Reenable hmp for preconfig mode

From: "Dr. David Alan Gilbert" <[email protected]>

Add a flag to command definitions to allow them to be used in preconfig and check it.

Signed-off-by Dr. David Alan Gilbert <[email protected]>

From: "Dr. David Alan Gilbert" <[email protected]>

Add a flag to command definitions to allow them to be used in preconfig and check it.

Signed-off-by Dr. David Alan Gilbert <[email protected]>

---
 monitor.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

monitor.c +14 -0

index 6d0cec552e..50b95f41db 100644
@@ -128,6 +128,7 @@ typedef struct mon_cmd_t {
     const char *args_type;
     const char *params;
     const char *help;
+    const char *flags; /* p=preconfig */
     void (*cmd)(Monitor *mon, const QDict *qdict);
     /* @sub_table is a list of 2nd level of commands. If it does not exist,
      * cmd should be used. If it exists, sub_table[?].cmd should be

@@ -936,6 +937,19 @@ static int parse_cmdline(const char *cmdline,
     return -1;
 }
 
+/*
+ * Returns true if the command can be executed in preconfig mode
+ * i.e. it has the 'p' flag.
+ */
+static bool cmd_can_preconfig(const mon_cmd_t *cmd)
+{
+    if (!cmd->flags) {
+        return false;
+    }
+
+    return strchr(cmd->flags, 'p');
+}
+
 static void help_cmd_dump_one(Monitor *mon,
                               const mon_cmd_t *cmd,
                               char **prefix_args,

@@ -2976,6 +2990,11 @@ static const mon_cmd_t *monitor_parse_command(Monitor *mon,
                        (int)(p - cmdp_start), cmdp_start);

Quoted 44 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Add a flag to command definitions to allow them to be used in preconfig and check it.

Signed-off-by Dr. David Alan Gilbert <[email protected]>

---
 monitor.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

monitor.c +14 -0

index 6d0cec552e..50b95f41db 100644
@@ -128,6 +128,7 @@ typedef struct mon_cmd_t {
     const char *args_type;
     const char *params;
     const char *help;
+    const char *flags; /* p=preconfig */
     void (*cmd)(Monitor *mon, const QDict *qdict);
     /* @sub_table is a list of 2nd level of commands. If it does not exist,
      * cmd should be used. If it exists, sub_table[?].cmd should be

@@ -936,6 +937,19 @@ static int parse_cmdline(const char *cmdline,
     return -1;
 }
 
+/*
+ * Returns true if the command can be executed in preconfig mode
+ * i.e. it has the 'p' flag.
+ */
+static bool cmd_can_preconfig(const mon_cmd_t *cmd)
+{
+    if (!cmd->flags) {
+        return false;
+    }
+
+    return strchr(cmd->flags, 'p');
+}
+
 static void help_cmd_dump_one(Monitor *mon,
                               const mon_cmd_t *cmd,
                               char **prefix_args,

@@ -2976,6 +2990,11 @@ static const mon_cmd_t *monitor_parse_command(Monitor *mon,
                        (int)(p - cmdp_start), cmdp_start);

monitor.c static const mon_cmd_t *monitor_parse_command(Monitor *mon, · line 3000

Quoted 10 lines

monitor.c +5 -0

         return NULL;
     }
+    if (runstate_check(RUN_STATE_PRECONFIG) && !cmd_can_preconfig(cmd)) {
+        monitor_printf(mon, "Command '%.*s' not available in preconfig\n",
+                       (int)(p - cmdp_start), cmdp_start);
+        return NULL;
+    }
 
     /* filter out following useless space */
     while (qemu_isspace(*p)) {

This

(qemu) c
Command 'c' not available in preconfig

is not a nice user experience. We can do better (paraphrasing myself):

Command 'c' not available with -preconfig until you complete configuration with QMP

Note that this talks to the user in the user's terms (-preconfig) instead of internal terms ("in preconfig", whatever that is), and is more specific on how to ready the monitor.

Obviously, "with QMP" needs an update once HMP acquires a command to exit preconfig state.

From: "Dr. David Alan Gilbert" <[email protected]>

Allow the 'help' command in preconfig state but
make it only list the preconfig commands.

