[PATCH v8 2/7] KVM: arm64: Use SMCCC 1.2 for FF-A initialization and in host handler
Per Larsen via B4 Relay
devnull+perlarsen.google.com at kernel.org
Fri Jul 18 19:11:24 PDT 2025
From: Per Larsen <perlarsen at google.com>
SMCCC 1.1 and prior allows four registers to be sent back as a result
of an FF-A interface. SMCCC 1.2 increases the number of results that can
be sent back to 8 and 16 for 32-bit and 64-bit SMC/HVCs respectively.
FF-A 1.0 references SMCCC 1.2 (reference [4] on page xi) and FF-A 1.2
explicitly requires SMCCC 1.2 so it should be safe to use this version
unconditionally. Moreover, it is simpler to implement FF-A features
without having to worry about compatibility with SMCCC 1.1 and older.
Update the FF-A initialization and host handler code to use SMCCC 1.2.
Signed-off-by: Per Larsen <perlarsen at google.com>
---
arch/arm64/kvm/hyp/nvhe/Makefile | 1 +
arch/arm64/kvm/hyp/nvhe/ffa.c | 186 ++++++++++++++++++++++++---------------
2 files changed, 118 insertions(+), 69 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index a76522d63c3e630795db5972a99abc3d24bc5e26..f859a8fb41a25effea1edd977bef889423153399 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -27,6 +27,7 @@ hyp-obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o
cache.o setup.o mm.o mem_protect.o sys_regs.o pkvm.o stacktrace.o ffa.o
hyp-obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
../fpsimd.o ../hyp-entry.o ../exception.o ../pgtable.o
+hyp-obj-y += ../../../kernel/smccc-call.o
hyp-obj-$(CONFIG_LIST_HARDENED) += list_debug.o
hyp-obj-y += $(lib-objs)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 2c199d40811efb5bfae199c4a67d8ae3d9307357..52ac3e2689f0c200ebbb57ec564f71a37b0ddc8f 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -71,36 +71,61 @@ static u32 hyp_ffa_version;
static bool has_version_negotiated;
static hyp_spinlock_t version_lock;
-static void ffa_to_smccc_error(struct arm_smccc_res *res, u64 ffa_errno)
+static void ffa_to_smccc_error(struct arm_smccc_1_2_regs *res, u64 ffa_errno)
{
- *res = (struct arm_smccc_res) {
+ *res = (struct arm_smccc_1_2_regs) {
.a0 = FFA_ERROR,
.a2 = ffa_errno,
};
}
-static void ffa_to_smccc_res_prop(struct arm_smccc_res *res, int ret, u64 prop)
+static void ffa_to_smccc_res_prop(struct arm_smccc_1_2_regs *res, int ret, u64 prop)
{
if (ret == FFA_RET_SUCCESS) {
- *res = (struct arm_smccc_res) { .a0 = FFA_SUCCESS,
- .a2 = prop };
+ *res = (struct arm_smccc_1_2_regs) { .a0 = FFA_SUCCESS,
+ .a2 = prop };
} else {
ffa_to_smccc_error(res, ret);
}
}
-static void ffa_to_smccc_res(struct arm_smccc_res *res, int ret)
+static void ffa_to_smccc_res(struct arm_smccc_1_2_regs *res, int ret)
{
ffa_to_smccc_res_prop(res, ret, 0);
}
static void ffa_set_retval(struct kvm_cpu_context *ctxt,
- struct arm_smccc_res *res)
+ struct arm_smccc_1_2_regs *res)
{
+ DECLARE_REG(u64, func_id, ctxt, 0);
cpu_reg(ctxt, 0) = res->a0;
cpu_reg(ctxt, 1) = res->a1;
cpu_reg(ctxt, 2) = res->a2;
cpu_reg(ctxt, 3) = res->a3;
+ cpu_reg(ctxt, 4) = res->a4;
+ cpu_reg(ctxt, 5) = res->a5;
+ cpu_reg(ctxt, 6) = res->a6;
+ cpu_reg(ctxt, 7) = res->a7;
+
+ /*
+ * DEN0028C 2.6: SMC32/HVC32 call from aarch64 must preserve x8-x30.
