[PATCH 0/2] Xen FF-A mediator

[PATCH 0/2] Xen FF-A mediator

[Jens Wiklander]

Hi,

This patch sets add a FF-A [1] mediator modeled after the TEE mediator
already present in Xen. The FF-A mediator implements the subset of the FF-A
1.1 specification needed to communicate with OP-TEE using FF-A as transport
mechanism instead of SMC/HVC as with the TEE mediator. It allows a similar
design in OP-TEE as with the TEE mediator where OP-TEE presents one virtual
partition of itself to each guest in Xen.

The FF-A mediator is generic in the sense it has nothing OP-TEE specific
except that only the subset needed for OP-TEE is implemented so far. The
hooks needed to inform OP-TEE that a guest is created or destroyed is part
of the FF-A specification.

It should be possible to extend the FF-A mediator to implement a larger
portion of the FF-A 1.1 specification without breaking with the way OP-TEE
is communicated with here. So it should be possible to support any TEE or
Secure Partition using FF-A as transport with this mediator.

[1] https://developer.arm.com/documentation/den0077/latest

Thanks,
Jens

Jens Wiklander (2):
  xen/arm: smccc: add support for SMCCCv1.2 extended input/output
    registers
  xen/arm: add FF-A mediator

 xen/arch/arm/Kconfig         |   11 +
 xen/arch/arm/Makefile        |    1 +
 xen/arch/arm/arm64/smc.S     |   43 +
 xen/arch/arm/domain.c        |   10 +
 xen/arch/arm/ffa.c           | 1624 ++++++++++++++++++++++++++++++++++
 xen/arch/arm/vsmc.c          |   19 +-
 xen/include/asm-arm/domain.h |    4 +
 xen/include/asm-arm/ffa.h    |   71 ++
 xen/include/asm-arm/smccc.h  |   42 +
 9 files changed, 1821 insertions(+), 4 deletions(-)
 create mode 100644 xen/arch/arm/ffa.c
 create mode 100644 xen/include/asm-arm/ffa.h

-- 
2.31.1

[PATCH 1/2] xen/arm: smccc: add support for SMCCCv1.2 extended input/output registers

[Jens Wiklander]

SMCCC v1.2 AArch64 allows x0-x17 to be used as both parameter registers
and result registers for the SMC and HVC instructions.

Arm Firmware Framework for Armv8-A specification makes use of x0-x7 as
parameter and result registers.

Let us add new interface to support this extended set of input/output
registers.

This is based on 3fdc0cb59d97 ("arm64: smccc: Add support for SMCCCv1.2
extended input/output registers") by Sudeep Holla from the Linux kernel

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
---
 xen/arch/arm/arm64/smc.S    | 43 +++++++++++++++++++++++++++++++++++++
 xen/arch/arm/vsmc.c         |  2 +-
 xen/include/asm-arm/smccc.h | 42 ++++++++++++++++++++++++++++++++++++
 3 files changed, 86 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/arm64/smc.S b/xen/arch/arm/arm64/smc.S
index b0752be57e8f..e024fa4d44d1 100644
--- a/xen/arch/arm/arm64/smc.S
+++ b/xen/arch/arm/arm64/smc.S
@@ -30,3 +30,46 @@ ENTRY(__arm_smccc_1_0_smc)
         stp     x2, x3, [x4, #SMCCC_RES_a2]
 1:
         ret
+
+
+/*
+ * void arm_smccc_1_2_smc(const struct arm_smccc_1_2_regs *args,
+ *                        struct arm_smccc_1_2_regs *res)
+ */
+ENTRY(arm_smccc_1_2_smc)
+    /* Save `res` and free a GPR that won't be clobbered */
+    stp     x1, x19, [sp, #-16]!
+
+    /* Ensure `args` won't be clobbered while loading regs in next step */
+    mov	x19, x0
+
+    /* Load the registers x0 - x17 from the struct arm_smccc_1_2_regs */
+    ldp	x0, x1, [x19, #0]
+    ldp	x2, x3, [x19, #16]
+    ldp	x4, x5, [x19, #32]
+    ldp	x6, x7, [x19, #48]
+    ldp	x8, x9, [x19, #64]
+    ldp	x10, x11, [x19, #80]
+    ldp	x12, x13, [x19, #96]
+    ldp	x14, x15, [x19, #112]
+    ldp	x16, x17, [x19, #128]
+
+    smc #0
+
+    /* Load the `res` from the stack */
+    ldr	x19, [sp]
+
+    /* Store the registers x0 - x17 into the result structure */
+    stp	x0, x1, [x19, #0]
+    stp	x2, x3, [x19, #16]
+    stp	x4, x5, [x19, #32]
+    stp	x6, x7, [x19, #48]
+    stp	x8, x9, [x19, #64]
+    stp	x10, x11, [x19, #80]
+    stp	x12, x13, [x19, #96]
+    stp	x14, x15, [x19, #112]
+    stp	x16, x17, [x19, #128]
+
+    /* Restore original x19 */
+    ldp     xzr, x19, [sp], #16
+    ret
diff --git a/xen/arch/arm/vsmc.c b/xen/arch/arm/vsmc.c
index a36db15fffc0..33b0ddc634da 100644
--- a/xen/arch/arm/vsmc.c
+++ b/xen/arch/arm/vsmc.c
@@ -93,7 +93,7 @@ static bool handle_arch(struct cpu_user_regs *regs)
     switch ( fid )
     {
     case ARM_SMCCC_VERSION_FID:
-        set_user_reg(regs, 0, ARM_SMCCC_VERSION_1_1);
+        set_user_reg(regs, 0, ARM_SMCCC_VERSION_1_2);
         return true;
 
     case ARM_SMCCC_ARCH_FEATURES_FID:
diff --git a/xen/include/asm-arm/smccc.h b/xen/include/asm-arm/smccc.h
index 9d94beb3df2d..8128283bc7b6 100644
--- a/xen/include/asm-arm/smccc.h
+++ b/xen/include/asm-arm/smccc.h
@@ -33,6 +33,7 @@
 
 #define ARM_SMCCC_VERSION_1_0   SMCCC_VERSION(1, 0)
 #define ARM_SMCCC_VERSION_1_1   SMCCC_VERSION(1, 1)
+#define ARM_SMCCC_VERSION_1_2   SMCCC_VERSION(1, 2)
 
 /*
  * This file provides common defines for ARM SMC Calling Convention as
@@ -217,6 +218,7 @@ struct arm_smccc_res {
 #ifdef CONFIG_ARM_32
 #define arm_smccc_1_0_smc(...) arm_smccc_1_1_smc(__VA_ARGS__)
 #define arm_smccc_smc(...) arm_smccc_1_1_smc(__VA_ARGS__)
+
 #else
 
 void __arm_smccc_1_0_smc(register_t a0, register_t a1, register_t a2,
@@ -265,8 +267,48 @@ void __arm_smccc_1_0_smc(register_t a0, register_t a1, register_t a2,
         else                                                    \
             arm_smccc_1_0_smc(__VA_ARGS__);                     \
     } while ( 0 )
+
+/**
+ * struct arm_smccc_1_2_regs - Arguments for or Results from SMC call
+ * @a0-a17 argument values from registers 0 to 17
+ */
+struct arm_smccc_1_2_regs {
+    unsigned long a0;
+    unsigned long a1;
+    unsigned long a2;
+    unsigned long a3;
+    unsigned long a4;
+    unsigned long a5;
+    unsigned long a6;
+    unsigned long a7;
+    unsigned long a8;
+    unsigned long a9;
+    unsigned long a10;
+    unsigned long a11;
+    unsigned long a12;
+    unsigned long a13;
+    unsigned long a14;
+    unsigned long a15;
+    unsigned long a16;
+    unsigned long a17;
+};
 #endif /* CONFIG_ARM_64 */
 
+/**
+ * arm_smccc_1_2_smc() - make SMC calls
+ * @args: arguments passed via struct arm_smccc_1_2_regs
+ * @res: result values via struct arm_smccc_1_2_regs
+ *
+ * This function is used to make SMC calls following SMC Calling Convention
+ * v1.2 or above. The content of the supplied param are copied from the
+ * structure to registers prior to the SMC instruction. The return values
+ * are updated with the content from registers on return from the SMC
+ * instruction.
+ */
+void arm_smccc_1_2_smc(const struct arm_smccc_1_2_regs *args,
+                       struct arm_smccc_1_2_regs *res);
+
+
 #endif /* __ASSEMBLY__ */
 
 /*
-- 
2.31.1

[PATCH 2/2] xen/arm: add FF-A mediator

[Jens Wiklander]

Adds a FF-A version 1.1 [1] mediator to communicate with a Secure
Partition in secure world.

The implementation is the bare minimum to be able to communicate with
OP-TEE running as an SPMC at S-EL1.

This is loosely based on the TEE mediator framework and the OP-TEE
mediator.

[1] https://developer.arm.com/documentation/den0077/latest
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
---
 xen/arch/arm/Kconfig         |   11 +
 xen/arch/arm/Makefile        |    1 +
 xen/arch/arm/domain.c        |   10 +
 xen/arch/arm/ffa.c           | 1624 ++++++++++++++++++++++++++++++++++
 xen/arch/arm/vsmc.c          |   17 +-
 xen/include/asm-arm/domain.h |    4 +
 xen/include/asm-arm/ffa.h    |   71 ++
 7 files changed, 1735 insertions(+), 3 deletions(-)
 create mode 100644 xen/arch/arm/ffa.c
 create mode 100644 xen/include/asm-arm/ffa.h

diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
index 277738826581..281edb85cbff 100644
--- a/xen/arch/arm/Kconfig
+++ b/xen/arch/arm/Kconfig
@@ -114,6 +114,17 @@ config TEE
 
 source "arch/arm/tee/Kconfig"
 
+config FFA
+	bool "Enable FF-A mediator support" if EXPERT
+	default n
+	depends on ARM_64
+	help
+	  This option enables a minamal FF-A mediator. The mediator is
+	  generic as it follows the FF-A specification [1], but it only
+	  implements a small substet of the specification.
+
+	  [1] https://developer.arm.com/documentation/den0077/latest
+
 endmenu
 
 menu "ARM errata workaround via the alternative framework"
diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index 1ded44d20047..90c43a4a9edf 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -17,6 +17,7 @@ obj-y += domain.o
 obj-y += domain_build.init.o
 obj-y += domctl.o
 obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
+obj-$(CONFIG_FFA) += ffa.o
 obj-y += gic.o
 obj-y += gic-v2.o
 obj-$(CONFIG_GICV3) += gic-v3.o
diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index ac6a419f55c9..451f3eed550f 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -25,6 +25,7 @@
 #include <asm/cpufeature.h>
 #include <asm/current.h>
 #include <asm/event.h>
+#include <asm/ffa.h>
 #include <asm/gic.h>
 #include <asm/guest_access.h>
 #include <asm/guest_atomics.h>
@@ -737,6 +738,9 @@ int arch_domain_create(struct domain *d,
     if ( (rc = tee_domain_init(d, config->arch.tee_type)) != 0 )
         goto fail;
 
