2023-11-20 15:16:59

by Mihai Carabas

[permalink] [raw]
Subject: [PATCH 2/7] x86/kvm: Move haltpoll_want() to be arch defined

From: Joao Martins <[email protected]>

Right now, kvm_para_has_hint(KVM_HINTS_REALTIME) is x86 only, and so in the
pursuit of making cpuidle-haltpoll arch independent, move the check for
haltpoll enablement to be defined per architecture. Same thing for
boot_option_idle_override. To that end, add a arch_haltpoll_want() and move the
check there.

Signed-off-by: Joao Martins <[email protected]>
Signed-off-by: Ankur Arora <[email protected]>
Signed-off-by: Mihai Carabas <[email protected]>
---
arch/x86/include/asm/cpuidle_haltpoll.h | 1 +
arch/x86/kernel/kvm.c | 10 ++++++++++
drivers/cpuidle/cpuidle-haltpoll.c | 8 ++------
include/linux/cpuidle_haltpoll.h | 5 +++++
4 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/cpuidle_haltpoll.h b/arch/x86/include/asm/cpuidle_haltpoll.h
index c8b39c6716ff..2c5a53ce266f 100644
--- a/arch/x86/include/asm/cpuidle_haltpoll.h
+++ b/arch/x86/include/asm/cpuidle_haltpoll.h
@@ -4,5 +4,6 @@

void arch_haltpoll_enable(unsigned int cpu);
void arch_haltpoll_disable(unsigned int cpu);
+bool arch_haltpoll_want(void);

#endif
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 1cceac5984da..75a24f107b2a 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -1151,4 +1151,14 @@ void arch_haltpoll_disable(unsigned int cpu)
smp_call_function_single(cpu, kvm_enable_host_haltpoll, NULL, 1);
}
EXPORT_SYMBOL_GPL(arch_haltpoll_disable);
+
+bool arch_haltpoll_want(void)
+{
+ /* Do not load haltpoll if idle= is passed */
+ if (boot_option_idle_override != IDLE_NO_OVERRIDE)
+ return false;
+
+ return kvm_para_has_hint(KVM_HINTS_REALTIME);
+}
+EXPORT_SYMBOL_GPL(arch_haltpoll_want);
#endif
diff --git a/drivers/cpuidle/cpuidle-haltpoll.c b/drivers/cpuidle/cpuidle-haltpoll.c
index e66df22f9695..72f9c84990c5 100644
--- a/drivers/cpuidle/cpuidle-haltpoll.c
+++ b/drivers/cpuidle/cpuidle-haltpoll.c
@@ -96,7 +96,7 @@ static void haltpoll_uninit(void)

static bool haltpoll_want(void)
{
- return kvm_para_has_hint(KVM_HINTS_REALTIME) || force;
+ return (kvm_para_available() && arch_haltpoll_want()) || force;
}

static int __init haltpoll_init(void)
@@ -104,11 +104,7 @@ static int __init haltpoll_init(void)
int ret;
struct cpuidle_driver *drv = &haltpoll_driver;

- /* Do not load haltpoll if idle= is passed */
- if (boot_option_idle_override != IDLE_NO_OVERRIDE)
- return -ENODEV;
-
- if (!kvm_para_available() || !haltpoll_want())
+ if (!haltpoll_want())
return -ENODEV;

cpuidle_poll_state_init(drv);
diff --git a/include/linux/cpuidle_haltpoll.h b/include/linux/cpuidle_haltpoll.h
index d50c1e0411a2..bae68a6603e3 100644
--- a/include/linux/cpuidle_haltpoll.h
+++ b/include/linux/cpuidle_haltpoll.h
@@ -12,5 +12,10 @@ static inline void arch_haltpoll_enable(unsigned int cpu)
static inline void arch_haltpoll_disable(unsigned int cpu)
{
}
+
+static inline bool arch_haltpoll_want(void)
+{
+ return false;
+}
#endif
#endif
--
1.8.3.1


2023-11-29 20:56:00

by Rafael J. Wysocki

[permalink] [raw]
Subject: Re: [PATCH 2/7] x86/kvm: Move haltpoll_want() to be arch defined

