diff options
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/arm64/kvm/arm.c | 2 | ||||
| -rw-r--r-- | arch/arm64/kvm/debug.c | 88 |
3 files changed, 63 insertions, 28 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 3d10e6527f7d..858c2fcfc043 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -713,6 +713,7 @@ static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} void kvm_arm_init_debug(void); +void kvm_arm_vcpu_init_debug(struct kvm_vcpu *vcpu); void kvm_arm_setup_debug(struct kvm_vcpu *vcpu); void kvm_arm_clear_debug(struct kvm_vcpu *vcpu); void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu); diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 7f06ba76698d..455274c704b8 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -580,6 +580,8 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu) vcpu->arch.has_run_once = true; + kvm_arm_vcpu_init_debug(vcpu); + if (likely(irqchip_in_kernel(kvm))) { /* * Map the VGIC hardware resources before running a vcpu the diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c index dbc890511631..2484b2cca74b 100644 --- a/arch/arm64/kvm/debug.c +++ b/arch/arm64/kvm/debug.c @@ -69,6 +69,64 @@ void kvm_arm_init_debug(void) } /** + * kvm_arm_setup_mdcr_el2 - configure vcpu mdcr_el2 value + * + * @vcpu: the vcpu pointer + * + * This ensures we will trap access to: + * - Performance monitors (MDCR_EL2_TPM/MDCR_EL2_TPMCR) + * - Debug ROM Address (MDCR_EL2_TDRA) + * - OS related registers (MDCR_EL2_TDOSA) + * - Statistical profiler (MDCR_EL2_TPMS/MDCR_EL2_E2PB) + * - Self-hosted Trace Filter controls (MDCR_EL2_TTRF) + */ +static void kvm_arm_setup_mdcr_el2(struct kvm_vcpu *vcpu) +{ + /* + * This also clears MDCR_EL2_E2PB_MASK to disable guest access + * to the profiling buffer. + */ + vcpu->arch.mdcr_el2 = __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK; + vcpu->arch.mdcr_el2 |= (MDCR_EL2_TPM | + MDCR_EL2_TPMS | + MDCR_EL2_TTRF | + MDCR_EL2_TPMCR | + MDCR_EL2_TDRA | + MDCR_EL2_TDOSA); + + /* Is the VM being debugged by userspace? */ + if (vcpu->guest_debug) + /* Route all software debug exceptions to EL2 */ + vcpu->arch.mdcr_el2 |= MDCR_EL2_TDE; + + /* + * Trap debug register access when one of the following is true: + * - Userspace is using the hardware to debug the guest + * (KVM_GUESTDBG_USE_HW is set). + * - The guest is not using debug (KVM_ARM64_DEBUG_DIRTY is clear). + */ + if ((vcpu->guest_debug & KVM_GUESTDBG_USE_HW) || + !(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)) + vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA; + + trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.mdcr_el2); +} + +/** + * kvm_arm_vcpu_init_debug - setup vcpu debug traps + * + * @vcpu: the vcpu pointer + * + * Set vcpu initial mdcr_el2 value. + */ +void kvm_arm_vcpu_init_debug(struct kvm_vcpu *vcpu) +{ + preempt_disable(); + kvm_arm_setup_mdcr_el2(vcpu); + preempt_enable(); +} + +/** * kvm_arm_reset_debug_ptr - reset the debug ptr to point to the vcpu state */ @@ -83,13 +141,7 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) * @vcpu: the vcpu pointer * * This is called before each entry into the hypervisor to setup any - * debug related registers. Currently this just ensures we will trap - * access to: - * - Performance monitors (MDCR_EL2_TPM/MDCR_EL2_TPMCR) - * - Debug ROM Address (MDCR_EL2_TDRA) - * - OS related registers (MDCR_EL2_TDOSA) - * - Statistical profiler (MDCR_EL2_TPMS/MDCR_EL2_E2PB) - * - Self-hosted Trace Filter controls (MDCR_EL2_TTRF) + * debug related registers. * * Additionally, KVM only traps guest accesses to the debug registers if * the guest is not actively using them (see the KVM_ARM64_DEBUG_DIRTY @@ -101,28 +153,14 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) { - bool trap_debug = !(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY); unsigned long mdscr, orig_mdcr_el2 = vcpu->arch.mdcr_el2; trace_kvm_arm_setup_debug(vcpu, vcpu->guest_debug); - /* - * This also clears MDCR_EL2_E2PB_MASK to disable guest access - * to the profiling buffer. - */ - vcpu->arch.mdcr_el2 = __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK; - vcpu->arch.mdcr_el2 |= (MDCR_EL2_TPM | - MDCR_EL2_TPMS | - MDCR_EL2_TTRF | - MDCR_EL2_TPMCR | - MDCR_EL2_TDRA | - MDCR_EL2_TDOSA); + kvm_arm_setup_mdcr_el2(vcpu); /* Is Guest debugging in effect? */ if (vcpu->guest_debug) { - /* Route all software debug exceptions to EL2 */ - vcpu->arch.mdcr_el2 |= MDCR_EL2_TDE; - /* Save guest debug state */ save_guest_debug_regs(vcpu); @@ -176,7 +214,6 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) vcpu->arch.debug_ptr = &vcpu->arch.external_debug_state; vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY; - trap_debug = true; trace_kvm_arm_set_regset("BKPTS", get_num_brps(), &vcpu->arch.debug_ptr->dbg_bcr[0], @@ -191,10 +228,6 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) BUG_ON(!vcpu->guest_debug && vcpu->arch.debug_ptr != &vcpu->arch.vcpu_debug_state); - /* Trap debug register access */ - if (trap_debug) - vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA; - /* If KDE or MDE are set, perform a full save/restore cycle. */ if (vcpu_read_sys_reg(vcpu, MDSCR_EL1) & (DBG_MDSCR_KDE | DBG_MDSCR_MDE)) vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY; @@ -203,7 +236,6 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) if (has_vhe() && orig_mdcr_el2 != vcpu->arch.mdcr_el2) write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); - trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.mdcr_el2); trace_kvm_arm_set_dreg32("MDSCR_EL1", vcpu_read_sys_reg(vcpu, MDSCR_EL1)); } |