+    if ( (rc = ffa_domain_init(d)) != 0 )
+        goto fail;
+
     update_domain_wallclock_time(d);
 
     /*
@@ -974,6 +978,7 @@ static int relinquish_memory(struct domain *d, struct page_list_head *list)
  */
 enum {
     PROG_tee = 1,
+    PROG_ffa,
     PROG_xen,
     PROG_page,
     PROG_mapping,
@@ -1012,6 +1017,11 @@ int domain_relinquish_resources(struct domain *d)
         if (ret )
             return ret;
 
+    PROGRESS(ffa):
+        ret = ffa_relinquish_resources(d);
+        if (ret )
+            return ret;
+
     PROGRESS(xen):
         ret = relinquish_memory(d, &d->xenpage_list);
         if ( ret )
diff --git a/xen/arch/arm/ffa.c b/xen/arch/arm/ffa.c
new file mode 100644
index 000000000000..9063b7f2b59e
--- /dev/null
+++ b/xen/arch/arm/ffa.c
@@ -0,0 +1,1624 @@
+/*
+ * xen/arch/arm/ffa.c
+ *
+ * Arm Firmware Framework for ARMv8-A(FFA) mediator
+ *
+ * Copyright (C) 2021  Linaro Limited
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <xen/domain_page.h>
+#include <xen/errno.h>
+#include <xen/init.h>
+#include <xen/lib.h>
+#include <xen/sched.h>
+#include <xen/types.h>
+#include <xen/sizes.h>
+#include <xen/bitops.h>
+
+#include <asm/smccc.h>
+#include <asm/event.h>
+#include <asm/ffa.h>
+#include <asm/regs.h>
+
+/* Error codes */
+#define FFA_RET_OK			0
+#define FFA_RET_NOT_SUPPORTED		-1
+#define FFA_RET_INVALID_PARAMETERS	-2
+#define FFA_RET_NO_MEMORY		-3
+#define FFA_RET_BUSY			-4
+#define FFA_RET_INTERRUPTED		-5
+#define FFA_RET_DENIED			-6
+#define FFA_RET_RETRY			-7
+#define FFA_RET_ABORTED			-8
+
+/* FFA_VERSION helpers */
+#define FFA_VERSION_MAJOR		_AC(1,U)
+#define FFA_VERSION_MAJOR_SHIFT		_AC(16,U)
+#define FFA_VERSION_MAJOR_MASK		_AC(0x7FFF,U)
+#define FFA_VERSION_MINOR		_AC(1,U)
+#define FFA_VERSION_MINOR_SHIFT		_AC(0,U)
+#define FFA_VERSION_MINOR_MASK		_AC(0xFFFF,U)
+#define MAKE_FFA_VERSION(major, minor)	\
+	((((major) & FFA_VERSION_MAJOR_MASK) << FFA_VERSION_MAJOR_SHIFT) | \
+	 ((minor) & FFA_VERSION_MINOR_MASK))
+
+#define FFA_MIN_VERSION		MAKE_FFA_VERSION(1, 0)
+#define FFA_VERSION_1_0		MAKE_FFA_VERSION(1, 0)
+#define FFA_VERSION_1_1		MAKE_FFA_VERSION(1, 1)
+#define FFA_MY_VERSION		MAKE_FFA_VERSION(FFA_VERSION_MAJOR, \
+						 FFA_VERSION_MINOR)
+
+
+#define FFA_HANDLE_HYP_FLAG             BIT(63,ULL)
+
+/* Memory attributes: Normal memory, Write-Back cacheable, Inner shareable */
+#define FFA_NORMAL_MEM_REG_ATTR		_AC(0x2f,U)
+
+/* Memory access permissions: Read-write */
+#define FFA_MEM_ACC_RW			_AC(0x2,U)
+
+/* Clear memory before mapping in receiver */
+#define FFA_MEMORY_REGION_FLAG_CLEAR		BIT(0, U)
+/* Relayer may time slice this operation */
+#define FFA_MEMORY_REGION_FLAG_TIME_SLICE	BIT(1, U)
+/* Clear memory after receiver relinquishes it */
+#define FFA_MEMORY_REGION_FLAG_CLEAR_RELINQUISH	BIT(2, U)
+
+/* Share memory transaction */
+#define FFA_MEMORY_REGION_TRANSACTION_TYPE_SHARE (_AC(1,U) << 3)
+/* Relayer must choose the alignment boundary */
+#define FFA_MEMORY_REGION_FLAG_ANY_ALIGNMENT	_AC(0,U)
+
+#define FFA_HANDLE_INVALID		_AC(0xffffffffffffffff,ULL)
+
+/* Framework direct request/response */
+#define FFA_MSG_FLAG_FRAMEWORK		BIT(31, U)
+#define FFA_MSG_TYPE_MASK		_AC(0xFF,U);
+#define FFA_MSG_PSCI			_AC(0x0,U)
+#define FFA_MSG_SEND_VM_CREATED		_AC(0x4,U)
+#define FFA_MSG_RESP_VM_CREATED		_AC(0x5,U)
+#define FFA_MSG_SEND_VM_DESTROYED	_AC(0x6,U)
+#define FFA_MSG_RESP_VM_DESTROYED	_AC(0x7,U)
+
+/*
+ * Flags used for the FFA_PARTITION_INFO_GET return message:
+ * BIT(0): Supports receipt of direct requests
+ * BIT(1): Can send direct requests
+ * BIT(2): Can send and receive indirect messages
+ * BIT(3): Supports receipt of notifications
+ * BIT(4-5): Partition ID is a PE endpoint ID
+ */
+#define FFA_PART_PROP_DIRECT_REQ_RECV   BIT(0,U)
+#define FFA_PART_PROP_DIRECT_REQ_SEND   BIT(1,U)
+#define FFA_PART_PROP_INDIRECT_MSGS     BIT(2,U)
+#define FFA_PART_PROP_RECV_NOTIF        BIT(3,U)
+#define FFA_PART_PROP_IS_PE_ID          (_AC(0,U) << 4)
+#define FFA_PART_PROP_IS_SEPID_INDEP    (_AC(1,U) << 4)
+#define FFA_PART_PROP_IS_SEPID_DEP      (_AC(2,U) << 4)
+#define FFA_PART_PROP_IS_AUX_ID         (_AC(3,U) << 4)
+#define FFA_PART_PROP_NOTIF_CREATED     BIT(6,U)
+#define FFA_PART_PROP_NOTIF_DESTROYED   BIT(7,U)
+#define FFA_PART_PROP_AARCH64_STATE     BIT(8,U)
+
+/* Function IDs */
+#define FFA_ERROR			_AC(0x84000060,U)
+#define FFA_SUCCESS_32			_AC(0x84000061,U)
+#define FFA_SUCCESS_64			_AC(0xC4000061,U)
+#define FFA_INTERRUPT			_AC(0x84000062,U)
+#define FFA_VERSION			_AC(0x84000063,U)
+#define FFA_FEATURES			_AC(0x84000064,U)
+#define FFA_RX_ACQUIRE			_AC(0x84000084,U)
+#define FFA_RX_RELEASE			_AC(0x84000065,U)
+#define FFA_RXTX_MAP_32			_AC(0x84000066,U)
+#define FFA_RXTX_MAP_64			_AC(0xC4000066,U)
+#define FFA_RXTX_UNMAP			_AC(0x84000067,U)
+#define FFA_PARTITION_INFO_GET		_AC(0x84000068,U)
+#define FFA_ID_GET			_AC(0x84000069,U)
+#define FFA_SPM_ID_GET			_AC(0x84000085,U)
+#define FFA_MSG_WAIT			_AC(0x8400006B,U)
+#define FFA_MSG_YIELD			_AC(0x8400006C,U)
+#define FFA_MSG_RUN			_AC(0x8400006D,U)
+#define FFA_MSG_SEND2			_AC(0x84000086,U)
+#define FFA_MSG_SEND_DIRECT_REQ_32	_AC(0x8400006F,U)
+#define FFA_MSG_SEND_DIRECT_REQ_64	_AC(0xC400006F,U)
+#define FFA_MSG_SEND_DIRECT_RESP_32	_AC(0x84000070,U)
+#define FFA_MSG_SEND_DIRECT_RESP_64	_AC(0xC4000070,U)
+#define FFA_MEM_DONATE_32		_AC(0x84000071,U)
+#define FFA_MEM_DONATE_64		_AC(0xC4000071,U)
+#define FFA_MEM_LEND_32			_AC(0x84000072,U)
+#define FFA_MEM_LEND_64			_AC(0xC4000072,U)
+#define FFA_MEM_SHARE_32		_AC(0x84000073,U)
+#define FFA_MEM_SHARE_64		_AC(0xC4000073,U)
+#define FFA_MEM_RETRIEVE_REQ_32		_AC(0x84000074,U)
+#define FFA_MEM_RETRIEVE_REQ_64		_AC(0xC4000074,U)
+#define FFA_MEM_RETRIEVE_RESP		_AC(0x84000075,U)
+#define FFA_MEM_RELINQUISH		_AC(0x84000076,U)
+#define FFA_MEM_RECLAIM			_AC(0x84000077,U)
+#define FFA_MEM_FRAG_RX			_AC(0x8400007A,U)
+#define FFA_MEM_FRAG_TX			_AC(0x8400007B,U)
+#define FFA_MSG_SEND			_AC(0x8400006E,U)
+#define FFA_MSG_POLL			_AC(0x8400006A,U)
+
+/* Partition information descriptor */
+struct ffa_partition_info_1_0 {
+    uint16_t id;
+    uint16_t execution_context;
+    uint32_t partition_properties;
+};
+
+struct ffa_partition_info_1_1 {
+    uint16_t id;
+    uint16_t execution_context;
+    uint32_t partition_properties;
+    uint8_t uuid[16];
+};
+
+/* Constituent memory region descriptor */
+struct ffa_address_range {
+    uint64_t address;
+    uint32_t page_count;
+    uint32_t reserved;
+};
+
+/* Composite memory region descriptor */
+struct ffa_mem_region {
+    uint32_t total_page_count;
+    uint32_t address_range_count;
+    uint64_t reserved;
+    struct ffa_address_range address_range_array[];
+};
+
+/* Memory access permissions descriptor */
+struct ffa_mem_access_perm {
+    uint16_t endpoint_id;
+    uint8_t perm;
+    uint8_t flags;
+};
+
+/* Endpoint memory access descriptor */
+struct ffa_mem_access {
+    struct ffa_mem_access_perm access_perm;
+    uint32_t region_offs;
+    uint64_t reserved;
+};
+
+/* Lend, donate or share memory transaction descriptor */
+struct ffa_mem_transaction_1_0 {
+    uint16_t sender_id;
+    uint8_t mem_reg_attr;
+    uint8_t reserved0;
+    uint32_t flags;
+    uint64_t global_handle;
+    uint64_t tag;
+    uint32_t reserved1;
+    uint32_t mem_access_count;
+    struct ffa_mem_access mem_access_array[];
+};
+
+struct ffa_mem_transaction_1_1 {
+    uint16_t sender_id;
+    uint16_t mem_reg_attr;
+    uint32_t flags;
+    uint64_t global_handle;
+    uint64_t tag;
+    uint32_t mem_access_size;
+    uint32_t mem_access_count;
+    uint32_t mem_access_offs;
+    uint8_t reserved[12];
+};
+
+/*
+ * The parts needed from struct ffa_mem_transaction_1_0 or struct
+ * ffa_mem_transaction_1_1, used to provide an abstraction of difference in
+ * data structures between version 1.0 and 1.1. This is just an internal
+ * interface and can be changed without changing any ABI.
+ */
+struct ffa_mem_transaction_x {
+    uint16_t sender_id;
+    uint8_t mem_reg_attr;
+    uint8_t flags;
+    uint8_t mem_access_size;
+    uint8_t mem_access_count;
+    uint16_t mem_access_offs;
+    uint64_t global_handle;
+    uint64_t tag;
+};
+
+/* Endpoint RX/TX descriptor */
+struct ffa_endpoint_rxtx_descriptor_1_0 {
+    uint16_t sender_id;
+    uint16_t reserved;
+    uint32_t rx_range_count;
+    uint32_t tx_range_count;
+};
+
+struct ffa_endpoint_rxtx_descriptor_1_1 {
+    uint16_t sender_id;
+    uint16_t reserved;
+    uint32_t rx_region_offs;
+    uint32_t tx_region_offs;
+};
+
+struct ffa_ctx {
+    void *rx;
+    void *tx;
+    struct page_info *rx_pg;
+    struct page_info *tx_pg;
+    unsigned int page_count;
+    uint32_t guest_vers;
+    bool tx_is_mine;
+    bool interrupted;
+};
+
+struct ffa_shm_mem {
+    struct list_head list;
+    uint16_t sender_id;
+    uint16_t ep_id;     /* endpoint, the one lending */
+    uint64_t handle;    /* FFA_HANDLE_INVALID if not set yet */
+    unsigned int page_count;
+    struct page_info *pages[];
+};
+
+struct mem_frag_state {
+    struct list_head list;
+    struct ffa_shm_mem *shm;
+    uint32_t range_count;
+    unsigned int current_page_idx;
+    unsigned int frag_offset;
+    unsigned int range_offset;
+    uint8_t *buf;
+    unsigned int buf_size;
+    struct ffa_address_range range;
+};
+
+/*
+ * Our rx/rx buffer shared with the SPMC
+ */
+static uint32_t ffa_version;
+static uint16_t *subsr_vm_created;
+static unsigned int subsr_vm_created_count;
+static uint16_t *subsr_vm_destroyed;
+static unsigned int subsr_vm_destroyed_count;
+static void *ffa_rx;
