352 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			352 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * vhost-user
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|  *
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|  * Copyright (c) 2013 Virtual Open Systems Sarl.
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|  *
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|  * This work is licensed under the terms of the GNU GPL, version 2 or later.
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|  * See the COPYING file in the top-level directory.
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|  *
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|  */
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| 
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| #include "hw/virtio/vhost.h"
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| #include "hw/virtio/vhost-backend.h"
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| #include "sysemu/char.h"
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| #include "sysemu/kvm.h"
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| #include "qemu/error-report.h"
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| #include "qemu/sockets.h"
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| #include "exec/ram_addr.h"
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| 
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| #include <fcntl.h>
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| #include <unistd.h>
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| #include <sys/ioctl.h>
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| #include <sys/socket.h>
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| #include <sys/un.h>
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| #include <linux/vhost.h>
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| 
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| #define VHOST_MEMORY_MAX_NREGIONS    8
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| 
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| typedef enum VhostUserRequest {
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|     VHOST_USER_NONE = 0,
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|     VHOST_USER_GET_FEATURES = 1,
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|     VHOST_USER_SET_FEATURES = 2,
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|     VHOST_USER_SET_OWNER = 3,
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|     VHOST_USER_RESET_OWNER = 4,
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|     VHOST_USER_SET_MEM_TABLE = 5,
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|     VHOST_USER_SET_LOG_BASE = 6,
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|     VHOST_USER_SET_LOG_FD = 7,
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|     VHOST_USER_SET_VRING_NUM = 8,
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|     VHOST_USER_SET_VRING_ADDR = 9,
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|     VHOST_USER_SET_VRING_BASE = 10,
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|     VHOST_USER_GET_VRING_BASE = 11,
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|     VHOST_USER_SET_VRING_KICK = 12,
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|     VHOST_USER_SET_VRING_CALL = 13,
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|     VHOST_USER_SET_VRING_ERR = 14,
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|     VHOST_USER_MAX
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| } VhostUserRequest;
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| 
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| typedef struct VhostUserMemoryRegion {
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|     uint64_t guest_phys_addr;
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|     uint64_t memory_size;
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|     uint64_t userspace_addr;
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|     uint64_t mmap_offset;
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| } VhostUserMemoryRegion;
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| 
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| typedef struct VhostUserMemory {
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|     uint32_t nregions;
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|     uint32_t padding;
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|     VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
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| } VhostUserMemory;
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| 
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| typedef struct VhostUserMsg {
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|     VhostUserRequest request;
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| 
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| #define VHOST_USER_VERSION_MASK     (0x3)
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| #define VHOST_USER_REPLY_MASK       (0x1<<2)
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|     uint32_t flags;
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|     uint32_t size; /* the following payload size */
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|     union {
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| #define VHOST_USER_VRING_IDX_MASK   (0xff)
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| #define VHOST_USER_VRING_NOFD_MASK  (0x1<<8)
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|         uint64_t u64;
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|         struct vhost_vring_state state;
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|         struct vhost_vring_addr addr;
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|         VhostUserMemory memory;
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|     };
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| } QEMU_PACKED VhostUserMsg;
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| 
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| static VhostUserMsg m __attribute__ ((unused));
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| #define VHOST_USER_HDR_SIZE (sizeof(m.request) \
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|                             + sizeof(m.flags) \
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|                             + sizeof(m.size))
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| 
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| #define VHOST_USER_PAYLOAD_SIZE (sizeof(m) - VHOST_USER_HDR_SIZE)
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| 
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| /* The version of the protocol we support */
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| #define VHOST_USER_VERSION    (0x1)
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| 
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| static bool ioeventfd_enabled(void)
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| {
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|     return kvm_enabled() && kvm_eventfds_enabled();
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| }
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| 
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| static unsigned long int ioctl_to_vhost_user_request[VHOST_USER_MAX] = {
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|     -1,                     /* VHOST_USER_NONE */
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|     VHOST_GET_FEATURES,     /* VHOST_USER_GET_FEATURES */
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|     VHOST_SET_FEATURES,     /* VHOST_USER_SET_FEATURES */
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|     VHOST_SET_OWNER,        /* VHOST_USER_SET_OWNER */
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|     VHOST_RESET_OWNER,      /* VHOST_USER_RESET_OWNER */
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|     VHOST_SET_MEM_TABLE,    /* VHOST_USER_SET_MEM_TABLE */
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|     VHOST_SET_LOG_BASE,     /* VHOST_USER_SET_LOG_BASE */
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|     VHOST_SET_LOG_FD,       /* VHOST_USER_SET_LOG_FD */
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|     VHOST_SET_VRING_NUM,    /* VHOST_USER_SET_VRING_NUM */
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|     VHOST_SET_VRING_ADDR,   /* VHOST_USER_SET_VRING_ADDR */
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|     VHOST_SET_VRING_BASE,   /* VHOST_USER_SET_VRING_BASE */
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|     VHOST_GET_VRING_BASE,   /* VHOST_USER_GET_VRING_BASE */
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|     VHOST_SET_VRING_KICK,   /* VHOST_USER_SET_VRING_KICK */
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|     VHOST_SET_VRING_CALL,   /* VHOST_USER_SET_VRING_CALL */
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|     VHOST_SET_VRING_ERR     /* VHOST_USER_SET_VRING_ERR */
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| };
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| 
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| static VhostUserRequest vhost_user_request_translate(unsigned long int request)
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| {
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|     VhostUserRequest idx;
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| 
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|     for (idx = 0; idx < VHOST_USER_MAX; idx++) {
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|         if (ioctl_to_vhost_user_request[idx] == request) {
