[PATCH v2 2/3] KVM: arm64: Bump the supported version of FF-A to 1.2
Per Larsen via B4 Relay
devnull+perlarsen.google.com at kernel.org
Thu May 8 01:38:53 PDT 2025
From: Per Larsen <perlarsen at google.com>
FF-A version 1.2 introduces the DIRECT_REQ2 ABI. Bump the FF-A version
preferred by the hypervisor as a precursor to implementing the 1.2-only
FFA_MSG_SEND_DIRECT_REQ2 and FFA_MSG_SEND_RESP2 messaging interfaces.
We must also use SMCCC 1.2 for 64-bit SMCs if hypervisor negotiated FF-A
1.2, so ffa_set_retval is updated and a new function to call 64-bit smcs
using SMCCC 1.2 with fallback to SMCCC 1.1 is introduced.
Update deny-list in ffa_call_supported to mark FFA_NOTIFICATION_* and
interfaces added in FF-A 1.2 as unsupported lest they get forwarded.
Co-developed-by: Ayrton Munoz <ayrton at google.com>
Signed-off-by: Ayrton Munoz <ayrton at google.com>
Signed-off-by: Per Larsen <perlarsen at google.com>
Signed-off-by: Per Larsen <perl at immunant.com>
---
arch/arm64/kvm/hyp/nvhe/Makefile | 1 +
arch/arm64/kvm/hyp/nvhe/ffa.c | 86 +++++++++++++++++++++++++++++++++++++---
include/linux/arm_ffa.h | 1 +
3 files changed, 82 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index b43426a493df5a388caa920e259cc8c54d118a1b..95404ff16dac0389f45a3ee2c13a93b3ebebaf6d 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..3fa5d1ae26c40fb96ad2deb834882bb3e0af5637 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -94,6 +94,7 @@ static void ffa_to_smccc_res(struct arm_smccc_res *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)
{
@@ -101,6 +102,64 @@ static void ffa_set_retval(struct kvm_cpu_context *ctxt,
cpu_reg(ctxt, 1) = res->a1;
cpu_reg(ctxt, 2) = res->a2;
cpu_reg(ctxt, 3) = res->a3;
+
+ /*
+ * Other result registers must be zero per DEN0077A but SMC32/HVC32 must
+ * preserve x8-x30 per DEN0028.
+ */
+ cpu_reg(ctxt, 4) = 0;
+ cpu_reg(ctxt, 5) = 0;
+ cpu_reg(ctxt, 6) = 0;
+ cpu_reg(ctxt, 7) = 0;
+
+ /*
+ * Per DEN0077A v1.2 11.2, the caller is expected to write zeroes to
+ * unused parameter registers.
+ */
+ if (ARM_SMCCC_IS_64(res->a0)) {
+ hyp_spin_lock(&version_lock);
+
+ if (hyp_ffa_version >= FFA_VERSION_1_2) {
+ cpu_reg(ctxt, 8) = 0;
+ cpu_reg(ctxt, 9) = 0;
+ cpu_reg(ctxt, 10) = 0;
+ cpu_reg(ctxt, 11) = 0;
+ cpu_reg(ctxt, 12) = 0;
+ cpu_reg(ctxt, 13) = 0;
+ cpu_reg(ctxt, 14) = 0;
+ cpu_reg(ctxt, 15) = 0;
+ cpu_reg(ctxt, 16) = 0;
+ cpu_reg(ctxt, 17) = 0;
+ }
+
+ hyp_spin_unlock(&version_lock);
+ }
+}
+
+/* Call SMC64 using SMCCC 1.2 if hyp negotiated FF-A 1.2 falling back to 1.1 */
+static void arm_smccc_1_x_smc(u64 func_id, u64 a1, u64 a2, u64 a3,
+ u64 a4, u64 a5, u64 a6, u64 a7,
+ struct arm_smccc_res *res)
+{
+ struct arm_smccc_1_2_regs args, regs = {0};
+
+ if (ARM_SMCCC_IS_64(func_id))
+ hyp_spin_lock(&version_lock);
+
+ /* SMC64 only as SMC32 must preserve x8-x30 per DEN0028 1.6G Sec 2.6 */