+static void *ffa_tx;
+static unsigned int ffa_page_count;
+static spinlock_t ffa_buffer_lock = SPIN_LOCK_UNLOCKED;
+
+static struct list_head ffa_mem_list = LIST_HEAD_INIT(ffa_mem_list);
+static struct list_head ffa_frag_list = LIST_HEAD_INIT(ffa_frag_list);
+static spinlock_t ffa_mem_list_lock = SPIN_LOCK_UNLOCKED;
+
+static uint64_t next_handle = FFA_HANDLE_HYP_FLAG;
+
+static uint64_t reg_pair_to_64(uint32_t reg0, uint32_t reg1)
+{
+    return (uint64_t)reg0 << 32 | reg1;
+}
+
+static void reg_pair_from_64(uint32_t *reg0, uint32_t *reg1, uint64_t val)
+{
+    *reg0 = val >> 32;
+    *reg1 = val;
+}
+
+static bool ffa_get_version(uint32_t *vers)
+{
+    const struct arm_smccc_1_2_regs arg = {
+        .a0 = FFA_VERSION, .a1 = FFA_MY_VERSION,
+    };
+    struct arm_smccc_1_2_regs resp;
+
+    arm_smccc_1_2_smc(&arg, &resp);
+    if ( resp.a0 == FFA_RET_NOT_SUPPORTED )
+    {
+        printk(XENLOG_ERR "ffa: FFA_VERSION returned not supported\n");
+        return false;
+    }
+
+    *vers = resp.a0;
+    return true;
+}
+
+static uint32_t ffa_rxtx_map(register_t tx_addr, register_t rx_addr,
+                             uint32_t page_count)
+{
+    const struct arm_smccc_1_2_regs arg = {
+#ifdef CONFIG_ARM_64
+        .a0 = FFA_RXTX_MAP_64,
+#endif
+#ifdef CONFIG_ARM_32
+        .a0 = FFA_RXTX_MAP_32,
+#endif
+	.a1 = tx_addr, .a2 = rx_addr,
+        .a3 = page_count,
+    };
+    struct arm_smccc_1_2_regs resp;
+
+    arm_smccc_1_2_smc(&arg, &resp);
+
+    if ( resp.a0 == FFA_ERROR )
+    {
+        if ( resp.a2 )
+            return resp.a2;
+        else
+            return FFA_RET_NOT_SUPPORTED;
+    }
+
+    return FFA_RET_OK;
+}
+
+static uint32_t ffa_rxtx_unmap(uint16_t vm_id)
+{
+    const struct arm_smccc_1_2_regs arg = {
+        .a0 = FFA_RXTX_UNMAP, .a1 = vm_id,
+    };
+    struct arm_smccc_1_2_regs resp;
+
+    arm_smccc_1_2_smc(&arg, &resp);
+
+    if ( resp.a0 == FFA_ERROR )
+    {
+        if ( resp.a2 )
+            return resp.a2;
+        else
+            return FFA_RET_NOT_SUPPORTED;
+    }
+
+    return FFA_RET_OK;
+}
+
+static uint32_t ffa_partition_info_get(uint32_t w1, uint32_t w2, uint32_t w3,
+                                       uint32_t w4, uint32_t w5,
+                                       uint32_t *count)
+{
+    const struct arm_smccc_1_2_regs arg = {
+        .a0 = FFA_PARTITION_INFO_GET, .a1 = w1, .a2 = w2, .a3 = w3, .a4 = w4,
+        .a5 = w5,
+    };
+    struct arm_smccc_1_2_regs resp;
+
+    arm_smccc_1_2_smc(&arg, &resp);
+
+    if ( resp.a0 == FFA_ERROR )
+    {
+        if ( resp.a2 )
+            return resp.a2;
+        else
+            return FFA_RET_NOT_SUPPORTED;
+    }
+
+    *count = resp.a2;
+
+    return FFA_RET_OK;
+}
+
+static uint32_t ffa_rx_release(void)
+{
+    const struct arm_smccc_1_2_regs arg = { .a0 = FFA_RX_RELEASE, };
+    struct arm_smccc_1_2_regs resp;
+
+    arm_smccc_1_2_smc(&arg, &resp);
+
+    if ( resp.a0 == FFA_ERROR )
+    {
+        if ( resp.a2 )
+            return resp.a2;
+        else
+            return FFA_RET_NOT_SUPPORTED;
+    }
+
+    return FFA_RET_OK;
+}
+
+static int32_t ffa_mem_share(uint32_t tot_len, uint32_t frag_len,
+                             register_t addr, uint32_t pg_count,
+                             uint64_t *handle)
+{
+    struct arm_smccc_1_2_regs arg = {
+        .a0 = FFA_MEM_SHARE_32, .a1 = tot_len, .a2 = frag_len, .a3 = addr,
+        .a4 = pg_count,
+    };
+    struct arm_smccc_1_2_regs resp;
+
+    /*
+     * For arm64 we must use 64-bit calling convention if the buffer isn't
+     * passed in our tx buffer.
+     */
+    if (sizeof(addr) > 4 && addr)
+        arg.a0 = FFA_MEM_SHARE_64;
+
+    arm_smccc_1_2_smc(&arg, &resp);
+
+    switch ( resp.a0 ) {
+    case FFA_ERROR:
+        if ( resp.a2 )
+            return resp.a2;
+        else
+            return FFA_RET_NOT_SUPPORTED;
+    case FFA_SUCCESS_32:
+        *handle = reg_pair_to_64(resp.a3, resp.a2);
+        return FFA_RET_OK;
+    case FFA_MEM_FRAG_RX:
+        *handle = reg_pair_to_64(resp.a2, resp.a1);
+        return resp.a3;
+    default:
+            return FFA_RET_NOT_SUPPORTED;
+    }
+}
+
+static int32_t ffa_mem_frag_tx(uint64_t handle, uint32_t frag_len,
+                               uint16_t sender_id)
+{
+    struct arm_smccc_1_2_regs arg = {
+        .a0 = FFA_MEM_FRAG_TX, .a1 = handle & UINT32_MAX, .a2 = handle >> 32,
+        .a3 = frag_len, .a4 = (uint32_t)sender_id << 16,
+    };
+    struct arm_smccc_1_2_regs resp;
+
+    arm_smccc_1_2_smc(&arg, &resp);
+
+    switch ( resp.a0 ) {
+    case FFA_ERROR:
+        if ( resp.a2 )
+            return resp.a2;
+        else
+            return FFA_RET_NOT_SUPPORTED;
+    case FFA_SUCCESS_32:
+        return FFA_RET_OK;
+    case FFA_MEM_FRAG_RX:
+        return resp.a3;
+    default:
+            return FFA_RET_NOT_SUPPORTED;
+    }
+}
+
+static uint32_t ffa_mem_reclaim(uint32_t handle_lo, uint32_t handle_hi,
+                                uint32_t flags)
+{
+    const struct arm_smccc_1_2_regs arg = {
+        .a0 = FFA_MEM_RECLAIM, .a1 = handle_lo, .a2 = handle_hi, .a3 = flags,
+    };
+    struct arm_smccc_1_2_regs resp;
+
+    arm_smccc_1_2_smc(&arg, &resp);
+
+    if ( resp.a0 == FFA_ERROR )
+    {
+        if ( resp.a2 )
+            return resp.a2;
+        else
+            return FFA_RET_NOT_SUPPORTED;
+    }
+
+    return FFA_RET_OK;
+}
+
+static int32_t ffa_direct_req_send_vm(uint16_t sp_id, uint16_t vm_id,
+                                      uint8_t msg)
+{
+    uint32_t exp_resp = FFA_MSG_FLAG_FRAMEWORK;
+    int32_t res;
+
+    if ( msg != FFA_MSG_SEND_VM_CREATED && msg !=FFA_MSG_SEND_VM_DESTROYED )
+        return FFA_RET_INVALID_PARAMETERS;
+
+    if ( msg == FFA_MSG_SEND_VM_CREATED )
+        exp_resp |= FFA_MSG_RESP_VM_CREATED;
+    else
+        exp_resp |= FFA_MSG_RESP_VM_DESTROYED;
+
+    do {
+        const struct arm_smccc_1_2_regs arg = {
+            .a0 = FFA_MSG_SEND_DIRECT_REQ_32,
+            .a1 = sp_id,
+            .a2 = FFA_MSG_FLAG_FRAMEWORK | msg,
+            .a5 = vm_id,
+        };
+        struct arm_smccc_1_2_regs resp;
+
+        arm_smccc_1_2_smc(&arg, &resp);
+        if ( resp.a0 != FFA_MSG_SEND_DIRECT_RESP_32 || resp.a2 != exp_resp ) {
+            /*
+             * This is an invalid response, likely due to some error in the
+             * implementation of the ABI.
+             */
+            return FFA_RET_INVALID_PARAMETERS;
+        }
+        res = resp.a3;
+    } while ( res == FFA_RET_INTERRUPTED || res == FFA_RET_RETRY );
+
+    return res;
+}
+
+static u16 get_vm_id(struct domain *d)
+{
+    /* +1 since 0 is reserved for the hypervisor in FF-A */
+    return d->domain_id + 1;
+}
+
+static void set_regs(struct cpu_user_regs *regs, register_t v0, register_t v1,
+                     register_t v2, register_t v3, register_t v4, register_t v5,
+                     register_t v6, register_t v7)
+{
+        set_user_reg(regs, 0, v0);
+        set_user_reg(regs, 1, v1);
+        set_user_reg(regs, 2, v2);
+        set_user_reg(regs, 3, v3);
+        set_user_reg(regs, 4, v4);
+        set_user_reg(regs, 5, v5);
+        set_user_reg(regs, 6, v6);
+        set_user_reg(regs, 7, v7);
+}
+
+static void set_regs_error(struct cpu_user_regs *regs, uint32_t error_code)
+{
+    set_regs(regs, FFA_ERROR, 0, error_code, 0, 0, 0, 0, 0);
+}
+
+static void set_regs_success(struct cpu_user_regs *regs, uint32_t w2,
+                             uint32_t w3)
+{
+    set_regs(regs, FFA_SUCCESS_32, 0, w2, w3, 0, 0, 0, 0);
+}
+
+static void set_regs_frag_rx(struct cpu_user_regs *regs, uint32_t handle_lo,
+                             uint32_t handle_hi, uint32_t frag_offset,
+                             uint16_t sender_id)
+{
+    set_regs(regs, FFA_MEM_FRAG_RX, handle_lo, handle_hi, frag_offset,
+             (uint32_t)sender_id << 16, 0, 0, 0);
+}
+
+static void handle_version(struct cpu_user_regs *regs)
+{
+    struct domain *d = current->domain;
+    struct ffa_ctx *ctx = d->arch.ffa;
+    uint32_t vers = get_user_reg(regs, 1);
+
+    if ( vers < FFA_VERSION_1_1 )
+        vers = FFA_VERSION_1_0;
+    else
+        vers = FFA_VERSION_1_1;
+
+    ctx->guest_vers = vers;
+    set_regs(regs, vers, 0, 0, 0, 0, 0, 0, 0);
+}
+
+static uint32_t handle_rxtx_map(uint32_t fid, register_t tx_addr,
+                                register_t rx_addr, uint32_t page_count)
+{
+    uint32_t ret = FFA_RET_NOT_SUPPORTED;
+    struct domain *d = current->domain;
+    struct ffa_ctx *ctx = d->arch.ffa;
+    struct page_info *tx_pg;
+    struct page_info *rx_pg;
+    p2m_type_t t;
+    void *rx;
+    void *tx;
+
+    if ( !smccc_is_conv_64(fid) )
+    {
+        tx_addr &= UINT32_MAX;
+        rx_addr &= UINT32_MAX;
+    }
+
+    /* For now to keep things simple, only deal with a single page */
+    if ( page_count != 1 )
+        return FFA_RET_NOT_SUPPORTED;
+
+    /* Already mapped */
+    if ( ctx->rx )
+        return FFA_RET_DENIED;
+
+    tx_pg = get_page_from_gfn(d, gaddr_to_gfn(tx_addr), &t, P2M_ALLOC);
+    if ( !tx_pg )
+        return FFA_RET_NOT_SUPPORTED;
+    /* Only normal RAM for now */
+    if (t != p2m_ram_rw)
+        goto err_put_tx_pg;
+
+    rx_pg = get_page_from_gfn(d, gaddr_to_gfn(rx_addr), &t, P2M_ALLOC);
+    if ( !tx_pg )
+        goto err_put_tx_pg;
+    /* Only normal RAM for now */
+    if ( t != p2m_ram_rw )
+        goto err_put_rx_pg;
+
+    tx = __map_domain_page_global(tx_pg);
+    if ( !tx )
+        goto err_put_rx_pg;
+
+    rx = __map_domain_page_global(rx_pg);
+    if ( !rx )
+        goto err_unmap_tx;
