[PATCH 1/3] KVM: arm64: Simplify handling of CNTKCTL_EL12

[Marc Zyngier]

We go trough a great deal of effort to map CNTKCTL_EL12 to CNTKCTL_EL1
while hidding this mapping from userspace via a special visibility helper.

However, it would be far simpler to just provide an accessor doing the
mapping job, removing the need for a visibility helper.

With that done, we can also remove the EL12_REG() macro which serves
no purpose.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 45c9e3b2acd4..5328fac8d547 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2105,15 +2105,6 @@ static unsigned int hidden_user_visibility(const struct kvm_vcpu *vcpu,
 	return REG_HIDDEN_USER;
 }
 
-#define EL12_REG(name, acc, rst, v) {		\
-	SYS_DESC(SYS_##name##_EL12),		\
-	.access = acc,				\
-	.reset = rst,				\
-	.reg = name##_EL1,			\
-	.val = v,				\
-	.visibility = hidden_user_visibility,	\
-}
-
 /*
  * Since reset() callback and field val are not used for idregs, they will be
  * used for specific purposes for idregs.
@@ -2221,6 +2212,18 @@ static bool access_spsr(struct kvm_vcpu *vcpu,
 	return true;
 }
 
+static bool access_cntkctl_el12(struct kvm_vcpu *vcpu,
+				struct sys_reg_params *p,
+				const struct sys_reg_desc *r)
+{
+	if (p->is_write)
+		__vcpu_sys_reg(vcpu, CNTKCTL_EL1) = p->regval;
+	else
+		p->regval = __vcpu_sys_reg(vcpu, CNTKCTL_EL1);
+
+	return true;
+}
+
 static u64 reset_hcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
 {
 	u64 val = r->val;
@@ -2825,7 +2828,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	EL2_REG_VNCR(CNTVOFF_EL2, reset_val, 0),
 	EL2_REG(CNTHCTL_EL2, access_rw, reset_val, 0),
 
-	EL12_REG(CNTKCTL, access_rw, reset_val, 0),
+	{ SYS_DESC(SYS_CNTKCTL_EL12), access_cntkctl_el12 },
 
 	EL2_REG(SP_EL2, NULL, reset_unknown, 0),
 };
-- 
2.39.2