[PATCH v4 0/7] KVM: arm64: Forward FFA_NOTIFICATION* calls to TrustZone

[PATCH v4 0/7] KVM: arm64: Forward FFA_NOTIFICATION* calls to TrustZone

[Sebastian Ene]

Remove the FFA_NOTIFICATION* calls from the blocklist used by the pKVM
FF-A proxy. This restriction was preventing the use of asynchronous
signaling mechanisms defined by the Arm FF-A specification to
communicate with the secure services.
While these calls are markes as optional, there is no reason why the
hypervisor proxy would block them because:

1. Host is the Sole Non-Secure Endpoint: The Host operates as the
   only Non-Secure VM ID (VM ID 0) recognized by the Secure World.
   Because all forwarded notifications are inherently attributed to
   the Host by the SPMC, there is no risk of VM ID spoofing
   originating from the Normal World.

2. No Memory Pointers or Addresses: The FFA_NOTIFICATION_* ABIs
   operate strictly via register-based parameters, passing only
   VM IDs, VCPU IDs, flags, and bitmaps. Because these calls do
   not contain memory addresses, offsets, or pointers, forwarding
   them doesn't pose a risk of memory-based confused deputy attack
   (e.g., tricking the SPMC into overwriting protected memory).

While the pKVM proxy behaves as a relayer, it doesn't currently have its
own FF-A ID(only the host has the ID 0). The behavior of the setup
flow is covered by the spec in the: '10.9 Notification support without
a Hypervisor'.

---
Changes in v4:
- previous series(v3) had serious issues with the patch number and it
  appeared like it used a mixed bag from v2 as well. Resend this to
  restore the correct order of the patches.
- fix strict check in ffa_check_unused_args_sbz and make it "<= 17"
- check the receiver endpoint Id in
  FFA_NOTIFICATION_BIND/FFA_NOTIFICATION_UNBIND instead of the sender
- use hyp_smccc_1_2_smc all along 
- check the receiver endpoit Id when doing FFA_NOTIFICATION_GET  

Changes in v3:
- applied Will's suggestion to use the introduced method
  ffa_check_unused_args_sbz for existing calls and added a new
patch in the beggining of the series to do this.
- merged the handling of
  FFA_NOTIFICATION_BITMAP_CREATE/FFA_NOTIFICATION_BITMAP_DESTROY into
one patch as Vincent suggested and create one handler for both.

Changes in v2:
- enforce the MBZ/SBZ fields
- split the calls into separate patches
- rebase on 7.1-rc7

Link to v3:
https://lore.kernel.org/all/20260616105417.2578670-1-sebastianene@google.com/
Link to v2:
https://lore.kernel.org/all/20260608165549.1479409-1-sebastianene@google.com/
Link to v1:
https://lore.kernel.org/all/20260501114447.2389222-2-sebastianene@google.com/

Sebastian Ene (7):
  KVM: arm64: Enforce strict SBZ checks in the FF-A proxy
  KVM: arm64: Forward FFA_NOTIFICATION_BITMAP calls to Trustzone
  KVM: arm64: Support FFA_NOTIFICATION_BIND in host handler
  KVM: arm64: Support FFA_NOTIFICATION_UNBIND in host handler
  KVM: arm64: Support FFA_NOTIFICATION_SET in host handler
  KVM: arm64: Support FFA_NOTIFICATION_GET in host handler
  KVM: arm64: Support FFA_NOTIFICATION_INFO_GET in host handler

 arch/arm64/kvm/hyp/nvhe/ffa.c | 211 ++++++++++++++++++++++++++++++++--
 1 file changed, 203 insertions(+), 8 deletions(-)

-- 
2.54.0.1136.gdb2ca164c4-goog

[PATCH v4 1/7] KVM: arm64: Enforce strict SBZ checks in the FF-A proxy

[Sebastian Ene]

Introduce a helper method ffa_check_unused_args_sbz to enforce strict
arguments checking when the hypervisor acts as a relayer between the
host and Trustzone.

