpu, ip + 1, handlers->get_tpr[modrm_reg(opcode[1])]); > + patch_byte(x86_cpu, ip, 0x90); > + patch_call(x86_cpu, ip + 1, handlers->get_tpr[modrm_reg(opcode[1])]); > break; > case 0xa1: /* mov abs to eax */ > - patch_call(s, cpu, ip, handlers->get_tpr[0]); > + patch_call(x86_cpu, ip, handlers->get_tpr[0]); > break; > case 0xa3: /* mov eax to abs */ > - patch_call(s, cpu, ip, handlers->set_tpr_eax); > + patch_call(x86_cpu, ip, handlers->set_tpr_eax); > break; > case 0xc7: /* mov imm32, r/m32 (c7/0) */ > - patch_byte(cpu, ip, 0x68); /* push imm32 */ > + patch_byte(x86_cpu, ip, 0x68); /* push imm32 */ > cpu_memory_rw_debug(cs, ip + 6, (void *)&imm32, sizeof(imm32), 0); > cpu_memory_rw_debug(cs, ip + 1, (void *)&imm32, sizeof(imm32), 1); > - patch_call(s, cpu, ip + 5, handlers->set_tpr); > + patch_call(x86_cpu, ip + 5, handlers->set_tpr); > break; > case 0xff: /* push r/m32 */ > - patch_byte(cpu, ip, 0x50); /* push eax */ > - patch_call(s, cpu, ip + 1, handlers->get_tpr_stack); > + patch_byte(x86_cpu, ip, 0x50); /* push eax */ > + patch_call(x86_cpu, ip + 1, handlers->get_tpr_stack); > break; > default: > abort(); > } > > - resume_all_vcpus(); > + g_free(info); > +} > > - if (!kvm_enabled()) { > - /* Both tb_lock and iothread_mutex will be reset when > - * longjmps back into the cpu_exec loop. */ > - tb_lock(); > - tb_gen_code(cs, current_pc, current_cs_base, current_flags, 1); > - cpu_loop_exit_noexc(cs); > +static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip) > +{ > + CPUState *cs = CPU(cpu); > + VAPICHandlers *handlers; > + struct PatchInfo *info; > + const run_on_cpu_func fn = do_patch_instruction; > + > + if (smp_cpus == 1) { > + handlers = &s->rom_state.up; > + } else { > + handlers = &s->rom_state.mp; > } > + > + info = g_new(struct PatchInfo, 1); > + info->handler = handlers; > + info->ip = ip; > + > + async_safe_run_on_cpu(cs, fn, RUN_ON_CPU_HOST_PTR(info)); > + cpu_exit(cs); > } > > void vapic_report_tpr_access(DeviceState *dev, CPUState *cs, target_ulong ip, -- Alex Bennée
On 29/06/2017 09:11, Pranith Kumar wrote: > In mttcg, calling pause_all_vcpus() during execution from the > generated TBs causes a deadlock if some vCPU is waiting for exclusive > execution in start_exclusive(). Fix this by using the aync_safe_* > framework instead of pausing vcpus for patching instructions. > > CC: Paolo Bonzini <pbonzini@redhat.com> > CC: Peter Maydell <peter.maydell@linaro.org> > Reviewed-by: Richard Henderson <rth@twiddle.net> > Reviewed-by: Alex Bennée <alex.bennee@linaro.org> > Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> > --- > hw/i386/kvmvapic.c | 73 +++++++++++++++++++++++++++++++----------------------- > 1 file changed, 42 insertions(+), 31 deletions(-) > > diff --git a/hw/i386/kvmvapic.c b/hw/i386/kvmvapic.c > index 82a49556af..5e0c8219b0 100644 > --- a/hw/i386/kvmvapic.c > +++ b/hw/i386/kvmvapic.c > @@ -383,8 +383,7 @@ static void patch_byte(X86CPU *cpu, target_ulong addr, uint8_t byte) > cpu_memory_rw_debug(CPU(cpu), addr, &byte, 1, 1); > } > > -static void patch_call(VAPICROMState *s, X86CPU *cpu, target_ulong ip, > - uint32_t target) > +static void patch_call(X86CPU *cpu, target_ulong ip, uint32_t target) > { > uint32_t offset; > > @@ -393,23 +392,24 @@ static void patch_call(VAPICROMState *s, X86CPU *cpu, target_ulong ip, > cpu_memory_rw_debug(CPU(cpu), ip + 1, (void *)&offset, sizeof(offset), 1); > } > > -static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip) > +struct PatchInfo { > + VAPICHandlers *handler; > + target_ulong ip; > +}; > + > +static void do_patch_instruction(CPUState *cs, run_on_cpu_data data) > { > - CPUState *cs = CPU(cpu); > - CPUX86State *env = &cpu->env; > - VAPICHandlers *handlers; > + X86CPU *x86_cpu = X86_CPU(cs); > + CPUX86State *env = &x86_cpu->env; > + struct PatchInfo *info = (struct PatchInfo *) data.host_ptr; > + VAPICHandlers *handlers = info->handler; > + target_ulong ip = info->ip; > uint8_t opcode[2]; > uint32_t imm32 = 0; > target_ulong current_pc = 0; > target_ulong current_cs_base = 0; > uint32_t current_flags = 0; > > - if (smp_cpus == 1) { > - handlers = &s->rom_state.up; > - } else { > - handlers = &s->rom_state.mp; > - } > - > if (!kvm_enabled()) { I think this "if" should stay in patch_instruction(), and... > cpu_get_tb_cpu_state(env, ¤t_pc, ¤t_cs_base, > ¤t_flags); > @@ -421,48 +421,59 @@ static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip) > } > } > > - pause_all_vcpus(); > - > cpu_memory_rw_debug(cs, ip, opcode, sizeof(opcode), 0); > > switch (opcode[0]) { > case 0x89: /* mov r32 to r/m32 */ > - patch_byte(cpu, ip, 0x50 + modrm_reg(opcode[1])); /* push reg */ > - patch_call(s, cpu, ip + 1, handlers->set_tpr); > + patch_byte(x86_cpu, ip, 0x50 + modrm_reg(opcode[1])); /* push reg */ > + patch_call(x86_cpu, ip + 1, handlers->set_tpr); > break; > case 0x8b: /* mov r/m32 to r32 */ > - patch_byte(cpu, ip, 0x90); > - patch_call(s, cpu, ip + 1, handlers->get_tpr[modrm_reg(opcode[1])]); > + patch_byte(x86_cpu, ip, 0x90); > + patch_call(x86_cpu, ip + 1, handlers->get_tpr[modrm_reg(opcode[1])]); > break; > case 0xa1: /* mov abs to eax */ > - patch_call(s, cpu, ip, handlers->get_tpr[0]); > + patch_call(x86_cpu, ip, handlers->get_tpr[0]); > break; > case 0xa3: /* mov eax to abs */ > - patch_call(s, cpu, ip, handlers->set_tpr_eax); > + patch_call(x86_cpu, ip, handlers->set_tpr_eax); > break; > case 0xc7: /* mov imm32, r/m32 (c7/0) */ > - patch_byte(cpu, ip, 0x68); /* push imm32 */ > + patch_byte(x86_cpu, ip, 0x68); /* push imm32 */ > cpu_memory_rw_debug(cs, ip + 6, (void *)&imm32, sizeof(imm32), 0); > cpu_memory_rw_debug(cs, ip + 1, (void *)&imm32, sizeof(imm32), 1); > - patch_call(s, cpu, ip + 5, handlers->set_tpr); > + patch_call(x86_cpu, ip + 5, handlers->set_tpr); > break; > case 0xff: /* push r/m32 */ > - patch_byte(cpu, ip, 0x50); /* push eax */ > - patch_call(s, cpu, ip + 1, handlers->get_tpr_stack); > + patch_byte(x86_cpu, ip, 0x50); /* push eax */ > + patch_call(x86_cpu, ip + 1, handlers->get_tpr_stack); > break; > default: > abort(); > } > > - resume_all_vcpus(); > + g_free(info); > +} > > - if (!kvm_enabled()) { > - /* Both tb_lock and iothread_mutex will be reset when > - * longjmps back into the cpu_exec loop. */ > - tb_lock(); > - tb_gen_code(cs, current_pc, current_cs_base, current_flags, 1); > - cpu_loop_exit_noexc(cs); > +static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip) > +{ > + CPUState *cs = CPU(cpu); > + VAPICHandlers *handlers; > + struct PatchInfo *info; > + const run_on_cpu_func fn = do_patch_instruction; > + > + if (smp_cpus == 1) { > + handlers = &s->rom_state.up; > + } else { > + handlers = &s->rom_state.mp; > } > + > + info = g_new(struct PatchInfo, 1); > + info->handler = handlers; > + info->ip = ip; > + > + async_safe_run_on_cpu(cs, fn, RUN_ON_CPU_HOST_PTR(info)); > + cpu_exit(cs); ... this cpu_exit is not necessary, since it's already done via async_safe_run_on_cpu->queue_work_on_cpu->qemu_cpu_kick. Thanks, Paolo > } > > void vapic_report_tpr_access(DeviceState *dev, CPUState *cs, target_ulong ip, >