+ if (ARM_SMCCC_IS_64(func_id) && hyp_ffa_version >= FFA_VERSION_1_2) {
+ args = (struct arm_smccc_1_2_regs) { func_id, a1, a2, a3, a4,
+ a5, a6, a7 };
+ arm_smccc_1_2_smc(&args, ®s);
+ *res = (struct arm_smccc_res) { .a0 = regs.a0, .a1 = regs.a1,
+ .a2 = regs.a2, .a3 = regs.a3 };
+ goto unlock;
+ }
+
+ arm_smccc_1_1_smc(func_id, a1, a2, a3, a4, a5, a6, a7, res);
+unlock:
+ if (ARM_SMCCC_IS_64(func_id))
+ hyp_spin_unlock(&version_lock);
}
static bool is_ffa_call(u64 func_id)
@@ -115,7 +174,7 @@ static int ffa_map_hyp_buffers(u64 ffa_page_count)
{
struct arm_smccc_res res;
- arm_smccc_1_1_smc(FFA_FN64_RXTX_MAP,
+ arm_smccc_1_x_smc(FFA_FN64_RXTX_MAP,
hyp_virt_to_phys(hyp_buffers.tx),
hyp_virt_to_phys(hyp_buffers.rx),
ffa_page_count,
@@ -174,7 +233,7 @@ static void ffa_mem_reclaim(struct arm_smccc_res *res, u32 handle_lo,
static void ffa_retrieve_req(struct arm_smccc_res *res, u32 len)
{
- arm_smccc_1_1_smc(FFA_FN64_MEM_RETRIEVE_REQ,
+ arm_smccc_1_x_smc(FFA_FN64_MEM_RETRIEVE_REQ,
len, len,
0, 0, 0, 0, 0,
res);
@@ -628,6 +687,20 @@ static bool ffa_call_supported(u64 func_id)
case FFA_RXTX_MAP:
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:
+ case FFA_NOTIFICATION_GET:
+ case FFA_NOTIFICATION_INFO_GET:
+ /* Unimplemented interfaces added in FF-A 1.2 */
+ case FFA_MSG_SEND_DIRECT_REQ2:
+ case FFA_MSG_SEND_DIRECT_RESP2:
+ case FFA_CONSOLE_LOG:
+ case FFA_PARTITION_INFO_GET_REGS:
+ case FFA_EL3_INTR_HANDLE:
return false;
}
@@ -680,7 +753,7 @@ static int hyp_ffa_post_init(void)
if (res.a0 != FFA_SUCCESS)
return -EOPNOTSUPP;
- switch (res.a2) {
+ switch (res.a2 & FFA_FEAT_RXTX_MIN_SZ_MASK) {
case FFA_FEAT_RXTX_MIN_SZ_4K:
min_rxtx_sz = SZ_4K;
break;
@@ -869,7 +942,7 @@ int hyp_ffa_init(void *pages)
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_1_smc(FFA_VERSION, FFA_VERSION_1_2, 0, 0, 0, 0, 0, 0, &res);
if (res.a0 == FFA_RET_NOT_SUPPORTED)
return 0;
@@ -889,10 +962,11 @@ int hyp_ffa_init(void *pages)
if (FFA_MAJOR_VERSION(res.a0) != 1)
return -EOPNOTSUPP;
- if (FFA_MINOR_VERSION(res.a0) < FFA_MINOR_VERSION(FFA_VERSION_1_1))
+ /* See do_ffa_guest_version before bumping maximum supported version. */
+ if (FFA_MINOR_VERSION(res.a0) < FFA_MINOR_VERSION(FFA_VERSION_1_2))
hyp_ffa_version = res.a0;
else
- hyp_ffa_version = FFA_VERSION_1_1;
+ hyp_ffa_version = FFA_VERSION_1_2;
tx = pages;
pages += KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE;
diff --git a/include/linux/arm_ffa.h b/include/linux/arm_ffa.h
index 5bded24dc24fea8cdcbe42bf79c7c025c3fa5f4b..c0dd6183d956043192114a522b7eef465e7078ac 100644
--- a/include/linux/arm_ffa.h
+++ b/include/linux/arm_ffa.h
@@ -128,6 +128,7 @@
#define FFA_FEAT_RXTX_MIN_SZ_4K 0
#define FFA_FEAT_RXTX_MIN_SZ_64K 1
#define FFA_FEAT_RXTX_MIN_SZ_16K 2
+#define FFA_FEAT_RXTX_MIN_SZ_MASK 3
/* FFA Bus/Device/Driver related */
struct ffa_device {
--
2.49.0.987.g0cc8ee98dc-goog
More information about the linux-arm-kernel
mailing list