Signed-off-by: Sebastian Ene <sebastianene@google.com>
---
 arch/arm64/kvm/hyp/nvhe/ffa.c | 47 +++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 1af722771178..c64c704f22f8 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -71,6 +71,18 @@ static u32 hyp_ffa_version;
 static bool has_version_negotiated;
 static hyp_spinlock_t version_lock;
 
+static bool ffa_check_unused_args_sbz(struct kvm_cpu_context *ctxt, int first_reg)
+{
+	int reg;
+
+	for (reg = first_reg; reg <= 17; reg++) {
+		if (cpu_reg(ctxt, reg))
+			return true;
+	}
+
+	return false;
+}
+
 static void ffa_to_smccc_error(struct arm_smccc_1_2_regs *res, u64 ffa_errno)
 {
 	*res = (struct arm_smccc_1_2_regs) {
@@ -239,6 +251,11 @@ static void do_ffa_rxtx_map(struct arm_smccc_1_2_regs *res,
 	int ret = 0;
 	void *rx_virt, *tx_virt;
 
+	if (ffa_check_unused_args_sbz(ctxt, 4)) {
+		ret = FFA_RET_INVALID_PARAMETERS;
+		goto out;
+	}
+
 	if (npages != (KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) / FFA_PAGE_SIZE) {
 		ret = FFA_RET_INVALID_PARAMETERS;
 		goto out;
@@ -315,6 +332,11 @@ static void do_ffa_rxtx_unmap(struct arm_smccc_1_2_regs *res,
 	DECLARE_REG(u32, id, ctxt, 1);
 	int ret = 0;
 
+	if (ffa_check_unused_args_sbz(ctxt, 2)) {
+		ret = FFA_RET_INVALID_PARAMETERS;
+		goto out;
+	}
+
 	if (id != HOST_FFA_ID) {
 		ret = FFA_RET_INVALID_PARAMETERS;
 		goto out;
@@ -421,6 +443,11 @@ static void do_ffa_mem_frag_tx(struct arm_smccc_1_2_regs *res,
 	int ret = FFA_RET_INVALID_PARAMETERS;
 	u32 nr_ranges;
 
+	if (ffa_check_unused_args_sbz(ctxt, 5)) {
+		ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS);
+		return;
+	}
+
 	if (fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE)
 		goto out;
 
@@ -482,6 +509,11 @@ static void __do_ffa_mem_xfer(const u64 func_id,
 	u32 offset, nr_ranges, checked_offset;
 	int ret = 0;
 
+	if (ffa_check_unused_args_sbz(ctxt, 5)) {
+		ret = FFA_RET_INVALID_PARAMETERS;
+		goto out;
+	}
+
 	if (addr_mbz || npages_mbz || fraglen > len ||
 	    fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) {
 		ret = FFA_RET_INVALID_PARAMETERS;
@@ -581,6 +613,11 @@ static void do_ffa_mem_reclaim(struct arm_smccc_1_2_regs *res,
 	int ret = 0;
 	u64 handle;
 
+	if (ffa_check_unused_args_sbz(ctxt, 4)) {
+		ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS);
+		return;
+	}
+
 	handle = PACK_HANDLE(handle_lo, handle_hi);
 
 	hyp_spin_lock(&host_buffers.lock);
@@ -769,6 +806,11 @@ static void do_ffa_version(struct arm_smccc_1_2_regs *res,
 {
 	DECLARE_REG(u32, ffa_req_version, ctxt, 1);
 
+	if (ffa_check_unused_args_sbz(ctxt, 2)) {
+		res->a0 = FFA_RET_NOT_SUPPORTED;
+		return;
+	}
+
 	if (FFA_MAJOR_VERSION(ffa_req_version) != 1) {
 		res->a0 = FFA_RET_NOT_SUPPORTED;
 		return;
@@ -818,6 +860,11 @@ static void do_ffa_part_get(struct arm_smccc_1_2_regs *res,
 	DECLARE_REG(u32, flags, ctxt, 5);
 	u32 count, partition_sz, copy_sz;
 
