diff options
Diffstat (limited to 'arch/arm64/kvm/debug.c')
| -rw-r--r-- | arch/arm64/kvm/debug.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c index 0b28d7db7c76..1bd2a1aee11c 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; } /** |