+
+    ctx->rx = rx;
+    ctx->tx = tx;
+    ctx->rx_pg = rx_pg;
+    ctx->tx_pg = tx_pg;
+    ctx->page_count = 1;
+    ctx->tx_is_mine = true;
+    return FFA_RET_OK;
+
+err_unmap_tx:
+    unmap_domain_page_global(tx);
+err_put_rx_pg:
+    put_page(rx_pg);
+err_put_tx_pg:
+    put_page(tx_pg);
+    return ret;
+}
+
+static uint32_t handle_rxtx_unmap(void)
+{
+    struct domain *d = current->domain;
+    struct ffa_ctx *ctx = d->arch.ffa;
+    uint32_t ret;
+
+    if ( !ctx-> rx )
+        return FFA_RET_INVALID_PARAMETERS;
+
+    ret = ffa_rxtx_unmap(get_vm_id(d));
+    if ( ret )
+        return ret;
+
+    unmap_domain_page_global(ctx->rx);
+    unmap_domain_page_global(ctx->tx);
+    put_page(ctx->rx_pg);
+    put_page(ctx->tx_pg);
+    ctx->rx = NULL;
+    ctx->tx = NULL;
+    ctx->rx_pg = NULL;
+    ctx->tx_pg = NULL;
+    ctx->page_count = 0;
+    ctx->tx_is_mine = false;
+
+    return FFA_RET_OK;
+}
+
+static uint32_t handle_partition_info_get(uint32_t w1, uint32_t w2, uint32_t w3,
+                                          uint32_t w4, uint32_t w5,
+                                          uint32_t *count)
+{
+    uint32_t ret = FFA_RET_DENIED;
+    struct domain *d = current->domain;
+    struct ffa_ctx *ctx = d->arch.ffa;
+
+    if ( !ffa_page_count )
+        return FFA_RET_DENIED;
+
+    spin_lock(&ffa_buffer_lock);
+    if ( !ctx->page_count || !ctx->tx_is_mine )
+        goto out;
+    ret = ffa_partition_info_get(w1, w2, w3, w4, w5, count);
+    if ( ret )
+        goto out;
+    if ( ctx->guest_vers == FFA_VERSION_1_0 ) {
+        size_t n;
+        struct ffa_partition_info_1_1 *src = ffa_rx;
+        struct ffa_partition_info_1_0 *dst = ctx->rx;
+
+        for ( n = 0; n < *count; n++ ) {
+            dst[n].id = src[n].id;
+            dst[n].execution_context = src[n].execution_context;
+            dst[n].partition_properties = src[n].partition_properties;
+        }
+    } else {
+        size_t sz = *count * sizeof(struct ffa_partition_info_1_1);
+
+        memcpy(ctx->rx, ffa_rx, sz);
+    }
+    ffa_rx_release();
+    ctx->tx_is_mine = false;
+out:
+    spin_unlock(&ffa_buffer_lock);
+
+    return ret;
+}
+
+static uint32_t handle_rx_release(void)
+{
+    uint32_t ret = FFA_RET_DENIED;
+    struct domain *d = current->domain;
+    struct ffa_ctx *ctx = d->arch.ffa;
+
+    spin_lock(&ffa_buffer_lock);
+    if ( !ctx->page_count || ctx->tx_is_mine )
+        goto out;
+    ret = FFA_RET_OK;
+    ctx->tx_is_mine = true;
+out:
+    spin_unlock(&ffa_buffer_lock);
+
+    return ret;
+}
+
+static void handle_msg_send_direct_req(struct cpu_user_regs *regs, uint32_t fid)
+{
+    struct arm_smccc_1_2_regs arg = { .a0 = fid, };
+    struct arm_smccc_1_2_regs resp = { };
+    struct domain *d = current->domain;
+    struct ffa_ctx *ctx = d->arch.ffa;
+    uint32_t src_dst;
+    uint64_t mask;
+
+    if ( smccc_is_conv_64(fid) )
+        mask = 0xffffffffffffffff;
+    else
+        mask = 0xffffffff;
+
+    src_dst = get_user_reg(regs, 1);
+    if ( (src_dst >> 16) != get_vm_id(d) )
+    {
+        resp.a0 = FFA_ERROR;
+        resp.a2 = FFA_RET_INVALID_PARAMETERS;
+        goto out;
+    }
+
+    arg.a1 = src_dst;
+    arg.a2 = get_user_reg(regs, 2) & mask;
+    arg.a3 = get_user_reg(regs, 3) & mask;
+    arg.a4 = get_user_reg(regs, 4) & mask;
+    arg.a5 = get_user_reg(regs, 5) & mask;
+    arg.a6 = get_user_reg(regs, 6) & mask;
+    arg.a7 = get_user_reg(regs, 7) & mask;
+
+    while ( true ) {
+        arm_smccc_1_2_smc(&arg, &resp);
+
+        switch ( resp.a0 )
+        {
+        case FFA_INTERRUPT:
+            ctx->interrupted = true;
+            goto out;
+        case FFA_ERROR:
+        case FFA_SUCCESS_32:
+        case FFA_SUCCESS_64:
+        case FFA_MSG_SEND_DIRECT_RESP_32:
+        case FFA_MSG_SEND_DIRECT_RESP_64:
+            goto out;
+        default:
+            /* Bad fid, report back. */
+            memset(&arg, 0, sizeof(arg));
+            arg.a0 = FFA_ERROR;
+            arg.a1 = src_dst;
+            arg.a2 = FFA_RET_NOT_SUPPORTED;
+            continue;
+        }
+    }
+
+out:
+    set_user_reg(regs, 0, resp.a0);
+    set_user_reg(regs, 2, resp.a2 & mask);
+    set_user_reg(regs, 1, resp.a1 & mask);
+    set_user_reg(regs, 3, resp.a3 & mask);
+    set_user_reg(regs, 4, resp.a4 & mask);
+    set_user_reg(regs, 5, resp.a5 & mask);
+    set_user_reg(regs, 6, resp.a6 & mask);
+    set_user_reg(regs, 7, resp.a7 & mask);
+}
+
+static int get_shm_pages(struct domain *d, struct ffa_shm_mem *shm,
+                         struct ffa_address_range *range, uint32_t range_count,
+                         unsigned int start_page_idx,
+                         unsigned int *last_page_idx)
+{
+    unsigned int pg_idx = start_page_idx;
+    unsigned long gfn;
+    unsigned int n;
+    unsigned int m;
+    p2m_type_t t;
+    uint64_t addr;
+
+    for ( n = 0; n < range_count; n++ ) {
+        for ( m = 0; m < range[n].page_count; m++ ) {
+            if ( pg_idx >= shm->page_count )
+                return FFA_RET_INVALID_PARAMETERS;
+
+            addr = read_atomic(&range[n].address);
+            gfn = gaddr_to_gfn(addr + m * PAGE_SIZE);
+            shm->pages[pg_idx] = get_page_from_gfn(d, gfn, &t, P2M_ALLOC);
+            if ( !shm->pages[pg_idx] )
+                return FFA_RET_DENIED;
+            pg_idx++;
+            /* Only normal RAM for now */
+            if ( t != p2m_ram_rw )
+                return FFA_RET_DENIED;
+        }
+    }
+
+    *last_page_idx = pg_idx;
+
+    return FFA_RET_OK;
+}
+
+static void put_shm_pages(struct ffa_shm_mem *shm)
+{
+    unsigned int n;
+
+    for ( n = 0; n < shm->page_count && shm->pages[n]; n++ )
+    {
+        if ( shm->pages[n] ) {
+            put_page(shm->pages[n]);
+            shm->pages[n] = NULL;
+        }
+    }
+}
+
+static void init_range(struct ffa_address_range *addr_range,
+                       paddr_t pa)
+{
+    memset(addr_range, 0, sizeof(*addr_range));
+    addr_range->address = pa;
+    addr_range->page_count = 1;
+}
+
+static int share_shm(struct ffa_shm_mem *shm)
+{
+    uint32_t max_frag_len = ffa_page_count * PAGE_SIZE;
+    struct ffa_mem_transaction_1_1 *descr = ffa_tx;
+    struct ffa_mem_access *mem_access_array;
+    struct ffa_mem_region *region_descr;
+    struct ffa_address_range *addr_range;
+    paddr_t pa;
+    paddr_t last_pa;
+    unsigned int n;
+    uint32_t frag_len;
+    uint32_t tot_len;
+    int ret;
+    unsigned int range_count;
+    unsigned int range_base;
+    bool first;
+
+    memset(descr, 0, sizeof(*descr));
+    descr->sender_id = shm->sender_id;
+    descr->global_handle = shm->handle;
+    descr->mem_reg_attr = FFA_NORMAL_MEM_REG_ATTR;
+    descr->mem_access_count = 1;
+    descr->mem_access_size = sizeof(*mem_access_array);
+    descr->mem_access_offs = sizeof(*descr);
+    mem_access_array = (void *)(descr + 1);
+    region_descr = (void *)(mem_access_array + 1);
+
+    memset(mem_access_array, 0, sizeof(*mem_access_array));
+    mem_access_array[0].access_perm.endpoint_id = shm->ep_id;
+    mem_access_array[0].access_perm.perm = FFA_MEM_ACC_RW;
+    mem_access_array[0].region_offs = (vaddr_t)region_descr - (vaddr_t)ffa_tx;
+
+    memset(region_descr, 0, sizeof(*region_descr));
+    region_descr->total_page_count = shm->page_count;
+
+    region_descr->address_range_count = 1;
+    last_pa = page_to_maddr(shm->pages[0]);
+    for ( n = 1; n < shm->page_count; last_pa = pa, n++ )
+    {
+        pa = page_to_maddr(shm->pages[n]);
+        if ( last_pa + PAGE_SIZE == pa )
+        {
+            continue;
+        }
+        region_descr->address_range_count++;
+    }
+
+    tot_len = sizeof(*descr) + sizeof(*mem_access_array) +
+              sizeof(*region_descr) +
+              region_descr->address_range_count * sizeof(*addr_range);
+
+    addr_range = region_descr->address_range_array;
+    frag_len = (vaddr_t)(addr_range + 1) - (vaddr_t)ffa_tx;
+    last_pa = page_to_maddr(shm->pages[0]);
+    init_range(addr_range, last_pa);
+    first = true;
+    range_count = 1;
+    range_base = 0;
+    for ( n = 1; n < shm->page_count; last_pa = pa, n++ )
+    {
+        pa = page_to_maddr(shm->pages[n]);
+        if ( last_pa + PAGE_SIZE == pa )
+        {
+            addr_range->page_count++;
+            continue;
+        }
+
+        if (frag_len == max_frag_len) {
+            if (first)
+            {
+                ret = ffa_mem_share(tot_len, frag_len, 0, 0, &shm->handle);
+                first = false;
+            }
+            else
+            {
+                ret = ffa_mem_frag_tx(shm->handle, frag_len, shm->sender_id);
+            }
+            if (ret <= 0)
+                return ret;
+            range_base = range_count;
+            range_count = 0;
+            frag_len = sizeof(*addr_range);
+            addr_range = ffa_tx;
+        } else {
+            frag_len += sizeof(*addr_range);
+            addr_range++;
+        }
+        init_range(addr_range, pa);
+        range_count++;
+    }
+
+    if (first)
+        return ffa_mem_share(tot_len, frag_len, 0, 0, &shm->handle);
+    else
+        return ffa_mem_frag_tx(shm->handle, frag_len, shm->sender_id);
+}
+
+static int read_mem_transaction(uint32_t ffa_vers, void *buf, size_t blen,
+                                struct ffa_mem_transaction_x *trans)
+{
+    uint16_t mem_reg_attr;
+    uint32_t flags;
+    uint32_t count;
+    uint32_t offs;
+    uint32_t size;
+
+    if (ffa_vers >= FFA_VERSION_1_1) {
+        struct ffa_mem_transaction_1_1 *descr;
+