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|             break;
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|         }
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|     }
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| 
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|     return (idx == VHOST_USER_MAX) ? VHOST_USER_NONE : idx;
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| }
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| 
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| static int vhost_user_read(struct vhost_dev *dev, VhostUserMsg *msg)
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| {
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|     CharDriverState *chr = dev->opaque;
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|     uint8_t *p = (uint8_t *) msg;
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|     int r, size = VHOST_USER_HDR_SIZE;
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| 
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|     r = qemu_chr_fe_read_all(chr, p, size);
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|     if (r != size) {
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|         error_report("Failed to read msg header. Read %d instead of %d.\n", r,
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|                 size);
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|         goto fail;
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|     }
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| 
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|     /* validate received flags */
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|     if (msg->flags != (VHOST_USER_REPLY_MASK | VHOST_USER_VERSION)) {
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|         error_report("Failed to read msg header."
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|                 " Flags 0x%x instead of 0x%x.\n", msg->flags,
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|                 VHOST_USER_REPLY_MASK | VHOST_USER_VERSION);
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|         goto fail;
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|     }
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| 
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|     /* validate message size is sane */
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|     if (msg->size > VHOST_USER_PAYLOAD_SIZE) {
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|         error_report("Failed to read msg header."
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|                 " Size %d exceeds the maximum %zu.\n", msg->size,
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|                 VHOST_USER_PAYLOAD_SIZE);
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|         goto fail;
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|     }
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| 
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|     if (msg->size) {
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|         p += VHOST_USER_HDR_SIZE;
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|         size = msg->size;
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|         r = qemu_chr_fe_read_all(chr, p, size);
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|         if (r != size) {
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|             error_report("Failed to read msg payload."
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|                          " Read %d instead of %d.\n", r, msg->size);
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|             goto fail;
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|         }
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|     }
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| 
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|     return 0;
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| 
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| fail:
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|     return -1;
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| }
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| 
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| static int vhost_user_write(struct vhost_dev *dev, VhostUserMsg *msg,
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|                             int *fds, int fd_num)
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| {
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|     CharDriverState *chr = dev->opaque;
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|     int size = VHOST_USER_HDR_SIZE + msg->size;
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| 
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|     if (fd_num) {
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|         qemu_chr_fe_set_msgfds(chr, fds, fd_num);
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|     }
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| 
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|     return qemu_chr_fe_write_all(chr, (const uint8_t *) msg, size) == size ?
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|             0 : -1;
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| }
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| 
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| static int vhost_user_call(struct vhost_dev *dev, unsigned long int request,
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|         void *arg)
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| {
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|     VhostUserMsg msg;
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|     VhostUserRequest msg_request;
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|     struct vhost_vring_file *file = 0;
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|     int need_reply = 0;
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|     int fds[VHOST_MEMORY_MAX_NREGIONS];
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|     int i, fd;
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|     size_t fd_num = 0;
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| 
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|     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
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| 
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|     msg_request = vhost_user_request_translate(request);
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|     msg.request = msg_request;
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|     msg.flags = VHOST_USER_VERSION;
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|     msg.size = 0;
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| 
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|     switch (request) {
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|     case VHOST_GET_FEATURES:
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|         need_reply = 1;
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|         break;
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| 
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|     case VHOST_SET_FEATURES:
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|     case VHOST_SET_LOG_BASE:
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|         msg.u64 = *((__u64 *) arg);
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|         msg.size = sizeof(m.u64);
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|         break;
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| 
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|     case VHOST_SET_OWNER:
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|     case VHOST_RESET_OWNER:
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|         break;
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| 
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|     case VHOST_SET_MEM_TABLE:
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|         for (i = 0; i < dev->mem->nregions; ++i) {
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|             struct vhost_memory_region *reg = dev->mem->regions + i;
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|             ram_addr_t ram_addr;
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| 
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|             assert((uintptr_t)reg->userspace_addr == reg->userspace_addr);
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|             qemu_ram_addr_from_host((void *)(uintptr_t)reg->userspace_addr, &ram_addr);
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|             fd = qemu_get_ram_fd(ram_addr);
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|             if (fd > 0) {
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|                 msg.memory.regions[fd_num].userspace_addr = reg->userspace_addr;
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|                 msg.memory.regions[fd_num].memory_size  = reg->memory_size;
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|                 msg.memory.regions[fd_num].guest_phys_addr = reg->guest_phys_addr;
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|                 msg.memory.regions[fd_num].mmap_offset = reg->userspace_addr -
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|                     (uintptr_t) qemu_get_ram_block_host_ptr(ram_addr);
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|                 assert(fd_num < VHOST_MEMORY_MAX_NREGIONS);
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|                 fds[fd_num++] = fd;
