| Message ID | 1473159066-26227-1-git-send-email-jgross@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 2016-09-06 at 12:51 +0200, Juergen Gross wrote: > Add a new xl command "qemu-monitor-command" to issue arbitrary > commands > to a domain's device model. Syntax is: > > xl qemu-monitor-command <domain> <command> > > The command is issued via qmp human-monitor-command command. Any > information returned by the command is printed to stdout. > > Signed-off-by: Juergen Gross <jgross@suse.com> > --- > V3: - add GC_FREE as requested by Dario Faggioli > - return with EXIT_FAILURE/SUCCESS as requested by Dario Faggioli > I think you missed one... > diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c > index 7540fb1..d1a2a14 100644 > --- a/tools/libxl/xl_cmdimpl.c > +++ b/tools/libxl/xl_cmdimpl.c > @@ -9536,6 +9536,35 @@ int main_psr_hwinfo(int argc, char **argv) > > #endif > > +int main_qemu_monitor_command(int argc, char **argv) > +{ > + int opt; > + uint32_t domid; > + char *cmd; > + char *output; > + int ret; > + > + SWITCH_FOREACH_OPT(opt, "", NULL, "qemu-monitor-command", 2) { > + /* No options */ > + } > + > + domid = find_domain(argv[optind]); > + cmd = argv[optind + 1]; > + > + if (argc - optind > 2) { > + fprintf(stderr, "Invalid arguments.\n"); > + return 1; > ...here. Anyway, this is Reviewed-by: Dario Faggioli <dario.faggioli@citrix.com> if possible, with the above 'return 1' converted to 'return EXIT_FAILURE' (either by resending or done upon commit). If a maintainer wants to ack and commit this as is, my R-b still stands. In fact, as I said, xl is still not yet 100% consistent wrt this, and although I think new code should comply with the rule, I won't stand in the way of a patch for something like this. Regards, Dario
On Tue, Sep 06, 2016 at 02:16:30PM +0200, Dario Faggioli wrote: > On Tue, 2016-09-06 at 12:51 +0200, Juergen Gross wrote: > > Add a new xl command "qemu-monitor-command" to issue arbitrary > > commands > > to a domain's device model. Syntax is: > > > > xl qemu-monitor-command <domain> <command> > > > > The command is issued via qmp human-monitor-command command. Any > > information returned by the command is printed to stdout. > > > > Signed-off-by: Juergen Gross <jgross@suse.com> > > --- > > V3: - add GC_FREE as requested by Dario Faggioli > > - return with EXIT_FAILURE/SUCCESS as requested by Dario Faggioli > > > I think you missed one... > > > diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c > > index 7540fb1..d1a2a14 100644 > > --- a/tools/libxl/xl_cmdimpl.c > > +++ b/tools/libxl/xl_cmdimpl.c > > @@ -9536,6 +9536,35 @@ int main_psr_hwinfo(int argc, char **argv) > > > > #endif > > > > +int main_qemu_monitor_command(int argc, char **argv) > > +{ > > + int opt; > > + uint32_t domid; > > + char *cmd; > > + char *output; > > + int ret; > > + > > + SWITCH_FOREACH_OPT(opt, "", NULL, "qemu-monitor-command", 2) { > > + /* No options */ > > + } > > + > > + domid = find_domain(argv[optind]); > > + cmd = argv[optind + 1]; > > + > > + if (argc - optind > 2) { > > + fprintf(stderr, "Invalid arguments.\n"); > > + return 1; > > > ...here. > > Anyway, this is > > Reviewed-by: Dario Faggioli <dario.faggioli@citrix.com> Thanks for reviewing. Acked-by: Wei Liu <wei.liu2@citrix.com> > > if possible, with the above 'return 1' converted to 'return > EXIT_FAILURE' (either by resending or done upon commit). > I can fix that up, no need to resend. Wei. > If a maintainer wants to ack and commit this as is, my R-b still > stands. In fact, as I said, xl is still not yet 100% consistent wrt > this, and although I think new code should comply with the rule, I > won't stand in the way of a patch for something like this. > > Regards, > Dario > -- > <<This happens because I choose it to happen!