[PATCH v4 3/7] KVM: arm64: Support FFA_NOTIFICATION_BIND in host handler

[Sebastian Ene <sebastianene@google.com>]

Verify the arguments of the FF-A notification bind call and forward the
message to Trustzone.

Signed-off-by: Sebastian Ene <sebastianene@google.com>
---
 arch/arm64/kvm/hyp/nvhe/ffa.c | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index a72f6d4b62f0..1f38ad008675 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -42,6 +42,8 @@
  */
 #define HOST_FFA_ID	0
 
+#define FFA_NOTIF_RECEIVER_ENDP_MASK	GENMASK(15, 0)
+
 /*
  * A buffer to hold the maximum descriptor size we can see from the host,
  * which is required when the SPMD returns a fragmented FFA_MEM_RETRIEVE_RESP
@@ -713,7 +715,6 @@ static bool ffa_call_supported(u64 func_id)
 	case FFA_MEM_DONATE:
 	case FFA_MEM_RETRIEVE_REQ:
        /* Optional notification interfaces added in FF-A 1.1 */
-	case FFA_NOTIFICATION_BIND:
 	case FFA_NOTIFICATION_UNBIND:
 	case FFA_NOTIFICATION_SET:
 	case FFA_NOTIFICATION_GET:
@@ -928,6 +929,32 @@ static void do_ffa_notif_bitmap(struct arm_smccc_1_2_regs *res,
 	hyp_smccc_1_2_smc(args, res);
 }
 
+static void do_ffa_notif_bind(struct arm_smccc_1_2_regs *res,
+			      struct kvm_cpu_context *ctxt)
+{
+	DECLARE_REG(u32, endp_id, ctxt, 1);
+	DECLARE_REG(u32, flags, ctxt, 2);
+	struct arm_smccc_1_2_regs *args;
+
+	if (ffa_check_unused_args_sbz(ctxt, 5)) {
+		ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS);
+		return;
+	}
+
+	if (FIELD_GET(FFA_NOTIF_RECEIVER_ENDP_MASK, endp_id) != HOST_FFA_ID) {
+		ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS);
+		return;
+	}
+
+	if (flags > 1) {
+		ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS);
+		return;
+	}
+
+	args = (void *)&ctxt->regs.regs[0];
+	hyp_smccc_1_2_smc(args, res);
+}
+
 bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt, u32 func_id)
 {
 	struct arm_smccc_1_2_regs res;
@@ -990,6 +1017,9 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt, u32 func_id)
 	case FFA_NOTIFICATION_BITMAP_DESTROY:
 		do_ffa_notif_bitmap(&res, host_ctxt);
 		goto out_handled;
+	case FFA_NOTIFICATION_BIND:
+		do_ffa_notif_bind(&res, host_ctxt);
+		goto out_handled;
 	}
 
 	if (ffa_call_supported(func_id))
-- 
2.54.0.1136.gdb2ca164c4-goog