+ *
+ * FF-A 1.2 allows FFA_MSG_WAIT (SMC32) to return a SMC64 reply (e.g.
+ * FFA_MSG_SEND_DIRECT_REQ2) but that isn't an issue as FFA_MSG_WAIT
+ * isn't supported by the hypervisor.
+ */
+ if (ARM_SMCCC_IS_64(func_id)) {
+ cpu_reg(ctxt, 8) = res->a8;
+ cpu_reg(ctxt, 9) = res->a9;
+ cpu_reg(ctxt, 10) = res->a10;
+ cpu_reg(ctxt, 11) = res->a11;
+ cpu_reg(ctxt, 12) = res->a12;
+ cpu_reg(ctxt, 13) = res->a13;
+ cpu_reg(ctxt, 14) = res->a14;
+ cpu_reg(ctxt, 15) = res->a15;
+ cpu_reg(ctxt, 16) = res->a16;
+ cpu_reg(ctxt, 17) = res->a17;
+ }
}
static bool is_ffa_call(u64 func_id)
@@ -113,82 +138,92 @@ static bool is_ffa_call(u64 func_id)
static int ffa_map_hyp_buffers(u64 ffa_page_count)
{
- struct arm_smccc_res res;
+ struct arm_smccc_1_2_regs res;
- arm_smccc_1_1_smc(FFA_FN64_RXTX_MAP,
- hyp_virt_to_phys(hyp_buffers.tx),
- hyp_virt_to_phys(hyp_buffers.rx),
- ffa_page_count,
- 0, 0, 0, 0,
- &res);
+ arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ .a0 = FFA_FN64_RXTX_MAP,
+ .a1 = hyp_virt_to_phys(hyp_buffers.tx),
+ .a2 = hyp_virt_to_phys(hyp_buffers.rx),
+ .a3 = ffa_page_count,
+ }, &res);
return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2;
}
static int ffa_unmap_hyp_buffers(void)
{
- struct arm_smccc_res res;
+ struct arm_smccc_1_2_regs res;
- arm_smccc_1_1_smc(FFA_RXTX_UNMAP,
- HOST_FFA_ID,
- 0, 0, 0, 0, 0, 0,
- &res);
+ arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ .a0 = FFA_RXTX_UNMAP,
+ .a1 = HOST_FFA_ID,
+ }, &res);
return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2;
}
-static void ffa_mem_frag_tx(struct arm_smccc_res *res, u32 handle_lo,
+static void ffa_mem_frag_tx(struct arm_smccc_1_2_regs *res, u32 handle_lo,
u32 handle_hi, u32 fraglen, u32 endpoint_id)
{
- arm_smccc_1_1_smc(FFA_MEM_FRAG_TX,
- handle_lo, handle_hi, fraglen, endpoint_id,
- 0, 0, 0,
- res);
+ arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ .a0 = FFA_MEM_FRAG_TX,
+ .a1 = handle_lo,
+ .a2 = handle_hi,
+ .a3 = fraglen,
+ .a4 = endpoint_id,
+ }, res);
}
-static void ffa_mem_frag_rx(struct arm_smccc_res *res, u32 handle_lo,
+static void ffa_mem_frag_rx(struct arm_smccc_1_2_regs *res, u32 handle_lo,
u32 handle_hi, u32 fragoff)
{
- arm_smccc_1_1_smc(FFA_MEM_FRAG_RX,
- handle_lo, handle_hi, fragoff, HOST_FFA_ID,
- 0, 0, 0,
- res);
+ arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ .a0 = FFA_MEM_FRAG_RX,
+ .a1 = handle_lo,
+ .a2 = handle_hi,
+ .a3 = fragoff,
+ .a4 = HOST_FFA_ID,
+ }, res);
}
-static void ffa_mem_xfer(struct arm_smccc_res *res, u64 func_id, u32 len,
+static void ffa_mem_xfer(struct arm_smccc_1_2_regs *res, u64 func_id, u32 len,
u32 fraglen)
{
- arm_smccc_1_1_smc(func_id, len, fraglen,
- 0, 0, 0, 0, 0,
- res);
+ arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ .a0 = func_id,
+ .a1 = len,
+ .a2 = fraglen,
+ }, res);