Signed-off-by Dr. David Alan Gilbert <[email protected]>

---
 hmp-commands.hx | 1 +
 monitor.c       | 8 +++++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

hmp-commands.hx +1 -0

index 0734fea931..8bf590ae4b 100644
@@ -15,6 +15,7 @@ ETEXI
         .params     = "[cmd]",
         .help       = "show the help",
         .cmd        = do_help_cmd,
+        .flags      = "p",
     },
 
 STEXI

monitor.c +4 -0

index 50b95f41db..7d1709c225 100644
@@ -957,6 +957,10 @@ static void help_cmd_dump_one(Monitor *mon,
 {
     int i;
 
+    if (runstate_check(RUN_STATE_PRECONFIG) && !cmd_can_preconfig(cmd)) {
+        return;
+    }
+
     for (i = 0; i < prefix_args_nb; i++) {
         monitor_printf(mon, "%s ", prefix_args[i]);
     }

From: "Dr. David Alan Gilbert" <[email protected]>

Don't show the commands that aren't available.

Signed-off-by Dr. David Alan Gilbert <[email protected]>

---
 monitor.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

monitor.c +2 -1

index 7d1709c225..9b29787a52 100644
@@ -3950,12 +3950,17 @@ static void monitor_find_completion_by_table(Monitor *mon,
             cmdname = args[0];
         readline_set_completion_index(mon->rs, strlen(cmdname));
         for (cmd = cmd_table; cmd->name != NULL; cmd++) {
-            cmd_completion(mon, cmdname, cmd->name);
+            if (!runstate_check(RUN_STATE_PRECONFIG) ||
+                 cmd_can_preconfig(cmd)) {

monitor.c +0 -0

                 break;
             }
         }

Signature · 1 line

2.17.0

From: "Dr. David Alan Gilbert" <[email protected]>

Allow a bunch of the info commands to be used in preconfig. Could probably add most of them.

Signed-off-by Dr. David Alan Gilbert <[email protected]>

Quoted 4 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Allow a bunch of the info commands to be used in preconfig. Could probably add most of them.

I guess some of them may not work yet during preconfig. E.g.:

$ ./x86_64-softmmu/qemu-system-x86_64 -preconfig -monitor stdio
QEMU 2.12.50 monitor - type 'help' for more information
(qemu) info mtree
address-space: memory
  0000000000000000-ffffffffffffffff (prio 0, i/o): system

address-space: I/O
0000000000000000-000000000000ffff (prio 0, i/o): io

But it's fine to enable that I guess.

(Which "info" command would you want to use during preconfig?)

Quoted 2 lines

Signed-off-by Dr. David Alan Gilbert <[email protected]>

Reviewed-by Peter Xu <[email protected]>

Quoted 17 lines · Peter Xu

Quoted 4 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Allow a bunch of the info commands to be used in preconfig. Could probably add most of them.

I guess some of them may not work yet during preconfig. E.g.:

$ ./x86_64-softmmu/qemu-system-x86_64 -preconfig -monitor stdio
QEMU 2.12.50 monitor - type 'help' for more information
(qemu) info mtree
address-space: memory
  0000000000000000-ffffffffffffffff (prio 0, i/o): system

address-space: I/O
0000000000000000-000000000000ffff (prio 0, i/o): io

Quoted 8 lines

But it's fine to enable that I guess.

(Which "info" command would you want to use during preconfig?)

Quoted 2 lines

Signed-off-by Dr. David Alan Gilbert <[email protected]>

Reviewed-by Peter Xu <[email protected]>

The reason for having -preconfig is us despairing of making -S do the right thing. We'd have to *understand* the tangled mess that is our startup, and rearrange it so QMP becomes available early enough for configuring NUMA (and other things), yet late enough for everything to work.

-preconfig is a cheap hack to avoid this headache, by bypassing almost all of "everything".

Now you bring back some of "everything". Dangerous. You better show it actually works. Until you do:

NAK

Quoted 37 lines · * Markus Armbruster ([email protected]) wrote:

Quoted 17 lines · Peter Xu

Quoted 4 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Allow a bunch of the info commands to be used in preconfig. Could probably add most of them.