+	if (ffa_check_unused_args_sbz(ctxt, 6)) {
+		ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS);
+		return;
+	}
+
 	hyp_spin_lock(&host_buffers.lock);
 	if (!host_buffers.rx) {
 		ffa_to_smccc_res(res, FFA_RET_BUSY);
-- 
2.54.0.1136.gdb2ca164c4-goog

[PATCH v4 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@google.com>
---
 arch/arm64/kvm/hyp/nvhe/ffa.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index c64c704f22f8..a72f6d4b62f0 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 +907,27 @@ 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;
+
+	if (ffa_check_unused_args_sbz(ctxt, func_id == FFA_NOTIFICATION_BITMAP_CREATE ? 3 : 2)) {
+		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 +986,10 @@ 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

[PATCH v4 3/7] KVM: arm64: Support FFA_NOTIFICATION_BIND in host handler

[Sebastian Ene]

Verify the arguments of the FF-A notification bind call and forward the
message to Trustzone.

Signed-off-by: Sebastian Ene <sebastianene@google.com>
---
 arch/arm64/kvm/hyp/nvhe/ffa.c | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index a72f6d4b62f0..1f38ad008675 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -42,6 +42,8 @@
  */
 #define HOST_FFA_ID	0
 
+#define FFA_NOTIF_RECEIVER_ENDP_MASK	GENMASK(15, 0)
+
 /*
  * A buffer to hold the maximum descriptor size we can see from the host,
  * which is required when the SPMD returns a fragmented FFA_MEM_RETRIEVE_RESP
@@ -713,7 +715,6 @@ 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_BIND:
 	case FFA_NOTIFICATION_UNBIND:
 	case FFA_NOTIFICATION_SET:
 	case FFA_NOTIFICATION_GET:
@@ -928,6 +929,32 @@ static void do_ffa_notif_bitmap(struct arm_smccc_1_2_regs *res,
 	hyp_smccc_1_2_smc(args, res);
 }
 
+static void do_ffa_notif_bind(struct arm_smccc_1_2_regs *res,
+			      struct kvm_cpu_context *ctxt)
+{
+	DECLARE_REG(u32, endp_id, ctxt, 1);
+	DECLARE_REG(u32, flags, ctxt, 2);
+	struct arm_smccc_1_2_regs *args;
+
+	if (ffa_check_unused_args_sbz(ctxt, 5)) {
+		ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS);
+		return;
+	}
+
+	if (FIELD_GET(FFA_NOTIF_RECEIVER_ENDP_MASK, endp_id) != HOST_FFA_ID) {
+		ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS);
+		return;
+	}
+
+	if (flags > 1) {
+		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;
@@ -990,6 +1017,9 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt, u32 func_id)
 	case FFA_NOTIFICATION_BITMAP_DESTROY:
 		do_ffa_notif_bitmap(&res, host_ctxt);
 		goto out_handled;
+	case FFA_NOTIFICATION_BIND:
+		do_ffa_notif_bind(&res, host_ctxt);
+		goto out_handled;
 	}
 
 	if (ffa_call_supported(func_id))
-- 
2.54.0.1136.gdb2ca164c4-goog

[PATCH v4 4/7] KVM: arm64: Support FFA_NOTIFICATION_UNBIND in host handler

[Sebastian Ene]

Verify the arguments of the FF-A notification unbind call and forward
the message to Trustzone.

