From 696673d192f52c2c5a702224ee21f005318a844b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Thu, 16 Nov 2017 15:39:19 +0000 Subject: [PATCH] KVM: arm/arm64: debug: Introduce helper for single-step MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit After emulating instructions we may want return to user-space to handle single-step debugging. Introduce a helper function, which, if single-step is enabled, sets the run structure for return and returns true. Signed-off-by: Alex Bennée Reviewed-by: Julien Thierry Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 5 +++++ arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/debug.c | 21 +++++++++++++++++++++ 3 files changed, 27 insertions(+) diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 242151ea6908..a9f7d3f47134 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -285,6 +285,11 @@ static inline void kvm_arm_init_debug(void) {} static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {} static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {} static inline void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) {} +static inline bool kvm_arm_handle_step_debug(struct kvm_vcpu *vcpu, + struct kvm_run *run) +{ + return false; +} int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 674912d7a571..ea6cb5b24258 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -370,6 +370,7 @@ void kvm_arm_init_debug(void); 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); +bool kvm_arm_handle_step_debug(struct kvm_vcpu *vcpu, struct kvm_run *run); int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu, diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c index dbadfaf850a7..fa63b28c65e0 100644 --- a/arch/arm64/kvm/debug.c +++ b/arch/arm64/kvm/debug.c @@ -221,3 +221,24 @@ void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) } } } + + +/* + * After successfully emulating an instruction, we might want to + * return to user space with a KVM_EXIT_DEBUG. We can only do this + * once the emulation is complete, though, so for userspace emulations + * we have to wait until we have re-entered KVM before calling this + * helper. + * + * Return true (and set exit_reason) to return to userspace or false + * if no further action is required. + */ +bool kvm_arm_handle_step_debug(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) { + run->exit_reason = KVM_EXIT_DEBUG; + run->debug.arch.hsr = ESR_ELx_EC_SOFTSTP_LOW << ESR_ELx_EC_SHIFT; + return true; + } + return false; +}