+        if (blen < sizeof(*descr))
+            return FFA_RET_INVALID_PARAMETERS;
+
+        descr = buf;
+        trans->sender_id = read_atomic(&descr->sender_id);
+        mem_reg_attr = read_atomic(&descr->mem_reg_attr);
+        flags = read_atomic(&descr->flags);
+        trans->global_handle = read_atomic(&descr->global_handle);
+        trans->tag = read_atomic(&descr->tag);
+
+        count = read_atomic(&descr->mem_access_count);
+        size = read_atomic(&descr->mem_access_size);
+        offs = read_atomic(&descr->mem_access_offs);
+    } else {
+        struct ffa_mem_transaction_1_0 *descr;
+
+        if (blen < sizeof(*descr))
+            return FFA_RET_INVALID_PARAMETERS;
+
+        descr = buf;
+        trans->sender_id = read_atomic(&descr->sender_id);
+        mem_reg_attr = read_atomic(&descr->mem_reg_attr);
+        flags = read_atomic(&descr->flags);
+        trans->global_handle = read_atomic(&descr->global_handle);
+        trans->tag = read_atomic(&descr->tag);
+
+        count = read_atomic(&descr->mem_access_count);
+        size = sizeof(struct ffa_mem_access);
+        offs = offsetof(struct ffa_mem_transaction_1_0, mem_access_array);
+    }
+
+    if (mem_reg_attr > UINT8_MAX || flags > UINT8_MAX || size > UINT8_MAX ||
+        count > UINT8_MAX || offs > UINT16_MAX)
+        return FFA_RET_INVALID_PARAMETERS;
+
+    /* Check that the endpoint memory access descriptor array fits */
+    if (size * count + offs > blen)
+        return FFA_RET_INVALID_PARAMETERS;
+
+    trans->mem_reg_attr = mem_reg_attr;
+    trans->flags = flags;
+    trans->mem_access_size = size;
+    trans->mem_access_count = count;
+    trans->mem_access_offs = offs;
+    return 0;
+}
+
+static int add_mem_share_frag(struct mem_frag_state *s, unsigned int offs,
+                              unsigned int frag_len)
+{
+    struct domain *d = current->domain;
+    unsigned int o = offs;
+    unsigned int l;
+    int ret;
+
+    if (frag_len < o)
+        return FFA_RET_INVALID_PARAMETERS;
+
+    /* Fill up the first struct ffa_address_range */
+    l = min_t(unsigned int, frag_len - o, sizeof(s->range) - s->range_offset);
+    memcpy((uint8_t *)&s->range + s->range_offset, s->buf + o, l);
+    s->range_offset += l;
+    o += l;
+    if (s->range_offset != sizeof(s->range))
+        goto out;
+    s->range_offset = 0;
+
+    while (true) {
+        ret = get_shm_pages(d, s->shm, &s->range, 1, s->current_page_idx,
+                            &s->current_page_idx);
+        if (ret)
+            return ret;
+        if (s->range_count == 1)
+            return 0;
+        s->range_count--;
+        if (frag_len - o < sizeof(s->range))
+            break;
+        memcpy(&s->range, s->buf + o, sizeof(s->range));
+        o += sizeof(s->range);
+    }
+
+    /* Collect any remaining bytes for the next struct ffa_address_range */
+    s->range_offset = frag_len - o;
+    memcpy(&s->range, s->buf + o, frag_len - o);
+out:
+    s->frag_offset += frag_len;
+    return s->frag_offset;
+}
+
+static void handle_mem_share(struct cpu_user_regs *regs)
+{
+    uint32_t tot_len = get_user_reg(regs, 1);
+    uint32_t frag_len = get_user_reg(regs, 2);
+    uint64_t addr = get_user_reg(regs, 3);
+    uint32_t page_count = get_user_reg(regs, 4);
+    struct ffa_mem_transaction_x trans;
+    struct ffa_mem_access *mem_access;
+    struct ffa_mem_region *region_descr;
+    struct domain *d = current->domain;
+    struct ffa_ctx *ctx = d->arch.ffa;
+    struct ffa_shm_mem *shm = NULL;
+    unsigned int last_page_idx = 0;
+    uint32_t range_count;
+    uint32_t region_offs;
+    int ret = FFA_RET_DENIED;
+    uint32_t handle_hi = 0;
+    uint32_t handle_lo = 0;
+
+    /*
+     * We're only accepting memory transaction descriptors via the rx/tx
+     * buffer.
+     */
+    if ( addr ) {
+        ret = FFA_RET_NOT_SUPPORTED;
+        goto out_unlock;
+    }
+
+    /* Check that fragment legnth doesn't exceed total length */
+    if (frag_len > tot_len) {
+        ret = FFA_RET_INVALID_PARAMETERS;
+        goto out_unlock;
+    }
+
+    spin_lock(&ffa_buffer_lock);
+
+    if ( frag_len > ctx->page_count * PAGE_SIZE )
+        goto out_unlock;
+
+    if ( !ffa_page_count ) {
+        ret = FFA_RET_NO_MEMORY;
+        goto out_unlock;
+    }
+
+    ret = read_mem_transaction(ctx->guest_vers, ctx->tx, frag_len, &trans);
+    if (ret)
+        goto out_unlock;
+
+    if ( trans.mem_reg_attr != FFA_NORMAL_MEM_REG_ATTR )
+    {
+        ret = FFA_RET_NOT_SUPPORTED;
+        goto out;
+    }
+
+    /* Only supports sharing it with one SP for now */
+    if ( trans.mem_access_count != 1 )
+    {
+        ret = FFA_RET_NOT_SUPPORTED;
+        goto out_unlock;
+    }
+
+    if ( trans.sender_id != get_vm_id(d) )
+    {
+        ret = FFA_RET_INVALID_PARAMETERS;
+        goto out_unlock;
+    }
+
+    /* Check that it fits in the supplied data */
+    if ( trans.mem_access_offs + trans.mem_access_size > frag_len)
+        goto out_unlock;
+
+    mem_access = (void *)((vaddr_t)ctx->tx + trans.mem_access_offs);
+    if ( read_atomic(&mem_access->access_perm.perm) != FFA_MEM_ACC_RW )
+    {
+        ret = FFA_RET_NOT_SUPPORTED;
+        goto out_unlock;
+    }
+
+    region_offs = read_atomic(&mem_access->region_offs);
+    if (sizeof(*region_descr) + region_offs > frag_len) {
+        ret = FFA_RET_NOT_SUPPORTED;
+        goto out_unlock;
+    }
+
+    region_descr = (void *)((vaddr_t)ctx->tx + region_offs);
+    range_count = read_atomic(&region_descr->address_range_count);
+    page_count = read_atomic(&region_descr->total_page_count);
+
+    shm = xzalloc_flex_struct(struct ffa_shm_mem, pages, page_count);
+    if ( !shm )
+    {
+        ret = FFA_RET_NO_MEMORY;
+        goto out;
+    }
+    shm->sender_id = trans.sender_id;
+    shm->ep_id = read_atomic(&mem_access->access_perm.endpoint_id);
+    shm->page_count = page_count;
+
+    if (frag_len != tot_len) {
+        struct mem_frag_state *s = xzalloc(struct mem_frag_state);
+
+        if (!s) {
+            ret = FFA_RET_NO_MEMORY;
+            goto out;
+        }
+        s->shm = shm;
+        s->range_count = range_count;
+        s->buf = ctx->tx;
+        s->buf_size = ffa_page_count * PAGE_SIZE;
+        ret = add_mem_share_frag(s, sizeof(*region_descr)  + region_offs,
+                                 frag_len);
+        if (ret <= 0) {
+            xfree(s);
+            if (ret < 0)
+                goto out;
+        } else {
+            shm->handle = next_handle++;
+            reg_pair_from_64(&handle_hi, &handle_lo, shm->handle);
+            spin_lock(&ffa_mem_list_lock);
+            list_add_tail(&s->list, &ffa_frag_list);
+            spin_unlock(&ffa_mem_list_lock);
+        }
+        goto out_unlock;
+    }
+
+    /*
+     * Check that the Composite memory region descriptor fits.
+     */
+    if ( sizeof(*region_descr) + region_offs +
+         range_count * sizeof(struct ffa_address_range) > frag_len) {
+        ret = FFA_RET_INVALID_PARAMETERS;
+        goto out;
+    }
+
+    ret = get_shm_pages(d, shm, region_descr->address_range_array, range_count,
+                        0, &last_page_idx);
+    if ( ret )
+        goto out;
+    if (last_page_idx != shm->page_count) {
+        ret = FFA_RET_INVALID_PARAMETERS;
+        goto out;
+    }
+
+    /* Note that share_shm() uses our tx buffer */
+    ret = share_shm(shm);
+    if ( ret )
+        goto out;
+
+    spin_lock(&ffa_mem_list_lock);
+    list_add_tail(&shm->list, &ffa_mem_list);
+    spin_unlock(&ffa_mem_list_lock);
+
+    reg_pair_from_64(&handle_hi, &handle_lo, shm->handle);
+
+out:
+    if ( ret && shm )
+    {
+        put_shm_pages(shm);
+        xfree(shm);
+    }
+out_unlock:
+    spin_unlock(&ffa_buffer_lock);
+
+    if ( ret > 0 )
+            set_regs_frag_rx(regs, handle_lo, handle_hi, ret, trans.sender_id);
+    else if ( ret == 0)
+            set_regs_success(regs, handle_lo, handle_hi);
+    else
+            set_regs_error(regs, ret);
+}
+
+static struct mem_frag_state *find_frag_state(uint64_t handle)
+{
+    struct mem_frag_state *s;
+
+    list_for_each_entry(s, &ffa_frag_list, list)
+        if ( s->shm->handle == handle)
+            return s;
+
+    return NULL;
+}
+
+static void handle_mem_frag_tx(struct cpu_user_regs *regs)
+{
+    uint32_t frag_len = get_user_reg(regs, 3);
+    uint32_t handle_lo = get_user_reg(regs, 1);
+    uint32_t handle_hi = get_user_reg(regs, 2);
+    uint64_t handle = reg_pair_to_64(handle_hi, handle_lo);
+    struct mem_frag_state *s;
+    uint16_t sender_id = 0;
+    int ret;
+
+    spin_lock(&ffa_buffer_lock);
+    s = find_frag_state(handle);
+    if (!s) {
+        ret = FFA_RET_INVALID_PARAMETERS;
+        goto out;
+    }
+    sender_id = s->shm->sender_id;
+
+    if (frag_len > s->buf_size) {
+        ret = FFA_RET_INVALID_PARAMETERS;
+        goto out;
+    }
+
+    ret = add_mem_share_frag(s, 0, frag_len);
+    if (ret == 0) {
+        /* Note that share_shm() uses our tx buffer */
+        ret = share_shm(s->shm);
+        if (ret == 0) {
+            spin_lock(&ffa_mem_list_lock);
+            list_add_tail(&s->shm->list, &ffa_mem_list);
+            spin_unlock(&ffa_mem_list_lock);
+        } else {
+            put_shm_pages(s->shm);
+            xfree(s->shm);
+        }
+        spin_lock(&ffa_mem_list_lock);
+        list_del(&s->list);
+        spin_unlock(&ffa_mem_list_lock);
+        xfree(s);
+    } else if (ret < 0) {
+        put_shm_pages(s->shm);
+        xfree(s->shm);
+        spin_lock(&ffa_mem_list_lock);
