| Message ID | 1410107494-25556-2-git-send-email-maddy@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07.09.14 18:31, Madhavan Srinivasan wrote: > This patch adds kernel side support for software breakpoint. > Design is that, by using an illegal instruction, we trap to hypervisor > via Emulation Assistance interrupt, where we check for the illegal instruction > and accordingly we return to Host or Guest. Patch also adds support for > software breakpoint in PR KVM. > > Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> > --- > arch/powerpc/include/asm/kvm_ppc.h | 6 ++++++ > arch/powerpc/kvm/book3s.c | 3 ++- > arch/powerpc/kvm/book3s_hv.c | 41 ++++++++++++++++++++++++++++++++++---- > arch/powerpc/kvm/book3s_pr.c | 3 +++ > arch/powerpc/kvm/emulate.c | 18 +++++++++++++++++ > 5 files changed, 66 insertions(+), 5 deletions(-) > > diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h > index fb86a22..dd83c9a 100644 > --- a/arch/powerpc/include/asm/kvm_ppc.h > +++ b/arch/powerpc/include/asm/kvm_ppc.h > @@ -38,6 +38,12 @@ > #include <asm/paca.h> > #endif > > +/* > + * KVMPPC_INST_SW_BREAKPOINT is debug Instruction > + * for supporting software breakpoint. > + */ > +#define KVMPPC_INST_SW_BREAKPOINT 0x00dddd00 > + > enum emulation_result { > EMULATE_DONE, /* no further processing */ > EMULATE_DO_MMIO, /* kvm_run filled with MMIO request */ > diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c > index dd03f6b..00e9c9f 100644 > --- a/arch/powerpc/kvm/book3s.c > +++ b/arch/powerpc/kvm/book3s.c > @@ -778,7 +778,8 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu, > int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, > struct kvm_guest_debug *dbg) > { > - return -EINVAL; > + vcpu->guest_debug = dbg->control; > + return 0; > } > > void kvmppc_decrementer_func(unsigned long data) > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c > index 27cced9..3a2414c 100644 > --- a/arch/powerpc/kvm/book3s_hv.c > +++ b/arch/powerpc/kvm/book3s_hv.c > @@ -725,6 +725,30 @@ static int kvmppc_hcall_impl_hv(unsigned long cmd) > return kvmppc_hcall_impl_hv_realmode(cmd); > } > > +static int kvmppc_emulate_debug_inst(struct kvm_run *run, > + struct kvm_vcpu *vcpu) > +{ > + u32 last_inst; > + > + if(kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) != > + EMULATE_DONE) { > + /* > + * Fetch failed, so return to guest and > + * try executing it again. > + */ > + return RESUME_GUEST; Please end the if() here. In the kernel we usually treat abort situations as separate. > + } else { > + if (last_inst == KVMPPC_INST_SW_BREAKPOINT) { > + run->exit_reason = KVM_EXIT_DEBUG; > + run->debug.arch.address = kvmppc_get_pc(vcpu); > + return RESUME_HOST; > + } else { > + kvmppc_core_queue_program(vcpu, SRR1_PROGILL); > + return RESUME_GUEST; > + } > + } > +} > + > static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu, > struct task_struct *tsk) > { > @@ -807,12 +831,18 @@ static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu, > break; > /* > * This occurs if the guest executes an illegal instruction. > - * We just generate a program interrupt to the guest, since > - * we don't emulate any guest instructions at this stage. > + * If the guest debug is disabled, generate a program interrupt > + * to the guest. If guest debug is enabled, we need to check > + * whether the instruction is a software breakpoint instruction. > + * Accordingly return to Guest or Host. > */ > case BOOK3S_INTERRUPT_H_EMUL_ASSIST: > - kvmppc_core_queue_program(vcpu, SRR1_PROGILL); > - r = RESUME_GUEST; > + if(vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP) { > + r = kvmppc_emulate_debug_inst(run, vcpu); > + } else { > + kvmppc_core_queue_program(vcpu, SRR1_PROGILL); > + r = RESUME_GUEST; > + } > break; > /* > * This occurs if the guest (kernel or userspace), does something that > @@ -922,6 +952,9 @@ static int kvmppc_get_one_reg_hv(struct kvm_vcpu *vcpu, u64 id, > long int i; > > switch (id) { > + case KVM_REG_PPC_DEBUG_INST: > + *val = get_reg_val(id, KVMPPC_INST_SW_BREAKPOINT); > + break; > case KVM_REG_PPC_HIOR: > *val = get_reg_val(id, 0); > break; > diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c > index faffb27..6d73708 100644 > --- a/arch/powerpc/kvm/book3s_pr.c > +++ b/arch/powerpc/kvm/book3s_pr.c > @@ -1319,6 +1319,9 @@ static int kvmppc_get_one_reg_pr(struct kvm_vcpu *vcpu, u64 id, > int r = 0; > > switch (id) { > + case KVM_REG_PPC_DEBUG_INST: > + *val = get_reg_val(id, KVMPPC_INST_SW_BREAKPOINT); > + break; > case KVM_REG_PPC_HIOR: > *val = get_reg_val(id, to_book3s(vcpu)->hior); > break; > diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c > index e96b50d..30f326b 100644 > --- a/arch/powerpc/kvm/emulate.c > +++ b/arch/powerpc/kvm/emulate.c > @@ -274,6 +274,24 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu) > } > break; > > + case 0: > + /* > + * Instruction with primary opcode 0. Based on PowerISA > + * these are illegal instructions. > + */ > + if(inst == KVMPPC_INST_SW_BREAKPOINT) { Here you're missing a space between if and (. Are you sure that you ran checkpatch.pl? > + run->exit_reason = KVM_EXIT_DEBUG; > + run->debug.arch.address = kvmppc_get_pc(vcpu); > + emulated = EMULATE_EXIT_USER; > + advance = 0; > + printk(KERN_INFO "pr_emulate: debug instr \n"); > + } else { > + kvmppc_core_queue_program(vcpu, SRR1_PROGILL); > + emulated = EMULATE_DONE; > + advance = 0; Just set emulated = EMULATE_FAIL here, the same as default:. Alex > + } > + break; > + > default: > emulated = EMULATE_FAIL; > } > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Monday 08 September 2014 06:35 PM, Alexander Graf wrote: > > > On 07.09.14 18:31, Madhavan Srinivasan wrote: >> This patch adds kernel side support for software breakpoint. >> Design is that, by using an illegal instruction, we trap to hypervisor >> via Emulation Assistance interrupt, where we check for the illegal instruction >> and accordingly we return to Host or Guest. Patch also adds support for >> software breakpoint in PR KVM. >> >> Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> >> --- >> arch/powerpc/include/asm/kvm_ppc.h | 6 ++++++ >> arch/powerpc/kvm/book3s.c | 3 ++- >> arch/powerpc/kvm/book3s_hv.c | 41 ++++++++++++++++++++++++++++++++++---- >> arch/powerpc/kvm/book3s_pr.c | 3 +++ >> arch/powerpc/kvm/emulate.c | 18 +++++++++++++++++ >> 5 files changed, 66 insertions(+), 5 deletions(-) >> >> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h >> index fb86a22..dd83c9a 100644 >> --- a/arch/powerpc/include/asm/kvm_ppc.h >> +++ b/arch/powerpc/include/asm/kvm_ppc.h >> @@ -38,6 +38,12 @@ >> #include <asm/paca.h> >> #endif >> >> +/* >> + * KVMPPC_INST_SW_BREAKPOINT is debug Instruction >> + * for supporting software breakpoint. >> + */ >> +#define KVMPPC_INST_SW_BREAKPOINT 0x00dddd00 >> + >> enum emulation_result { >> EMULATE_DONE, /* no further processing */ >> EMULATE_DO_MMIO, /* kvm_run filled with MMIO request */ >> diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c >> index dd03f6b..00e9c9f 100644 >> --- a/arch/powerpc/kvm/book3s.c >> +++ b/arch/powerpc/kvm/book3s.c >> @@ -778,7 +778,8 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu, >> int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, >> struct kvm_guest_debug *dbg) >> { >> - return -EINVAL; >> + vcpu->guest_debug = dbg->control; >> + return 0; >> } >> >> void kvmppc_decrementer_func(unsigned long data) >> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c >> index 27cced9..3a2414c 100644 >> --- a/arch/powerpc/kvm/book3s_hv.c >> +++ b/arch/powerpc/kvm/book3s_hv.c >> @@ -725,6 +725,30 @@ static int kvmppc_hcall_impl_hv(unsigned long cmd) >> return kvmppc_hcall_impl_hv_realmode(cmd); >> } >> >> +static int kvmppc_emulate_debug_inst(struct kvm_run *run, >> + struct kvm_vcpu *vcpu) >> +{ >> + u32 last_inst; >> + >> + if(kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) != >> + EMULATE_DONE) { >> + /* >> + * Fetch failed, so return to guest and >> + * try executing it again. >> + */ >> + return RESUME_GUEST; > > Please