Re: [Qemu-devel] [PATCH] spice: add chardev (v2)

[Alon Levy]

On Fri, Dec 17, 2010 at 03:22:13PM +0200, Alon Levy wrote:
> Adding a chardev backend for spice, for usage by spice vdagent in
> conjunction with a properly named virtio-serial device.
> 
> Example usage:
>  qemu -device virtio-serial -chardev spicevmc,name=vdagent,id=vdagent -devic
> 
> This is equivalent to the old:
>  qemu -device virtio-serial -device spicevmc,subtype=vdagent
> 
> longer to write, but generated by libvirt, and requires one less device.
> 
> v1->v2 changes:
>  * removed spice-qemu-char.h, folded into spice-qemu-char.h
NAK self on account of this silly typo.

>  * removed dead IOCTL code
>  * removed comment
>  * removed ifdef CONFIG_SPICE from qemu-config.c and qemu-options.hx help.
> ---
>  Makefile.objs     |    2 +-
>  qemu-char.c       |    4 +
>  qemu-config.c     |    6 ++
>  qemu-options.hx   |   16 ++++-
>  spice-qemu-char.c |  185 
> +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  ui/qemu-spice.h   |    3 +
>  6 files changed, 214 insertions(+), 2 deletions(-)
>  create mode 100644 spice-qemu-char.c
> 
> diff --git a/Makefile.objs b/Makefile.objs
> index cebb945..320b2a9 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -102,7 +102,7 @@ common-obj-$(CONFIG_BRLAPI) += baum.o
>  common-obj-$(CONFIG_POSIX) += migration-exec.o migration-unix.o 
> migration-fd.o
>  common-obj-$(CONFIG_WIN32) += version.o
>  
> -common-obj-$(CONFIG_SPICE) += ui/spice-core.o ui/spice-input.o 
> ui/spice-display.o
> +common-obj-$(CONFIG_SPICE) += ui/spice-core.o ui/spice-input.o 
> ui/spice-display.o spice-qemu-char.o
>  
>  audio-obj-y = audio.o noaudio.o wavaudio.o mixeng.o
>  audio-obj-$(CONFIG_SDL) += sdlaudio.o
> diff --git a/qemu-char.c b/qemu-char.c
> index edc9ad6..acc7130 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -97,6 +97,7 @@
>  #endif
>  
>  #include "qemu_socket.h"
> +#include "ui/qemu-spice.h"
>  
>  #define READ_BUF_LEN 4096
>  
> @@ -2495,6 +2496,9 @@ static const struct {
>      || defined(__FreeBSD_kernel__)
>      { .name = "parport",   .open = qemu_chr_open_pp },
>  #endif
> +#ifdef CONFIG_SPICE
> +    { .name = "spicevmc",     .open = qemu_chr_open_spice },
> +#endif
>  };
>  
>  CharDriverState *qemu_chr_open_opts(QemuOpts *opts,
> diff --git a/qemu-config.c b/qemu-config.c
> index 965fa46..323d3c2 100644
> --- a/qemu-config.c
> +++ b/qemu-config.c
> @@ -146,6 +146,12 @@ static QemuOptsList qemu_chardev_opts = {
>          },{
>              .name = "signal",
>              .type = QEMU_OPT_BOOL,
> +        },{
> +            .name = "name",
> +            .type = QEMU_OPT_STRING,
> +        },{
> +            .name = "debug",
> +            .type = QEMU_OPT_NUMBER,
>          },
>          { /* end of list */ }
>      },
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 4d99a58..5c13f0f 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -1357,6 +1357,9 @@ DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
>  #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
>      "-chardev parport,id=id,path=path[,mux=on|off]\n"
>  #endif
> +#if defined(CONFIG_SPICE)
> +    "-chardev spicevmc,id=id,debug=debug,name=name\n"
> +#endif
>      , QEMU_ARCH_ALL
>  )
>  
> @@ -1381,7 +1384,8 @@ Backend is one of:
>  @option{stdio},
>  @option{braille},
>  @option{tty},
> address@hidden
> address@hidden
> address@hidden
>  The specific backend will determine the applicable options.
>  
>  All devices must have an id, which can be any string up to 127 characters 
> long.
> @@ -1557,6 +1561,16 @@ Connect to a local parallel port.