+        list_del(&s->list);
+        spin_unlock(&ffa_mem_list_lock);
+        xfree(s);
+    }
+out:
+    spin_unlock(&ffa_buffer_lock);
+
+    if ( ret > 0 )
+            set_regs_frag_rx(regs, handle_lo, handle_hi, ret, sender_id);
+    else if ( ret == 0)
+            set_regs_success(regs, handle_lo, handle_hi);
+    else
+            set_regs_error(regs, ret);
+}
+
+static int handle_mem_reclaim(uint64_t handle, uint32_t flags)
+{
+    struct ffa_shm_mem *shm;
+    uint32_t handle_hi;
+    uint32_t handle_lo;
+    int ret;
+
+    spin_lock(&ffa_mem_list_lock);
+    list_for_each_entry(shm, &ffa_mem_list, list) {
+        if ( shm->handle == handle )
+            goto found_it;
+    }
+    shm = NULL;
+found_it:
+    spin_unlock(&ffa_mem_list_lock);
+
+    if ( !shm )
+        return FFA_RET_INVALID_PARAMETERS;
+
+    reg_pair_from_64(&handle_hi, &handle_lo, handle);
+    ret = ffa_mem_reclaim(handle_lo, handle_hi, flags);
+    if ( ret )
+        return ret;
+
+    spin_lock(&ffa_mem_list_lock);
+    list_del(&shm->list);
+    spin_unlock(&ffa_mem_list_lock);
+
+    put_shm_pages(shm);
+    xfree(shm);
+
+    return ret;
+}
+
+bool ffa_handle_call(struct cpu_user_regs *regs, uint32_t fid)
+{
+    struct domain *d = current->domain;
+    struct ffa_ctx *ctx = d->arch.ffa;
+    uint32_t count;
+    uint32_t e;
+
+    if ( !ctx )
+        return false;
+
+    switch ( fid )
+    {
+    case FFA_VERSION:
+        handle_version(regs);
+        return true;
+    case FFA_ID_GET:
+        set_regs_success(regs, get_vm_id(d), 0);
+        return true;
+    case FFA_RXTX_MAP_32:
+#ifdef CONFIG_ARM_64
+    case FFA_RXTX_MAP_64:
+#endif
+        e = handle_rxtx_map(fid, get_user_reg(regs, 1), get_user_reg(regs, 2),
+                            get_user_reg(regs, 3));
+        if ( e )
+            set_regs_error(regs, e);
+        else
+            set_regs_success(regs, 0, 0);
+        return true;
+    case FFA_RXTX_UNMAP:
+        e = handle_rxtx_unmap();
+        if ( e )
+            set_regs_error(regs, e);
+        else
+            set_regs_success(regs, 0, 0);
+        return true;
+    case FFA_PARTITION_INFO_GET:
+        e = handle_partition_info_get(get_user_reg(regs, 1),
+                                      get_user_reg(regs, 2),
+                                      get_user_reg(regs, 3),
+                                      get_user_reg(regs, 4),
+                                      get_user_reg(regs, 5), &count);
+        if ( e )
+            set_regs_error(regs, e);
+        else
+            set_regs_success(regs, count, 0);
+        return true;
+    case FFA_RX_RELEASE:
+        e = handle_rx_release();
+        if ( e )
+            set_regs_error(regs, e);
+        else
+            set_regs_success(regs, 0, 0);
+        return true;
+    case FFA_MSG_SEND_DIRECT_REQ_32:
+#ifdef CONFIG_ARM_64
+    case FFA_MSG_SEND_DIRECT_REQ_64:
+#endif
+        handle_msg_send_direct_req(regs, fid);
+        return true;
+    case FFA_MEM_SHARE_32:
+#ifdef CONFIG_ARM_64
+    case FFA_MEM_SHARE_64:
+#endif
+        handle_mem_share(regs);
+        return true;
+    case FFA_MEM_RECLAIM:
+        e = handle_mem_reclaim(reg_pair_to_64(get_user_reg(regs, 2),
+                                              get_user_reg(regs, 1)),
+                               get_user_reg(regs, 3));
+        if ( e )
+            set_regs_error(regs, e);
+        else
+            set_regs_success(regs, 0, 0);
+        return true;
+    case FFA_MEM_FRAG_TX:
+        handle_mem_frag_tx(regs);
+        return true;
+
+    default:
+        printk(XENLOG_ERR "ffa: unhandled fid 0x%x\n", fid);
+        return false;
+    }
+}
+
+int ffa_domain_init(struct domain *d)
+{
+    struct ffa_ctx *ctx;
+    unsigned int n;
+    unsigned int m;
+    unsigned int c_pos;
+    int32_t res;
+
+    if ( !ffa_version )
+        return 0;
+
+    ctx = xzalloc(struct ffa_ctx);
+    if ( !ctx )
+        return -ENOMEM;
+
+    for ( n = 0; n < subsr_vm_created_count; n++ ) {
+        res = ffa_direct_req_send_vm(subsr_vm_created[n], get_vm_id(d),
+                                     FFA_MSG_SEND_VM_CREATED);
+        if ( res ) {
+            printk(XENLOG_ERR "ffa: Failed to report creation of vm_id %u to  %u: res %d\n",
+                   get_vm_id(d), subsr_vm_created[n], res);
+            c_pos = n;
+            goto err;
+        }
+    }
+
+    d->arch.ffa = ctx;
+
+    return 0;
+
+err:
+    /* Undo any already sent vm created messaged */
+    for ( n = 0; n < c_pos; n++ )
+        for ( m = 0; m < subsr_vm_destroyed_count; m++ )
+            if ( subsr_vm_destroyed[m] == subsr_vm_created[n] )
+                ffa_direct_req_send_vm(subsr_vm_destroyed[n], get_vm_id(d),
+                                       FFA_MSG_SEND_VM_DESTROYED);
+    return -ENOMEM;
+}
+
+int ffa_relinquish_resources(struct domain *d)
+{
+    struct ffa_ctx *ctx = d->arch.ffa;
+    unsigned int n;
+    int32_t res;
+
+    if ( !ctx )
+        return 0;
+
+    for ( n = 0; n < subsr_vm_destroyed_count; n++ ) {
+        res = ffa_direct_req_send_vm(subsr_vm_destroyed[n], get_vm_id(d),
+                                     FFA_MSG_SEND_VM_DESTROYED);
+
+        if ( res )
+            printk(XENLOG_ERR "ffa: Failed to report destruction of vm_id %u to  %u: res %d\n",
+                   get_vm_id(d), subsr_vm_destroyed[n], res);
+    }
+
+    XFREE(d->arch.ffa);
+
+    return 0;
+}
+
+static bool __init init_subscribers(void)
+{
+    struct ffa_partition_info_1_1 *fpi;
+    bool ret = false;
+    uint32_t count;
+    uint32_t e;
+    uint32_t n;
+    uint32_t c_pos;
+    uint32_t d_pos;
+
+    if ( ffa_version < FFA_VERSION_1_1 )
+        return true;
+
+    e = ffa_partition_info_get(0, 0, 0, 0, 1, &count);
+    ffa_rx_release();
+    if ( e ) {
+        printk(XENLOG_ERR "ffa: Failed to get list of SPs: %d\n", (int)e);
+        goto out;
+    }
+
+    fpi = ffa_rx;
+    subsr_vm_created_count = 0;
+    subsr_vm_destroyed_count = 0;
+    for ( n = 0; n < count; n++ ) {
+        if (fpi[n].partition_properties & FFA_PART_PROP_NOTIF_CREATED)
+            subsr_vm_created_count++;
+        if (fpi[n].partition_properties & FFA_PART_PROP_NOTIF_DESTROYED)
+            subsr_vm_destroyed_count++;
+    }
+
+    if ( subsr_vm_created_count )
+        subsr_vm_created = xzalloc_array(uint16_t, subsr_vm_created_count);
+    if ( subsr_vm_destroyed_count )
+        subsr_vm_destroyed = xzalloc_array(uint16_t, subsr_vm_destroyed_count);
+    if ( (subsr_vm_created_count && !subsr_vm_created) ||
+        (subsr_vm_destroyed_count && !subsr_vm_destroyed) ) {
+        printk(XENLOG_ERR "ffa: Failed to allocate subscription lists\n");
+        subsr_vm_created_count = 0;
+        subsr_vm_destroyed_count = 0;
+        XFREE(subsr_vm_created);
+        XFREE(subsr_vm_destroyed);
+        goto out;
+    }
+
+    for ( c_pos = 0, d_pos = 0, n = 0; n < count; n++ ) {
+        if (fpi[n].partition_properties & FFA_PART_PROP_NOTIF_CREATED)
+            subsr_vm_created[c_pos++] = fpi[n].id;
+        if (fpi[n].partition_properties & FFA_PART_PROP_NOTIF_DESTROYED)
+            subsr_vm_destroyed[d_pos++] = fpi[n].id;
+    }
+
+    ret = true;
+out:
+    ffa_rx_release();
+    return ret;
+}
+
+static int __init ffa_init(void)
+{
+    uint32_t vers;
+    uint32_t e;
+    unsigned int major_vers;
+    unsigned int minor_vers;
+
+    /*
+     * psci_init_smccc() updates this value with what's reported by EL-3
+     * or secure world.
+     */
+    if ( smccc_ver < ARM_SMCCC_VERSION_1_2 )
+    {
+        printk(XENLOG_ERR
+               "ffa: unsupported SMCCC version %#x (need at least %#x)\n",
+               smccc_ver, ARM_SMCCC_VERSION_1_2);
+        return 0;
+    }
+
+    if ( !ffa_get_version(&vers) )
+        return 0;
+
+    if ( vers < FFA_MIN_VERSION || vers > FFA_MY_VERSION )
+    {
+        printk(XENLOG_ERR "ffa: Incompatible version %#x found\n", vers);
+        return 0;
+    }
+
+    major_vers = (vers >> FFA_VERSION_MAJOR_SHIFT) & FFA_VERSION_MAJOR_MASK;
+    minor_vers = vers & FFA_VERSION_MINOR_MASK;
+    printk(XENLOG_ERR "ARM FF-A Mediator version %u.%u\n",
+           FFA_VERSION_MAJOR, FFA_VERSION_MINOR);
+    printk(XENLOG_ERR "ARM FF-A Firmware version %u.%u\n",
+           major_vers, minor_vers);
+
+    ffa_rx = alloc_xenheap_pages(0, 0);
+    if ( !ffa_rx )
+        return 0;
+
+    ffa_tx = alloc_xenheap_pages(0, 0);
+    if ( !ffa_tx )
+        goto err_free_ffa_rx;
+
+    e = ffa_rxtx_map(__pa(ffa_tx), __pa(ffa_rx), 1);
+    if ( e )
+    {
+        printk(XENLOG_ERR "ffa: Failed to map rxtx: error %d\n", (int)e);
+        goto err_free_ffa_tx;
+    }
+    ffa_page_count = 1;
+    ffa_version = vers;
+
+    if ( !init_subscribers() )
+        goto err_free_ffa_tx;
+
+    return 0;
+
+err_free_ffa_tx:
+    free_xenheap_pages(ffa_tx, 0);
+    ffa_tx = NULL;
+err_free_ffa_rx:
+    free_xenheap_pages(ffa_rx, 0);
+    ffa_rx = NULL;
+    ffa_page_count = 0;
+    ffa_version = 0;
+    XFREE(subsr_vm_created);
+    subsr_vm_created_count = 0;
+    XFREE(subsr_vm_destroyed);
+    subsr_vm_destroyed_count = 0;
+    return 0;
+}
+
+__initcall(ffa_init);
diff --git a/xen/arch/arm/vsmc.c b/xen/arch/arm/vsmc.c
index 33b0ddc634da..cfc56715191b 100644
--- a/xen/arch/arm/vsmc.c
+++ b/xen/arch/arm/vsmc.c
@@ -20,6 +20,7 @@
 #include <public/arch-arm/smccc.h>
 #include <asm/cpuerrata.h>
 #include <asm/cpufeature.h>
+#include <asm/ffa.h>
 #include <asm/monitor.h>
 #include <asm/regs.h>
 #include <asm/smccc.h>
@@ -32,7 +33,7 @@
 #define XEN_SMCCC_FUNCTION_COUNT 3
 
