Introduce a virtio-msg bus implementation based on the Arm FF-A (Firmware Framework for Arm) communication interface.
This bus enables virtio-msg transport over secure channels typically used between the normal world OS and a secure OS or hypervisor. It leverages the standardized FF-A interface to exchange messages with a remote backend service.
The implementation integrates with the core virtio-msg transport and uses FF-A service calls to transmit and receive messages.
Optionally, this bus supports attaching a reserved-memory region to constrain DMA-coherent and streaming DMA allocations to a well-defined contiguous area. This memory can be pre-mapped on the remote side, reducing runtime overhead and preventing accidental sharing of unrelated pages due to page-granularity mapping.
To enable reserved memory, the following device tree node should be defined (the node must be named "vmsgffa"):
reserved-memory { #address-cells = <2>; #size-cells = <2>; ranges;
vmsgffa@100000000 { compatible = "restricted-dma-pool"; reg = <0x00000001 0x00000000 0x0 0x00400000>; /* 4 MiB */ }; };
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/virtio/Kconfig | 12 +- drivers/virtio/Makefile | 1 + drivers/virtio/virtio_msg_ffa.c | 505 ++++++++++++++++++++++++++++ include/uapi/linux/virtio_msg_ffa.h | 94 ++++++ 4 files changed, 611 insertions(+), 1 deletion(-) create mode 100644 drivers/virtio/virtio_msg_ffa.c create mode 100644 include/uapi/linux/virtio_msg_ffa.h
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index a86025c9e008..683152477e3f 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -176,7 +176,8 @@ config VIRTIO_MSG select VIRTIO help This enables support for Virtio message transport. This option is - selected by any driver which implements the virtio message bus. + selected by any driver which implements the virtio message bus, such + as VIRTIO_MSG_FFA.
config VIRTIO_MSG_USER tristate "Userspace interface for virtio message transport" @@ -186,6 +187,15 @@ config VIRTIO_MSG_USER can be used to read / write messages over virtio-msg transport from userspace.
+config VIRTIO_MSG_FFA + tristate "FF-A bus driver for virtio message transport" + depends on ARM_FFA_TRANSPORT + select VIRTIO_MSG + help + This implements a Virtio message bus based on ARM FF-A protocol. + + If unsure, say N. + config VIRTIO_DMA_SHARED_BUFFER tristate depends on DMA_SHARED_BUFFER diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile index 5b664c5f5f25..96ec0a9c4a7a 100644 --- a/drivers/virtio/Makefile +++ b/drivers/virtio/Makefile @@ -7,6 +7,7 @@ obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o virtio_msg_transport-y := virtio_msg.o virtio_msg_transport-$(CONFIG_VIRTIO_MSG_USER) += virtio_msg_user.o obj-$(CONFIG_VIRTIO_MSG) += virtio_msg_transport.o +obj-$(CONFIG_VIRTIO_MSG_FFA) += virtio_msg_ffa.o obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o virtio_pci-$(CONFIG_VIRTIO_PCI_LEGACY) += virtio_pci_legacy.o diff --git a/drivers/virtio/virtio_msg_ffa.c b/drivers/virtio/virtio_msg_ffa.c new file mode 100644 index 000000000000..f7b0337c2df7 --- /dev/null +++ b/drivers/virtio/virtio_msg_ffa.c @@ -0,0 +1,505 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * FF-A bus implementation for Virtio message transport. + * + * Copyright (C) 2025 Google LLC and Linaro. + * Viresh Kumar viresh.kumar@linaro.org + * + * This implements the FF-A (Arm Firmware Framework) bus for Virtio msg + * transport. + */ + +#define pr_fmt(fmt) "virtio-msg-ffa: " fmt + +#include <linux/arm_ffa.h> +#include <linux/err.h> +#include <linux/module.h> +#include <linux/of_reserved_mem.h> +#include <linux/pm.