From: Hollis Blanchard <[EMAIL PROTECTED]> Allow host userspace to program hardware debug registers to set breakpoints inside guests.
Signed-off-by: Jerone Young <[EMAIL PROTECTED]> Signed-off-by: Hollis Blanchard <[EMAIL PROTECTED]> Signed-off-by: Avi Kivity <[EMAIL PROTECTED]> --- arch/powerpc/include/asm/kvm_host.h | 5 ++ arch/powerpc/kvm/booke_guest.c | 15 ++++++ arch/powerpc/kvm/booke_interrupts.S | 11 ++++- arch/powerpc/kvm/powerpc.c | 84 ++++++++++++++++++++++++++++++++++- 4 files changed, 113 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 2655e2a..23bad40 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -86,6 +86,11 @@ struct kvm_vcpu_arch { u32 host_stack; u32 host_pid; + u32 host_dbcr0; + u32 host_dbcr1; + u32 host_dbcr2; + u32 host_iac[4]; + u32 host_msr; u64 fpr[32]; u32 gpr[32]; diff --git a/arch/powerpc/kvm/booke_guest.c b/arch/powerpc/kvm/booke_guest.c index 9c8ad85..3cca079 100644 --- a/arch/powerpc/kvm/booke_guest.c +++ b/arch/powerpc/kvm/booke_guest.c @@ -410,6 +410,21 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu, break; } + case BOOKE_INTERRUPT_DEBUG: { + u32 dbsr; + + vcpu->arch.pc = mfspr(SPRN_CSRR0); + + /* clear IAC events in DBSR register */ + dbsr = mfspr(SPRN_DBSR); + dbsr &= DBSR_IAC1 | DBSR_IAC2 | DBSR_IAC3 | DBSR_IAC4; + mtspr(SPRN_DBSR, dbsr); + + run->exit_reason = KVM_EXIT_DEBUG; + r = RESUME_HOST; + break; + } + default: printk(KERN_EMERG "exit_nr %d\n", exit_nr); BUG(); diff --git a/arch/powerpc/kvm/booke_interrupts.S b/arch/powerpc/kvm/booke_interrupts.S index 3b653b5..8eaba26 100644 --- a/arch/powerpc/kvm/booke_interrupts.S +++ b/arch/powerpc/kvm/booke_interrupts.S @@ -42,7 +42,8 @@ #define HOST_STACK_LR (HOST_STACK_SIZE + 4) /* In caller stack frame. */ #define NEED_INST_MASK ((1<<BOOKE_INTERRUPT_PROGRAM) | \ - (1<<BOOKE_INTERRUPT_DTLB_MISS)) + (1<<BOOKE_INTERRUPT_DTLB_MISS) | \ + (1<<BOOKE_INTERRUPT_DEBUG)) #define NEED_DEAR_MASK ((1<<BOOKE_INTERRUPT_DATA_STORAGE) | \ (1<<BOOKE_INTERRUPT_DTLB_MISS)) @@ -431,6 +432,14 @@ lightweight_exit: oris r3, r3, [EMAIL PROTECTED] ori r3, r3, [EMAIL PROTECTED] mtsrr1 r3 + + /* Clear any debug events which occurred since we disabled MSR[DE]. + * XXX This gives us a 3-instruction window in which a breakpoint + * intended for guest context could fire in the host instead. */ + lis r3, 0xffff + ori r3, r3, 0xffff + mtspr SPRN_DBSR, r3 + lwz r3, VCPU_GPR(r3)(r4) lwz r4, VCPU_GPR(r4)(r4) rfi diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 53826a5..b756071 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -239,18 +239,100 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) { } +/* Note: clearing MSR[DE] just means that the debug interrupt will not be + * delivered *immediately*. Instead, it simply sets the appropriate DBSR bits. + * If those DBSR bits are still set when MSR[DE] is re-enabled, the interrupt + * will be delivered as an "imprecise debug event" (which is indicated by + * DBSR[IDE]. + */ +static void kvmppc_disable_debug_interrupts(void) +{ + mtmsr(mfmsr() & ~MSR_DE); +} + +static void kvmppc_restore_host_debug_state(struct kvm_vcpu *vcpu) +{ + kvmppc_disable_debug_interrupts(); + + mtspr(SPRN_IAC1, vcpu->arch.host_iac[0]); + mtspr(SPRN_IAC2, vcpu->arch.host_iac[1]); + mtspr(SPRN_IAC3, vcpu->arch.host_iac[2]); + mtspr(SPRN_IAC4, vcpu->arch.host_iac[3]); + mtspr(SPRN_DBCR1, vcpu->arch.host_dbcr1); + mtspr(SPRN_DBCR2, vcpu->arch.host_dbcr2); + mtspr(SPRN_DBCR0, vcpu->arch.host_dbcr0); + mtmsr(vcpu->arch.host_msr); +} + +static void kvmppc_load_guest_debug_registers(struct kvm_vcpu *vcpu) +{ + struct kvm_guest_debug *dbg = &vcpu->guest_debug; + u32 dbcr0 = 0; + + vcpu->arch.host_msr = mfmsr(); + kvmppc_disable_debug_interrupts(); + + /* Save host debug register state. */ + vcpu->arch.host_iac[0] = mfspr(SPRN_IAC1); + vcpu->arch.host_iac[1] = mfspr(SPRN_IAC2); + vcpu->arch.host_iac[2] = mfspr(SPRN_IAC3); + vcpu->arch.host_iac[3] = mfspr(SPRN_IAC4); + vcpu->arch.host_dbcr0 = mfspr(SPRN_DBCR0); + vcpu->arch.host_dbcr1 = mfspr(SPRN_DBCR1); + vcpu->arch.host_dbcr2 = mfspr(SPRN_DBCR2); + + /* set registers up for guest */ + + if (dbg->bp[0]) { + mtspr(SPRN_IAC1, dbg->bp[0]); + dbcr0 |= DBCR0_IAC1 | DBCR0_IDM; + } + if (dbg->bp[1]) { + mtspr(SPRN_IAC2, dbg->bp[1]); + dbcr0 |= DBCR0_IAC2 | DBCR0_IDM; + } + if (dbg->bp[2]) { + mtspr(SPRN_IAC3, dbg->bp[2]); + dbcr0 |= DBCR0_IAC3 | DBCR0_IDM; + } + if (dbg->bp[3]) { + mtspr(SPRN_IAC4, dbg->bp[3]); + dbcr0 |= DBCR0_IAC4 | DBCR0_IDM; + } + + mtspr(SPRN_DBCR0, dbcr0); + mtspr(SPRN_DBCR1, 0); + mtspr(SPRN_DBCR2, 0); +} + void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { + if (vcpu->guest_debug.enabled) + kvmppc_load_guest_debug_registers(vcpu); } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { + if (vcpu->guest_debug.enabled) + kvmppc_restore_host_debug_state(vcpu); } int kvm_arch_vcpu_ioctl_debug_guest(struct kvm_vcpu *vcpu, struct kvm_debug_guest *dbg) { - return -ENOTSUPP; + int i; + + vcpu->guest_debug.enabled = dbg->enabled; + if (vcpu->guest_debug.enabled) { + for (i=0; i < ARRAY_SIZE(vcpu->guest_debug.bp); i++) { + if (dbg->breakpoints[i].enabled) + vcpu->guest_debug.bp[i] = dbg->breakpoints[i].address; + else + vcpu->guest_debug.bp[i] = 0; + } + } + + return 0; } static void kvmppc_complete_dcr_load(struct kvm_vcpu *vcpu, -- 1.6.0.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html