KVM: arm64: nv: Compute NV view of idregs as a one-off

Now that we have a full copy of the idregs for each VM, there is
no point in repainting the sysregs on each access. Instead, we
can simply perform the transmation as a one-off and be done
with it.

Reviewed-by: Oliver Upton <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>

1 files changed, 15 insertions, 7 deletions

diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 042695a210ce..ba95d044bc98 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -23,13 +23,9 @@
  * This list should get updated as new features get added to the NV
  * support, and new extension to the architecture.
  */
-void access_nested_id_reg(struct kvm_vcpu *v, struct sys_reg_params *p,
-			  const struct sys_reg_desc *r)
+static u64 limit_nv_id_reg(u32 id, u64 val)
 {
-	u32 id = reg_to_encoding(r);
-	u64 val, tmp;
-
-	val = p->regval;
+	u64 tmp;
 
 	switch (id) {
 	case SYS_ID_AA64ISAR0_EL1:
@@ -158,5 +154,17 @@ void access_nested_id_reg(struct kvm_vcpu *v, struct sys_reg_params *p,
 		break;
 	}
 
-	p->regval = val;
+	return val;
+}
+int kvm_init_nv_sysregs(struct kvm *kvm)
+{
+	mutex_lock(&kvm->arch.config_lock);
+
+	for (int i = 0; i < KVM_ARM_ID_REG_NUM; i++)
+		kvm->arch.id_regs[i] = limit_nv_id_reg(IDX_IDREG(i),
+						       kvm->arch.id_regs[i]);
+
+	mutex_unlock(&kvm->arch.config_lock);
+
+	return 0;
 }