}
-static void ffa_mem_reclaim(struct arm_smccc_res *res, u32 handle_lo,
+static void ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, u32 handle_lo,
u32 handle_hi, u32 flags)
{
- arm_smccc_1_1_smc(FFA_MEM_RECLAIM,
- handle_lo, handle_hi, flags,
- 0, 0, 0, 0,
- res);
+ arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ .a0 = FFA_MEM_RECLAIM,
+ .a1 = handle_lo,
+ .a2 = handle_hi,
+ .a3 = flags,
+ }, res);
}
-static void ffa_retrieve_req(struct arm_smccc_res *res, u32 len)
+static void ffa_retrieve_req(struct arm_smccc_1_2_regs *res, u32 len)
{
- arm_smccc_1_1_smc(FFA_FN64_MEM_RETRIEVE_REQ,
- len, len,
- 0, 0, 0, 0, 0,
- res);
+ arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ .a0 = FFA_FN64_MEM_RETRIEVE_REQ,
+ .a1 = len,
+ .a2 = len,
+ }, res);
}
-static void ffa_rx_release(struct arm_smccc_res *res)
+static void ffa_rx_release(struct arm_smccc_1_2_regs *res)
{
- arm_smccc_1_1_smc(FFA_RX_RELEASE,
- 0, 0,
- 0, 0, 0, 0, 0,
- res);
+ arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ .a0 = FFA_RX_RELEASE,
+ }, res);
}
-static void do_ffa_rxtx_map(struct arm_smccc_res *res,
+static void do_ffa_rxtx_map(struct arm_smccc_1_2_regs *res,
struct kvm_cpu_context *ctxt)
{
DECLARE_REG(phys_addr_t, tx, ctxt, 1);
@@ -267,7 +302,7 @@ static void do_ffa_rxtx_map(struct arm_smccc_res *res,
goto out_unlock;
}
-static void do_ffa_rxtx_unmap(struct arm_smccc_res *res,
+static void do_ffa_rxtx_unmap(struct arm_smccc_1_2_regs *res,
struct kvm_cpu_context *ctxt)
{
DECLARE_REG(u32, id, ctxt, 1);
@@ -368,7 +403,7 @@ static int ffa_host_unshare_ranges(struct ffa_mem_region_addr_range *ranges,
return ret;
}
-static void do_ffa_mem_frag_tx(struct arm_smccc_res *res,
+static void do_ffa_mem_frag_tx(struct arm_smccc_1_2_regs *res,
struct kvm_cpu_context *ctxt)
{
DECLARE_REG(u32, handle_lo, ctxt, 1);
@@ -427,7 +462,7 @@ static void do_ffa_mem_frag_tx(struct arm_smccc_res *res,
}
static void __do_ffa_mem_xfer(const u64 func_id,
- struct arm_smccc_res *res,
+ struct arm_smccc_1_2_regs *res,
struct kvm_cpu_context *ctxt)
{
DECLARE_REG(u32, len, ctxt, 1);
@@ -521,7 +556,7 @@ static void __do_ffa_mem_xfer(const u64 func_id,
__do_ffa_mem_xfer((fid), (res), (ctxt)); \
} while (0);
-static void do_ffa_mem_reclaim(struct arm_smccc_res *res,
+static void do_ffa_mem_reclaim(struct arm_smccc_1_2_regs *res,
struct kvm_cpu_context *ctxt)
{
DECLARE_REG(u32, handle_lo, ctxt, 1);
@@ -634,7 +669,7 @@ static bool ffa_call_supported(u64 func_id)
return true;
}
-static bool do_ffa_features(struct arm_smccc_res *res,
+static bool do_ffa_features(struct arm_smccc_1_2_regs *res,
struct kvm_cpu_context *ctxt)
{
DECLARE_REG(u32, id, ctxt, 1);
@@ -666,17 +701,21 @@ static bool do_ffa_features(struct arm_smccc_res *res,
static int hyp_ffa_post_init(void)
{
size_t min_rxtx_sz;