>> (Raistlin Majere) > ----------------------------------------------------------------- > Dario Faggioli, Ph.D, http://about.me/dario.faggioli > Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) >
On Fri, Sep 09, 2016 at 11:05:19AM +0100, Wei Liu wrote: > On Tue, Sep 06, 2016 at 02:16:30PM +0200, Dario Faggioli wrote: > > On Tue, 2016-09-06 at 12:51 +0200, Juergen Gross wrote: > > > Add a new xl command "qemu-monitor-command" to issue arbitrary > > > commands > > > to a domain's device model. Syntax is: > > > > > > xl qemu-monitor-command <domain> <command> > > > > > > The command is issued via qmp human-monitor-command command. Any > > > information returned by the command is printed to stdout. > > > > > > Signed-off-by: Juergen Gross <jgross@suse.com> > > > --- > > > V3: - add GC_FREE as requested by Dario Faggioli > > > - return with EXIT_FAILURE/SUCCESS as requested by Dario Faggioli > > > > > I think you missed one... > > > > > diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c > > > index 7540fb1..d1a2a14 100644 > > > --- a/tools/libxl/xl_cmdimpl.c > > > +++ b/tools/libxl/xl_cmdimpl.c > > > @@ -9536,6 +9536,35 @@ int main_psr_hwinfo(int argc, char **argv) > > > > > > #endif > > > > > > +int main_qemu_monitor_command(int argc, char **argv) > > > +{ > > > + int opt; > > > + uint32_t domid; > > > + char *cmd; > > > + char *output; > > > + int ret; > > > + > > > + SWITCH_FOREACH_OPT(opt, "", NULL, "qemu-monitor-command", 2) { > > > + /* No options */ > > > + } > > > + > > > + domid = find_domain(argv[optind]); > > > + cmd = argv[optind + 1]; > > > + > > > + if (argc - optind > 2) { > > > + fprintf(stderr, "Invalid arguments.\n"); > > > + return 1; > > > > > ...here. > > > > Anyway, this is > > > > Reviewed-by: Dario Faggioli <dario.faggioli@citrix.com> > > Thanks for reviewing. > > Acked-by: Wei Liu <wei.liu2@citrix.com> > > > > > if possible, with the above 'return 1' converted to 'return > > EXIT_FAILURE' (either by resending or done upon commit). > > > > I can fix that up, no need to resend. > Fixed up the patch and pushed. Wei.
diff --git a/docs/man/xl.pod.1.in b/docs/man/xl.pod.1.in index 1adf322..a2be541 100644 --- a/docs/man/xl.pod.1.in +++ b/docs/man/xl.pod.1.in @@ -1516,6 +1516,42 @@ List pass-through usb devices for a domain. =back +=head1 DEVICE-MODEL CONTROL + +=over 4 + +=item B<qemu-monitor-command> I<domain-id> I<command> + +Issue a monitor command to the device model of the domain specified by +I<domain-id>. I<command> can be any valid command qemu understands. This +can be e.g. used to add non-standard devices or devices with non-standard +parameters to a domain. The output of the command is printed to stdout. + +B<Warning:> This qemu monitor access is provided for convenience when +debugging, troubleshooting, and experimenting. Its use is not +supported by the Xen Project. + +Specifically, not all information printed by the qemu monitor will +necessarily be accurate or complete, because in a Xen system qemu +does not have a complete view of the guest. + +Furthermore, modifying the guest's setup via the