1 /*
2  * Copyright 2025 The Hafnium Authors.
3  *
4  * Use of this source code is governed by a BSD-style
5  * license that can be found in the LICENSE file or at
6  * https://opensource.org/licenses/BSD-3-Clause.
7  */
8 
9 #include "hf/arch/ffa.h"
10 #include "hf/arch/other_world.h"
11 
12 #include "hf/check.h"
13 #include "hf/dlog.h"
14 #include "hf/ffa/setup_and_discovery.h"
15 #include "hf/vcpu.h"
16 #include "hf/vm.h"
17 
18 static bool ffa_tee_enabled = false;
19 
ffa_init_is_tee_enabled(void)20 bool ffa_init_is_tee_enabled(void)
21 {
22 	return ffa_tee_enabled;
23 }
24 
ffa_init_set_tee_enabled(bool tee_enabled)25 void ffa_init_set_tee_enabled(bool tee_enabled)
26 {
27 	ffa_tee_enabled = tee_enabled;
28 }
29 
ffa_init_log(void)30 void ffa_init_log(void)
31 {
32 	dlog_info("Initializing Hafnium (Hypervisor)\n");
33 }
34 
ffa_init(struct mpool * ppool)35 void ffa_init(struct mpool *ppool)
36 {
37 	struct vm *other_world_vm = vm_find(HF_OTHER_WORLD_ID);
38 	struct ffa_value ret;
39 	struct mm_stage1_locked mm_stage1_locked;
40 
41 	/* This is a segment from TDRAM for the NS memory in the FVP platform.
42 	 *
43 	 * TODO: We ought to provide a better way to do this, if porting the
44 	 * hypervisor to other platforms. One option would be to provide this
45 	 * via DTS.
46 	 */
47 	const uint64_t start = 0x90000000;
48 	const uint64_t len = 0x60000000;
49 	const paddr_t send_addr = pa_init(start + len - PAGE_SIZE * 1);
50 	const paddr_t recv_addr = pa_init(start + len - PAGE_SIZE * 2);
51 
52 	(void)ppool;
53 
54 	if (!ffa_init_is_tee_enabled()) {
55 		return;
56 	}
57 
58 	CHECK(other_world_vm != NULL);
59 
60 	arch_ffa_init();
61 
62 	/*
63 	 * Call FFA_VERSION so the SPMC can store the hypervisor's
64 	 * version. This may be useful if there is a mismatch of
65 	 * versions.
66 	 */
67 	ret = arch_other_world_call((struct ffa_value){
68 		.func = FFA_VERSION_32, .arg1 = FFA_VERSION_COMPILED});
69 	if (ret.func == FFA_NOT_SUPPORTED) {
70 		panic("Hypervisor and SPMC versions are not compatible.\n");
71 	}
72 
73 	/*
74 	 * Setup TEE VM RX/TX buffers.
75 	 * Using the following hard-coded addresses, as they must be within the
76 	 * NS memory node in the SPMC manifest. From that region we should
77 	 * exclude the Hypervisor's address space to prevent SPs from using that
78 	 * memory in memory region nodes, or for the NWd to misuse that memory
79 	 * in runtime via memory sharing interfaces.
80 	 */
81 
82 	// NOLINTNEXTLINE(performance-no-int-to-ptr)
83 	other_world_vm->mailbox.send = (void *)pa_addr(send_addr);
84 	// NOLINTNEXTLINE(performance-no-int-to-ptr)
85 	other_world_vm->mailbox.recv = (void *)pa_addr(recv_addr);
86 
87 	/*
88 	 * Note that send and recv are swapped around, as the send buffer from
89 	 * Hafnium's perspective is the recv buffer from the EL3 dispatcher's
90 	 * perspective and vice-versa.
91 	 */
92 	dlog_verbose("Setting up buffers for TEE.\n");
93 	ffa_setup_rxtx_map_spmc(
94 		pa_from_va(va_from_ptr(other_world_vm->mailbox.recv)),
95 		pa_from_va(va_from_ptr(other_world_vm->mailbox.send)),
96 		HF_MAILBOX_SIZE / FFA_PAGE_SIZE);
97 
98 	ffa_init_set_tee_enabled(true);
99 
100 	/*
101 	 * Hypervisor will write to secure world receive buffer, and will read
102 	 * from the secure world send buffer.
103 	 *
104 	 * Mapping operation is necessary because the ranges are outside of the
105 	 * hypervisor's binary.
106 	 */
107 	mm_stage1_locked = mm_lock_stage1();
108 	CHECK(mm_identity_map(mm_stage1_locked, send_addr,
109 			      pa_add(send_addr, PAGE_SIZE),
110 			      MM_MODE_R | MM_MODE_SHARED, ppool) != NULL);
111 	CHECK(mm_identity_map(
112 		      mm_stage1_locked, recv_addr, pa_add(recv_addr, PAGE_SIZE),
113 		      MM_MODE_R | MM_MODE_W | MM_MODE_SHARED, ppool) != NULL);
114 	mm_unlock_stage1(&mm_stage1_locked);
115 
116 	dlog_verbose("TEE finished setting up buffers.\n");
117 }
118