I guess some of them may not work yet during preconfig. E.g.:

$ ./x86_64-softmmu/qemu-system-x86_64 -preconfig -monitor stdio
QEMU 2.12.50 monitor - type 'help' for more information
(qemu) info mtree
address-space: memory
  0000000000000000-ffffffffffffffff (prio 0, i/o): system

address-space: I/O
0000000000000000-000000000000ffff (prio 0, i/o): io

Quoted 8 lines

But it's fine to enable that I guess.

(Which "info" command would you want to use during preconfig?)

Quoted 2 lines

Signed-off-by Dr. David Alan Gilbert <[email protected]>

Reviewed-by Peter Xu <[email protected]>

The reason for having -preconfig is us despairing of making -S do the right thing. We'd have to *understand* the tangled mess that is our startup, and rearrange it so QMP becomes available early enough for configuring NUMA (and other things), yet late enough for everything to work.

-preconfig is a cheap hack to avoid this headache, by bypassing almost all of "everything".

Quoted 4 lines

Now you bring back some of "everything". Dangerous. You better show it actually works. Until you do:

NAK

Well I did test each command in here to make sure it didn't crash/produce complete junk; but here's the output with the v2 of this patch that Igor R-b:

Quoted 43 lines · Dr. David Alan Gilbert

Quoted 41 lines · * Markus Armbruster ([email protected]) wrote:

Quoted 17 lines · Peter Xu

Quoted 4 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Allow a bunch of the info commands to be used in preconfig. Could probably add most of them.

I guess some of them may not work yet during preconfig. E.g.:

$ ./x86_64-softmmu/qemu-system-x86_64 -preconfig -monitor stdio
QEMU 2.12.50 monitor - type 'help' for more information
(qemu) info mtree
address-space: memory
  0000000000000000-ffffffffffffffff (prio 0, i/o): system

address-space: I/O
0000000000000000-000000000000ffff (prio 0, i/o): io

Quoted 8 lines

But it's fine to enable that I guess.

(Which "info" command would you want to use during preconfig?)

Quoted 2 lines

Signed-off-by Dr. David Alan Gilbert <[email protected]>

Reviewed-by Peter Xu <[email protected]>

The reason for having -preconfig is us despairing of making -S do the right thing. We'd have to *understand* the tangled mess that is our startup, and rearrange it so QMP becomes available early enough for configuring NUMA (and other things), yet late enough for everything to work.

-preconfig is a cheap hack to avoid this headache, by bypassing almost all of "everything".

Now you bring back some of "everything". Dangerous. You better show it actually works. Until you do:

NAK

Quoted 3 lines

Well I did test each command in here to make sure it didn't crash/produce complete junk; but here's the output with the v2 of this patch that Igor R-b:

[...]

For the sake of the argument, let's assume these commands all work in preconfig state. Are their QMP equivalents all available in preconfig state?

Quoted 50 lines · * Markus Armbruster ([email protected]) wrote:

Quoted 46 lines · Dr. David Alan Gilbert

Quoted 34 lines · * Markus Armbruster ([email protected]) wrote:

Quoted 17 lines · Peter Xu

Quoted 4 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Allow a bunch of the info commands to be used in preconfig. Could probably add most of them.

I guess some of them may not work yet during preconfig. E.g.:

$ ./x86_64-softmmu/qemu-system-x86_64 -preconfig -monitor stdio
QEMU 2.12.50 monitor - type 'help' for more information
(qemu) info mtree
address-space: memory
  0000000000000000-ffffffffffffffff (prio 0, i/o): system

address-space: I/O
0000000000000000-000000000000ffff (prio 0, i/o): io

Quoted 8 lines

But it's fine to enable that I guess.

(Which "info" command would you want to use during preconfig?)

Quoted 2 lines

Signed-off-by Dr. David Alan Gilbert <[email protected]>

Reviewed-by Peter Xu <[email protected]>

The reason for having -preconfig is us despairing of making -S do the right thing. We'd have to *understand* the tangled mess that is our startup, and rearrange it so QMP becomes available early enough for configuring NUMA (and other things), yet late enough for everything to work.

Quoted 7 lines

-preconfig is a cheap hack to avoid this headache, by bypassing almost all of "everything".

Now you bring back some of "everything". Dangerous. You better show it actually works. Until you do:

NAK

Well I did test each command in here to make sure it didn't crash/produce complete junk; but here's the output with the v2 of this patch that Igor R-b:

[...]