>  @option{path} specifies the path to the parallel port device. @option{path} 
> is
>  required.
>  
> +#if defined(CONFIG_SPICE)
> address@hidden -chardev spicevmc ,address@hidden ,address@hidden, 
> address@hidden
> +
> address@hidden debug level for spicevmc
> +
> address@hidden name of spice channel to connect to
> +
> +Connect to a spice virtual machine channel, such as vdiport.
> +#endif
> +
>  @end table
>  ETEXI
>  
> diff --git a/spice-qemu-char.c b/spice-qemu-char.c
> new file mode 100644
> index 0000000..0ffa674
> --- /dev/null
> +++ b/spice-qemu-char.c
> @@ -0,0 +1,185 @@
> +#include "config-host.h"
> +#include "ui/qemu-spice.h"
> +#include <spice.h>
> +#include <spice-experimental.h>
> +
> +#include "osdep.h"
> +
> +#define dprintf(_scd, _level, _fmt, ...)                                \
> +    do {                                                                \
> +        static unsigned __dprintf_counter = 0;                          \
> +        if (_scd->debug >= _level) {                                    \
> +            fprintf(stderr, "scd: %3d: " _fmt, ++__dprintf_counter, ## 
> __VA_ARGS__);\
> +        }                                                               \
> +    } while (0)
> +
> +#define VMC_MAX_HOST_WRITE    2048
> +
> +typedef struct SpiceCharDriver {
> +    CharDriverState*      chr;
> +    SpiceCharDeviceInstance     sin;
> +    char                  *subtype;
> +    bool                  active;
> +    uint8_t               *buffer;
> +    uint8_t               *datapos;
> +    ssize_t               bufsize, datalen;
> +    uint32_t              debug;
> +} SpiceCharDriver;
> +
> +static int vmc_write(SpiceCharDeviceInstance *sin, const uint8_t *buf, int 
> len)
> +{
> +    SpiceCharDriver *scd = container_of(sin, SpiceCharDriver, sin);
> +    ssize_t out = 0;
> +    ssize_t last_out;
> +    uint8_t* p = (uint8_t*)buf;
> +
> +    while (len > 0) {
> +        last_out = MIN(len, VMC_MAX_HOST_WRITE);
> +        qemu_chr_read(scd->chr, p, last_out);
> +        if (last_out > 0) {
> +            out += last_out;
> +            len -= last_out;
> +            p += last_out;
> +        } else {
> +            break;
> +        }
> +    }
> +
> +    dprintf(scd, 3, "%s: %lu/%zd\n", __func__, out, len + out);
> +    return out;
> +}
> +
> +static int vmc_read(SpiceCharDeviceInstance *sin, uint8_t *buf, int len)
> +{
> +    SpiceCharDriver *scd = container_of(sin, SpiceCharDriver, sin);
> +    int bytes = MIN(len, scd->datalen);
> +
> +    dprintf(scd, 2, "%s: %p %d/%d/%zd\n", __func__, scd->datapos, len, 
> bytes, scd->datalen);
> +    if (bytes > 0) {
> +        memcpy(buf, scd->datapos, bytes);
> +        scd->datapos += bytes;
> +        scd->datalen -= bytes;
> +        assert(scd->datalen >= 0);
> +        if (scd->datalen == 0) {
> +            scd->datapos = 0;
> +        }
> +    }
> +    return bytes;
> +}
> +
> +static SpiceCharDeviceInterface vmc_interface = {
> +    .base.type          = SPICE_INTERFACE_CHAR_DEVICE,
> +    .base.description   = "spice virtual channel char device",
> +    .base.major_version = SPICE_INTERFACE_CHAR_DEVICE_MAJOR,
> +    .base.minor_version = SPICE_INTERFACE_CHAR_DEVICE_MINOR,
> +    .write              = vmc_write,
> +    .read               = vmc_read,
> +};
> +
> +
> +static void vmc_register_interface(SpiceCharDriver *scd)
> +{
> +    if (scd->active) {
> +        return;
> +    }
> +    dprintf(scd, 1, "%s\n", __func__);