qemu monitor may +conflict with the Xen toolstack's assumptions. Resulting problems +may include, but are not limited to: guest crashes; toolstack error +messages; inability to migrate the guest; and security +vulnerabilities which are not covered by the Xen Project security +response policy. + +B<EXAMPLE> + +Obtain information of USB devices connected as such via the device model +(only!) to a domain: + + xl qemu-monitor-command vm1 'info usb' + Device 0.2, Port 5, Speed 480 Mb/s, Product Mass Storage + +=back + =head1 TMEM =over 4 diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h index e4c25c4..7cfa540 100644 --- a/tools/libxl/libxl.h +++ b/tools/libxl/libxl.h @@ -275,6 +275,12 @@ #define LIBXL_HAVE_BUILD_ID 1 /* + * LIBXL_HAVE_QEMU_MONITOR_COMMAND indiactes the availability of the + * libxl_qemu_monitor_command() function. + */ +#define LIBXL_HAVE_QEMU_MONITOR_COMMAND 1 + +/* * libxl ABI compatibility * * The only guarantee which libxl makes regarding ABI compatibility @@ -2152,6 +2158,14 @@ void libxl_psr_cat_info_list_free(libxl_psr_cat_info *list, int nr); int libxl_fd_set_cloexec(libxl_ctx *ctx, int fd, int cloexec); int libxl_fd_set_nonblock(libxl_ctx *ctx, int fd, int nonblock); +/* + * Issue a qmp monitor command to the device model of the specified domain. + * The function returns the output of the command in a new allocated buffer + * via output. + */ +int libxl_qemu_monitor_command(libxl_ctx *ctx, uint32_t domid, + const char *command_line, char **output); + #include <libxl_event.h> #endif /* LIBXL_H */ diff --git a/tools/libxl/libxl_colo_qdisk.c b/tools/libxl/libxl_colo_qdisk.c index c23b81b..d271d1f 100644 --- a/tools/libxl/libxl_colo_qdisk.c +++ b/tools/libxl/libxl_colo_qdisk.c @@ -173,7 +173,7 @@ static void colo_qdisk_save_preresume(libxl__egc *egc, "file.driver=nbd,file.host=%s,file.port=%d," "file.export=%s,node-name=%s,if=none", host, port, export_name, node); - ret = libxl__qmp_hmp(gc, domid, cmd); + ret = libxl__qmp_hmp(gc, domid, cmd, NULL); if (ret) rc = ERROR_FAIL; diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h index ce8e17a..9f534c4 100644 --- a/tools/libxl/libxl_internal.h +++ b/tools/libxl/libxl_internal.h @@ -1818,7 +1818,8 @@ _hidden int libxl__qmp_x_blockdev_change(libxl__gc *gc, int domid, const char *parant, const char *child, const char *node); /* run a hmp command in qmp mode */ -_hidden int libxl__qmp_hmp(libxl__gc *gc, int domid, const char *command_line); +_hidden int libxl__qmp_hmp(libxl__gc *gc, int domid, const char *command_line, + char **out); /* close and free the QMP handler */ _hidden void libxl__qmp_close(libxl__qmp_handler *qmp); /* remove the socket file, if the file has already been removed, diff --git a/tools/libxl/libxl_qmp.c b/tools/libxl/libxl_qmp.c index 63c49c5..0d8d5f4 100644 --- a/tools/libxl/libxl_qmp.c +++ b/tools/libxl/libxl_qmp.c @@ -1103,14 +1103,54 @@ int libxl__qmp_x_blockdev_change(libxl__gc *gc, int domid, const char *parent, return qmp_run_command(gc, domid, "x-blockdev-change", args, NULL, NULL); } -int libxl__qmp_hmp(libxl__gc *gc, int domid, const char *command_line) +static int hmp_callback(libxl__qmp_handler *qmp, + const libxl__json_object *response, + void *opaque) +{ + char **output = opaque; + GC_INIT(qmp->ctx); + int rc; + + rc = 0; + if (!output) + goto out; + + *output = NULL; + + if (libxl__json_object_is_string(response)) { + *output = libxl__strdup(NOGC, libxl__json_object_get_string(response)); + goto