hv: rework the MMIO handler callback hv_mem_io_handler_t arguments

commit 026ae83 ("hv: include: fix 'Unused procedure parameter'")
removed the then unused parameter handler_private_data from
hv_mem_io_handler_t because MISRA-C requires that there should be no
unused parameters in functions.

This patch removes vcpu from the parameter list as well since this may
not be used by all users. Also it brings back handler_private_data which
is more flexible. For example, vioapic_mmio_access_handler() can use it
to pass vcpu pointer.

Tracked-On: #861
Signed-off-by: dongshen <dongsheng.x.zhang@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Reviewed-by: Li, Fei1 <fei1.li@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>

Author: ZideChen0

hypervisor/arch/x86/io.c

@@ -257,7 +257,7 @@ hv_emulate_mmio(struct vcpu *vcpu, struct io_request *io_req)
 			return -EIO;
 		} else {
 			/* Handle this MMIO operation */
-			status = mmio_handler->read_write(vcpu, io_req);
+			status = mmio_handler->read_write(io_req, mmio_handler->handler_private_data);
 			break;
 		}
 	}

hypervisor/dm/vioapic.c

@@ -511,7 +511,7 @@ vioapic_init(struct vm *vm)
 			vioapic_mmio_access_handler,
 			(uint64_t)VIOAPIC_BASE,
 			(uint64_t)VIOAPIC_BASE + VIOAPIC_SIZE,
-			NULL);
+			vm);
 }
 
 void
@@ -532,9 +532,9 @@ vioapic_pincount(const struct vm *vm)
 	}
 }
 
-int vioapic_mmio_access_handler(struct vcpu *vcpu, struct io_request *io_req)
+int vioapic_mmio_access_handler(struct io_request *io_req, void *handler_private_data)
 {
-	struct vm *vm = vcpu->vm;
+	struct vm *vm = (struct vm *)handler_private_data;
 	struct acrn_vioapic *vioapic;
 	struct mmio_request *mmio = &io_req->reqs.mmio;
 	uint64_t gpa = mmio->address;

hypervisor/include/arch/x86/guest/vioapic.h

@@ -60,8 +60,7 @@ void	vioapic_update_tmr(struct vcpu *vcpu);
 uint32_t	vioapic_pincount(const struct vm *vm);
 void	vioapic_process_eoi(struct vm *vm, uint32_t vector);
 void	vioapic_get_rte(struct vm *vm, uint32_t pin, union ioapic_rte *rte);
-int	vioapic_mmio_access_handler(struct vcpu *vcpu,
-	struct io_request *io_req);
+int		vioapic_mmio_access_handler(struct io_request *io_req, void *handler_private_data);
 
 #ifdef HV_DEBUG
 void get_vioapic_info(char *str_arg, size_t str_max, uint16_t vmid);

hypervisor/include/arch/x86/ioreq.h

@@ -94,8 +94,7 @@ struct vm_io_handler {
 
 /* Typedef for MMIO handler and range check routine */
 struct mmio_request;
-typedef int (*hv_mem_io_handler_t)(struct vcpu *vcpu,
-					struct io_request *io_req);
+typedef int (*hv_mem_io_handler_t)(struct io_request *io_req, void *handler_private_data);
 
 /* Structure for MMIO handler node */
 struct mem_io_node {