Quoted 3 lines

For the sake of the argument, let's assume these commands all work in preconfig state. Are their QMP equivalents all available in preconfig state?

That I don't know; I was happy to fix my list to the ones Igor recommended. If you object to some particular entries I'll be happy to change them.

Quoted 51 lines · Dr. David Alan Gilbert

Quoted 50 lines · * Markus Armbruster ([email protected]) wrote:

Quoted 46 lines · Dr. David Alan Gilbert

Quoted 34 lines · * Markus Armbruster ([email protected]) wrote:

Quoted 17 lines · Peter Xu

Quoted 4 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Allow a bunch of the info commands to be used in preconfig. Could probably add most of them.

I guess some of them may not work yet during preconfig. E.g.:

$ ./x86_64-softmmu/qemu-system-x86_64 -preconfig -monitor stdio
QEMU 2.12.50 monitor - type 'help' for more information
(qemu) info mtree
address-space: memory
  0000000000000000-ffffffffffffffff (prio 0, i/o): system

address-space: I/O
0000000000000000-000000000000ffff (prio 0, i/o): io

Quoted 8 lines

But it's fine to enable that I guess.

(Which "info" command would you want to use during preconfig?)

Quoted 2 lines

Signed-off-by Dr. David Alan Gilbert <[email protected]>

Reviewed-by Peter Xu <[email protected]>

The reason for having -preconfig is us despairing of making -S do the right thing. We'd have to *understand* the tangled mess that is our startup, and rearrange it so QMP becomes available early enough for configuring NUMA (and other things), yet late enough for everything to work.

Quoted 7 lines

-preconfig is a cheap hack to avoid this headache, by bypassing almost all of "everything".

Now you bring back some of "everything". Dangerous. You better show it actually works. Until you do:

NAK

Well I did test each command in here to make sure it didn't crash/produce complete junk; but here's the output with the v2 of this patch that Igor R-b:

[...]

Quoted 7 lines

Quoted 3 lines

For the sake of the argument, let's assume these commands all work in preconfig state. Are their QMP equivalents all available in preconfig state?

That I don't know; I was happy to fix my list to the ones Igor recommended. If you object to some particular entries I'll be happy to change them.

HMP must not provide more functionality than QMP. Specifically, we may provide "info FOO" only when we also provide query-FOO.

There are exceptions to this rule. I don't think they apply here. I'm prepared to discuss them, of course.

I wish there was a way to automate "provide command in HMP when its buddy is available in QMP", but since the buddies are only connected by code, that seems infeasible.

Without such automation, the two sets of available commands need to be kept consistent manually. The larger they are, the more of a bother.

Bother is fine when it provides commensurate value to users. Options in increasing order of value provided:

(1) HMP becomes ready only after we exit preconfig state (what I

    proposed in Message-ID: <[email protected]>.

(2) HMP provides help, quit, exit-preconfig.

(3) HMP provides (a subset of) the commands QMP provides.

I figure the maintenance cost of (1) and (2) will be negligible, but (3) could be a drag. Are you sure it's worthwhile?

Quoted 61 lines · * Markus Armbruster ([email protected]) wrote:

Quoted 51 lines · Dr. David Alan Gilbert

Quoted 50 lines · * Markus Armbruster ([email protected]) wrote:

Quoted 46 lines · Dr. David Alan Gilbert

Quoted 34 lines · * Markus Armbruster ([email protected]) wrote:

Quoted 17 lines · Peter Xu

Quoted 4 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Allow a bunch of the info commands to be used in preconfig. Could probably add most of them.

I guess some of them may not work yet during preconfig. E.g.:

$ ./x86_64-softmmu/qemu-system-x86_64 -preconfig -monitor stdio
QEMU 2.12.50 monitor - type 'help' for more information
(qemu) info mtree
address-space: memory
  0000000000000000-ffffffffffffffff (prio 0, i/o): system

address-space: I/O
0000000000000000-000000000000ffff (prio 0, i/o): io

Quoted 8 lines

But it's fine to enable that I guess.

(Which "info" command would you want to use during preconfig?)

Quoted 2 lines

Signed-off-by Dr. David Alan Gilbert <[email protected]>

Reviewed-by Peter Xu <[email protected]>

The reason for having -preconfig is us despairing of making -S do the right thing. We'd have to *understand* the tangled mess that is our startup, and rearrange it so QMP becomes available early enough for configuring NUMA (and other things), yet late enough for everything to work.