out; + } + + LOG(ERROR, "Response has unexpected format"); + rc = ERROR_FAIL; + +out: + GC_FREE; + return rc; +} + +int libxl__qmp_hmp(libxl__gc *gc, int domid, const char *command_line, + char **output) { libxl__json_object *args = NULL; qmp_parameters_add_string(gc, &args, "command-line", command_line); return qmp_run_command(gc, domid, "human-monitor-command", args, - NULL, NULL); + hmp_callback, output); +} + +int libxl_qemu_monitor_command(libxl_ctx *ctx, uint32_t domid, + const char *command_line, char **output) +{ + GC_INIT(ctx); + int rc; + + rc = libxl__qmp_hmp(gc, domid, command_line, output); + + GC_FREE; + return rc; } int libxl__qmp_initializations(libxl__gc *gc, uint32_t domid, diff --git a/tools/libxl/xl.h b/tools/libxl/xl.h index e601ca1..0a8c813 100644 --- a/tools/libxl/xl.h +++ b/tools/libxl/xl.h @@ -133,6 +133,7 @@ int main_psr_cmt_show(int argc, char **argv); int main_psr_cat_cbm_set(int argc, char **argv); int main_psr_cat_show(int argc, char **argv); #endif +int main_qemu_monitor_command(int argc, char **argv); void help(const char *command); diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c index 7540fb1..d1a2a14 100644 --- a/tools/libxl/xl_cmdimpl.c +++ b/tools/libxl/xl_cmdimpl.c @@ -9536,6 +9536,35 @@ int main_psr_hwinfo(int argc, char **argv) #endif +int main_qemu_monitor_command(int argc, char **argv) +{ + int opt; + uint32_t domid; + char *cmd; + char *output; + int ret; + + SWITCH_FOREACH_OPT(opt, "", NULL, "qemu-monitor-command", 2) { + /* No options */ + } + + domid = find_domain(argv[optind]); + cmd = argv[optind + 1]; + + if (argc - optind > 2) { + fprintf(stderr, "Invalid arguments.\n"); + return 1; + } + + ret = libxl_qemu_monitor_command(ctx, domid, cmd, &output); + if (!ret && output) { + printf("%s\n", output); + free(output); + } + + return ret ? EXIT_FAILURE : EXIT_SUCCESS; +} + /* * Local variables: * mode: C diff --git a/tools/libxl/xl_cmdtable.c b/tools/libxl/xl_cmdtable.c index 85c1e0f..78786fe 100644 --- a/tools/libxl/xl_cmdtable.c +++ b/tools/libxl/xl_cmdtable.c @@ -584,6 +584,11 @@ struct cmd_spec cmd_table[] = { "List information about all USB controllers and devices for a domain", "<Domain>", }, + { "qemu-monitor-command", + &main_qemu_monitor_command, 0, 1, + "Issue a qemu monitor command to the device model of a domain", + "<Domain> <Command>", + }, }; int cmdtable_len = sizeof(cmd_table)/sizeof(struct cmd_spec);
Add a new xl command "qemu-monitor-command" to issue arbitrary commands to a domain's device model. Syntax is: xl qemu-monitor-command <domain> <command> The command is issued via qmp human-monitor-command command. Any information returned by the command is printed to stdout. Signed-off-by: Juergen Gross <jgross@suse.com> --- V3: - add GC_FREE as requested by Dario Faggioli - return with EXIT_FAILURE/SUCCESS as requested by Dario Faggioli - don't initialize rc statically as requested by Dario Faggioli V2: - add warning to man page as requested by Ian Jackson --- docs/man/xl.pod.1.in | 36 ++++++++++++++++++++++++++++++++++ tools/libxl/libxl.h | 14 ++++++++++++++ tools/libxl/libxl_colo_qdisk.c | 2 +- tools/libxl/libxl_internal.h | 3 ++- tools/libxl/libxl_qmp.c | 44 ++++++++++++++++++++++++++++++++++++++++-- tools/libxl/xl.h | 1 + tools/libxl/xl_cmdimpl.c | 29 ++++++++++++++++++++++++++++ tools/libxl/xl_cmdtable.c | 5 +++++ 8 files changed, 130 insertions(+), 4 deletions(-)