On Mon, 20 Jun 2011, Chunyan Liu wrote:
> Add code to support logging xen-domU console, as what xenconsoled does. Log
> info
> will be saved in /var/log/xen/console/guest-domUname.log.
>
> Signed-off-by: Chunyan Liu <cy...@novell.com>
> ---
> hw/xen_console.c | 63
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 63 insertions(+), 0 deletions(-)
>
> diff --git a/hw/xen_console.c b/hw/xen_console.c
> index c6c8163..ac3208d 100644
> --- a/hw/xen_console.c
> +++ b/hw/xen_console.c
> @@ -36,6 +36,8 @@
> #include "qemu-char.h"
> #include "xen_backend.h"
>
> +static int log_guest = 0;
> +
> struct buffer {
> uint8_t *data;
> size_t consumed;
> @@ -52,8 +54,24 @@ struct XenConsole {
> void *sring;
> CharDriverState *chr;
> int backlog;
> + int log_fd;
> };
>
> +static int write_all(int fd, const char* buf, size_t len)
> +{
> + while (len) {
> + ssize_t ret = write(fd, buf, len);
> + if (ret == -1 && errno == EINTR)
> + continue;
> + if (ret <= 0)
> + return -1;
> + len -= ret;
> + buf += ret;
> + }
> +
> + return 0;
> +}
> +
If I am not mistaken ret == 0 doesn't always mean an error on write.
> static void buffer_append(struct XenConsole *con)
> {
> struct buffer *buffer = &con->buffer;
> @@ -81,6 +99,14 @@ static void buffer_append(struct XenConsole *con)
> intf->out_cons = cons;
> xen_be_send_notify(&con->xendev);
>
> + if (con->log_fd != -1) {
> + int logret;
> + logret = write_all(con->log_fd, buffer->data + buffer->size - size,
> size);
> + if (logret < 0)
> + xen_be_printf(&con->xendev, 1, "Write to log failed on domain
> %d: %d (%s)\n",
> + con->xendev.dom, errno, strerror(errno));
> + }
code style: you needs brackets around the xen_be_printf statement
> if (buffer->max_capacity &&
> buffer->size > buffer->max_capacity) {
> /* Discard the middle of the data. */
> @@ -174,12 +200,36 @@ static void xencons_send(struct XenConsole *con)
> }
> }
>
> +static int create_domain_log(struct XenConsole *con)
> +{
> + char *logfile;
> + char *path, *domname;
> + int fd;
> +
> + path = xs_get_domain_path(xenstore, con->xendev.dom);
> + domname = xenstore_read_str(path, "name");
> + free(path);
> + if (!domname)
> + return -1;
> +
> + asprintf(&logfile, "/var/log/xen/console/guest-%s.log", domname);
> + qemu_free(domname);
> +
> + fd = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0644);
> + free(logfile);
> + if (fd == -1)
> + xen_be_printf(&con->xendev, 1, "Failed to open log %s: %d (%s)",
> logfile, errno, strerror(errno));
> +
> + return fd;
> +}
> +
What if the "console" subdirectory is missing? Maybe we should create
the directory automatically here.
> /* -------------------------------------------------------------------- */
>
> static int con_init(struct XenDevice *xendev)
> {
> struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
> char *type, *dom;
> + char *logenv = NULL;
>
> /* setup */
> dom = xs_get_domain_path(xenstore, con->xendev.dom);
> @@ -198,6 +248,10 @@ static int con_init(struct XenDevice *xendev)
> else
> con->chr = serial_hds[con->xendev.dev];
>
> + logenv = getenv("XENCONSOLED_TRACE");
> + if (logenv != NULL && !strcmp(logenv, "guest")) {
> + log_guest = 1;
> + }
> return 0;
> }
please check the length of logenv before using strcmp on it