 /* Number of functions currently supported by Standard Service Service Calls. */
-#define SSSC_SMCCC_FUNCTION_COUNT (3 + VPSCI_NR_FUNCS)
+#define SSSC_SMCCC_FUNCTION_COUNT (3 + VPSCI_NR_FUNCS + FFA_NR_FUNCS)
 
 static bool fill_uid(struct cpu_user_regs *regs, xen_uuid_t uuid)
 {
@@ -186,13 +187,23 @@ static bool handle_existing_apis(struct cpu_user_regs *regs)
     return do_vpsci_0_1_call(regs, fid);
 }
 
+static bool is_psci_fid(uint32_t fid)
+{
+    uint32_t fn = fid & ARM_SMCCC_FUNC_MASK;
+
+    return fn >= 0 && fn <= 0x1fU;
+}
+
 /* PSCI 0.2 interface and other Standard Secure Calls */
 static bool handle_sssc(struct cpu_user_regs *regs)
 {
     uint32_t fid = (uint32_t)get_user_reg(regs, 0);
 
-    if ( do_vpsci_0_2_call(regs, fid) )
-        return true;
+    if ( is_psci_fid(fid) )
+        return do_vpsci_0_2_call(regs, fid);
+
+    if ( is_ffa_fid(fid) )
+        return ffa_handle_call(regs, fid);
 
     switch ( fid )
     {
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index 4e2f582006a5..e8ac49e29899 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -91,6 +91,10 @@ struct arch_domain
 #ifdef CONFIG_TEE
     void *tee;
 #endif
+
+#ifdef CONFIG_FFA
+    void *ffa;
+#endif
 }  __cacheline_aligned;
 
 struct arch_vcpu
diff --git a/xen/include/asm-arm/ffa.h b/xen/include/asm-arm/ffa.h
new file mode 100644
index 000000000000..1c6ce6421294
--- /dev/null
+++ b/xen/include/asm-arm/ffa.h
@@ -0,0 +1,71 @@
+/*
+ * xen/arch/arm/ffa.c
+ *
+ * Arm Firmware Framework for ARMv8-A(FFA) mediator
+ *
+ * Copyright (C) 2021  Linaro Limited
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef __ASM_ARM_FFA_H__
+#define __ASM_ARM_FFA_H__
+
+#include <xen/const.h>
+
+#include <asm/smccc.h>
+#include <asm/types.h>
+
+#define FFA_FNUM_MIN_VALUE              _AC(0x60,U)
+#define FFA_FNUM_MAX_VALUE              _AC(0x86,U)
+
+static inline bool is_ffa_fid(uint32_t fid)
+{
+    uint32_t fn = fid & ARM_SMCCC_FUNC_MASK;
+
+    return fn >= FFA_FNUM_MIN_VALUE && fn <= FFA_FNUM_MAX_VALUE;
+}
+
+#ifdef CONFIG_FFA
+#define FFA_NR_FUNCS    11
+
+bool ffa_handle_call(struct cpu_user_regs *regs, uint32_t fid);
+int ffa_domain_init(struct domain *d);
+int ffa_relinquish_resources(struct domain *d);
+#else
+#define FFA_NR_FUNCS    0
+
+static inline bool ffa_handle_call(struct cpu_user_regs *regs, uint32_t fid)
+{
+    return false;
+}
+
+static inline int ffa_domain_init(struct domain *d)
+{
+    return 0;
+}
+
+static inline int ffa_relinquish_resources(struct domain *d)
+{
+    return 0;
+}
+#endif
+
+#endif /*__ASM_ARM_FFA_H__*/
-- 
2.31.1

