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Diffstat (limited to 'arch/arm64/kvm/handle_exit.c')
-rw-r--r--arch/arm64/kvm/handle_exit.c57
1 files changed, 42 insertions, 15 deletions
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index b71247995469..304203fa9e33 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -28,6 +28,7 @@
#include <asm/kvm_emulate.h>
#include <asm/kvm_mmu.h>
#include <asm/kvm_psci.h>
+#include <asm/debug-monitors.h>
#define CREATE_TRACE_POINTS
#include "trace.h"
@@ -187,14 +188,46 @@ static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
}
/*
+ * We may be single-stepping an emulated instruction. If the emulation
+ * has been completed in the kernel, we can return to userspace with a
+ * KVM_EXIT_DEBUG, otherwise userspace needs to complete its
+ * emulation first.
+ */
+static int handle_trap_exceptions(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+ int handled;
+
+ /*
+ * See ARM ARM B1.14.1: "Hyp traps on instructions
+ * that fail their condition code check"
+ */
+ if (!kvm_condition_valid(vcpu)) {
+ kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
+ handled = 1;
+ } else {
+ exit_handle_fn exit_handler;
+
+ exit_handler = kvm_get_exit_handler(vcpu);
+ handled = exit_handler(vcpu, run);
+ }
+
+ /*
+ * kvm_arm_handle_step_debug() sets the exit_reason on the kvm_run
+ * structure if we need to return to userspace.
+ */
+ if (handled > 0 && kvm_arm_handle_step_debug(vcpu, run))
+ handled = 0;
+
+ return handled;
+}
+
+/*
* Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
* proper exit to userspace.
*/
int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
int exception_index)
{
- exit_handle_fn exit_handler;
-
if (ARM_SERROR_PENDING(exception_index)) {
u8 hsr_ec = ESR_ELx_EC(kvm_vcpu_get_hsr(vcpu));
@@ -220,20 +253,14 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
return 1;
case ARM_EXCEPTION_EL1_SERROR:
kvm_inject_vabt(vcpu);
- return 1;
- case ARM_EXCEPTION_TRAP:
- /*
- * See ARM ARM B1.14.1: "Hyp traps on instructions
- * that fail their condition code check"
- */
- if (!kvm_condition_valid(vcpu)) {
- kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
+ /* We may still need to return for single-step */
+ if (!(*vcpu_cpsr(vcpu) & DBG_SPSR_SS)
+ && kvm_arm_handle_step_debug(vcpu, run))
+ return 0;
+ else
return 1;
- }
-
- exit_handler = kvm_get_exit_handler(vcpu);
-
- return exit_handler(vcpu, run);
+ case ARM_EXCEPTION_TRAP:
+ return handle_trap_exceptions(vcpu, run);
case ARM_EXCEPTION_HYP_GONE:
/*
* EL2 has been reset to the hyp-stub. This happens when a guest