On Mon, Nov 20, 2023 at 4:15 PM Mihai Carabas <[email protected]> wrote:
>
> From: Joao Martins <[email protected]>
>
> Right now, kvm_para_has_hint(KVM_HINTS_REALTIME) is x86 only, and so in the
> pursuit of making cpuidle-haltpoll arch independent, move the check for
> haltpoll enablement to be defined per architecture. Same thing for
> boot_option_idle_override. To that end, add a arch_haltpoll_want() and move the
> check there.
>
> Signed-off-by: Joao Martins <[email protected]>
> Signed-off-by: Ankur Arora <[email protected]>
> Signed-off-by: Mihai Carabas <[email protected]>

From the cpuidle side:

Acked-by: Rafael J. Wysocki <[email protected]>

> ---
> arch/x86/include/asm/cpuidle_haltpoll.h | 1 +
> arch/x86/kernel/kvm.c | 10 ++++++++++
> drivers/cpuidle/cpuidle-haltpoll.c | 8 ++------
> include/linux/cpuidle_haltpoll.h | 5 +++++
> 4 files changed, 18 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/include/asm/cpuidle_haltpoll.h b/arch/x86/include/asm/cpuidle_haltpoll.h
> index c8b39c6716ff..2c5a53ce266f 100644
> --- a/arch/x86/include/asm/cpuidle_haltpoll.h
> +++ b/arch/x86/include/asm/cpuidle_haltpoll.h
> @@ -4,5 +4,6 @@
>
> void arch_haltpoll_enable(unsigned int cpu);
> void arch_haltpoll_disable(unsigned int cpu);
> +bool arch_haltpoll_want(void);
>
> #endif
> diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
> index 1cceac5984da..75a24f107b2a 100644
> --- a/arch/x86/kernel/kvm.c
> +++ b/arch/x86/kernel/kvm.c
> @@ -1151,4 +1151,14 @@ void arch_haltpoll_disable(unsigned int cpu)
> smp_call_function_single(cpu, kvm_enable_host_haltpoll, NULL, 1);
> }
> EXPORT_SYMBOL_GPL(arch_haltpoll_disable);
> +
> +bool arch_haltpoll_want(void)
> +{
> + /* Do not load haltpoll if idle= is passed */
> + if (boot_option_idle_override != IDLE_NO_OVERRIDE)
> + return false;
> +
> + return kvm_para_has_hint(KVM_HINTS_REALTIME);
> +}
> +EXPORT_SYMBOL_GPL(arch_haltpoll_want);
> #endif
> diff --git a/drivers/cpuidle/cpuidle-haltpoll.c b/drivers/cpuidle/cpuidle-haltpoll.c
> index e66df22f9695..72f9c84990c5 100644
> --- a/drivers/cpuidle/cpuidle-haltpoll.c
> +++ b/drivers/cpuidle/cpuidle-haltpoll.c
> @@ -96,7 +96,7 @@ static void haltpoll_uninit(void)
>
> static bool haltpoll_want(void)
> {
> - return kvm_para_has_hint(KVM_HINTS_REALTIME) || force;
> + return (kvm_para_available() && arch_haltpoll_want()) || force;
> }
>
> static int __init haltpoll_init(void)
> @@ -104,11 +104,7 @@ static int __init haltpoll_init(void)
> int ret;
> struct cpuidle_driver *drv = &haltpoll_driver;
>
> - /* Do not load haltpoll if idle= is passed */
> - if (boot_option_idle_override != IDLE_NO_OVERRIDE)
> - return -ENODEV;
> -
> - if (!kvm_para_available() || !haltpoll_want())
> + if (!haltpoll_want())
> return -ENODEV;
>
> cpuidle_poll_state_init(drv);
> diff --git a/include/linux/cpuidle_haltpoll.h b/include/linux/cpuidle_haltpoll.h
> index d50c1e0411a2..bae68a6603e3 100644
> --- a/include/linux/cpuidle_haltpoll.h
> +++ b/include/linux/cpuidle_haltpoll.h
> @@ -12,5 +12,10 @@ static inline void arch_haltpoll_enable(unsigned int cpu)
> static inline void arch_haltpoll_disable(unsigned int cpu)
> {
> }
> +
> +static inline bool arch_haltpoll_want(void)
> +{
> + return false;
> +}
> #endif
> #endif
> --
> 1.8.3.1
>