diff mbox series

[1/5] sysemu: add set_virtual_time to accel ops

Message ID 20240516222047.1853459-2-pierrick.bouvier@linaro.org
State Superseded
Headers show
Series Implement icount=auto using TCG Plugins | expand

Commit Message

Pierrick Bouvier May 16, 2024, 10:20 p.m. UTC 
From: Alex Bennée <alex.bennee@linaro.org>

We are about to remove direct calls to individual accelerators for
this information and will need a central point for plugins to hook
into time changes.

From: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/sysemu/accel-ops.h                     | 18 +++++++++++++++++-
 include/sysemu/cpu-timers.h                    |  3 ++-
 ...et-virtual-clock.c => cpus-virtual-clock.c} |  5 +++++
 system/cpus.c                                  | 11 +++++++++++
 stubs/meson.build                              |  6 +++++-
 5 files changed, 40 insertions(+), 3 deletions(-)
 rename stubs/{cpus-get-virtual-clock.c => cpus-virtual-clock.c} (68%)

Comments

Alex Bennée May 28, 2024, 5:11 p.m. UTC | #1 
Pierrick Bouvier <pierrick.bouvier@linaro.org> writes:

> From: Alex Bennée <alex.bennee@linaro.org>
>
> We are about to remove direct calls to individual accelerators for
> this information and will need a central point for plugins to hook
> into time changes.
>
> From: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Just a note, when patches written by other people come via your tree you
should add your s-o-b tag to indicate:

  "I'm legally okay to contribute this and happy for it to go into QEMU"
Pierrick Bouvier May 28, 2024, 6:57 p.m. UTC | #2 
On 5/28/24 10:11, Alex Bennée wrote:
> Pierrick Bouvier <pierrick.bouvier@linaro.org> writes:
> 
>> From: Alex Bennée <alex.bennee@linaro.org>
>>
>> We are about to remove direct calls to individual accelerators for
>> this information and will need a central point for plugins to hook
>> into time changes.
>>
>> From: Alex Bennée <alex.bennee@linaro.org>
>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> 
> Just a note, when patches written by other people come via your tree you
> should add your s-o-b tag to indicate:
> 
>    "I'm legally okay to contribute this and happy for it to go into QEMU"
> 

Thanks for clarifying, I didn't know it was needed as a committer (vs 
author), and checkpatch.pl does not seem to check for this.

I'll add this when reposting the series, if we have some comments.
Philippe Mathieu-Daudé May 29, 2024, 12:29 p.m. UTC | #3 
On 17/5/24 00:20, Pierrick Bouvier wrote:
> From: Alex Bennée <alex.bennee@linaro.org>
> 
> We are about to remove direct calls to individual accelerators for
> this information and will need a central point for plugins to hook
> into time changes.
> 
> From: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>   include/sysemu/accel-ops.h                     | 18 +++++++++++++++++-
>   include/sysemu/cpu-timers.h                    |  3 ++-
>   ...et-virtual-clock.c => cpus-virtual-clock.c} |  5 +++++
>   system/cpus.c                                  | 11 +++++++++++
>   stubs/meson.build                              |  6 +++++-
>   5 files changed, 40 insertions(+), 3 deletions(-)


> diff --git a/stubs/meson.build b/stubs/meson.build
> index 3b9d42023cb..672213b7482 100644
> --- a/stubs/meson.build
> +++ b/stubs/meson.build
> @@ -3,6 +3,11 @@
>   # below, so that it is clear who needs the stubbed functionality.
>   
>   stub_ss.add(files('cpu-get-clock.c'))
> +stub_ss.add(files('cpus-virtual-clock.c'))

Are these lines <...

> +stub_ss.add(files('qemu-timer-notify-cb.c'))
> +stub_ss.add(files('icount.c'))
> +stub_ss.add(files('dump.c'))
> +stub_ss.add(files('error-printf.c'))

...> due to a failed git-rebase?

>   stub_ss.add(files('fdset.c'))
>   stub_ss.add(files('iothread-lock.c'))
>   stub_ss.add(files('is-daemonized.c'))
> @@ -28,7 +33,6 @@ endif
>   if have_block or have_ga
>     stub_ss.add(files('replay-tools.c'))
>     # stubs for hooks in util/main-loop.c, util/async.c etc.
> -  stub_ss.add(files('cpus-get-virtual-clock.c'))
>     stub_ss.add(files('icount.c'))
>     stub_ss.add(files('graph-lock.c'))
>     if linux_io_uring.found()
Pierrick Bouvier May 29, 2024, 6:57 p.m. UTC | #4 
On 5/29/24 05:29, Philippe Mathieu-Daudé wrote:
> On 17/5/24 00:20, Pierrick Bouvier wrote:
>> From: Alex Bennée <alex.bennee@linaro.org>
>>
>> We are about to remove direct calls to individual accelerators for
>> this information and will need a central point for plugins to hook
>> into time changes.
>>
>> From: Alex Bennée <alex.bennee@linaro.org>
>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>> ---
>>    include/sysemu/accel-ops.h                     | 18 +++++++++++++++++-
>>    include/sysemu/cpu-timers.h                    |  3 ++-
>>    ...et-virtual-clock.c => cpus-virtual-clock.c} |  5 +++++
>>    system/cpus.c                                  | 11 +++++++++++
>>    stubs/meson.build                              |  6 +++++-
>>    5 files changed, 40 insertions(+), 3 deletions(-)
> 
> 
>> diff --git a/stubs/meson.build b/stubs/meson.build
>> index 3b9d42023cb..672213b7482 100644
>> --- a/stubs/meson.build
>> +++ b/stubs/meson.build
>> @@ -3,6 +3,11 @@
>>    # below, so that it is clear who needs the stubbed functionality.
>>    
>>    stub_ss.add(files('cpu-get-clock.c'))
>> +stub_ss.add(files('cpus-virtual-clock.c'))
> 
> Are these lines <...
> 
>> +stub_ss.add(files('qemu-timer-notify-cb.c'))
>> +stub_ss.add(files('icount.c'))
>> +stub_ss.add(files('dump.c'))
>> +stub_ss.add(files('error-printf.c'))
> 
> ...> due to a failed git-rebase?
> 