Re: [PATCH 0/2] Xen FF-A mediator

[Stefano Stabellini]

On Tue, 7 Jun 2022, Jens Wiklander wrote:
> Hi,
> 
> This patch sets add a FF-A [1] mediator modeled after the TEE mediator
> already present in Xen. The FF-A mediator implements the subset of the FF-A
> 1.1 specification needed to communicate with OP-TEE using FF-A as transport
> mechanism instead of SMC/HVC as with the TEE mediator. It allows a similar
> design in OP-TEE as with the TEE mediator where OP-TEE presents one virtual
> partition of itself to each guest in Xen.
> 
> The FF-A mediator is generic in the sense it has nothing OP-TEE specific
> except that only the subset needed for OP-TEE is implemented so far. The
> hooks needed to inform OP-TEE that a guest is created or destroyed is part
> of the FF-A specification.
> 
> It should be possible to extend the FF-A mediator to implement a larger
> portion of the FF-A 1.1 specification without breaking with the way OP-TEE
> is communicated with here. So it should be possible to support any TEE or
> Secure Partition using FF-A as transport with this mediator.
> 
> [1] https://developer.arm.com/documentation/den0077/latest
> 
> Thanks,
> Jens

Hi Jens,

Many thanks for the patches! I tried to apply them to the master branch
but unfortunately they don't apply any longer. Could you please rebase
them on master (or even better rebase them on staging) and resend?

Thank you!



> Jens Wiklander (2):
>   xen/arm: smccc: add support for SMCCCv1.2 extended input/output
>     registers
>   xen/arm: add FF-A mediator
> 
>  xen/arch/arm/Kconfig         |   11 +
>  xen/arch/arm/Makefile        |    1 +
>  xen/arch/arm/arm64/smc.S     |   43 +
>  xen/arch/arm/domain.c        |   10 +
>  xen/arch/arm/ffa.c           | 1624 ++++++++++++++++++++++++++++++++++
>  xen/arch/arm/vsmc.c          |   19 +-
>  xen/include/asm-arm/domain.h |    4 +
>  xen/include/asm-arm/ffa.h    |   71 ++
>  xen/include/asm-arm/smccc.h  |   42 +
>  9 files changed, 1821 insertions(+), 4 deletions(-)
>  create mode 100644 xen/arch/arm/ffa.c
>  create mode 100644 xen/include/asm-arm/ffa.h

Re: [PATCH 0/2] Xen FF-A mediator

[Stefano Stabellini]

On Tue, 7 Jun 2022, Stefano Stabellini wrote:
> On Tue, 7 Jun 2022, Jens Wiklander wrote:
> > Hi,
> > 
> > This patch sets add a FF-A [1] mediator modeled after the TEE mediator
> > already present in Xen. The FF-A mediator implements the subset of the FF-A
> > 1.1 specification needed to communicate with OP-TEE using FF-A as transport
> > mechanism instead of SMC/HVC as with the TEE mediator. It allows a similar
> > design in OP-TEE as with the TEE mediator where OP-TEE presents one virtual
> > partition of itself to each guest in Xen.
> > 
> > The FF-A mediator is generic in the sense it has nothing OP-TEE specific
> > except that only the subset needed for OP-TEE is implemented so far. The
> > hooks needed to inform OP-TEE that a guest is created or destroyed is part
> > of the FF-A specification.
> > 
> > It should be possible to extend the FF-A mediator to implement a larger
> > portion of the FF-A 1.1 specification without breaking with the way OP-TEE
> > is communicated with here. So it should be possible to support any TEE or
> > Secure Partition using FF-A as transport with this mediator.
> > 
> > [1] https://developer.arm.com/documentation/den0077/latest
> > 
> > Thanks,
> > Jens
> 
> Hi Jens,
> 
> Many thanks for the patches! I tried to apply them to the master branch
> but unfortunately they don't apply any longer. Could you please rebase
> them on master (or even better rebase them on staging) and resend?
> 
> Thank you!

One question without having looked at the patches in details. These
patches are necessary to mediate OS (e.g. Linux) interactions with
OPTEE. The difference between xen/arch/arm/ffa.c and
xen/arch/arm/tee/optee.c is the transport mechanism: shared mem vs. SMC.
Is that right?

If only the transport is different, would it make sense to place ffa.c
under xen/arch/arm/tee?

Without having looked at the details of the transport or the FF-A
protocol let me ask you a question. Do you think it would be possible to
share part of the implementation with xen/arch/arm/tee/optee.c? I am
asking because intuitively, if only the transport is differenti I would
have thought that some things could be common. But it doesn't look like
the current patches are reusing anything from xen/arch/arm/tee/optee.c.
Are the two protocols too different?

Re: [PATCH 0/2] Xen FF-A mediator

[Jens Wiklander]

Hi Stefano,

On Tue, Jun 7, 2022 at 11:55 PM Stefano Stabellini
<sstabellini@kernel.org> wrote:
>
> On Tue, 7 Jun 2022, Jens Wiklander wrote:
> > Hi,
> >
> > This patch sets add a FF-A [1] mediator modeled after the TEE mediator
> > already present in Xen. The FF-A mediator implements the subset of the FF-A
> > 1.1 specification needed to communicate with OP-TEE using FF-A as transport
> > mechanism instead of SMC/HVC as with the TEE mediator. It allows a similar
> > design in OP-TEE as with the TEE mediator where OP-TEE presents one virtual
> > partition of itself to each guest in Xen.
> >
> > The FF-A mediator is generic in the sense it has nothing OP-TEE specific
> > except that only the subset needed for OP-TEE is implemented so far. The
> > hooks needed to inform OP-TEE that a guest is created or destroyed is part
> > of the FF-A specification.
> >
> > It should be possible to extend the FF-A mediator to implement a larger
> > portion of the FF-A 1.1 specification without breaking with the way OP-TEE
> > is communicated with here. So it should be possible to support any TEE or
> > Secure Partition using FF-A as transport with this mediator.
> >
> > [1] https://developer.arm.com/documentation/den0077/latest
> >
> > Thanks,
> > Jens
>
> Hi Jens,
>
> Many thanks for the patches! I tried to apply them to the master branch
> but unfortunately they don't apply any longer. Could you please rebase
> them on master (or even better rebase them on staging) and resend?

No problem, I'll rebase and send out a v2.

Thanks,
Jens

>
> Thank you!
>
>
>
> > Jens Wiklander (2):
> >   xen/arm: smccc: add support for SMCCCv1.2 extended input/output
> >     registers
> >   xen/arm: add FF-A mediator
> >
> >  xen/arch/arm/Kconfig         |   11 +
> >  xen/arch/arm/Makefile        |    1 +
> >  xen/arch/arm/arm64/smc.S     |   43 +
> >  xen/arch/arm/domain.c        |   10 +
> >  xen/arch/arm/ffa.c           | 1624 ++++++++++++++++++++++++++++++++++
> >  xen/arch/arm/vsmc.c          |   19 +-
> >  xen/include/asm-arm/domain.h |    4 +
> >  xen/include/asm-arm/ffa.h    |   71 ++
> >  xen/include/asm-arm/smccc.h  |   42 +
> >  9 files changed, 1821 insertions(+), 4 deletions(-)
> >  create mode 100644 xen/arch/arm/ffa.c
> >  create mode 100644 xen/include/asm-arm/ffa.h
>

Re: [PATCH 0/2] Xen FF-A mediator

[Jens Wiklander]

On Wed, Jun 8, 2022 at 1:07 AM Stefano Stabellini
<sstabellini@kernel.org> wrote:
>
> On Tue, 7 Jun 2022, Stefano Stabellini wrote:
> > On Tue, 7 Jun 2022, Jens Wiklander wrote:
> > > Hi,
> > >
> > > This patch sets add a FF-A [1] mediator modeled after the TEE mediator
> > > already present in Xen. The FF-A mediator implements the subset of the FF-A
> > > 1.1 specification needed to communicate with OP-TEE using FF-A as transport
> > > mechanism instead of SMC/HVC as with the TEE mediator. It allows a similar
> > > design in OP-TEE as with the TEE mediator where OP-TEE presents one virtual
> > > partition of itself to each guest in Xen.
> > >
> > > The FF-A mediator is generic in the sense it has nothing OP-TEE specific
> > > except that only the subset needed for OP-TEE is implemented so far. The
> > > hooks needed to inform OP-TEE that a guest is created or destroyed is part
> > > of the FF-A specification.
> > >
> > > It should be possible to extend the FF-A mediator to implement a larger
> > > portion of the FF-A 1.1 specification without breaking with the way OP-TEE
> > > is communicated with here. So it should be possible to support any TEE or
> > > Secure Partition using FF-A as transport with this mediator.
> > >
> > > [1] https://developer.arm.com/documentation/den0077/latest
> > >
> > > Thanks,
> > > Jens
> >
> > Hi Jens,
> >
> > Many thanks for the patches! I tried to apply them to the master branch
> > but unfortunately they don't apply any longer. Could you please rebase
> > them on master (or even better rebase them on staging) and resend?
> >
> > Thank you!
>
> One question without having looked at the patches in details. These
> patches are necessary to mediate OS (e.g. Linux) interactions with
> OPTEE. The difference between xen/arch/arm/ffa.c and
> xen/arch/arm/tee/optee.c is the transport mechanism: shared mem vs. SMC.
> Is that right?
>
> If only the transport is different, would it make sense to place ffa.c
> under xen/arch/arm/tee?

FF-A is a standard Arm service with a different range of SMC Function
Identifiers. FF-A is used to communicate with SPs, Secure Partitions.
An SP can be a TEE but also something different.

There are similarities between xen/arch/arm/ffa.c and
xen/arch/arm/tee/optee.c, but I believe it's more in broader terms on
the surface.

FF-A is a generic transport protocol that is generic enough that Xen
doesn't even need to know anything about the entity it's facilitating
communication with except what's provided by FF-A. The idea is that
it's only the end points that need to be aware of details of the
protocol run on top of FF-A. This means that EL2 (Xen), EL3
(SPMD/TF-A) and S-EL2 (SPMC/Hafnium) in principle can be kept
unchanged and agnostic to Trusted OSes and what not.

>
> Without having looked at the details of the transport or the FF-A
> protocol let me ask you a question. Do you think it would be possible to
> share part of the implementation with xen/arch/arm/tee/optee.c? I am
> asking because intuitively, if only the transport is differenti I would
> have thought that some things could be common. But it doesn't look like
> the current patches are reusing anything from xen/arch/arm/tee/optee.c.
> Are the two protocols too different?

The two protocols are quite different. So far I haven't been able to
identify suitable common helper functions.

Thanks,
Jens