Signed-off-by: Sebastian Ene <sebastianene@google.com>
---
 arch/arm64/kvm/hyp/nvhe/ffa.c | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 1f38ad008675..adf8680f3266 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -715,7 +715,6 @@ 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_UNBIND:
 	case FFA_NOTIFICATION_SET:
 	case FFA_NOTIFICATION_GET:
 	case FFA_NOTIFICATION_INFO_GET:
@@ -955,6 +954,27 @@ static void do_ffa_notif_bind(struct arm_smccc_1_2_regs *res,
 	hyp_smccc_1_2_smc(args, res);
 }
 
+static void do_ffa_notif_unbind(struct arm_smccc_1_2_regs *res,
+				struct kvm_cpu_context *ctxt)
+{
+	DECLARE_REG(u32, endp_id, ctxt, 1);
+	DECLARE_REG(u32, reserved, ctxt, 2);
+	struct arm_smccc_1_2_regs *args;
+
+	if (ffa_check_unused_args_sbz(ctxt, 5) || reserved) {
+		ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS);
+		return;
+	}
+
+	if (FIELD_GET(FFA_NOTIF_RECEIVER_ENDP_MASK, endp_id) != 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;
@@ -1020,6 +1040,9 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt, u32 func_id)
 	case FFA_NOTIFICATION_BIND:
 		do_ffa_notif_bind(&res, host_ctxt);
 		goto out_handled;
+	case FFA_NOTIFICATION_UNBIND:
+		do_ffa_notif_unbind(&res, host_ctxt);
+		goto out_handled;
 	}
 
 	if (ffa_call_supported(func_id))
-- 
2.54.0.1136.gdb2ca164c4-goog

[PATCH v4 5/7] KVM: arm64: Support FFA_NOTIFICATION_SET in host handler

[Sebastian Ene]

Allow FF-A notification SET messages to be proxied from the pKVM
hypervisor to Trustzone and enforce MBZ/SBZ fields.

Signed-off-by: Sebastian Ene <sebastianene@google.com>
---
 arch/arm64/kvm/hyp/nvhe/ffa.c | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index adf8680f3266..fdf1e5fb6726 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -43,6 +43,7 @@
 #define HOST_FFA_ID	0
 
 #define FFA_NOTIF_RECEIVER_ENDP_MASK	GENMASK(15, 0)
+#define FFA_NOTIF_SENDER_ENDP_MASK	GENMASK(31, 16)
 
 /*
  * A buffer to hold the maximum descriptor size we can see from the host,
@@ -715,7 +716,6 @@ 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_SET:
 	case FFA_NOTIFICATION_GET:
 	case FFA_NOTIFICATION_INFO_GET:
 	/* Optional interfaces added in FF-A 1.2 */
@@ -975,6 +975,32 @@ static void do_ffa_notif_unbind(struct arm_smccc_1_2_regs *res,
 	hyp_smccc_1_2_smc(args, res);
 }
 
+static void do_ffa_notif_set(struct arm_smccc_1_2_regs *res,
+			     struct kvm_cpu_context *ctxt)
+{
+	DECLARE_REG(u32, endp_id, ctxt, 1);
+	DECLARE_REG(u32, flags, ctxt, 2);
+	struct arm_smccc_1_2_regs *args;
+
+	if (FIELD_GET(FFA_NOTIF_SENDER_ENDP_MASK, endp_id) != HOST_FFA_ID) {
+		ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS);
+		return;
+	}
+
+	if (ffa_check_unused_args_sbz(ctxt, 5)) {
+		ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS);
+		return;
+	}
+
+	if (flags & GENMASK(15, 2)) {
+		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;
@@ -1043,6 +1069,9 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt, u32 func_id)
 	case FFA_NOTIFICATION_UNBIND:
 		do_ffa_notif_unbind(&res, host_ctxt);
 		goto out_handled;
+	case FFA_NOTIFICATION_SET:
+		do_ffa_notif_set(&res, host_ctxt);
+		goto out_handled;
 	}
 
 	if (ffa_call_supported(func_id))
-- 
2.54.0.1136.gdb2ca164c4-goog

[PATCH v4 6/7] KVM: arm64: Support FFA_NOTIFICATION_GET in host handler

[Sebastian Ene]

Allow FF-A notification GET messages to be proxied from the pKVM
hypervisor to Trustzone and enforce MBZ/SBZ fields.

