Re: [Qemu-devel] [PATCH 3/3] spice-qemu-char: register interface on post load

[Markus Armbruster]

Alon Levy <address@hidden> writes:

> The target has not seen the guest_connected event via
> spice_chr_guest_open or spice_chr_write, and so spice server wrongly
> assumes there is no agent active, while the client continues to send
> motion events only by the agent channel, which the server ignores. The
> net effect is that the mouse is static in the guest.
>
> By registering the interface on post load spice server will pass on the
> agent messages fixing the mouse behavior after migration.
>
> RHBZ #725965
>
> Signed-off-by: Alon Levy <address@hidden>
> ---
>  spice-qemu-char.c | 34 ++++++++++++++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
>
> diff --git a/spice-qemu-char.c b/spice-qemu-char.c
> index 09aa22d..08b6ba0 100644
> --- a/spice-qemu-char.c
> +++ b/spice-qemu-char.c
> @@ -1,6 +1,7 @@
>  #include "config-host.h"
>  #include "trace.h"
>  #include "ui/qemu-spice.h"
> +#include "hw/virtio-serial.h"
>  #include <spice.h>
>  #include <spice-experimental.h>
>  
> @@ -25,6 +26,7 @@ typedef struct SpiceCharDriver {
>      uint8_t               *datapos;
>      ssize_t               bufsize, datalen;
>      uint32_t              debug;
> +    QEMUTimer             *post_load_timer;
>  } SpiceCharDriver;
>  
>  static int vmc_write(SpiceCharDeviceInstance *sin, const uint8_t *buf, int 
> len)
> @@ -156,6 +158,7 @@ static void spice_chr_close(struct CharDriverState *chr)
>  
>      printf("%s\n", __func__);
>      vmc_unregister_interface(s);
> +    qemu_free_timer(s->post_load_timer);
>      g_free(s);
>  }
>  
> @@ -188,6 +191,33 @@ static void print_allowed_subtypes(void)
>      fprintf(stderr, "\n");
>  }
>  
> +static void spice_chr_post_load_cb(void *opaque)
> +{
> +    SpiceCharDriver *s = opaque;
> +
> +    vmc_register_interface(s);
> +}
> +
> +static int spice_chr_post_load(void *opaque, int version_id)
> +{
> +    SpiceCharDriver *s = opaque;
> +
> +    if (s && s->chr && qemu_chr_be_connected(s->chr)) {
> +        qemu_mod_timer(s->post_load_timer, 1);
> +    }

You use the time to delay spice_chr_post_load_cb(), right?  Can you
explain why you have to delay?

> +    return 0;
> +}
> +
> +static VMStateDescription spice_chr_vmstate = {
> +    .name               = "spice-chr",
> +    .version_id         = 1,
> +    .minimum_version_id = 1,
> +    .post_load          = spice_chr_post_load,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_END_OF_LIST()
> +    },
> +};
> +
>  CharDriverState *qemu_chr_open_spice(QemuOpts *opts)
>  {
>      CharDriverState *chr;
> @@ -220,12 +250,16 @@ CharDriverState *qemu_chr_open_spice(QemuOpts *opts)
>      s->debug = debug;
>      s->active = false;
>      s->sin.subtype = subtype;
> +    s->post_load_timer = qemu_new_timer_ns(vm_clock,
> +                                           spice_chr_post_load_cb, s);
>      chr->opaque = s;
>      chr->chr_write = spice_chr_write;
>      chr->chr_close = spice_chr_close;
>      chr->chr_guest_open = spice_chr_guest_open;
>      chr->chr_guest_close = spice_chr_guest_close;
>  
> +    vmstate_register(NULL, -1, &spice_chr_vmstate, s);
> +
>  #if SPICE_SERVER_VERSION < 0x000901
>      /* See comment in vmc_state() */
>      if (strcmp(subtype, "vdagent") == 0) {