Quoted 7 lines

-preconfig is a cheap hack to avoid this headache, by bypassing almost all of "everything".

Now you bring back some of "everything". Dangerous. You better show it actually works. Until you do:

NAK

Well I did test each command in here to make sure it didn't crash/produce complete junk; but here's the output with the v2 of this patch that Igor R-b:

[...]

Quoted 7 lines

Quoted 3 lines

For the sake of the argument, let's assume these commands all work in preconfig state. Are their QMP equivalents all available in preconfig state?

That I don't know; I was happy to fix my list to the ones Igor recommended. If you object to some particular entries I'll be happy to change them.

Quoted 5 lines

HMP must not provide more functionality than QMP. Specifically, we may provide "info FOO" only when we also provide query-FOO.

There are exceptions to this rule. I don't think they apply here. I'm prepared to discuss them, of course.

No, that's strictly not true; HMP can provide anything that helps a human debug stuff. The requirement is that if a tool needs it then it must be provided in QMP.

Quoted 17 lines

I wish there was a way to automate "provide command in HMP when its buddy is available in QMP", but since the buddies are only connected by code, that seems infeasible.

Without such automation, the two sets of available commands need to be kept consistent manually. The larger they are, the more of a bother.

Bother is fine when it provides commensurate value to users. Options in increasing order of value provided:

(1) HMP becomes ready only after we exit preconfig state (what I

    proposed in Message-ID: <[email protected]>.

(2) HMP provides help, quit, exit-preconfig.

(3) HMP provides (a subset of) the commands QMP provides.

Quoted 2 lines

I figure the maintenance cost of (1) and (2) will be negligible, but (3) could be a drag. Are you sure it's worthwhile?

I'm not prepared to restrict to (2), and I'm not prepared to restrict HMP to a subset of QMP; As I said previously, if there's a command that you think is incorrect/broken that I've enabled then I'm happy to remove it.

Dave

--
Dr. David Alan Gilbert / [email protected] / Manchester, UK

Quoted 61 lines · * Markus Armbruster ([email protected]) wrote:

Quoted 58 lines · Dr. David Alan Gilbert

Quoted 45 lines · * Markus Armbruster ([email protected]) wrote:

Quoted 43 lines · Dr. David Alan Gilbert

Quoted 41 lines · * Markus Armbruster ([email protected]) wrote:

Quoted 17 lines · Peter Xu

Quoted 4 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Allow a bunch of the info commands to be used in preconfig. Could probably add most of them.

I guess some of them may not work yet during preconfig. E.g.:

$ ./x86_64-softmmu/qemu-system-x86_64 -preconfig -monitor stdio
QEMU 2.12.50 monitor - type 'help' for more information
(qemu) info mtree
address-space: memory
  0000000000000000-ffffffffffffffff (prio 0, i/o): system

address-space: I/O
0000000000000000-000000000000ffff (prio 0, i/o): io

Quoted 8 lines

But it's fine to enable that I guess.

(Which "info" command would you want to use during preconfig?)

Quoted 2 lines

Signed-off-by Dr. David Alan Gilbert <[email protected]>

Reviewed-by Peter Xu <[email protected]>

The reason for having -preconfig is us despairing of making -S do the right thing. We'd have to *understand* the tangled mess that is our startup, and rearrange it so QMP becomes available early enough for configuring NUMA (and other things), yet late enough for everything to work.

-preconfig is a cheap hack to avoid this headache, by bypassing almost all of "everything".

Now you bring back some of "everything". Dangerous. You better show it actually works. Until you do:

NAK

Quoted 8 lines

Quoted 3 lines

Well I did test each command in here to make sure it didn't crash/produce complete junk; but here's the output with the v2 of this patch that Igor R-b:

[...]

For the sake of the argument, let's assume these commands all work in preconfig state. Are their QMP equivalents all available in preconfig state?

That I don't know; I was happy to fix my list to the ones Igor recommended. If you object to some particular entries I'll be happy to change them.

Quoted 5 lines

HMP must not provide more functionality than QMP. Specifically, we may provide "info FOO" only when we also provide query-FOO.