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|             }
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|         }
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| 
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|         msg.memory.nregions = fd_num;
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| 
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|         if (!fd_num) {
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|             error_report("Failed initializing vhost-user memory map\n"
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|                     "consider using -object memory-backend-file share=on\n");
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|             return -1;
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|         }
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| 
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|         msg.size = sizeof(m.memory.nregions);
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|         msg.size += sizeof(m.memory.padding);
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|         msg.size += fd_num * sizeof(VhostUserMemoryRegion);
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| 
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|         break;
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| 
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|     case VHOST_SET_LOG_FD:
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|         fds[fd_num++] = *((int *) arg);
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|         break;
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| 
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|     case VHOST_SET_VRING_NUM:
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|     case VHOST_SET_VRING_BASE:
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|         memcpy(&msg.state, arg, sizeof(struct vhost_vring_state));
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|         msg.size = sizeof(m.state);
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|         break;
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| 
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|     case VHOST_GET_VRING_BASE:
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|         memcpy(&msg.state, arg, sizeof(struct vhost_vring_state));
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|         msg.size = sizeof(m.state);
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|         need_reply = 1;
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|         break;
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| 
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|     case VHOST_SET_VRING_ADDR:
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|         memcpy(&msg.addr, arg, sizeof(struct vhost_vring_addr));
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|         msg.size = sizeof(m.addr);
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|         break;
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| 
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|     case VHOST_SET_VRING_KICK:
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|     case VHOST_SET_VRING_CALL:
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|     case VHOST_SET_VRING_ERR:
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|         file = arg;
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|         msg.u64 = file->index & VHOST_USER_VRING_IDX_MASK;
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|         msg.size = sizeof(m.u64);
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|         if (ioeventfd_enabled() && file->fd > 0) {
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|             fds[fd_num++] = file->fd;
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|         } else {
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|             msg.u64 |= VHOST_USER_VRING_NOFD_MASK;
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|         }
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|         break;
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|     default:
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|         error_report("vhost-user trying to send unhandled ioctl\n");
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|         return -1;
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|         break;
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|     }
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| 
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|     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
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|         return 0;
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|     }
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| 
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|     if (need_reply) {
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|         if (vhost_user_read(dev, &msg) < 0) {
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|             return 0;
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|         }
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| 
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|         if (msg_request != msg.request) {
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|             error_report("Received unexpected msg type."
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|                     " Expected %d received %d\n", msg_request, msg.request);
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|             return -1;
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|         }
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| 
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|         switch (msg_request) {
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|         case VHOST_USER_GET_FEATURES:
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|             if (msg.size != sizeof(m.u64)) {
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|                 error_report("Received bad msg size.\n");
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|                 return -1;
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|             }
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|             *((__u64 *) arg) = msg.u64;
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|             break;
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|         case VHOST_USER_GET_VRING_BASE:
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|             if (msg.size != sizeof(m.state)) {
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|                 error_report("Received bad msg size.\n");
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|                 return -1;
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|             }
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|             memcpy(arg, &msg.state, sizeof(struct vhost_vring_state));
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|             break;
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|         default:
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|             error_report("Received unexpected msg type.\n");
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|             return -1;
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|             break;
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|         }
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|     }
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| 
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|     return 0;
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| }
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| 
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| static int vhost_user_init(struct vhost_dev *dev, void *opaque)
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| {
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|     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
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| 
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|     dev->opaque = opaque;
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| 
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|     return 0;
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| }
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| 
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| static int vhost_user_cleanup(struct vhost_dev *dev)
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| {
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|     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
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| 
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|     dev->opaque = 0;
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| 
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|     return 0;
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| }
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| 
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| const VhostOps user_ops = {
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|         .backend_type = VHOST_BACKEND_TYPE_USER,
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|         .vhost_call = vhost_user_call,
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|         .vhost_backend_init = vhost_user_init,
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|         .vhost_backend_cleanup = vhost_user_cleanup
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|         };
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