diff --git a/hw/i386/kvmvapic.c b/hw/i386/kvmvapic.c index 82a49556af..5e0c8219b0 100644 --- a/hw/i386/kvmvapic.c +++ b/hw/i386/kvmvapic.c @@ -383,8 +383,7 @@ static void patch_byte(X86CPU *cpu, target_ulong addr, uint8_t byte) cpu_memory_rw_debug(CPU(cpu), addr, &byte, 1, 1); } -static void patch_call(VAPICROMState *s, X86CPU *cpu, target_ulong ip, - uint32_t target) +static void patch_call(X86CPU *cpu, target_ulong ip, uint32_t target) { uint32_t offset; @@ -393,23 +392,24 @@ static void patch_call(VAPICROMState *s, X86CPU *cpu, target_ulong ip, cpu_memory_rw_debug(CPU(cpu), ip + 1, (void *)&offset, sizeof(offset), 1); } -static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip) +struct PatchInfo { + VAPICHandlers *handler; + target_ulong ip; +}; + +static void do_patch_instruction(CPUState *cs, run_on_cpu_data data) { - CPUState *cs = CPU(cpu); - CPUX86State *env = &cpu->env; - VAPICHandlers *handlers; + X86CPU *x86_cpu = X86_CPU(cs); + CPUX86State *env = &x86_cpu->env; + struct PatchInfo *info = (struct PatchInfo *) data.host_ptr; + VAPICHandlers *handlers = info->handler; + target_ulong ip = info->ip; uint8_t opcode[2]; uint32_t imm32 = 0; target_ulong current_pc = 0; target_ulong current_cs_base = 0; uint32_t current_flags = 0; - if (smp_cpus == 1) { - handlers = &s->rom_state.up; - } else { - handlers = &s->rom_state.mp; - } - if (!kvm_enabled()) { cpu_get_tb_cpu_state(env, ¤t_pc, ¤t_cs_base, ¤t_flags); @@ -421,48 +421,59 @@ static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip) } } - pause_all_vcpus(); - cpu_memory_rw_debug(cs, ip, opcode, sizeof(opcode), 0); switch (opcode[0]) { case 0x89: /* mov r32 to r/m32 */ - patch_byte(cpu, ip, 0x50 + modrm_reg(opcode[1])); /* push reg */ - patch_call(s, cpu, ip + 1, handlers->set_tpr); + patch_byte(x86_cpu, ip, 0x50 + modrm_reg(opcode[1])); /* push reg */ + patch_call(x86_cpu, ip + 1, handlers->set_tpr); break; case 0x8b: /* mov r/m32 to r32 */ - patch_byte(cpu, ip, 0x90); - patch_call(s, cpu, ip + 1, handlers->get_tpr[modrm_reg(opcode[1])]); + patch_byte(x86_cpu, ip, 0x90); + patch_call(x86_cpu, ip + 1, handlers->get_tpr[modrm_reg(opcode[1])]); break; case 0xa1: /* mov abs to eax */ - patch_call(s, cpu, ip, handlers->get_tpr[0]); + patch_call(x86_cpu, ip, handlers->get_tpr[0]); break; case 0xa3: /* mov eax to abs */ - patch_call(s, cpu, ip, handlers->set_tpr_eax); + patch_call(x86_cpu, ip, handlers->set_tpr_eax); break; case 0xc7: /* mov imm32, r/m32 (c7/0) */ - patch_byte(cpu, ip, 0x68); /* push imm32 */ + patch_byte(x86_cpu, ip, 0x68); /* push imm32 */ cpu_memory_rw_debug(cs, ip + 6, (void *)&imm32, sizeof(imm32), 0); cpu_memory_rw_debug(cs, ip + 1, (void *)&imm32, sizeof(imm32), 1); - patch_call(s, cpu, ip + 5, handlers->set_tpr); + patch_call(x86_cpu, ip + 5, handlers->set_tpr); break; case 0xff: /* push r/m32 */ - patch_byte(cpu, ip, 0x50); /* push eax */ - patch_call(s, cpu, ip + 1, handlers->get_tpr_stack); + patch_byte(x86_cpu, ip, 0x50); /* push eax */ + patch_call(x86_cpu, ip + 1, handlers->get_tpr_stack); break; default: abort(); } - resume_all_vcpus(); + g_free(info); +} - if (!kvm_enabled()) { - /* Both tb_lock and iothread_mutex will be reset when - * longjmps back into the cpu_exec loop. */ - tb_lock(); - tb_gen_code(cs, current_pc, current_cs_base, current_flags, 1); - cpu_loop_exit_noexc(cs); +static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip) +{ + CPUState *cs = CPU(cpu); + VAPICHandlers *handlers; + struct PatchInfo *info; + const run_on_cpu_func fn = do_patch_instruction; + + if (smp_cpus == 1) { + handlers = &s->rom_state.up; + } else { + handlers = &s->rom_state.mp; } + + info = g_new(struct PatchInfo, 1); + info->handler = handlers; + info->ip = ip; + + async_safe_run_on_cpu(cs, fn, RUN_ON_CPU_HOST_PTR(info)); + cpu_exit(cs); } void vapic_report_tpr_access(DeviceState *dev, CPUState *cs, target_ulong ip,