There are exceptions to this rule. I don't think they apply here. I'm prepared to discuss them, of course.

No, that's strictly not true; HMP can provide anything that helps a human debug stuff.

The requirement is that if a tool needs it then it
must be provided in QMP.

Quoted 62 lines · Dr. David Alan Gilbert

Quoted 61 lines · * Markus Armbruster ([email protected]) wrote:

Quoted 58 lines · Dr. David Alan Gilbert

Quoted 45 lines · * Markus Armbruster ([email protected]) wrote:

Quoted 43 lines · Dr. David Alan Gilbert

Quoted 41 lines · * Markus Armbruster ([email protected]) wrote:

Quoted 17 lines · Peter Xu

Quoted 4 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Allow a bunch of the info commands to be used in preconfig. Could probably add most of them.

I guess some of them may not work yet during preconfig. E.g.:

$ ./x86_64-softmmu/qemu-system-x86_64 -preconfig -monitor stdio
QEMU 2.12.50 monitor - type 'help' for more information
(qemu) info mtree
address-space: memory
  0000000000000000-ffffffffffffffff (prio 0, i/o): system

address-space: I/O
0000000000000000-000000000000ffff (prio 0, i/o): io

Quoted 8 lines

But it's fine to enable that I guess.

(Which "info" command would you want to use during preconfig?)

Quoted 2 lines

Signed-off-by Dr. David Alan Gilbert <[email protected]>

Reviewed-by Peter Xu <[email protected]>

The reason for having -preconfig is us despairing of making -S do the right thing. We'd have to *understand* the tangled mess that is our startup, and rearrange it so QMP becomes available early enough for configuring NUMA (and other things), yet late enough for everything to work.

-preconfig is a cheap hack to avoid this headache, by bypassing almost all of "everything".

Now you bring back some of "everything". Dangerous. You better show it actually works. Until you do:

NAK

Quoted 8 lines

Quoted 3 lines

Well I did test each command in here to make sure it didn't crash/produce complete junk; but here's the output with the v2 of this patch that Igor R-b:

[...]

For the sake of the argument, let's assume these commands all work in preconfig state. Are their QMP equivalents all available in preconfig state?

That I don't know; I was happy to fix my list to the ones Igor recommended. If you object to some particular entries I'll be happy to change them.

Quoted 8 lines

Quoted 5 lines

HMP must not provide more functionality than QMP. Specifically, we may provide "info FOO" only when we also provide query-FOO.

There are exceptions to this rule. I don't think they apply here. I'm prepared to discuss them, of course.

No, that's strictly not true; HMP can provide anything that helps a human debug stuff.

Yes, but...

Quoted 2 lines

The requirement is that if a tool needs it then it
must be provided in QMP.

... it must not do that at the expense of QMP's completeness. Permitting that would be a break from how we worked since QMP became supported in 0.14 or so. Seven years, time flies.

The hard requirement for QMP from day one was "provide everything machine clients need". To avoid speculation and endless arguments about what might be needed / not needed, we resolved to approximate this by "provide everything, except stuff that's *clearly* of no use to machines". This has been spelled out on this list several times. Here are two relatively recent iterations:

Message-ID: <[email protected]>
https://lists.gnu.org/archive/html/qemu-devel/2017-04/msg05309.html

Message-ID: <[email protected]>
https://lists.gnu.org/archive/html/qemu-devel/2017-05/msg00247.html

Quoting the latter:

In general, functionality available in HMP should also available in QMP. Exceptions include functionality that makes no sense in QMP, or is of use only for human users. If you think your command is an exception, please explain why in the commit message.

If it isn't, you need to implement it for QMP (including suitable test cases), then rewrite the HMP version to reuse either the QMP command or a common core.

Example for "makes no sense in QMP": setting the current CPU[1], because a QMP monitor doesn't have a current CPU.

Examples for "is of use only for human users": HMP command "help", the integrated pocket calculator[2].

End quote.

But we're not even arguing about a new HMP command, we're arguing about making existing commands available in preconfig state. I assume that if an HMP command is useful in preconfig state, then its QMP buddy is also useful there. I therefore asked you whether their QMP equivalents are all available in preconfig state. The answer I expected was a short table of three columns: HMP command you propose to enable, QMP buddy if any, whether the QMP buddy is available in preconfig state yes/no. Estimated effort: minutes. What I got instead of this data was an argument about fundamental design decisions. Fine, reexaminating fundamentals once in a while isn't a bad idea. But may I have my data now?