Signed-off-by: Sebastian Ene <sebastianene@google.com>
---
 arch/arm64/kvm/hyp/nvhe/ffa.c | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index fdf1e5fb6726..de4794338388 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -716,7 +716,6 @@ 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_GET:
 	case FFA_NOTIFICATION_INFO_GET:
 	/* Optional interfaces added in FF-A 1.2 */
 	case FFA_MSG_SEND_DIRECT_REQ2:		/* Optional per 7.5.1 */
@@ -1001,6 +1000,32 @@ static void do_ffa_notif_set(struct arm_smccc_1_2_regs *res,
 	hyp_smccc_1_2_smc(args, res);
 }
 
+static void do_ffa_notif_get(struct arm_smccc_1_2_regs *res,
+			     struct kvm_cpu_context *ctxt)
+{
+	DECLARE_REG(u32, endp_id, ctxt, 1);
+	DECLARE_REG(u32, flags, ctxt, 2);
+	struct arm_smccc_1_2_regs *args;
+
+	if (FIELD_GET(FFA_NOTIF_RECEIVER_ENDP_MASK, endp_id) != HOST_FFA_ID) {
+		ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS);
+		return;
+	}
+
+	if (ffa_check_unused_args_sbz(ctxt, 3)) {
+		ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS);
+		return;
+	}
+
+	if (flags & GENMASK(31, 4)) {
+		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;
@@ -1072,6 +1097,9 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt, u32 func_id)
 	case FFA_NOTIFICATION_SET:
 		do_ffa_notif_set(&res, host_ctxt);
 		goto out_handled;
+	case FFA_NOTIFICATION_GET:
+		do_ffa_notif_get(&res, host_ctxt);
+		goto out_handled;
 	}
 
 	if (ffa_call_supported(func_id))
-- 
2.54.0.1136.gdb2ca164c4-goog

[PATCH v4 7/7] KVM: arm64: Support FFA_NOTIFICATION_INFO_GET in host handler

[Sebastian Ene]

Allow the host to query the FF-A notifiction status and proxy the info
get message to Trustzone. Make sure that the SBZ fields are enforced.

Signed-off-by: Sebastian Ene <sebastianene@google.com>
---
 arch/arm64/kvm/hyp/nvhe/ffa.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index de4794338388..ffb6d44b5010 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -715,8 +715,6 @@ 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_INFO_GET:
 	/* Optional interfaces added in FF-A 1.2 */
 	case FFA_MSG_SEND_DIRECT_REQ2:		/* Optional per 7.5.1 */
 	case FFA_MSG_SEND_DIRECT_RESP2:		/* Optional per 7.5.1 */
@@ -1026,6 +1024,20 @@ static void do_ffa_notif_get(struct arm_smccc_1_2_regs *res,
 	hyp_smccc_1_2_smc(args, res);
 }
 
+static void do_ffa_notif_info_get(struct arm_smccc_1_2_regs *res,
+				  struct kvm_cpu_context *ctxt)
+{
+	struct arm_smccc_1_2_regs *args;
+
+	if (ffa_check_unused_args_sbz(ctxt, 1)) {
+		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;
@@ -1100,6 +1112,9 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt, u32 func_id)
 	case FFA_NOTIFICATION_GET:
 		do_ffa_notif_get(&res, host_ctxt);
 		goto out_handled;
+	case FFA_NOTIFICATION_INFO_GET:
+		do_ffa_notif_info_get(&res, host_ctxt);
+		goto out_handled;
 	}
 
 	if (ffa_call_supported(func_id))
-- 
2.54.0.1136.gdb2ca164c4-goog