diff options
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 4 | ||||
| -rw-r--r-- | arch/arm64/kvm/debug.c | 34 | ||||
| -rw-r--r-- | arch/arm64/kvm/guest.c | 1 | ||||
| -rw-r--r-- | arch/arm64/kvm/handle_exit.c | 8 |
4 files changed, 45 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index e9c9388ccc02..45e2136322ba 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -393,6 +393,7 @@ struct kvm_vcpu_arch { */ struct { u32 mdscr_el1; + bool pstate_ss; } guest_debug_preserved; /* vcpu power state */ @@ -535,6 +536,9 @@ struct kvm_vcpu_arch { #define IN_WFIT __vcpu_single_flag(sflags, BIT(3)) /* vcpu system registers loaded on physical CPU */ #define SYSREGS_ON_CPU __vcpu_single_flag(sflags, BIT(4)) +/* Software step state is Active-pending */ +#define DBG_SS_ACTIVE_PENDING __vcpu_single_flag(sflags, BIT(5)) + /* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */ #define vcpu_sve_pffr(vcpu) (kern_hyp_va((vcpu)->arch.sve_state) + \ diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c index 3f7563d768e2..fccf9ec01813 100644 --- a/arch/arm64/kvm/debug.c +++ b/arch/arm64/kvm/debug.c @@ -32,6 +32,10 @@ static DEFINE_PER_CPU(u64, mdcr_el2); * * Guest access to MDSCR_EL1 is trapped by the hypervisor and handled * after we have restored the preserved value to the main context. + * + * When single-step is enabled by userspace, we tweak PSTATE.SS on every + * guest entry. Preserve PSTATE.SS so we can restore the original value + * for the vcpu after the single-step is disabled. */ static void save_guest_debug_regs(struct kvm_vcpu *vcpu) { @@ -41,6 +45,9 @@ static void save_guest_debug_regs(struct kvm_vcpu *vcpu) trace_kvm_arm_set_dreg32("Saved MDSCR_EL1", vcpu->arch.guest_debug_preserved.mdscr_el1); + + vcpu->arch.guest_debug_preserved.pstate_ss = + (*vcpu_cpsr(vcpu) & DBG_SPSR_SS); } static void restore_guest_debug_regs(struct kvm_vcpu *vcpu) @@ -51,6 +58,11 @@ static void restore_guest_debug_regs(struct kvm_vcpu *vcpu) trace_kvm_arm_set_dreg32("Restored MDSCR_EL1", vcpu_read_sys_reg(vcpu, MDSCR_EL1)); + + if (vcpu->arch.guest_debug_preserved.pstate_ss) + *vcpu_cpsr(vcpu) |= DBG_SPSR_SS; + else + *vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS; } /** @@ -188,7 +200,18 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) * debugging the system. */ if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) { - *vcpu_cpsr(vcpu) |= DBG_SPSR_SS; + /* + * If the software step state at the last guest exit + * was Active-pending, we don't set DBG_SPSR_SS so + * that the state is maintained (to not run another + * single-step until the pending Software Step + * exception is taken). + */ + if (!vcpu_get_flag(vcpu, DBG_SS_ACTIVE_PENDING)) + *vcpu_cpsr(vcpu) |= DBG_SPSR_SS; + else + *vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS; + mdscr = vcpu_read_sys_reg(vcpu, MDSCR_EL1); mdscr |= DBG_MDSCR_SS; vcpu_write_sys_reg(vcpu, mdscr, MDSCR_EL1); @@ -262,6 +285,15 @@ void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) * Restore the guest's debug registers if we were using them. */ if (vcpu->guest_debug || kvm_vcpu_os_lock_enabled(vcpu)) { + if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) { + if (!(*vcpu_cpsr(vcpu) & DBG_SPSR_SS)) + /* + * Mark the vcpu as ACTIVE_PENDING + * until Software Step exception is taken. + */ + vcpu_set_flag(vcpu, DBG_SS_ACTIVE_PENDING); + } + restore_guest_debug_regs(vcpu); /* diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index f802a3b3f8db..2ff13a3f8479 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -937,6 +937,7 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, } else { /* If not enabled clear all flags */ vcpu->guest_debug = 0; + vcpu_clear_flag(vcpu, DBG_SS_ACTIVE_PENDING); } out: diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index bbe5b393d689..e778eefcf214 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -152,8 +152,14 @@ static int kvm_handle_guest_debug(struct kvm_vcpu *vcpu) run->debug.arch.hsr_high = upper_32_bits(esr); run->flags = KVM_DEBUG_ARCH_HSR_HIGH_VALID; - if (ESR_ELx_EC(esr) == ESR_ELx_EC_WATCHPT_LOW) + switch (ESR_ELx_EC(esr)) { + case ESR_ELx_EC_WATCHPT_LOW: run->debug.arch.far = vcpu->arch.fault.far_el2; + break; + case ESR_ELx_EC_SOFTSTP_LOW: + vcpu_clear_flag(vcpu, DBG_SS_ACTIVE_PENDING); + break; + } return 0; } |