[PATCH v3 2/7] x86/kvm: Move haltpoll_want() to be arch defined

From: Mihai Carabas
Date: Mon Jan 29 2024 - 06:58:09 EST


From: Joao Martins <joao.m.martins@xxxxxxxxxx>

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 <joao.m.martins@xxxxxxxxxx>
Signed-off-by: Ankur Arora <ankur.a.arora@xxxxxxxxxx>
Signed-off-by: Mihai Carabas <mihai.carabas@xxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael@xxxxxxxxxx>
---
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 b8ab9ee5896c..2ba12da13fc1 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -1149,4 +1149,14 @@ 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