Re: [Qemu-devel] [multiprocess RFC PATCH 20/37] multi-process: Add QMP & HMP commands to list remote processes

[Dr. David Alan Gilbert]

* address@hidden (address@hidden) wrote:
> From: Jagannathan Raman <address@hidden>
> 
> Add query-remote QMP command and remote-proc-list HMP command, to list
> the remote processes spawned by QEMU.
> 
> Signed-off-by: Jagannathan Raman <address@hidden>
> Signed-off-by: John G Johnson <address@hidden>
> Signed-off-by: Elena Ufimtseva <address@hidden>
> ---
>  hmp-commands.hx        | 16 +++++++++
>  hmp.h                  |  1 +
>  hw/proxy/Makefile.objs |  1 +
>  hw/proxy/monitor.c     | 89 
> ++++++++++++++++++++++++++++++++++++++++++++++++++
>  qapi/block-core.json   | 29 ++++++++++++++++
>  5 files changed, 136 insertions(+)
>  create mode 100644 hw/proxy/monitor.c
> 
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index 9b40359..fb3c8ba 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -725,6 +725,22 @@ STEXI
>  Add device.
>  ETEXI
>  
> +#if defined(CONFIG_MPQEMU)
> +    {
> +        .name       = "remote_proc_list",
> +        .args_type  = "",
> +        .params     = "",
> +        .help       = "list remote devices and their linux process IDs",

Should probably just say 'process IDs' - it's not that Linux specific.

> +        .cmd        = hmp_remote_proc_list,
> +    },
> +
> +STEXI
> address@hidden remote_proc_list
> address@hidden remote_proc_list
> +List remote devices and their linux process IDs.
> +ETEXI
> +#endif
> +
>      {
>          .name       = "device_del",
>          .args_type  = "id:s",
> diff --git a/hmp.h b/hmp.h
> index e0f32f0..0940634 100644
> --- a/hmp.h
> +++ b/hmp.h
> @@ -149,5 +149,6 @@ void hmp_hotpluggable_cpus(Monitor *mon, const QDict 
> *qdict);
>  void hmp_info_vm_generation_id(Monitor *mon, const QDict *qdict);
>  void hmp_info_memory_size_summary(Monitor *mon, const QDict *qdict);
>  void hmp_info_sev(Monitor *mon, const QDict *qdict);
> +void hmp_remote_proc_list(Monitor *mon, const QDict *qdict);
>  
>  #endif
> diff --git a/hw/proxy/Makefile.objs b/hw/proxy/Makefile.objs
> index f562f5a..e642060 100644
> --- a/hw/proxy/Makefile.objs
> +++ b/hw/proxy/Makefile.objs
> @@ -1,2 +1,3 @@
>  common-obj-$(CONFIG_MPQEMU) += qemu-proxy.o
>  common-obj-$(CONFIG_MPQEMU) += proxy-lsi53c895a.o
> +common-obj-$(CONFIG_MPQEMU) += monitor.o
> diff --git a/hw/proxy/monitor.c b/hw/proxy/monitor.c
> new file mode 100644
> index 0000000..3005eec
> --- /dev/null
> +++ b/hw/proxy/monitor.c
> @@ -0,0 +1,89 @@
> +/*
> + * QEMU monitor command handler for multi-process QEMU
> + *
> + * Copyright 2019, Oracle and/or its affiliates. All rights reserved.
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a 
> copy
> + * of this software and associated documentation files (the "Software"), to 
> deal
> + * in the Software without restriction, including without limitation the 
> rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
> FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#include <sys/types.h>
> +
> +#include "qemu/osdep.h"
> +#include "qapi/qapi-types-block-core.h"
> +#include "qapi/qapi-commands-block-core.h"
> +#include "monitor/monitor.h"
> +#include "qemu/option.h"
> +#include "hmp.h"
> +#include "hw/boards.h"
> +#include "hw/i386/pc.h"
> +#include "hw/proxy/qemu-proxy.h"
> +
> +/*
> + * TODO: Is there a callback where the allocated memory for QMP could be 
> free'd

I think qmp will clean that up when it returns your list that you
create (by making calls to qapi_free_RemoteProc or
qapi_free_RemoteProcList as appropriate.)


