From: "Philippe Mathieu-Daudé" <f4bug@amsat.org>
To: Claudio Fontana <cfontana@suse.de>, qemu-devel@nongnu.org
Cc: Peter Maydell <peter.maydell@linaro.org>,
Thomas Huth <thuth@redhat.com>,
qemu-riscv@nongnu.org, Eduardo Habkost <ehabkost@redhat.com>,
David Hildenbrand <david@redhat.com>,
Cornelia Huck <cohuck@redhat.com>,
Richard Henderson <richard.henderson@linaro.org>,
Laurent Vivier <laurent@vivier.eu>, Greg Kurz <groug@kaod.org>,
qemu-s390x@nongnu.org, qemu-arm@nongnu.org, qemu-ppc@nongnu.org,
Paolo Bonzini <pbonzini@redhat.com>,
David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [RFC PATCH v2 6/8] cpu: Declare cpu_has_work() in 'sysemu/tcg.h'
Date: Mon, 8 Mar 2021 14:37:19 +0100 [thread overview]
Message-ID: <a034fce7-57bb-09fb-fda6-058b14e1b3c1@amsat.org> (raw)
In-Reply-To: <ddd0572a-bba2-62ac-27b8-4a7d04257695@suse.de>
On 3/8/21 1:17 PM, Claudio Fontana wrote:
> On 3/4/21 11:23 PM, Philippe Mathieu-Daudé wrote:
>> We can only check if a vCPU has work with TCG.
>> Move the cpu_has_work() prototype to "sysemu/tcg.h".
>>
>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>> ---
>> RFC: could another accelerator do that?
>> can we rename this tcg_vcpu_has_work()?
>> ---
>> include/hw/core/cpu.h | 16 ----------------
>> include/sysemu/tcg.h | 11 +++++++++++
>> accel/tcg/cpu-exec.c | 7 +++++++
>> softmmu/cpus.c | 1 +
>> 4 files changed, 19 insertions(+), 16 deletions(-)
>>
>> diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
>> index 1376e496a3f..66109bcca35 100644
>> --- a/include/hw/core/cpu.h
>> +++ b/include/hw/core/cpu.h
>> @@ -670,22 +670,6 @@ CPUState *cpu_create(const char *typename);
>> */
>> const char *parse_cpu_option(const char *cpu_option);
>>
>> -/**
>> - * cpu_has_work:
>> - * @cpu: The vCPU to check.
>> - *
>> - * Checks whether the CPU has work to do.
>> - *
>> - * Returns: %true if the CPU has work, %false otherwise.
>> - */
>> -static inline bool cpu_has_work(CPUState *cpu)
>> -{
>> - CPUClass *cc = CPU_GET_CLASS(cpu);
>> -
>> - g_assert(cc->has_work);
>> - return cc->has_work(cpu);
>> -}
>> -
>> /**
>> * qemu_cpu_is_self:
>> * @cpu: The vCPU to check against.
>> diff --git a/include/sysemu/tcg.h b/include/sysemu/tcg.h
>> index c16c13c3c69..3d46b0a7a93 100644
>> --- a/include/sysemu/tcg.h
>> +++ b/include/sysemu/tcg.h
>> @@ -10,6 +10,7 @@
>>
>> #ifndef CONFIG_TCG
>> #define tcg_enabled() 0
>> +#define cpu_has_work(cpu) false
>
> email errors, so not sure if my previous message went off.
Yes, got it.
>
> I am not convinced by this approach of _hiding_ the fact that cpu_has_work is TCG-only from the context where it is used.
>
> When reading the actual code using this, how to get an immediate clue that this is TCG-only?
>
> I think cpu_has_work should either be renamed to tcg_cpu_has_work(), thus providing the context in the name,
> or it should not be visible/called for non-TCG at all, its call protected in some way (if (tcg_enabled() or ifdef or such..)
If no other accelerator can do that, then I agree. I don't know enough
all accelerators to be sure.
>
> Ciao,
>
> Claudio
>
>
>> #else
>>
>> void tcg_exec_init(unsigned long tb_size, int splitwx);
>> @@ -26,6 +27,16 @@ extern bool tcg_allowed;
>> extern bool mttcg_enabled;
>> #define qemu_tcg_mttcg_enabled() (mttcg_enabled)
>>
>> +/**
>> + * cpu_has_work:
>> + * @cpu: The vCPU to check.
>> + *
>> + * Checks whether the CPU has work to do.
>> + *
>> + * Returns: %true if the CPU has work, %false otherwise.
>> + */
>> +bool cpu_has_work(CPUState *cpu);
>> +
>> #endif /* CONFIG_TCG */
>>
>> #endif
>> diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
>> index 7e67ade35b9..b9ce36e59e2 100644
>> --- a/accel/tcg/cpu-exec.c
>> +++ b/accel/tcg/cpu-exec.c
>> @@ -447,6 +447,13 @@ static inline TranslationBlock *tb_find(CPUState *cpu,
>> return tb;
>> }
>>
>> +bool cpu_has_work(CPUState *cpu)
>> +{
>> + CPUClass *cc = CPU_GET_CLASS(cpu);
>> +
>> + return cc->has_work(cpu);
>> +}
>> +
>> static inline bool cpu_handle_halt(CPUState *cpu)
>> {
>> if (cpu->halted) {
>> diff --git a/softmmu/cpus.c b/softmmu/cpus.c
>> index a7ee431187a..548ab9236f1 100644
>> --- a/softmmu/cpus.c
>> +++ b/softmmu/cpus.c
>> @@ -42,6 +42,7 @@
>> #include "sysemu/runstate.h"
>> #include "sysemu/cpu-timers.h"
>> #include "sysemu/whpx.h"
>> +#include "sysemu/tcg.h"
>> #include "hw/boards.h"
>> #include "hw/hw.h"
>>
>>
>
>
next prev parent reply other threads:[~2021-03-08 14:13 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-04 22:23 [RFC PATCH v2 0/8] cpu: Move CPUClass::has_work() to TCGCPUOps Philippe Mathieu-Daudé
2021-03-04 22:23 ` [RFC PATCH v2 1/8] sysemu/tcg: Restrict tcg_exec_init() to CONFIG_TCG Philippe Mathieu-Daudé
2021-03-08 13:40 ` David Hildenbrand
2021-03-08 14:50 ` Claudio Fontana
2021-03-04 22:23 ` [RFC PATCH v2 2/8] sysemu/tcg: Restrict qemu_tcg_mttcg_enabled() to TCG Philippe Mathieu-Daudé
2021-03-08 14:52 ` Claudio Fontana
2021-03-04 22:23 ` [RFC PATCH v2 3/8] target/arm: Directly use arm_cpu_has_work instead of CPUClass::has_work Philippe Mathieu-Daudé
2021-03-08 14:53 ` Claudio Fontana
2021-03-04 22:23 ` [RFC PATCH v2 4/8] target/s390x: Move s390_cpu_has_work to excp_helper.c Philippe Mathieu-Daudé
2021-03-04 22:23 ` [RFC PATCH v2 5/8] target/ppc: Duplicate the TCGCPUOps structure for POWER CPUs Philippe Mathieu-Daudé
2021-03-05 1:05 ` David Gibson
2021-03-04 22:23 ` [RFC PATCH v2 6/8] cpu: Declare cpu_has_work() in 'sysemu/tcg.h' Philippe Mathieu-Daudé
2021-03-08 12:13 ` Claudio Fontana
2021-03-08 12:17 ` Claudio Fontana
2021-03-08 13:37 ` Philippe Mathieu-Daudé [this message]
2021-03-04 22:23 ` [RFC PATCH v2 7/8] cpu: Move CPUClass::has_work() to TCGCPUOps Philippe Mathieu-Daudé
2021-03-05 1:05 ` David Gibson
2021-03-04 22:23 ` [RFC PATCH v2 8/8] target/arm: Restrict arm_cpu_has_work() to TCG Philippe Mathieu-Daudé
2021-03-13 23:55 ` [RFC PATCH v2 0/8] cpu: Move CPUClass::has_work() to TCGCPUOps Philippe Mathieu-Daudé
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