> +    scd->sin.base.sif = &vmc_interface.base;
> +    qemu_spice_add_interface(&scd->sin.base);
> +    scd->active = true;
> +}
> +
> +static void vmc_unregister_interface(SpiceCharDriver *scd)
> +{
> +    if (!scd->active) {
> +        return;
> +    }
> +    dprintf(scd, 1, "%s\n", __func__);
> +    spice_server_remove_interface(&scd->sin.base);
> +    scd->active = false;
> +}
> +
> +
> +static int spice_chr_write(CharDriverState *chr, const uint8_t *buf, int len)
> +{
> +    SpiceCharDriver *s = chr->opaque;
> +
> +    dprintf(s, 2, "%s: %d\n", __func__, len);
> +    vmc_register_interface(s);
> +    assert(s->datalen == 0);
> +    if (s->bufsize < len) {
> +        s->bufsize = len;
> +        s->buffer = qemu_realloc(s->buffer, s->bufsize);
> +    }
> +    memcpy(s->buffer, buf, len);
> +    s->datapos = s->buffer;
> +    s->datalen = len;
> +    spice_server_char_device_wakeup(&s->sin);
> +    return len;
> +}
> +
> +static void spice_chr_close(struct CharDriverState *chr)
> +{
> +    SpiceCharDriver *s = chr->opaque;
> +
> +    printf("%s\n", __func__);
> +    vmc_unregister_interface(s);
> +    qemu_free(s);
> +}
> +
> +static void print_allowed_subtypes(void)
> +{
> +    const char** psubtype;
> +    int i;
> +
> +    fprintf(stderr, "allowed names: ");
> +    for(i=0, psubtype = spice_server_char_device_recognized_subtypes();
> +        *psubtype != NULL; ++psubtype, ++i) {
> +        if (i == 0) {
> +            fprintf(stderr, "%s", *psubtype);
> +        } else {
> +            fprintf(stderr, ", %s", *psubtype);
> +        }
> +    }
> +    fprintf(stderr, "\n");
> +}
> +
> +CharDriverState *qemu_chr_open_spice(QemuOpts *opts)
> +{
> +    CharDriverState *chr;
> +    SpiceCharDriver *s;
> +    const char* name = qemu_opt_get(opts, "name");
> +    uint32_t debug = qemu_opt_get_number(opts, "debug", 0);
> +    const char** psubtype = spice_server_char_device_recognized_subtypes();
> +    const char *subtype = NULL;
> +
> +    if (name == NULL) {
> +        fprintf(stderr, "spice-qemu-char: missing name parameter\n");
> +        print_allowed_subtypes();
> +        return NULL;
> +    }
> +    for(;*psubtype != NULL; ++psubtype) {
> +        if (strcmp(name, *psubtype) == 0) {
> +            subtype = *psubtype;
> +            break;
> +        }
> +    }
> +    if (subtype == NULL) {
> +        fprintf(stderr, "spice-qemu-char: unsupported name\n");
> +        print_allowed_subtypes();
> +        return NULL;
> +    }
> +
> +    chr = qemu_mallocz(sizeof(CharDriverState));
> +    s = qemu_mallocz(sizeof(SpiceCharDriver));
> +    s->chr = chr;
> +    s->debug = debug;
> +    s->active = false;
> +    s->sin.subtype = subtype;
> +    chr->opaque = s;
> +    chr->chr_write = spice_chr_write;
> +    chr->chr_close = spice_chr_close;
> +
> +    qemu_chr_generic_open(chr);
> +
> +    return chr;
> +}
> diff --git a/ui/qemu-spice.h b/ui/qemu-spice.h
> index 0e3ad9b..e06af17 100644
> --- a/ui/qemu-spice.h
> +++ b/ui/qemu-spice.h
> @@ -24,6 +24,7 @@
>  
>  #include "qemu-option.h"
>  #include "qemu-config.h"
> +#include "qemu-char.h"
>  
>  extern int using_spice;
>  
> @@ -33,6 +34,8 @@ void qemu_spice_audio_init(void);
>  void qemu_spice_display_init(DisplayState *ds);
>  int qemu_spice_add_interface(SpiceBaseInstance *sin);
>  
> +CharDriverState *qemu_chr_open_spice(QemuOpts *opts);
> +
>  #else  /* CONFIG_SPICE */
>  
>  #define using_spice 0
> -- 
> 1.7.3.3
> 
>