> + */
> +RemoteProcList *qmp_query_remote(Error **errp)
> +{
> +    PCMachineState *pcms = PC_MACHINE(current_machine);
> +    RemoteProcList *proclist, *proc;
> +    GHashTableIter itr;
> +    PCIProxyDev *pdev;
> +    PCIProxyDevClass *k;
> +    DeviceState *d;
> +    char *id;
> +
> +    proclist = NULL;
> +
> +    g_hash_table_iter_init(&itr, pcms->remote_devs);
> +
> +    while (g_hash_table_iter_next(&itr, (gpointer *)&id, (gpointer *)&pdev)) 
> {
> +        k = PCI_PROXY_DEV_GET_CLASS(pdev);
> +        d = DEVICE(pdev);
> +
> +        proc = g_malloc0(sizeof(RemoteProcList));
> +        proc->next = proclist;
> +        proclist = proc;
> +        proc->value = g_malloc0(sizeof(RemoteProc));
> +        proc->value->pid = pdev->remote_pid;
> +        proc->value->id = g_strdup(d->id);
> +        proc->value->proc = g_strdup(k->command);
> +    }
> +
> +    return proclist;
> +}
> +
> +void hmp_remote_proc_list(Monitor *mon, const QDict *qdict)
> +{
> +    PCMachineState *pcms = PC_MACHINE(current_machine);
> +    GHashTableIter itr;
> +    PCIProxyDev *pdev;
> +    PCIProxyDevClass *k;
> +    char *id;
> +
> +    g_hash_table_iter_init(&itr, pcms->remote_devs);
> +
> +    monitor_printf(mon, "%8.8s\t%16.16s\t%16.16s\t%16.16s\n\n", "PID", "RID",
> +                   "QEMU ID", "PROCESS NAME");
> +
> +    while (g_hash_table_iter_next(&itr, (gpointer *)&id, (gpointer *)&pdev)) 
> {
> +        k = PCI_PROXY_DEV_GET_CLASS(pdev);
> +
> +        monitor_printf(mon, "%8.8d\t%16.16s\t%16.16s\t%16.16s\n",
> +                       pdev->remote_pid, pdev->rid, id, k->command);

I don't think I understand what a RID is here.

A more common way to write HMP commands is to call the qmp command and
format it's output;  having said that your code here is probably
simpler.

> +    }
> +}
> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index 2b8afbb..05394c4 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -647,6 +647,23 @@
>             '*dirty-bitmaps': ['BlockDirtyInfo'] } }
>  
>  ##
> +# @RemoteProc:
> +#
> +# Remote process information.
> +#
> +# @id: Device ID
> +#
> +# @pid: Linux Process ID
> +#
> +# @proc: Process name
> +#
> +# Since:  3.0.93

Note 'Since:' should be the version it gets merged into
so it'll be 4.1 or 5.0 etc

> +##
> +{ 'struct': 'RemoteProc',
> +  'data': {'id': 'str', 'pid': 'int32', 'proc': 'str' },
> +  'if': 'defined(CONFIG_MPQEMU)' }
> +
> +##
>  # @BlockMeasureInfo:
>  #
>  # Image file size calculation information.  This structure describes the size
> @@ -768,6 +785,18 @@
>  ##
>  { 'command': 'query-block', 'returns': ['BlockInfo'] }
>  
> +##
> +# @query-remote:
> +#
> +# Get a list of all the remote processes spawned by QEMU.
> +#
> +# Returns: a list of @RemoteProc describing each remote process.
> +#
> +# Since: 3.0.93
> +#
> +##
> +{ 'command': 'query-remote', 'returns': ['RemoteProc'],
> +  'if': 'defined(CONFIG_MPQEMU)' }
>  
>  ##
>  # @BlockDeviceTimedStats:
> -- 
> 1.8.3.1
> 
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK