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-rw-r--r--arch/arm64/include/asm/kvm_host.h3
-rw-r--r--arch/arm64/kvm/debug.c22
-rw-r--r--arch/arm64/kvm/guest.c1
-rw-r--r--arch/arm64/kvm/handle_exit.c8
4 files changed, 32 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index ccf8a144f009..45e2136322ba 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -536,6 +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 1bd2a1aee11c..56361e512b8a 100644
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c
@@ -200,7 +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);
@@ -274,6 +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;
}