end the if() here. In the kernel we usually treat abort > situations as separate. > OK. Will change it. >> + } else { >> + if (last_inst == KVMPPC_INST_SW_BREAKPOINT) { >> + run->exit_reason = KVM_EXIT_DEBUG; >> + run->debug.arch.address = kvmppc_get_pc(vcpu); >> + return RESUME_HOST; >> + } else { >> + kvmppc_core_queue_program(vcpu, SRR1_PROGILL); >> + return RESUME_GUEST; >> + } >> + } >> +} >> + >> static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu, >> struct task_struct *tsk) >> { >> @@ -807,12 +831,18 @@ static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu, >> break; >> /* >> * This occurs if the guest executes an illegal instruction. >> - * We just generate a program interrupt to the guest, since >> - * we don't emulate any guest instructions at this stage. >> + * If the guest debug is disabled, generate a program interrupt >> + * to the guest. If guest debug is enabled, we need to check >> + * whether the instruction is a software breakpoint instruction. >> + * Accordingly return to Guest or Host. >> */ >> case BOOK3S_INTERRUPT_H_EMUL_ASSIST: >> - kvmppc_core_queue_program(vcpu, SRR1_PROGILL); >> - r = RESUME_GUEST; >> + if(vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP) { >> + r = kvmppc_emulate_debug_inst(run, vcpu); >> + } else { >> + kvmppc_core_queue_program(vcpu, SRR1_PROGILL); >> + r = RESUME_GUEST; >> + } >> break; >> /* >> * This occurs if the guest (kernel or userspace), does something that >> @@ -922,6 +952,9 @@ static int kvmppc_get_one_reg_hv(struct kvm_vcpu *vcpu, u64 id, >> long int i; >> >> switch (id) { >> + case KVM_REG_PPC_DEBUG_INST: >> + *val = get_reg_val(id, KVMPPC_INST_SW_BREAKPOINT); >> + break; >> case KVM_REG_PPC_HIOR: >> *val = get_reg_val(id, 0); >> break; >> diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c >> index faffb27..6d73708 100644 >> --- a/arch/powerpc/kvm/book3s_pr.c >> +++ b/arch/powerpc/kvm/book3s_pr.c >> @@ -1319,6 +1319,9 @@ static int kvmppc_get_one_reg_pr(struct kvm_vcpu *vcpu, u64 id, >> int r = 0; >> >> switch (id) { >> + case KVM_REG_PPC_DEBUG_INST: >> + *val = get_reg_val(id, KVMPPC_INST_SW_BREAKPOINT); >> + break; >> case KVM_REG_PPC_HIOR: >> *val = get_reg_val(id, to_book3s(vcpu)->hior); >> break; >> diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c >> index e96b50d..30f326b 100644 >> --- a/arch/powerpc/kvm/emulate.c >> +++ b/arch/powerpc/kvm/emulate.c >> @@ -274,6 +274,24 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu) >> } >> break; >> >> + case 0: >> + /* >> + * Instruction with primary opcode 0. Based on PowerISA >> + * these are illegal instructions. >> + */ >> + if(inst == KVMPPC_INST_SW_BREAKPOINT) { > > Here you're missing a space between if and (. Are you sure that you ran > checkpatch.pl? > No. my bad. Did not run checkpatch.pl. Will fix it. > >> + run->exit_reason = KVM_EXIT_DEBUG; >> + run->debug.arch.address = kvmppc_get_pc(vcpu); >> + emulated = EMULATE_EXIT_USER; >> + advance = 0; >> + printk(KERN_INFO "pr_emulate: debug instr \n"); >> + } else { >> + kvmppc_core_queue_program(vcpu, SRR1_PROGILL); >> + emulated = EMULATE_DONE; >> + advance = 0; > > Just set emulated = EMULATE_FAIL here, the same as default:. > > Ok sure will do. Thanks for review. Maddy > Alex > >> + } >> + break; >> + >> default: >> emulated = EMULATE_FAIL; >> } >> > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h index fb86a22..dd83c9a 100644 --- a/arch/powerpc/include/asm/kvm_ppc.h +++ b/arch/powerpc/include/asm/kvm_ppc.h @@ -38,6 +38,12 @@ #include <asm/paca.h> #endif +/* + * KVMPPC_INST_SW_BREAKPOINT is debug Instruction + * for supporting software breakpoint. + */ +#define KVMPPC_INST_SW_BREAKPOINT 0x00dddd00 + enum emulation_result { EMULATE_DONE, /* no further processing */ EMULATE_DO_MMIO, /* kvm_run filled with MMIO request */ diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index dd03f6b..00e9c9f 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -778,7 +778,8 