You're right, fixed this!

>>    stub_ss.add(files('fdset.c'))
>>    stub_ss.add(files('iothread-lock.c'))
>>    stub_ss.add(files('is-daemonized.c'))
>> @@ -28,7 +33,6 @@ endif
>>    if have_block or have_ga
>>      stub_ss.add(files('replay-tools.c'))
>>      # stubs for hooks in util/main-loop.c, util/async.c etc.
>> -  stub_ss.add(files('cpus-get-virtual-clock.c'))
>>      stub_ss.add(files('icount.c'))
>>      stub_ss.add(files('graph-lock.c'))
>>      if linux_io_uring.found()
>
Paolo Bonzini May 30, 2024, 6:30 a.m. UTC | #5 
On Fri, May 17, 2024 at 12:21 AM Pierrick Bouvier
<pierrick.bouvier@linaro.org> wrote:
> diff --git a/stubs/meson.build b/stubs/meson.build
> index 3b9d42023cb..672213b7482 100644
> --- a/stubs/meson.build
> +++ b/stubs/meson.build
> @@ -3,6 +3,11 @@
>  # below, so that it is clear who needs the stubbed functionality.
>
>  stub_ss.add(files('cpu-get-clock.c'))
> +stub_ss.add(files('cpus-virtual-clock.c'))
> +stub_ss.add(files('qemu-timer-notify-cb.c'))
> +stub_ss.add(files('icount.c'))
> +stub_ss.add(files('dump.c'))
> +stub_ss.add(files('error-printf.c'))

Was there a problem when rebasing?

Paolo

>  stub_ss.add(files('fdset.c'))
>  stub_ss.add(files('iothread-lock.c'))
>  stub_ss.add(files('is-daemonized.c'))
> @@ -28,7 +33,6 @@ endif
>  if have_block or have_ga
>    stub_ss.add(files('replay-tools.c'))
>    # stubs for hooks in util/main-loop.c, util/async.c etc.
> -  stub_ss.add(files('cpus-get-virtual-clock.c'))
>    stub_ss.add(files('icount.c'))
>    stub_ss.add(files('graph-lock.c'))
>    if linux_io_uring.found()
> --
> 2.39.2
>
Pierrick Bouvier May 30, 2024, 5:18 p.m. UTC | #6 
On 5/29/24 23:30, Paolo Bonzini wrote:
> On Fri, May 17, 2024 at 12:21 AM Pierrick Bouvier
> <pierrick.bouvier@linaro.org> wrote:
>> diff --git a/stubs/meson.build b/stubs/meson.build
>> index 3b9d42023cb..672213b7482 100644
>> --- a/stubs/meson.build
>> +++ b/stubs/meson.build
>> @@ -3,6 +3,11 @@
>>   # below, so that it is clear who needs the stubbed functionality.
>>
>>   stub_ss.add(files('cpu-get-clock.c'))
>> +stub_ss.add(files('cpus-virtual-clock.c'))
>> +stub_ss.add(files('qemu-timer-notify-cb.c'))
>> +stub_ss.add(files('icount.c'))
>> +stub_ss.add(files('dump.c'))
>> +stub_ss.add(files('error-printf.c'))
> 
> Was there a problem when rebasing?
> 
> Paolo
> 

Hi Paolo,

Yes, Philippe made the same comment. I'll fix it in next revision.
Thanks!

