From: Shuo Liu
An I/O request of a User VM, which is constructed by the hypervisor, is
distributed by the ACRN Hypervisor Service Module to an I/O client
corresponding to the address range of the I/O request.
For each User VM, there is a shared 4-KByte memory region used for I/O
requests communication between the hypervisor and Service VM. An I/O
request is a 256-byte structure buffer, which is 'struct
acrn_io_request', that is filled by an I/O handler of the hypervisor
when a trapped I/O access happens in a User VM. ACRN userspace in the
Service VM first allocates a 4-KByte page and passes the GPA (Guest
Physical Address) of the buffer to the hypervisor. The buffer is used as
an array of 16 I/O request slots with each I/O request slot being 256
bytes. This array is indexed by vCPU ID.
An I/O client, which is 'struct acrn_ioreq_client', is responsible for
handling User VM I/O requests whose accessed GPA falls in a certain
range. Multiple I/O clients can be associated with each User VM. There
is a special client associated with each User VM, called the default
client, that handles all I/O requests that do not fit into the range of
any other I/O clients. The ACRN userspace acts as the default client for
each User VM.
The state transitions of a ACRN I/O request are as follows.
FREE -> PENDING -> PROCESSING -> COMPLETE -> FREE -> ...
FREE: this I/O request slot is empty
PENDING: a valid I/O request is pending in this slot
PROCESSING: the I/O request is being processed
COMPLETE: the I/O request has been processed
An I/O request in COMPLETE or FREE state is owned by the hypervisor. HSM
and ACRN userspace are in charge of processing the others.
The processing flow of I/O requests are listed as following:
a) The I/O handler of the hypervisor will fill an I/O request with
PENDING state when a trapped I/O access happens in a User VM.
b) The hypervisor makes an upcall, which is a notification interrupt, to
the Service VM.
c) The upcall handler schedules a tasklet to dispatch I/O requests.
d) The tasklet looks for the PENDING I/O requests, assigns them to
different registered clients based on the address of the I/O accesses,
updates their state to PROCESSING, and notifies the corresponding
client to handle.
e) The notified client handles the assigned I/O requests.
f) The HSM updates I/O requests states to COMPLETE and notifies the
hypervisor of the completion via hypercalls.
Signed-off-by: Shuo Liu
Reviewed-by: Zhi Wang
Reviewed-by: Reinette Chatre
Cc: Zhi Wang
Cc: Zhenyu Wang
Cc: Yu Wang
Cc: Reinette Chatre
Cc: Greg Kroah-Hartman
---
drivers/virt/acrn/Makefile| 2 +-
drivers/virt/acrn/acrn_drv.h | 82 ++
drivers/virt/acrn/hsm.c | 34 ++-
drivers/virt/acrn/hypercall.h | 28 ++
drivers/virt/acrn/ioreq.c | 509 ++
drivers/virt/acrn/vm.c| 27 +-
include/uapi/linux/acrn.h | 134 +
7 files changed, 806 insertions(+), 10 deletions(-)
create mode 100644 drivers/virt/acrn/ioreq.c
diff --git a/drivers/virt/acrn/Makefile b/drivers/virt/acrn/Makefile
index 38bc44b6edcd..21721cbf6a80 100644
--- a/drivers/virt/acrn/Makefile
+++ b/drivers/virt/acrn/Makefile
@@ -1,3 +1,3 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_ACRN_HSM) := acrn.o
-acrn-y := hsm.o vm.o mm.o
+acrn-y := hsm.o vm.o mm.o ioreq.o
diff --git a/drivers/virt/acrn/acrn_drv.h b/drivers/virt/acrn/acrn_drv.h
index e47a45280eea..7e89e4944d0f 100644
--- a/drivers/virt/acrn/acrn_drv.h
+++ b/drivers/virt/acrn/acrn_drv.h
@@ -12,10 +12,15 @@
extern struct miscdevice acrn_dev;
+#define ACRN_NAME_LEN 16
#define ACRN_MEM_MAPPING_MAX 256
#define ACRN_MEM_REGION_ADD0
#define ACRN_MEM_REGION_DEL2
+
+struct acrn_vm;
+struct acrn_ioreq_client;
+
/**
* struct vm_memory_region_op - Hypervisor memory operation
* @type: Operation type (ACRN_MEM_REGION_*)
@@ -75,9 +80,63 @@ struct vm_memory_mapping {
size_t size;
};
+/**
+ * struct acrn_ioreq_buffer - Data for setting the ioreq buffer of User VM
+ * @ioreq_buf: The GPA of the IO request shared buffer of a VM
+ *
+ * The parameter for the HC_SET_IOREQ_BUFFER hypercall used to set up
+ * the shared I/O request buffer between Service VM and ACRN hypervisor.
+ */
+struct acrn_ioreq_buffer {
+ u64 ioreq_buf;
+};
+
+struct acrn_ioreq_range {
+ struct list_headlist;
+ u32 type;
+ u64 start;
+ u64 end;
+};
+
+#define ACRN_IOREQ_CLIENT_DESTROYING 0U
+typedefint (*ioreq_handler_t)(struct acrn_ioreq_client *client,
+ struct acrn_io_request *req);
+/**
+ * struct acrn_ioreq_client - Structure of I/O client.
+ * @name: Client name
+ * @vm:The VM that the client belongs to
+ * @list: List node for this acrn_ioreq_client
+ * @is_default:If this client is the default one
+ * @flags: Flags