[...]

Quoted 24 lines · Peter Xu

Quoted 4 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Allow a bunch of the info commands to be used in preconfig. Could probably add most of them.

I guess some of them may not work yet during preconfig. E.g.:

$ ./x86_64-softmmu/qemu-system-x86_64 -preconfig -monitor stdio
QEMU 2.12.50 monitor - type 'help' for more information
(qemu) info mtree
address-space: memory
  0000000000000000-ffffffffffffffff (prio 0, i/o): system

address-space: I/O
0000000000000000-000000000000ffff (prio 0, i/o): io

But it's fine to enable that I guess.

(Which "info" command would you want to use during preconfig?)

Quoted 2 lines

Signed-off-by Dr. David Alan Gilbert <[email protected]>

Quoted 1 line

Reviewed-by Peter Xu <[email protected]>

The reason for having -preconfig is us despairing of making -S do the right thing. We'd have to *understand* the tangled mess that is our startup, and rearrange it so QMP becomes available early enough for configuring NUMA (and other things), yet late enough for everything to work.

-preconfig is a cheap hack to avoid this headache, by bypassing almost all of "everything".

Now you bring back some of "everything". Dangerous. You better show it actually works. Until you do:

NAK

Quoted 26 lines · On Thu, 07 Jun 2018 14:22:34 +0200 Markus Armbruster <[email protected]> wrote:

Quoted 24 lines · Peter Xu

Quoted 4 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Allow a bunch of the info commands to be used in preconfig. Could probably add most of them.

I guess some of them may not work yet during preconfig. E.g.:

$ ./x86_64-softmmu/qemu-system-x86_64 -preconfig -monitor stdio
QEMU 2.12.50 monitor - type 'help' for more information
(qemu) info mtree
address-space: memory
  0000000000000000-ffffffffffffffff (prio 0, i/o): system

address-space: I/O
0000000000000000-000000000000ffff (prio 0, i/o): io

But it's fine to enable that I guess.

(Which "info" command would you want to use during preconfig?)

Quoted 2 lines

Signed-off-by Dr. David Alan Gilbert <[email protected]>

Quoted 7 lines

Quoted 1 line

Reviewed-by Peter Xu <[email protected]>

The reason for having -preconfig is us despairing of making -S do the right thing. We'd have to *understand* the tangled mess that is our startup, and rearrange it so QMP becomes available early enough for configuring NUMA (and other things), yet late enough for everything to work.

We solve concrete NUMA problem at -S time as was demonstrated by thread:
"RFC v2 0/4] enable numa configuration before machine is running from HMP/QMP" were pros and cons are were summarized. But that won't scale to other things.

Quoted 2 lines

-preconfig is a cheap hack to avoid this headache, by bypassing almost all of "everything".

hack should allow to move configuration steps to early stage one by one until the point we could obsolete -S (from configuration point) without breaking current -S users and clean up start up mess in process.

Quoted 2 lines

Now you bring back some of "everything". Dangerous. You better show it actually works. Until you do:

Tested v2, works as expected so far.

Quoted 3 lines

NAK

From: "Dr. David Alan Gilbert" <[email protected]>

Allow a bunch of the info commands to be used in preconfig. Could probably add most of them.

Signed-off-by Dr. David Alan Gilbert <[email protected]>

---
 hmp-commands-info.hx | 9 +++++++++
 hmp-commands.hx      | 1 +
 2 files changed, 10 insertions(+)

hmp-commands-info.hx +1 -0

index ddfcd5adcc..00735e7d1c 100644
@@ -19,6 +19,7 @@ ETEXI
         .params     = "",
         .help       = "show the version of QEMU",
         .cmd        = hmp_info_version,
+        .flags      = "p",
     },
 
 STEXI

hmp-commands-info.hx +1 -0

     },
 
 STEXI

@@ -47,6 +49,7 @@ ETEXI
         .params     = "",
         .help       = "show the character devices",
         .cmd        = hmp_info_chardev,
+        .flags      = "p",
     },
 