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu, int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg) { - return -EINVAL; + vcpu->guest_debug = dbg->control; + return 0; } void kvmppc_decrementer_func(unsigned long data) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 27cced9..3a2414c 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -725,6 +725,30 @@ static int kvmppc_hcall_impl_hv(unsigned long cmd) return kvmppc_hcall_impl_hv_realmode(cmd); } +static int kvmppc_emulate_debug_inst(struct kvm_run *run, + struct kvm_vcpu *vcpu) +{ + u32 last_inst; + + if(kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) != + EMULATE_DONE) { + /* + * Fetch failed, so return to guest and + * try executing it again. + */ + return RESUME_GUEST; + } else { + if (last_inst == KVMPPC_INST_SW_BREAKPOINT) { + run->exit_reason = KVM_EXIT_DEBUG; + run->debug.arch.address = kvmppc_get_pc(vcpu); + return RESUME_HOST; + } else { + kvmppc_core_queue_program(vcpu, SRR1_PROGILL); + return RESUME_GUEST; + } + } +} + static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu, struct task_struct *tsk) { @@ -807,12 +831,18 @@ static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu, break; /* * This occurs if the guest executes an illegal instruction. - * We just generate a program interrupt to the guest, since - * we don't emulate any guest instructions at this stage. + * If the guest debug is disabled, generate a program interrupt + * to the guest. If guest debug is enabled, we need to check + * whether the instruction is a software breakpoint instruction. + * Accordingly return to Guest or Host. */ case BOOK3S_INTERRUPT_H_EMUL_ASSIST: - kvmppc_core_queue_program(vcpu, SRR1_PROGILL); - r = RESUME_GUEST; + if(vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP) { + r = kvmppc_emulate_debug_inst(run, vcpu); + } else { + kvmppc_core_queue_program(vcpu, SRR1_PROGILL); + r = RESUME_GUEST; + } break; /* * This occurs if the guest (kernel or userspace), does something that @@ -922,6 +952,9 @@ static int kvmppc_get_one_reg_hv(struct kvm_vcpu *vcpu, u64 id, long int i; switch (id) { + case KVM_REG_PPC_DEBUG_INST: + *val = get_reg_val(id, KVMPPC_INST_SW_BREAKPOINT); + break; case KVM_REG_PPC_HIOR: *val = get_reg_val(id, 0); break; diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index faffb27..6d73708 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -1319,6 +1319,9 @@ static int kvmppc_get_one_reg_pr(struct kvm_vcpu *vcpu, u64 id, int r = 0; switch (id) { + case KVM_REG_PPC_DEBUG_INST: + *val = get_reg_val(id, KVMPPC_INST_SW_BREAKPOINT); + break; case KVM_REG_PPC_HIOR: *val = get_reg_val(id, to_book3s(vcpu)->hior); break; diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c index e96b50d..30f326b 100644 --- a/arch/powerpc/kvm/emulate.c +++ b/arch/powerpc/kvm/emulate.c @@ -274,6 +274,24 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu) } break; + case 0: + /* + * Instruction with primary opcode 0. Based on PowerISA + * these are illegal instructions. + */ + if(inst == KVMPPC_INST_SW_BREAKPOINT) { + run->exit_reason = KVM_EXIT_DEBUG; + run->debug.arch.address = kvmppc_get_pc(vcpu); + emulated = EMULATE_EXIT_USER; + advance = 0; + printk(KERN_INFO "pr_emulate: debug instr \n"); + } else { + kvmppc_core_queue_program(vcpu, SRR1_PROGILL); + emulated = EMULATE_DONE; + advance = 0; + } + break; + default: emulated = EMULATE_FAIL; }
This patch adds kernel side support for software breakpoint. Design is that, by using an illegal instruction, we trap to hypervisor via Emulation Assistance interrupt, where we check for the illegal instruction and accordingly we return to Host or Guest. Patch also adds support for software breakpoint in PR KVM. Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> --- arch/powerpc/include/asm/kvm_ppc.h | 6 ++++++ arch/powerpc/kvm/book3s.c | 3 ++- arch/powerpc/kvm/book3s_hv.c | 41 ++++++++++++++++++++++++++++++++++---- arch/powerpc/kvm/book3s_pr.c | 3 +++ arch/powerpc/kvm/emulate.c | 18 +++++++++++++++++ 5 files changed, 66 insertions(+), 5 deletions(-)