hv: support asyncio request

Current IO emulation is synchronous. The user VM need to wait for the
completion of the the I/O request before return. But Virtio Spec
introduces introduces asynchronous IO with a new register in MMIO/PIO
space named NOTIFY, to be used for FE driver to notify BE driver, ACRN
hypervisor can emulate this register by sending a notification to vCPU
in Service VM side. This way, FE side can resume to work without waiting
for the full completion of BE side response.

Tracked-On: #8209
Signed-off-by: Conghui <conghui.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/include/arch/x86/asm/guest/vm.h

@@ -69,6 +69,7 @@ struct vm_sw_info {
 	struct sw_module_info acpi_info;
 	/* HVA to IO shared page */
 	void *io_shared_page;
+	void *asyncio_sbuf;
 	/* If enable IO completion polling mode */
 	bool is_polling_ioreq;
 };

hypervisor/include/arch/x86/asm/per_cpu.h

@@ -25,7 +25,7 @@ struct per_cpu_region {
 	uint8_t vmxon_region[PAGE_SIZE];
 	void *vmcs_run;
 #ifdef HV_DEBUG
-	struct shared_buf *sbuf[ACRN_SBUF_ID_MAX];
+	struct shared_buf *sbuf[ACRN_SBUF_PER_PCPU_ID_MAX];
 	char logbuf[LOG_MESSAGE_MAX_SIZE];
 	uint32_t npk_log_ref;
 #endif

hypervisor/include/dm/io_req.h

@@ -291,6 +291,8 @@ void register_mmio_emulation_handler(struct acrn_vm *vm,
 void unregister_mmio_emulation_handler(struct acrn_vm *vm,
 					uint64_t start, uint64_t end);
 void deinit_emul_io(struct acrn_vm *vm);
+
+int init_asyncio(struct acrn_vm *vm, uint64_t *hva);
 /**
  * @}
  */

hypervisor/include/public/acrn_common.h

@@ -746,7 +746,9 @@ enum {
 	ACRN_HVLOG,
 	ACRN_SEP,
 	ACRN_SOCWATCH,
-	ACRN_SBUF_ID_MAX,
+	/* The sbuf with above ids are created each pcpu */
+	ACRN_SBUF_PER_PCPU_ID_MAX,
+	ACRN_ASYNCIO = 64,
 };
 
 /* Make sure sizeof(struct shared_buf) == SBUF_HEAD_SIZE */