 STEXI

hmp-commands-info.hx +1 -0

 STEXI

@@ -165,6 +170,7 @@ ETEXI
         .params     = "",
         .help       = "show the command line history",
         .cmd        = hmp_info_history,
+        .flags      = "p",
     },
 
 STEXI

hmp-commands-info.hx +2 -0

 STEXI

@@ -399,6 +406,7 @@ ETEXI
         .params     = "",
         .help       = "show the current VM status (running|paused)",
         .cmd        = hmp_info_status,
+        .flags      = "p",
     },
 
 STEXI

@@ -829,6 +837,7 @@ ETEXI
         .params     = "",
         .help       = "Show information about hotpluggable CPUs",
         .cmd        = hmp_hotpluggable_cpus,
+        .flags      = "p",
     },
 
 STEXI

hmp-commands.hx +0 -0

index 8bf590ae4b..dc82ed526f 100644

From: "Dr. David Alan Gilbert" <[email protected]>

Add the exit_preconfig command to return to normality.

Signed-off-by Dr. David Alan Gilbert <[email protected]>

From: "Dr. David Alan Gilbert" <[email protected]>

Now we can cope with preconfig in HMP, reenable by reverting commit 71dc578e116599ea73c8a2a4e693134702ec0e83.

Signed-off-by Dr. David Alan Gilbert <[email protected]>

From: "Dr. David Alan Gilbert" <[email protected]>

Reenable HMP in preconfig mode; it's pretty
easy and anyway I want to do a similar thing for OOB eventually. We'll want to enable more commands in preconfig mode to make it useful at some point.

Dave

Quoted 8 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Reenable HMP in preconfig mode; it's pretty
easy and anyway I want to do a similar thing for OOB eventually. We'll want to enable more commands in preconfig mode to make it useful at some point.

Dave

Wanna add "quit" into the preconfig-allowed list for HMP as well?

Tested-by Peter Xu <[email protected]>

Signature · 1 line

Peter Xu

Quoted 8 lines · * Peter Xu ([email protected]) wrote:

Quoted 7 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Reenable HMP in preconfig mode; it's pretty
easy and anyway I want to do a similar thing for OOB eventually. We'll want to enable more commands in preconfig mode to make it useful at some point.

Quoted 3 lines

Quoted 1 line

Dave

Wanna add "quit" into the preconfig-allowed list for HMP as well?

I tried; quit triggers a disallowed state transition!

Quoted 8 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Reenable HMP in preconfig mode; it's pretty
easy and anyway I want to do a similar thing for OOB eventually. We'll want to enable more commands in preconfig mode to make it useful at some point.

Dave

Wanna add "quit" into the preconfig-allowed list for HMP as well?

Tested-by Peter Xu <[email protected]>

Quoted 8 lines · On Thu, 7 Jun 2018 16:54:44 +0800 Peter Xu <[email protected]> wrote:

Quoted 7 lines · Dr. David Alan Gilbert (git)

From: "Dr. David Alan Gilbert" <[email protected]>

Reenable HMP in preconfig mode; it's pretty
easy and anyway I want to do a similar thing for OOB eventually. We'll want to enable more commands in preconfig mode to make it useful at some point.

Quoted 3 lines

Quoted 1 line

Dave

Wanna add "quit" into the preconfig-allowed list for HMP as well?

There is exit-preconfig, but yeah it just forwards us to the next state

But for human users that just want to play with HMP 'quit' might be useful, but only to the extent of trying out things out.

From: "Dr. David Alan Gilbert" <[email protected]>

Reenable HMP in preconfig mode; it's pretty
easy and anyway I want to do a similar thing for OOB eventually. We'll want to enable more commands in preconfig mode to make it useful at some point.

Dave

Dr. David Alan Gilbert (6):
hmp: Add flag for preconfig commands
hmp: Allow help on preconfig commands
hmp: Restrict auto-complete in preconfig
hmp: Add info commands for preconfig
hmp: add exit_preconfig
hmp: Allow HMP in preconfig state again

 hmp-commands-info.hx |  9 +++++++++
 hmp-commands.hx      | 17 +++++++++++++++++
 hmp.c                |  7 +++++++
 hmp.h                |  1 +
 monitor.c            | 42 +++++++++++++++++++++++++++++++++---------
 5 files changed, 67 insertions(+), 9 deletions(-)