[PATCH v3 2/7] KVM: arm64: Forward FFA_NOTIFICATION_BITMAP calls to Trustzone

[Sebastian Ene]

Allow FF-A notification bitmap messages to be forwarded to
Trustzone from the host kernel driver enforce checking for
SBZ fields.

Signed-off-by: Sebastian Ene <sebastianene at google.com>
---
 arch/arm64/kvm/hyp/nvhe/ffa.c | 28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index c723a21006aa..dc7496ec295f 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -713,8 +713,6 @@ 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_BITMAP_CREATE:
-	case FFA_NOTIFICATION_BITMAP_DESTROY:
 	case FFA_NOTIFICATION_BIND:
 	case FFA_NOTIFICATION_UNBIND:
 	case FFA_NOTIFICATION_SET:
@@ -909,6 +907,28 @@ static void do_ffa_part_get(struct arm_smccc_1_2_regs *res,
 	hyp_spin_unlock(&host_buffers.lock);
 }
 
+static void do_ffa_notif_bitmap(struct arm_smccc_1_2_regs *res,
+				struct kvm_cpu_context *ctxt)
+{
+	DECLARE_REG(u32, func_id, ctxt, 0);
+	DECLARE_REG(u32, vmid, ctxt, 1);
+	struct arm_smccc_1_2_regs *args;
+	u32 idx_unused_args = func_id == FFA_NOTIFICATION_BITMAP_CREATE ? 3 : 2;
+
+	if (ffa_check_unused_args_sbz(ctxt, idx_unused_args)) {
+		ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS);
+		return;
+	}
+
+	if (vmid != HOST_FFA_ID) {
+		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;
@@ -967,6 +987,10 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt, u32 func_id)
 	case FFA_PARTITION_INFO_GET:
 		do_ffa_part_get(&res, host_ctxt);
 		goto out_handled;
+	case FFA_NOTIFICATION_BITMAP_CREATE:
+	case FFA_NOTIFICATION_BITMAP_DESTROY:
+		do_ffa_notif_bitmap(&res, host_ctxt);
+		goto out_handled;
 	}
 
 	if (ffa_call_supported(func_id))
-- 
2.54.0.1136.gdb2ca164c4-goog