[PATCH v11 07/43] KVM: arm64: Introduce a bad_trap() primitive for unexpected trap handling

[Marc Zyngier]

In order to ease the debugging of NV, it is helpful to have the kernel
shout at you when an unexpected trap is handled. We already have this
in a couple of cases. Make this a more generic infrastructure that we
will make use of very shortly.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 6405d9ebc28a..a529ce5ba987 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -45,24 +45,31 @@ static u64 sys_reg_to_index(const struct sys_reg_desc *reg);
 static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
 		      u64 val);
 
-static bool read_from_write_only(struct kvm_vcpu *vcpu,
-				 struct sys_reg_params *params,
-				 const struct sys_reg_desc *r)
+static bool bad_trap(struct kvm_vcpu *vcpu,
+		     struct sys_reg_params *params,
+		     const struct sys_reg_desc *r,
+		     const char *msg)
 {
-	WARN_ONCE(1, "Unexpected sys_reg read to write-only register\n");
+	WARN_ONCE(1, "Unexpected %s\n", msg);
 	print_sys_reg_instr(params);
 	kvm_inject_undefined(vcpu);
 	return false;
 }
 
+static bool read_from_write_only(struct kvm_vcpu *vcpu,
+				 struct sys_reg_params *params,
+				 const struct sys_reg_desc *r)
+{
+	return bad_trap(vcpu, params, r,
+			"sys_reg read to write-only register");
+}
+
 static bool write_to_read_only(struct kvm_vcpu *vcpu,
 			       struct sys_reg_params *params,
 			       const struct sys_reg_desc *r)
 {
-	WARN_ONCE(1, "Unexpected sys_reg write to read-only register\n");
-	print_sys_reg_instr(params);
-	kvm_inject_undefined(vcpu);
-	return false;
+	return bad_trap(vcpu, params, r,
+			"sys_reg write to read-only register");
 }
 
 u64 vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg)
-- 
2.39.2