Re: [PATCH] qemu-trad: xenstore: use relative path for device-model node

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 30/03/15 13:37, Wei Liu wrote:
> For QEMU traditional stubdom, this is incompatible startup protocol
> change.  This change needs to work with corresponding libxl changeset.
> QEMU traditional is shipped with Xen so we are allowed to do such
> change.
>
> For QEMU traditional running in Dom0, there is no functional change
> because it will still write to the same /local/domain/0 path.
>
> Signed-off-by: Wei Liu <wei.liu2@citrix.com>
> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

For the change, Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

However, it would be nice if you also unsplit the pasprintf() calls.  It
looks as if all of them should fit on a single line now.

~Andrew

> ---
>  xenstore.c | 24 ++++++++++++------------
>  1 file changed, 12 insertions(+), 12 deletions(-)
>
> diff --git a/xenstore.c b/xenstore.c
> index b0d6f77..09319c7 100644
> --- a/xenstore.c
> +++ b/xenstore.c
> @@ -711,7 +711,7 @@ void xenstore_parse_domain_config(int hvm_domid)
>  
>  
>      /* Set a watch for log-dirty commands from the migration tools */
> -    if (pasprintf(&buf, "/local/domain/0/device-model/%u/logdirty/cmd",
> +    if (pasprintf(&buf, "device-model/%u/logdirty/cmd",
>                    domid) != -1) {
>          xs_watch(xsh, buf, "logdirty");
>          fprintf(logfile, "Watching %s\n", buf);
> @@ -719,7 +719,7 @@ void xenstore_parse_domain_config(int hvm_domid)
>  
>      /* Set a watch for suspend requests from the migration tools */
>      if (pasprintf(&buf, 
> -                  "/local/domain/0/device-model/%u/command", domid) != -1) {
> +                  "device-model/%u/command", domid) != -1) {
>          xs_watch(xsh, buf, "dm-command");
>          fprintf(logfile, "Watching %s\n", buf);
>      }
> @@ -777,7 +777,7 @@ int xenstore_parse_disable_pf_config ()
>      int disable_pf = 0;
>      unsigned int len;
>  
> -    if (pasprintf(&buf, "/local/domain/0/device-model/%u/disable_pf",domid) == -1)
> +    if (pasprintf(&buf, "device-model/%u/disable_pf",domid) == -1)
>          goto out;
>  
>      params = xs_read(xsh, XBT_NULL, buf, &len);
> @@ -808,13 +808,13 @@ static void xenstore_process_logdirty_event(void)
>  
>      /* Remember the paths for the command and response entries */
>      if (pasprintf(&ret_path,
> -                "/local/domain/0/device-model/%u/logdirty/ret",
> +                "device-model/%u/logdirty/ret",
>                  domid) == -1) {
>          fprintf(logfile, "Log-dirty: out of memory\n");
>          exit(1);
>      }
>      if (pasprintf(&cmd_path,
> -                "/local/domain/0/device-model/%u/logdirty/cmd",
> +                "device-model/%u/logdirty/cmd",
>                  domid) == -1) {
>          fprintf(logfile, "Log-dirty: out of memory\n");
>          exit(1);
> @@ -855,7 +855,7 @@ static void xenstore_process_dm_command_event(void)
>      unsigned int len;
>  
>      if (pasprintf(&path, 
> -                  "/local/domain/0/device-model/%u/command", domid) == -1) {
> +                  "device-model/%u/command", domid) == -1) {
>          fprintf(logfile, "out of memory reading dm command\n");
>          goto out;
>      }
> @@ -875,7 +875,7 @@ static void xenstore_process_dm_command_event(void)
>      } else if (!strncmp(command, "usb-add", len)) {
>          fprintf(logfile, "dm-command: usb-add a usb device\n");
>          if (pasprintf(&path,
> -                "/local/domain/0/device-model/%u/parameter", domid) == -1) {
> +                "device-model/%u/parameter", domid) == -1) {
>              fprintf(logfile, "out of memory reading dm command parameter\n");
>              goto out;
>          }
> @@ -889,7 +889,7 @@ static void xenstore_process_dm_command_event(void)
>      } else if (!strncmp(command, "usb-del", len)) {
>          fprintf(logfile, "dm-command: usb-del a usb device\n");
>          if (pasprintf(&path,
> -                "/local/domain/0/device-model/%u/parameter", domid) == -1) {
> +                "device-model/%u/parameter", domid) == -1) {
>              fprintf(logfile, "out of memory reading dm command parameter\n");
>              goto out;
>          }
> @@ -905,7 +905,7 @@ static void xenstore_process_dm_command_event(void)
>          fprintf(logfile, "dm-command: hot remove pass-through pci dev \n");
>  
>          if (pasprintf(&path, 
> -                      "/local/domain/0/device-model/%u/parameter", domid) == -1) {
> +                      "device-model/%u/parameter", domid) == -1) {
>              fprintf(logfile, "out of memory reading dm command parameter\n");
>              goto out;
>          }
> @@ -919,7 +919,7 @@ static void xenstore_process_dm_command_event(void)
>          fprintf(logfile, "dm-command: hot insert pass-through pci dev \n");
>  
>          if (pasprintf(&path, 
> -                      "/local/domain/0/device-model/%u/parameter", domid) == -1) {
> +                      "device-model/%u/parameter", domid) == -1) {
>              fprintf(logfile, "out of memory reading dm command parameter\n");
>              goto out;
>          }
> @@ -944,7 +944,7 @@ void xenstore_record_dm(const char *subpath, const char *state)
>      char *path = NULL;
>  
>      if (pasprintf(&path, 
> -                  "/local/domain/0/device-model/%u/%s", domid, subpath) == -1) {
> +                  "device-model/%u/%s", domid, subpath) == -1) {
>          fprintf(logfile, "out of memory recording dm \n");
>          goto out;
>      }
> @@ -1521,7 +1521,7 @@ char *xenstore_device_model_read(int domid, const char *key, unsigned int *len)
>  {
>      char *path = NULL, *value = NULL;
>  
> -    if (pasprintf(&path, "/local/domain/0/device-model/%d/%s", domid, key) == -1)
> +    if (pasprintf(&path, "device-model/%d/%s", domid, key) == -1)
>          return NULL;
>  
>      value = xs_read(xsh, XBT_NULL, path, len);