Hi Alex
On Mon, Oct 23, 2023 at 8:34 PM Alex Bennée <alex.ben...@linaro.org> wrote:
>
>
> Hi,
>
> I'm trying to get the contrib/vhost-user-input working but it exits
> during the boot up sequence:
>
> ➜ gdb --args ./vhost-user-input -p /dev/input/event22 -s /tmp/mouse.sock
> GNU gdb (GDB) 15.0.50.20231012-git
> <snip>
> Reading symbols from ./vhost-user-input...
> (gdb) b map_ring
> Breakpoint 1 at 0x7634c: file
> ../../subprojects/libvhost-user/libvhost-user.c, line 618.
> (gdb) r
> Starting program:
> /home/alex/lsrc/qemu.git/builds/arm.debug/contrib/vhost-user-input/vhost-user-input
> -p /dev/input/event22 -s /tmp/mouse.sock
> [Thread debugging using libthread_db enabled]
> Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
> [New Thread 0x7ffff7afb6c0 (LWP 3807698)]
> ================ Vhost user message ================
> Request: VHOST_USER_GET_FEATURES (1)
> Flags: 0x1
> Size: 0
> Sending back to guest u64: 0x0000000175000000
> ================ Vhost user message ================
> Request: VHOST_USER_GET_PROTOCOL_FEATURES (15)
> Flags: 0x1
> Size: 0
> ================ Vhost user message ================
> Request: VHOST_USER_SET_PROTOCOL_FEATURES (16)
> Flags: 0x1
> Size: 8
> u64: 0x0000000000008e2b
> ================ Vhost user message ================
> Request: VHOST_USER_GET_QUEUE_NUM (17)
> Flags: 0x1
> Size: 0
> ================ Vhost user message ================
> Request: VHOST_USER_GET_MAX_MEM_SLOTS (36)
> Flags: 0x1
> Size: 0
> u64: 0x0000000000000020
> ================ Vhost user message ================
> Request: VHOST_USER_SET_BACKEND_REQ_FD (21)
> Flags: 0x9
> Size: 0
> Fds: 6
> Got backend_fd: 6
> ================ Vhost user message ================
> Request: VHOST_USER_SET_OWNER (3)
> Flags: 0x1
> Size: 0
> ================ Vhost user message ================
> Request: VHOST_USER_GET_FEATURES (1)
> Flags: 0x1
> Size: 0
> Sending back to guest u64: 0x0000000175000000
> ================ Vhost user message ================
> Request: VHOST_USER_SET_VRING_CALL (13)
> Flags: 0x1
> Size: 8
> Fds: 7
> u64: 0x0000000000000000
> Got call_fd: 7 for vq: 0
> ================ Vhost user message ================
> Request: VHOST_USER_SET_VRING_ERR (14)
> Flags: 0x1
> Size: 8
> Fds: 8
> u64: 0x0000000000000000
> ================ Vhost user message ================
> Request: VHOST_USER_SET_VRING_CALL (13)
> Flags: 0x1
> Size: 8
> Fds: 9
> u64: 0x0000000000000001
> Got call_fd: 9 for vq: 1
> ================ Vhost user message ================
> Request: VHOST_USER_SET_VRING_ERR (14)
> Flags: 0x1
> Size: 8
> Fds: 10
> u64: 0x0000000000000001
> ================ Vhost user message ================
> Request: VHOST_USER_GET_CONFIG (24)
> Flags: 0x1
> Size: 148
> ================ Vhost user message ================
> Request: VHOST_USER_GET_CONFIG (24)
> Flags: 0x1
> Size: 148
> ================ Vhost user message ================
> Request: VHOST_USER_GET_CONFIG (24)
> Flags: 0x1
> Size: 148
> ================ Vhost user message ================
> Request: VHOST_USER_GET_CONFIG (24)
> Flags: 0x1
> Size: 148
> ================ Vhost user message ================
> Request: VHOST_USER_GET_CONFIG (24)
> Flags: 0x1
> Size: 148
> ================ Vhost user message ================
> Request: VHOST_USER_GET_CONFIG (24)
> Flags: 0x1
> Size: 148
> ================ Vhost user message ================
> Request: VHOST_USER_GET_CONFIG (24)
> Flags: 0x1
> Size: 148
> ================ Vhost user message ================
> Request: VHOST_USER_GET_CONFIG (24)
> Flags: 0x1
> Size: 148
> ================ Vhost user message ================
> Request: VHOST_USER_GET_CONFIG (24)
> Flags: 0x1
> Size: 148
> ================ Vhost user message ================
> Request: VHOST_USER_GET_CONFIG (24)
> Flags: 0x1
> Size: 148
> ================ Vhost user message ================
> Request: VHOST_USER_GET_CONFIG (24)
> Flags: 0x1
> Size: 148
> ================ Vhost user message ================
> Request: VHOST_USER_GET_CONFIG (24)
> Flags: 0x1
> Size: 148
> ================ Vhost user message ================
> Request: VHOST_USER_SET_FEATURES (2)
> Flags: 0x1
> Size: 8
> u64: 0x0000000170000000
> ================ Vhost user message ================
> Request: VHOST_USER_SET_VRING_NUM (8)
> Flags: 0x1
> Size: 8
> State.index: 0
> State.num: 64
> ================ Vhost user message ================
> Request: VHOST_USER_SET_VRING_BASE (10)
> Flags: 0x1
> Size: 8
> State.index: 0
> State.num: 0
> ================ Vhost user message ================
> Request: VHOST_USER_SET_VRING_ADDR (9)
> Flags: 0x1
> Size: 40
> vhost_vring_addr:
> index: 0
> flags: 0
> desc_user_addr: 0x00007f283491a000
> used_user_addr: 0x00007f283491a4c0
> avail_user_addr: 0x00007f283491a400
> log_guest_addr: 0x0000000100b1a4c0
>
> Thread 1 "vhost-user-inpu" hit Breakpoint 1, map_ring (dev=0x7fffffffdd60,
> vq=0x555555609ea0) at ../../subprojects/libvhost-user/libvhost-user.c:618
> warning: Source file is more recent than executable.
> 618 vq->vring.desc = qva_to_va(dev, vq->vra.desc_user_addr);
> (gdb) s
> qva_to_va (dev=0x7fffffffdd60, qemu_addr=139810657378304) at
> ../../subprojects/libvhost-user/libvhost-user.c:231
> 231 for (i = 0; i < dev->nregions; i++) {
> (gdb) p dev->nregions
> $1 = 0
> (gdb) n
> 240 return NULL;
> (gdb)
> 241 }
> (gdb) c
> Continuing.
> Setting virtq addresses:
> vring_desc at (nil)
> vring_used at (nil)
> vring_avail at (nil)
>
> ** (vhost-user-input:3807669): CRITICAL **: 17:16:14.554: Invalid
> vring_addr message
>
> [Thread 0x7ffff7afb6c0 (LWP 3807698) exited]
> [Inferior 1 (process 3807669) exited with code 01]
> (gdb) q
>
> Which looks like libvhost-user is expecting
> VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS to be negotiated and the
> resulting VHOST_USER_ADD_MEM_REG to be sent. How is this meant to work
> if the protocol feature isn't negotiated?
How did you start QEMU ? Did you forget to use shared memory ? We
should probably add some error at QEMU level when vhost-user devices
are used without shared memory!