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/virtio.h> +#include <uapi/linux/virtio_msg_ffa.h> + +#include "virtio_msg.h" + +struct virtio_msg_indirect_data { + struct completion completion; + struct virtio_msg *response; +}; + +struct virtio_msg_device_data { + struct virtio_msg_device vmdev; + struct virtio_msg_indirect_data idata; +}; + +/* Represents FF-A corresponding to a partition */ +struct virtio_msg_ffa_device { + struct ffa_device *ffa_dev; + struct reserved_mem *rmem; + struct virtio_msg_indirect_data idata; + struct virtio_msg_device_data *vmdevs; + int (*send)(struct virtio_msg_ffa_device *vmfdev, + struct virtio_msg *request, + struct virtio_msg *response, + struct virtio_msg_indirect_data *idata); + int vmdev_count; + u16 msg_size; +}; + +#define to_vmdevdata(_vmdev) \ + container_of(_vmdev, struct virtio_msg_device_data, vmdev) +#define to_vmfdev(_vmdev) ((struct virtio_msg_ffa_device *)(_vmdev)->bus_data) + +static int vmsg_ffa_send_direct(struct virtio_msg_ffa_device *vmfdev, + struct virtio_msg *request, + struct virtio_msg *response, + struct virtio_msg_indirect_data *idata_unused) +{ + struct ffa_device *ffa_dev = vmfdev->ffa_dev; + struct ffa_send_direct_data2 ffa_data; + int ret; + + memcpy(&ffa_data, request, request->msg_size); + + ret = ffa_dev->ops->msg_ops->sync_send_receive2(ffa_dev, &ffa_data); + if (ret) { + dev_dbg(&ffa_dev->dev, + "Unable to send direct FF-A message: %d\n", ret); + return ret; + } + + if (response) + memcpy(response, &ffa_data, vmfdev->msg_size); + + return 0; +} + +static int vmsg_ffa_send_indirect(struct virtio_msg_ffa_device *vmfdev, + struct virtio_msg *request, + struct virtio_msg *response, + struct virtio_msg_indirect_data *idata) +{ + struct ffa_device *ffa_dev = vmfdev->ffa_dev; + struct device *dev = &ffa_dev->dev; + int ret, count = 10; + + /* + * Store the response pointer in idata structure. This will be updated + * by vmsg_ffa_notifier_cb() later. + */ + idata->response = response; + +try_again: + ret = ffa_dev->ops->msg_ops->indirect_send(ffa_dev, request, + request->msg_size); + if (ret == -EBUSY && --count) { + cpu_relax(); + goto try_again; + } + + if (ret) { + dev_err(dev, "Failed sending indirect FF-A message: %d\n", ret); + return ret; + } + + /* + * Always wait for the operation to finish, otherwise we may start + * another operation while the previous one is still ongoing. + */ + ret = wait_for_completion_interruptible_timeout(&idata->completion, 1000); + if (ret < 0) { + dev_err(dev, "Interrupted - waiting for a response: %d\n", ret); + } else if (!ret) { + dev_err(dev, "Timed out waiting for a response\n"); + ret = -ETIMEDOUT; + } else { + ret = 0; + } + + return ret; +} + +static struct virtio_msg_device * +find_vmdev(struct virtio_msg_ffa_device *vmfdev, u16 dev_id) +{ + int i; + + /* Find the device corresponding to a dev_id */ + for (i = 0; i < vmfdev->vmdev_count; i++) { + if (vmfdev->vmdevs[i].vmdev.dev_id == dev_id) + return &vmfdev->vmdevs[i].vmdev; + } + + dev_err(&vmfdev->ffa_dev->dev, "Couldn't find matching vmdev: %d\n", + dev_id); + return NULL; +} + +static void vmsg_ffa_notifier_cb(int notify_id, void *cb_data, void *buf) +{ + struct virtio_msg_ffa_device *vmfdev = cb_data; + struct ffa_device *ffa_dev = vmfdev->ffa_dev; + struct virtio_msg_indirect_data *idata; + struct virtio_msg_device *vmdev; + struct virtio_msg *vmsg = buf; + + /* + * We can either receive a response message (to a previously sent + * request), or an EVENT_USED request message. + */ + if (vmsg->type & VIRTIO_MSG_TYPE_RESPONSE) { + if (vmsg->type & VIRTIO_MSG_TYPE_BUS) { + idata = &vmfdev->idata; + } else { + vmdev = find_vmdev(vmfdev, le16_to_cpu(vmsg->dev_id)); + if (!vmdev) + return; + + idata = &to_vmdevdata(vmdev)->idata; + } + + if (idata->response) + memcpy(idata->response, vmsg, vmsg->msg_size); + + complete(&idata->completion); + + return; + } + + /* Only support EVENT_USED virtio request messages */ + if (vmsg->type & VIRTIO_MSG_TYPE_BUS || + vmsg->msg_id != VIRTIO_MSG_EVENT_USED) { + dev_err(&ffa_dev->dev, "Unsupported message received\n"); + return; + } + + vmdev = find_vmdev(vmfdev, le16_to_cpu(vmsg->dev_id)); + if (!vmdev) + return; + + virtio_msg_event(vmdev, vmsg); +} + +static int vmsg_ffa_notify_setup(struct virtio_msg_ffa_device *vmfdev) +{ + struct ffa_device *ffa_dev = vmfdev->ffa_dev; + int ret; + + ret = ffa_dev->ops->notifier_ops->fwk_notify_request(ffa_dev, + &vmsg_ffa_notifier_cb, vmfdev, 0); + if (ret) + dev_err(&ffa_dev->dev, "Unable to request notifier: %d\n", ret); + + return ret; +} + +static void vmsg_ffa_notify_cleanup(struct virtio_msg_ffa_device *vmfdev) +{ + struct ffa_device *ffa_dev = vmfdev->ffa_dev; + int ret; + + ret = ffa_dev->ops->notifier_ops->fwk_notify_relinquish(ffa_dev, 0); + if (ret) + dev_err(&ffa_dev->dev, "Unable to relinquish notifier: %d\n", ret); +} + +static int vmsg_ffa_bus_get_devices(struct virtio_msg_ffa_device *vmfdev, + u16 *map, u16 *count) +{ + u8 req_buf[VIRTIO_MSG_FFA_BUS_MSG_SIZE]; + u8 res_buf[VIRTIO_MSG_FFA_BUS_MSG_SIZE]; + struct virtio_msg *request = (struct virtio_msg *)&req_buf; + struct virtio_msg *response = (struct virtio_msg *)&res_buf; + struct bus_get_devices *req_payload = virtio_msg_payload(request); + struct bus_get_devices_resp *res_payload = virtio_msg_payload(response); + int ret; + + static_assert(sizeof(*request) + sizeof(*req_payload) < + VIRTIO_MSG_FFA_BUS_MSG_SIZE); + static_assert(sizeof(*response) + sizeof(*res_payload) < + VIRTIO_MSG_FFA_BUS_MSG_SIZE); + + virtio_msg_prepare(request, VIRTIO_MSG_BUS_GET_DEVICES, + sizeof(*req_payload)); + req_payload->offset = 0; + req_payload->num = cpu_to_le16(0xFF); + + ret = vmfdev->send(vmfdev, request, response, &vmfdev->idata); + if (ret < 0) + return ret; + + *count = le16_to_cpu(res_payload->num); + if (!