>>   stub_ss.add(files('fdset.c'))
>>   stub_ss.add(files('iothread-lock.c'))
>>   stub_ss.add(files('is-daemonized.c'))
>> @@ -28,7 +33,6 @@ endif
>>   if have_block or have_ga
>>     stub_ss.add(files('replay-tools.c'))
>>     # stubs for hooks in util/main-loop.c, util/async.c etc.
>> -  stub_ss.add(files('cpus-get-virtual-clock.c'))
>>     stub_ss.add(files('icount.c'))
>>     stub_ss.add(files('graph-lock.c'))
>>     if linux_io_uring.found()
>> --
>> 2.39.2
>>
>
diff mbox series

Patch

diff --git a/include/sysemu/accel-ops.h b/include/sysemu/accel-ops.h
index ef91fc28bbd..a0886722305 100644
--- a/include/sysemu/accel-ops.h
+++ b/include/sysemu/accel-ops.h
@@ -20,7 +20,12 @@ 
 typedef struct AccelOpsClass AccelOpsClass;
 DECLARE_CLASS_CHECKERS(AccelOpsClass, ACCEL_OPS, TYPE_ACCEL_OPS)
 
-/* cpus.c operations interface */
+/**
+ * struct AccelOpsClass - accelerator interfaces
+ *
+ * This structure is used to abstract accelerator differences from the
+ * core CPU code. Not all have to be implemented.
+ */
 struct AccelOpsClass {
     /*< private >*/
     ObjectClass parent_class;
@@ -44,7 +49,18 @@  struct AccelOpsClass {
 
     void (*handle_interrupt)(CPUState *cpu, int mask);
 
+    /**
+     * @get_virtual_clock: fetch virtual clock
+     * @set_virtual_clock: set virtual clock
+     *
+     * These allow the timer subsystem to defer to the accelerator to
+     * fetch time. The set function is needed if the accelerator wants
+     * to track the changes to time as the timer is warped through
+     * various timer events.
+     */
     int64_t (*get_virtual_clock)(void);
+    void (*set_virtual_clock)(int64_t time);
+
     int64_t (*get_elapsed_ticks)(void);
 
     /* gdbstub hooks */
diff --git a/include/sysemu/cpu-timers.h b/include/sysemu/cpu-timers.h
index d86738a378d..7bfa960fbd6 100644
--- a/include/sysemu/cpu-timers.h
+++ b/include/sysemu/cpu-timers.h
@@ -96,8 +96,9 @@  int64_t cpu_get_clock(void);
 
 void qemu_timer_notify_cb(void *opaque, QEMUClockType type);
 
-/* get the VIRTUAL clock and VM elapsed ticks via the cpus accel interface */
+/* get/set VIRTUAL clock and VM elapsed ticks via the cpus accel interface */
 int64_t cpus_get_virtual_clock(void);
+void cpus_set_virtual_clock(int64_t new_time);
 int64_t cpus_get_elapsed_ticks(void);
 
 #endif /* SYSEMU_CPU_TIMERS_H */
diff --git a/stubs/cpus-get-virtual-clock.c b/stubs/cpus-virtual-clock.c
similarity index 68%
rename from stubs/cpus-get-virtual-clock.c
rename to stubs/cpus-virtual-clock.c
index fd447d53f3c..af7c1a1d403 100644
--- a/stubs/cpus-get-virtual-clock.c
+++ b/stubs/cpus-virtual-clock.c
@@ -6,3 +6,8 @@  int64_t cpus_get_virtual_clock(void)
 {
     return cpu_get_clock();
 }
+
+void cpus_set_virtual_clock(int64_t new_time)
+{
+    /* do nothing */
+}
diff --git a/system/cpus.c b/system/cpus.c
index 68d161d96b7..03ba026667c 100644
--- a/system/cpus.c
+++ b/system/cpus.c
@@ -229,6 +229,17 @@  int64_t cpus_get_virtual_clock(void)
     return cpu_get_clock();
 }
 
+/*
+ * Signal the new virtual time to the accelerator. This is only needed
+ * by accelerators that need to track the changes as we warp time.
+ */
+void cpus_set_virtual_clock(int64_t new_time)
+{
+    if (cpus_accel && cpus_accel->set_virtual_clock) {
+        cpus_accel->set_virtual_clock(new_time);
+    }
+}
+
 /*
  * return the time elapsed in VM between vm_start and vm_stop.  Unless
  * icount is active, cpus_get_elapsed_ticks() uses units of the host CPU cycle
diff --git a/stubs/meson.build b/stubs/meson.build
index 3b9d42023cb..672213b7482 100644
--- a/stubs/meson.build
+++ b/stubs/meson.build
@@ -3,6 +3,11 @@ 
 # below, so that it is clear who needs the stubbed functionality.
 
 stub_ss.add(files('cpu-get-clock.c'))
+stub_ss.add(files('cpus-virtual-clock.c'))
+stub_ss.add(files('qemu-timer-notify-cb.c'))
+stub_ss.add(files('icount.c'))
+stub_ss.add(files('dump.c'))
+stub_ss.add(files('error-printf.c'))
 stub_ss.add(files('fdset.c'))
 stub_ss.add(files('iothread-lock.c'))
 stub_ss.add(files('is-daemonized.c'))
@@ -28,7 +33,6 @@  endif
 if have_block or have_ga
   stub_ss.add(files('replay-tools.c'))
   # stubs for hooks in util/main-loop.c, util/async.c etc.
-  stub_ss.add(files('cpus-get-virtual-clock.c'))
   stub_ss.add(files('icount.c'))
   stub_ss.add(files('graph-lock.c'))
   if linux_io_uring.found()