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Re: [PATCH v2 38/53] qapi: introduce x-query-lapic QMP command
From: |
Daniel P . Berrangé |
Subject: |
Re: [PATCH v2 38/53] qapi: introduce x-query-lapic QMP command |
Date: |
Wed, 22 Sep 2021 17:30:44 +0100 |
User-agent: |
Mutt/2.0.7 (2021-05-04) |
On Mon, Sep 20, 2021 at 10:27:06PM -0700, Dongli Zhang wrote:
> Hi Daniel,
>
> On 9/14/21 7:20 AM, Daniel P. Berrangé wrote:
> > This is a counterpart to the HMP "info lapic" command. It is being
> > added with an "x-" prefix because this QMP command is intended as an
> > adhoc debugging tool and will thus not be modelled in QAPI as fully
> > structured data, nor will it have long term guaranteed stability.
> > The existing HMP command is rewritten to call the QMP command.
> >
> > This command is unable to use the pre-existing HumanReadableText,
> > because if 'common.json' is included into 'machine-target.json'
> > the static marshalling method for HumanReadableText will be reported
> > as unused by the compiler on all architectures except s390x.
> >
> > Possible options were
> >
> > 1 Support 'if' conditionals on 'include' statements in QAPI
> > 2 Add further commands to 'machine-target.json' that use
> > HumanReadableText, such that it has at least one usage
> > on all architecture targets.
> > 3 Duplicate HumanReadableText as TargetHumanReadableText
> > adding conditions
> >
> > This patch takes option (3) in the belief that we will eventually
> > get to a point where option (2) happens, and TargetHumanReadableText
> > can be removed again.
> >
> > Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> > ---
> > hw/core/cpu-common.c | 7 ++
> > include/hw/core/cpu.h | 10 +++
> > qapi/machine-target.json | 19 ++++-
> > target/i386/cpu-dump.c | 161 ++++++++++++++++++++-------------------
> > target/i386/cpu.h | 4 +-
> > target/i386/monitor.c | 46 +++++++++--
> > 6 files changed, 160 insertions(+), 87 deletions(-)
> > diff --git a/target/i386/monitor.c b/target/i386/monitor.c
> > index 19468c4e85..fc09f90059 100644
> > --- a/target/i386/monitor.c
> > +++ b/target/i386/monitor.c
> > @@ -33,6 +33,7 @@
> > #include "qapi/error.h"
> > #include "sev_i386.h"
> > #include "qapi/qapi-commands-misc-target.h"
> > +#include "qapi/qapi-commands-machine-target.h"
> > #include "qapi/qapi-commands-misc.h"
> > #include "hw/i386/pc.h"
> >
> > @@ -650,23 +651,52 @@ const MonitorDef *target_monitor_defs(void)
> > return monitor_defs;
> > }
> >
> > +TargetHumanReadableText *qmp_x_query_lapic(int64_t apicid,
> > + Error **errp)
> > +{
> > + TargetHumanReadableText *ret;
> > + g_autoptr(GString) buf = NULL;
> > + CPUState *cs = cpu_by_arch_id(apicid);
> > +
> > + if (!cs) {
> > + error_setg(errp, "No CPU with APIC ID %" PRId64 " available",
> > apicid);
> > + return NULL;
> > + }
>
> Suppose the accelerator is KVM, the CPUState (cs) might not be syncrhonized
> with
> KVM kernel space (APIC+PIR). As a result, the data is stale.
>
> I sent below patch long time ago but it never got reviewed.
>
> https://lore.kernel.org/qemu-devel/20210908143803.29191-1-dongli.zhang@oracle.com/
I'll include your patch in the next version of this series
just before this patch, and then update this patch to take
it into account.
>
> > +
> > + buf = x86_cpu_format_local_apic_state(cs, CPU_DUMP_FPU, errp);
> > + if (!buf) {
> > + return NULL;
> > + }
> > +
> > + ret = g_new0(TargetHumanReadableText, 1);
> > + ret->human_readable_text = g_steal_pointer(&buf->str);
> > + return ret;
> > +}
> > +
> > void hmp_info_local_apic(Monitor *mon, const QDict *qdict)
> > {
> > - CPUState *cs;
> > + Error *err = NULL;
> > + g_autoptr(TargetHumanReadableText) info = NULL;
> > + int64_t apicid;
> >
> > if (qdict_haskey(qdict, "apic-id")) {
> > - int id = qdict_get_try_int(qdict, "apic-id", 0);
> > - cs = cpu_by_arch_id(id);
> > + apicid = qdict_get_try_int(qdict, "apic-id", 0);
>
> Here is where I used to fix with the patch.
>
> Thank you very much!
>
> Dongli Zhang
>
> > } else {
> > - cs = mon_get_cpu(mon);
> > + CPUState *cs = mon_get_cpu(mon);
> > + if (!cs) {
> > + monitor_printf(mon, "No CPU available\n");
> > + return;
> > + }
> > + apicid = cpu_get_arch_id(cs);
> > }
> >
> > -
> > - if (!cs) {
> > - monitor_printf(mon, "No CPU available\n");
> > + info = qmp_x_query_lapic(apicid, &err);
> > + if (err) {
> > + error_report_err(err);
> > return;
> > }
> > - x86_cpu_dump_local_apic_state(cs, CPU_DUMP_FPU);
> > +
> > + monitor_printf(mon, "%s", info->human_readable_text);
> > }
> >
> > SevInfo *qmp_query_sev(Error **errp)
> >
>
Regards,
Daniel
--
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- Re: [PATCH v2 30/53] qapi: introduce x-query-roms QMP command, (continued)
- [PATCH v2 31/53] qapi: introduce x-query-profile QMP command, Daniel P . Berrangé, 2021/09/14
- [PATCH v2 32/53] qapi: introduce x-query-numa QMP command, Daniel P . Berrangé, 2021/09/14
- [PATCH v2 33/53] qapi: introduce x-query-usb QMP command, Daniel P . Berrangé, 2021/09/14
- [PATCH v2 35/53] qapi: introduce x-query-ramblock QMP command, Daniel P . Berrangé, 2021/09/14
- [PATCH v2 34/53] qapi: introduce x-query-rdma QMP command, Daniel P . Berrangé, 2021/09/14
- [PATCH v2 36/53] qapi: introduce x-query-skeys QMP command, Daniel P . Berrangé, 2021/09/14
- [PATCH v2 37/53] qapi: introduce x-query-cmma QMP command, Daniel P . Berrangé, 2021/09/14
- [PATCH v2 38/53] qapi: introduce x-query-lapic QMP command, Daniel P . Berrangé, 2021/09/14
- [PATCH v2 39/53] qapi: introduce x-query-irq QMP command, Daniel P . Berrangé, 2021/09/14
- [PATCH v2 40/53] hw/core: drop "dump_state" callback from CPU targets, Daniel P . Berrangé, 2021/09/14
- [PATCH v2 41/53] hw/core: drop support for NULL pointer for FILE * in cpu_dump_state, Daniel P . Berrangé, 2021/09/14
- [PATCH v2 42/53] hw/core: introduce a 'format_tlb' callback, Daniel P . Berrangé, 2021/09/14
[PATCH v2 43/53] target/i386: convert to use format_tlb callback, Daniel P . Berrangé, 2021/09/14
[PATCH v2 44/53] target/m68k: convert to use format_tlb callback, Daniel P . Berrangé, 2021/09/14