*count) + return -ENODEV; + + if (res_payload->offset != req_payload->offset) + return -EINVAL; + + /* Support up to 16 devices for now */ + if (res_payload->next_offset) + return -EINVAL; + + map[0] = res_payload->devices[0]; + map[1] = res_payload->devices[1]; + + return 0; +} + +static int vmsg_ffa_bus_version(struct virtio_msg_ffa_device *vmfdev) +{ + u8 req_buf[VIRTIO_MSG_FFA_BUS_MSG_SIZE]; + u8 res_buf[VIRTIO_MSG_FFA_BUS_MSG_SIZE]; + struct virtio_msg *request = (struct virtio_msg *)&req_buf; + struct virtio_msg *response = (struct virtio_msg *)&res_buf; + struct bus_ffa_version *req_payload = virtio_msg_payload(request); + struct bus_ffa_version_resp *res_payload = virtio_msg_payload(response); + u32 features; + int ret; + + static_assert(sizeof(*request) + sizeof(*req_payload) < + VIRTIO_MSG_FFA_BUS_MSG_SIZE); + static_assert(sizeof(*response) + sizeof(*res_payload) < + VIRTIO_MSG_FFA_BUS_MSG_SIZE); + + virtio_msg_prepare(request, VIRTIO_MSG_FFA_BUS_VERSION, + sizeof(*req_payload)); + req_payload->driver_version = cpu_to_le32(VIRTIO_MSG_FFA_BUS_VERSION_1_0); + req_payload->vmsg_revision = cpu_to_le32(VIRTIO_MSG_REVISION_1); + req_payload->vmsg_features = cpu_to_le32(VIRTIO_MSG_FEATURES); + req_payload->features = cpu_to_le32(VIRTIO_MSG_FFA_FEATURE_BOTH_SUPP); + req_payload->area_num = cpu_to_le16(VIRTIO_MSG_FFA_AREA_ID_MAX); + + ret = vmfdev->send(vmfdev, request, response, &vmfdev->idata); + if (ret < 0) + return ret; + + if (le32_to_cpu(res_payload->device_version) != VIRTIO_MSG_FFA_BUS_VERSION_1_0) + return -EINVAL; + + if (le32_to_cpu(res_payload->vmsg_revision) != VIRTIO_MSG_REVISION_1) + return -EINVAL; + + if (le32_to_cpu(res_payload->vmsg_features) != VIRTIO_MSG_FEATURES) + return -EINVAL; + + features = le32_to_cpu(res_payload->features); + + /* + * - Direct message must be supported if it already worked. + * - Indirect message must be supported if it already worked + * - And direct message must not be supported since it didn't work. + */ + if ((ffa_partition_supports_direct_recv(vmfdev->ffa_dev) && + !(features & VIRTIO_MSG_FFA_FEATURE_DIRECT_MSG_SUPP)) || + (ffa_partition_supports_indirect_msg(vmfdev->ffa_dev) && + !(features & VIRTIO_MSG_FFA_FEATURE_INDIRECT_MSG_SUPP))) { + dev_err(&vmfdev->ffa_dev->dev, "Invalid features\n"); + return -EINVAL; + } + + return 0; +} + +static int virtio_msg_ffa_transfer(struct virtio_msg_device *vmdev, + struct virtio_msg *request, + struct virtio_msg *response) +{ + struct virtio_msg_indirect_data *idata = &to_vmdevdata(vmdev)->idata; + struct virtio_msg_ffa_device *vmfdev = to_vmfdev(vmdev); + + return vmfdev->send(vmfdev, request, response, idata); +} + +static const char *virtio_msg_ffa_bus_info(struct virtio_msg_device *vmdev, + u16 *msg_size, u32 *rev) +{ + struct virtio_msg_ffa_device *vmfdev = to_vmfdev(vmdev); + + *msg_size = vmfdev->msg_size; + *rev = VIRTIO_MSG_REVISION_1; + + return dev_name(&vmfdev->ffa_dev->dev); +} + +static struct virtio_msg_ops vmf_ops = { + .transfer = virtio_msg_ffa_transfer, + .bus_info = virtio_msg_ffa_bus_info, +}; + +static void remove_vmdevs(struct virtio_msg_ffa_device *vmfdev, int count) +{ + while (count--) + virtio_msg_unregister(&vmfdev->vmdevs[count].vmdev); +} + +static int virtio_msg_ffa_probe(struct ffa_device *ffa_dev) +{ + struct virtio_msg_ffa_device *vmfdev; + struct device *dev = &ffa_dev->dev; + struct virtio_msg_device *vmdev; + unsigned long devices = 0; + int ret, i = 0, bit; + u16 count; + + vmfdev = devm_kzalloc(dev, sizeof(*vmfdev), GFP_KERNEL); + if (!vmfdev) + return -ENOMEM; + + if (ffa_partition_supports_direct_recv(ffa_dev)) { + vmfdev->send = vmsg_ffa_send_direct; + } else if (ffa_partition_supports_indirect_msg(ffa_dev)) { + vmfdev->send = vmsg_ffa_send_indirect; + } else { + dev_err(dev, "Direct or Indirect messages not supported\n"); + return -EINVAL; + } + + vmfdev->ffa_dev = ffa_dev; + vmfdev->msg_size = VIRTIO_MSG_FFA_BUS_MSG_SIZE; + ffa_dev_set_drvdata(ffa_dev, vmfdev); + init_completion(&vmfdev->idata.completion); + + ret = vmsg_ffa_notify_setup(vmfdev); + if (ret) + return ret; + + ret = vmsg_ffa_bus_version(vmfdev); + if (ret) + goto notify_cleanup; + + ret = vmsg_ffa_bus_get_devices(vmfdev, (u16 *)&devices, &count); + if (ret) + goto notify_cleanup; + + ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64)); + if (ret) + dev_warn(dev, "Failed to enable 64-bit or 32-bit DMA\n"); + + vmfdev->rmem = of_reserved_mem_lookup_by_name("vmsgffa"); + if (!IS_ERR(vmfdev->rmem)) { + ret = reserved_mem_device_init(dev, vmfdev->rmem); + if (ret) + goto rmem_free; + } else { + dev_info(dev, "Continuing without reserved-memory block\n"); + } + + vmfdev->vmdevs = devm_kcalloc(dev, count, sizeof(*vmfdev->vmdevs), + GFP_KERNEL); + if (!vmfdev->vmdevs) { + ret = -ENOMEM; + goto rmem_free; + } + vmfdev->vmdev_count = count; + + for_each_set_bit(bit, &devices, sizeof(devices)) { + init_completion(&vmfdev->vmdevs[i].idata.completion); + vmdev = &vmfdev->vmdevs[i].vmdev; + vmdev->dev_id = bit; + vmdev->ops = &vmf_ops; + vmdev->vdev.dev.parent = dev; + vmdev->bus_data = vmfdev; + + ret = virtio_msg_register(vmdev); + if (ret) { + dev_err(dev, "Failed to register virtio-msg device (%d)\n", ret); + goto unregister; + } + + i++; + } + + return 0; + +unregister: + remove_vmdevs(vmfdev, i); +rmem_free: + if (!IS_ERR(vmfdev->rmem)) + of_reserved_mem_device_release(dev); +notify_cleanup: + vmsg_ffa_notify_cleanup(vmfdev); + return ret; +} + +static void virtio_msg_ffa_remove(struct ffa_device *ffa_dev) +{ + struct virtio_msg_ffa_device *vmfdev = ffa_dev->dev.driver_data; + + remove_vmdevs(vmfdev, vmfdev->vmdev_count); + + if (!IS_ERR(vmfdev->rmem)) + of_reserved_mem_device_release(&ffa_dev->dev); + + vmsg_ffa_notify_cleanup(vmfdev); +} + +static const struct ffa_device_id virtio_msg_ffa_device_ids[] = { + /* c66028b5-2498-4aa1-9de7-77da6122abf0 */ + { UUID_INIT(0xc66028b5, 0x2498, 0x4aa1, + 0x9d, 0xe7, 0x77, 0xda, 0x61, 0x22, 0xab, 0xf0) }, + {} +}; + +static int __maybe_unused virtio_msg_ffa_suspend(struct device *dev) +{ + struct virtio_msg_ffa_device *vmfdev = dev_get_drvdata(dev); + int ret, i, index; + + for (i = 0; i < vmfdev->vmdev_count; i++) { + index = vmfdev->vmdev_count - i - 1; + ret = virtio_device_freeze(&vmfdev->vmdevs[index].vmdev.vdev); + if (ret) + return ret; + } + + return 0; +} + +static int __maybe_unused virtio_msg_ffa_resume(struct device *dev) +{ + struct virtio_msg_ffa_device *vmfdev = dev_get_drvdata(dev); + int ret, i; + + for (i = 0; i < vmfdev->vmdev_count; i++) { + ret = virtio_device_restore(&vmfdev->vmdevs[i].vmdev.vdev); + if (ret) + return ret; + } + + return 0; +} + +static const struct dev_pm_ops virtio_msg_ffa_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(virtio_msg_ffa_suspend, virtio_msg_ffa_resume) +}; + +static struct ffa_driver virtio_msg_ffa_driver = { + .name = "virtio-msg-ffa", + .probe = virtio_msg_ffa_probe, + .remove = virtio_msg_ffa_remove, + .id_table = virtio_msg_ffa_device_ids, + .driver = { + .pm = &virtio_msg_ffa_pm_ops, + }, +}; + +static int virtio_msg_ffa_init(void) +{ + if (IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT)) + return ffa_register(&virtio_msg_ffa_driver); + else + return -EOPNOTSUPP; +} +module_init(virtio_msg_ffa_init); + +static void virtio_msg_ffa_exit(void) +{ + if (IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT)) + ffa_unregister(&virtio_msg_ffa_driver); +} +module_exit(virtio_msg_ffa_exit); + +MODULE_AUTHOR("Viresh Kumar viresh.kumar@linaro.org"); +MODULE_DESCRIPTION("Virtio message FF-A bus driver"); +MODULE_LICENSE("GPL"); diff --git a/include/uapi/linux/virtio_msg_ffa.h b/include/uapi/linux/virtio_msg_ffa.h new file mode 100644 index 000000000000..adcc081b483a --- /dev/null +++ b/include/uapi/linux/virtio_msg_ffa.h @@ -0,0 +1,94 @@ +/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */ +/* + * Virtio message FF-A (Arm Firmware Framework) bus header. + * + * Copyright (C) 2025 Google LLC and Linaro. + * Viresh Kumar viresh.kumar@linaro.org + */ + +#ifndef _LINUX_VIRTIO_MSG_FFA_H +#define _LINUX_VIRTIO_MSG_FFA_H + +#include <linux/types.h> + +/* Message types */ +#define VIRTIO_MSG_FFA_BUS_VERSION 0x80 +#define VIRTIO_MSG_FFA_BUS_AREA_SHARE 0x81 +#define VIRTIO_MSG_FFA_BUS_AREA_UNSHARE 0x82 +#define VIRTIO_MSG_FFA_BUS_RESET 0x83 +#define VIRTIO_MSG_FFA_BUS_EVENT_POLL 0x84 +#define VIRTIO_MSG_FFA_BUS_AREA_RELEASE 0xC0 + +#define VIRTIO_MSG_FEATURES 0 +#define VIRTIO_MSG_FFA_BUS_VERSION_1_0 0x1 +#define VIRTIO_MSG_FFA_BUS_MSG_SIZE VIRTIO_MSG_MIN_SIZE + +#define VIRTIO_MSG_FFA_FEATURE_DIRECT_MSG_RX_SUPP (1 << 0) +#define VIRTIO_MSG_FFA_FEATURE_DIRECT_MSG_TX_SUPP (1 << 1) +#define VIRTIO_MSG_FFA_FEATURE_DIRECT_MSG_SUPP \ + (VIRTIO_MSG_FFA_FEATURE_DIRECT_MSG_RX_SUPP | \ + VIRTIO_MSG_FFA_FEATURE_DIRECT_MSG_TX_SUPP) + +#define VIRTIO_MSG_FFA_FEATURE_INDIRECT_MSG_RX_SUPP (1 << 2) +#define VIRTIO_MSG_FFA_FEATURE_INDIRECT_MSG_TX_SUPP (1 << 3) +#define VIRTIO_MSG_FFA_FEATURE_INDIRECT_MSG_SUPP \ + (VIRTIO_MSG_FFA_FEATURE_INDIRECT_MSG_RX_SUPP | \ + VIRTIO_MSG_FFA_FEATURE_INDIRECT_MSG_TX_SUPP) + +#define VIRTIO_MSG_FFA_FEATURE_BOTH_SUPP \ + (VIRTIO_MSG_FFA_FEATURE_DIRECT_MSG_SUPP | \ + VIRTIO_MSG_FFA_FEATURE_INDIRECT_MSG_SUPP) + +#define VIRTIO_MSG_FFA_AREA_ID_MAX 0xFF +#define VIRTIO_MSG_FFA_AREA_ID_OFFSET 56 +#define VIRTIO_MSG_FFA_OFFSET_MASK \ + ((ULL(1) << VIRTIO_MSG_FFA_AREA_ID_OFFSET) - 1) + +#define VIRTIO_MSG_FFA_RESULT_ERROR (1 << 0) +#define VIRTIO_MSG_FFA_RESULT_BUSY (1 << 1) + +/* Message payload format */ + +struct bus_ffa_version { + __le32 driver_version; + __le32 vmsg_revision; + __le32 vmsg_features; + __le32 features; + __le16 area_num; +} __attribute__((packed)); + +struct bus_ffa_version_resp { + __le32 device_version; + __le32 vmsg_revision; + __le32 vmsg_features; + __le32 features; + __le16 area_num; +} __attribute__((packed)); + +struct bus_area_share { + __le16 area_id; + __le64 mem_handle; + __le64 tag; + __le32 count; + __le32 attr; +} __attribute__((packed)); + +struct bus_area_share_resp { + __le16 area_id; + __le16 result; +} __attribute__((packed)); + +struct bus_area_unshare { + __le16 area_id; +} __attribute__((packed)); + +struct bus_area_unshare_resp { + __le16 area_id; + __le16 result; +} __attribute__((packed)); + +struct bus_area_release { + __le16 area_id; +} __attribute__((packed)); + +#endif /* _LINUX_VIRTIO_MSG_FFA_H */