[PATCH 2/3] KVM: arm64: Bump the supported version of FF-A to 1.2
Per Larsen
perl at immunant.com
Thu May 1 20:53:51 PDT 2025
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.
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 | 109 ++++++++++++++++++++++++++-----
2 files changed, 94 insertions(+), 16 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index b43426a493df..95404ff16dac 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 10e88207b78e..8102dd6a19f7 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -94,13 +94,57 @@ 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,
+static void ffa_set_retval(u64 func_id,
+ struct kvm_cpu_context *ctxt,
struct arm_smccc_res *res)
{
cpu_reg(ctxt, 0) = res->a0;
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, x8-x17 must be zero for SMC64/HVC64 results*/
+ if (ARM_SMCCC_IS_64(func_id) && 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;
+ }
+}
+
+/* Call SMC64 using SMCCC 1.2 if hyp negotiated FF-A 1.2 falling back to 1.1 */
+static void arm_smccc_1_2_smc_fallback(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;
+
+ /* 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 };
+ return;
+ }
+
+ arm_smccc_1_1_smc(func_id, a1, a2, a3, a4, a5, a6, a7, res);
}
static bool is_ffa_call(u64 func_id)
@@ -115,12 +159,12 @@ static int ffa_map_hyp_buffers(u64 ffa_page_count)
{
struct arm_smccc_res 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_fallback(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);
return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2;
}
@@ -174,10 +218,10 @@ 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,
- len, len,
- 0, 0, 0, 0, 0,
- res);
+ arm_smccc_1_2_smc_fallback(FFA_FN64_MEM_RETRIEVE_REQ,
+ len, len,
+ 0, 0, 0, 0, 0,
+ res);
}
static void ffa_rx_release(struct arm_smccc_res *res)
@@ -628,6 +672,37 @@ 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:
+
+ /*
+ * FFA_MSG_SEND_DIRECT_RESP2 is not meant to be invoked by the host or
+ * a guest VM because pkvm does not support communication between VMs
+ * via FF-A. Direct messages can only be sent from a non-secure sender
+ * endpoint to a secure receiver endpoint. Only receiver endpoints are
+ * expected to invoke FFA_MSG_SEND_DIRECT_RESP2.
+ */
+ case FFA_MSG_SEND_DIRECT_RESP2:
+
+ /* Reserved for secure endpoints per DEN0077A 1.2 REL0 Table 13.53. */
+ case FFA_CONSOLE_LOG:
+
+ /*
+ * Mandatory for secure endpoints per DEN0077A 1.2 REL0 Table 13.1 and
+ * optional for non-secure endpoints according to Table 13.38.
+ */
+ case FFA_PARTITION_INFO_GET_REGS:
+
+ /* Reserved for secure endpoints per DEN0077A 1.2 REL0 Table 17.2. */
+ case FFA_EL3_INTR_HANDLE:
return false;
}
@@ -680,7 +755,8 @@ static int hyp_ffa_post_init(void)
if (res.a0 != FFA_SUCCESS)
return -EOPNOTSUPP;
- switch (res.a2) {
+ /* Bit[0:1] holds minimum buffer size and alignment boundary */
+ switch (res.a2 & 0x3) {
case FFA_FEAT_RXTX_MIN_SZ_4K:
min_rxtx_sz = SZ_4K;
break;
@@ -871,7 +947,7 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context
*host_ctxt, u32 func_id)
ffa_to_smccc_error(&res, FFA_RET_NOT_SUPPORTED);
out_handled:
- ffa_set_retval(host_ctxt, &res);
+ ffa_set_retval(func_id, host_ctxt, &res);
return true;
}
@@ -883,7 +959,7 @@ 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;
@@ -903,10 +979,11 @@ 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;
--
2.49.0.906.g1f30a19c02-goog
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