- struct arm_smccc_res res;
+ struct arm_smccc_1_2_regs res;
- arm_smccc_1_1_smc(FFA_ID_GET, 0, 0, 0, 0, 0, 0, 0, &res);
+ arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){
+ .a0 = FFA_ID_GET,
+ }, &res);
if (res.a0 != FFA_SUCCESS)
return -EOPNOTSUPP;
if (res.a2 != HOST_FFA_ID)
return -EINVAL;
- arm_smccc_1_1_smc(FFA_FEATURES, FFA_FN64_RXTX_MAP,
- 0, 0, 0, 0, 0, 0, &res);
+ arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){
+ .a0 = FFA_FEATURES,
+ .a1 = FFA_FN64_RXTX_MAP,
+ }, &res);
if (res.a0 != FFA_SUCCESS)
return -EOPNOTSUPP;
@@ -700,7 +739,7 @@ static int hyp_ffa_post_init(void)
return 0;
}
-static void do_ffa_version(struct arm_smccc_res *res,
+static void do_ffa_version(struct arm_smccc_1_2_regs *res,
struct kvm_cpu_context *ctxt)
{
DECLARE_REG(u32, ffa_req_version, ctxt, 1);
@@ -724,9 +763,10 @@ static void do_ffa_version(struct arm_smccc_res *res,
* first if TEE supports it.
*/
if (FFA_MINOR_VERSION(ffa_req_version) < FFA_MINOR_VERSION(hyp_ffa_version)) {
- arm_smccc_1_1_smc(FFA_VERSION, ffa_req_version, 0,
- 0, 0, 0, 0, 0,
- res);
+ arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ .a0 = FFA_VERSION,
+ .a1 = ffa_req_version,
+ }, res);
if (res->a0 == FFA_RET_NOT_SUPPORTED)
goto unlock;
@@ -743,7 +783,7 @@ static void do_ffa_version(struct arm_smccc_res *res,
hyp_spin_unlock(&version_lock);
}
-static void do_ffa_part_get(struct arm_smccc_res *res,
+static void do_ffa_part_get(struct arm_smccc_1_2_regs *res,
struct kvm_cpu_context *ctxt)
{
DECLARE_REG(u32, uuid0, ctxt, 1);
@@ -759,9 +799,14 @@ static void do_ffa_part_get(struct arm_smccc_res *res,
goto out_unlock;
}
- arm_smccc_1_1_smc(FFA_PARTITION_INFO_GET, uuid0, uuid1,
- uuid2, uuid3, flags, 0, 0,
- res);
+ arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ .a0 = FFA_PARTITION_INFO_GET,
+ .a1 = uuid0,
+ .a2 = uuid1,
+ .a3 = uuid2,
+ .a4 = uuid3,
+ .a5 = flags,
+ }, res);
if (res->a0 != FFA_SUCCESS)
goto out_unlock;
@@ -794,7 +839,7 @@ static void do_ffa_part_get(struct arm_smccc_res *res,
bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt, u32 func_id)
{
- struct arm_smccc_res res;
+ struct arm_smccc_1_2_regs res;
/*
* There's no way we can tell what a non-standard SMC call might
@@ -863,13 +908,16 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt, u32 func_id)
int hyp_ffa_init(void *pages)
{
- struct arm_smccc_res res;
+ struct arm_smccc_1_2_regs res;
void *tx, *rx;
if (kvm_host_psci_config.smccc_version < ARM_SMCCC_VERSION_1_2)
return 0;
- arm_smccc_1_1_smc(FFA_VERSION, FFA_VERSION_1_1, 0, 0, 0, 0, 0, 0, &res);
+ arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ .a0 = FFA_VERSION,
+ .a1 = FFA_VERSION_1_1,
+ }, &res);
if (res.a0 == FFA_RET_NOT_SUPPORTED)
return 0;
--
2.50.0.727.gbf7dc18ff4-goog
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