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Re: [Qemu-devel] [PATCH 1/3] qemu-char: Add new char backend CirMemCharD
From: |
Luiz Capitulino |
Subject: |
Re: [Qemu-devel] [PATCH 1/3] qemu-char: Add new char backend CirMemCharDriver |
Date: |
Tue, 22 Jan 2013 14:14:23 -0200 |
On Tue, 22 Jan 2013 16:12:50 +0800
Lei Li <address@hidden> wrote:
> Signed-off-by: Lei Li <address@hidden>
> ---
> qemu-char.c | 120
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> qemu-options.hx | 10 +++++
> 2 files changed, 130 insertions(+), 0 deletions(-)
>
> diff --git a/qemu-char.c b/qemu-char.c
> index 9ba0573..b323e94 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -98,6 +98,7 @@
> #include "ui/qemu-spice.h"
>
> #define READ_BUF_LEN 4096
> +#define CBUFF_SIZE 65536
>
> /***********************************************************/
> /* character device */
> @@ -2643,6 +2644,116 @@ size_t qemu_chr_mem_osize(const CharDriverState *chr)
> return d->outbuf_size;
> }
>
> +/*********************************************************/
> +/*CircularMemory chardev*/
> +
> +typedef struct {
> + size_t size;
> + size_t prod;
> + size_t cons;
> + uint8_t *cbuf;
> +} CirMemCharDriver;
> +
> +static bool cirmem_chr_is_empty(const CharDriverState *chr)
> +{
> + const CirMemCharDriver *d = chr->opaque;
> +
> + return d->cons == d->prod;
> +}
> +
> +static bool cirmem_chr_is_full(const CharDriverState *chr)
> +{
> + const CirMemCharDriver *d = chr->opaque;
> +
> + return (d->prod - d->cons) == d->size;
> +}
> +
> +static size_t qemu_chr_cirmem_count(const CharDriverState *chr)
> +{
> + const CirMemCharDriver *d = chr->opaque;
> +
> + return (d->prod - d->cons);
> +}
> +
> +static int cirmem_chr_write(CharDriverState *chr, const uint8_t *buf, int
> len)
> +{
> + CirMemCharDriver *d = chr->opaque;
> + int i;
> +
> + if (!buf || (len < 0)) {
> + return -1;
> + }
Is the above checks really needed? I don't see other char drivers
doing that.
> +
> + for (i = 0; i < len; i++ ) {
> + /* Avoid writing the IAC information to the queue. */
> + if ((unsigned char)buf[i] == IAC) {
> + continue;
> + }
> +
> + d->cbuf[d->prod++ % d->size] = buf[i];
You never reset d->prod, can't it overflow?
> + if ((d->prod - d->cons) > d->size) {
> + d->cons = d->prod - d->size;
> + }
Why is the the if block above needed?
> + }
> +
> + return 0;
> +}
> +
> +static int cirmem_chr_read(CharDriverState *chr, uint8_t *buf, int len)
> +{
> + CirMemCharDriver *d = chr->opaque;
> + int i;
> +
> + for (i = 0; i < len && !cirmem_chr_is_empty(chr); i++) {
> + buf[i] = d->cbuf[d->cons++ % d->size];
You never reset d->cons, can't it overflow?
> + }
> +
> + return i;
> +}
> +
> +static void cirmem_chr_close(struct CharDriverState *chr)
> +{
> + CirMemCharDriver *d = chr->opaque;
> +
> + g_free(d->cbuf);
> + g_free(d);
> + chr->opaque = NULL;
> +}
> +
> +static CharDriverState *qemu_chr_open_cirmemchr(QemuOpts *opts)
> +{
> + CharDriverState *chr;
> + CirMemCharDriver *d;
> +
> + chr = g_malloc0(sizeof(CharDriverState));
> + d = g_malloc(sizeof(*d));
> +
> + d->size = qemu_opt_get_number(opts, "maxcapacity", 0);
> + if (d->size == 0) {
> + d->size = CBUFF_SIZE;
> + }
> +
> + /* The size must be power of 2 */
> + if (d->size & (d->size - 1)) {
Please, print a descriptive error message. Otherwise all the user will get
is a generic error.
> + goto fail;
> + }
> +
> + d->prod = 0;
> + d->cons = 0;
> + d->cbuf = g_malloc0(d->size);
> +
> + chr->opaque = d;
> + chr->chr_write = cirmem_chr_write;
> + chr->chr_close = cirmem_chr_close;
> +
> + return chr;
> +
> +fail:
> + g_free(d);
> + g_free(chr);
> + return NULL;
> +}
> +
> QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)
> {
> char host[65], port[33], width[8], height[8];
> @@ -2707,6 +2818,11 @@ QemuOpts *qemu_chr_parse_compat(const char *label,
> const char *filename)
> qemu_opt_set(opts, "path", p);
> return opts;
> }
> + if (strstart(filename, "memory", &p)) {
> + qemu_opt_set(opts, "backend", "memory");
> + qemu_opt_set(opts, "maxcapacity", p);
> + return opts;
> + }
> if (strstart(filename, "tcp:", &p) ||
> strstart(filename, "telnet:", &p)) {
> if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
> @@ -2796,6 +2912,7 @@ static const struct {
> { .name = "udp", .open = qemu_chr_open_udp },
> { .name = "msmouse", .open = qemu_chr_open_msmouse },
> { .name = "vc", .open = text_console_init },
> + { .name = "memory", .open = qemu_chr_open_cirmemchr },
> #ifdef _WIN32
> { .name = "file", .open = qemu_chr_open_win_file_out },
> { .name = "pipe", .open = qemu_chr_open_win_pipe },
> @@ -3055,6 +3172,9 @@ QemuOptsList qemu_chardev_opts = {
> },{
> .name = "debug",
> .type = QEMU_OPT_NUMBER,
> + },{
> + .name = "maxcapacity",
> + .type = QEMU_OPT_NUMBER,
> },
> { /* end of list */ }
> },
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 4e2b499..2d44137 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -1736,6 +1736,7 @@ DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
> "-chardev msmouse,id=id[,mux=on|off]\n"
> "-chardev
> vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
> " [,mux=on|off]\n"
> + "-chardev memory,id=id,maxcapacity=maxcapacity\n"
> "-chardev file,id=id,path=path[,mux=on|off]\n"
> "-chardev pipe,id=id,path=path[,mux=on|off]\n"
> #ifdef _WIN32
> @@ -1777,6 +1778,7 @@ Backend is one of:
> @option{udp},
> @option{msmouse},
> @option{vc},
> address@hidden,
> @option{file},
> @option{pipe},
> @option{console},
> @@ -1885,6 +1887,14 @@ the console, in pixels.
> @option{cols} and @option{rows} specify that the console be sized to fit a
> text
> console with the given dimensions.
>
> address@hidden -chardev memory ,address@hidden ,address@hidden
> +
> +Create a circular buffer with fixed size indicated by optionally
> @option{maxcapacity}
> +which will be default 64K if it is not given.
> +
> address@hidden specifies the max capacity of the size of circular buffer
> +to create. Should be power of 2.
> +
> @item -chardev file ,address@hidden ,address@hidden
>
> Log all traffic received from the guest to a file.
[Qemu-devel] [PATCH 2/3] QAPI: Introduce memchar-write QMP command, Lei Li, 2013/01/22
[Qemu-devel] [PATCH 3/3] QAPI: Introduce memchar-read QMP command, Lei Li, 2013/01/22