linux-kernel - [PATCH 3/7] x86/kvm: Move haltpoll

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Message-Id: <1691581193-8416-4-git-send-email-mihai.carabas@oracle.com>
Date:   Wed,  9 Aug 2023 14:39:37 +0300
From:   Mihai Carabas <mihai.carabas@...cle.com>
To:     unlisted-recipients:; (no To-header on input)
Cc:     Joao Martins <joao.m.martins@...cle.com>,
        Ankur Arora <ankur.a.arora@...cle.com>,
        Mihai Carabas <mihai.carabas@...cle.com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
        "H. Peter Anvin" <hpa@...or.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Kees Cook <keescook@...omium.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Petr Mladek <pmladek@...e.com>,
        Ard Biesheuvel <ardb@...nel.org>,
        Sami Tolvanen <samitolvanen@...gle.com>,
        Nicholas Piggin <npiggin@...il.com>,
        Juerg Haefliger <juerg.haefliger@...onical.com>,
        Mickaël Salaün <mic@...ikod.net>,
        Arnd Bergmann <arnd@...db.de>, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, kvm@...r.kernel.org,
        linux-pm@...r.kernel.org
Subject: [PATCH 3/7] x86/kvm: Move haltpoll_want() to be arch defined

From: Joao Martins <joao.m.martins@...cle.com>

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. To that end, add
a arch_haltpoll_want() and move the check there.

Signed-off-by: Joao Martins <joao.m.martins@...cle.com>
Signed-off-by: Ankur Arora <ankur.a.arora@...cle.com>
Signed-off-by: Mihai Carabas <mihai.carabas@...cle.com>
---
 arch/x86/include/asm/cpuidle_haltpoll.h | 1 +
 arch/x86/kernel/kvm.c                   | 6 ++++++
 drivers/cpuidle/cpuidle-haltpoll.c      | 4 ++--
 include/linux/cpuidle_haltpoll.h        | 5 +++++
 4 files changed, 14 insertions(+), 2 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..817594cbda11 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -1151,4 +1151,10 @@ 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)
+{
+	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 0ca3c8422eb6..e2d4d78744ae 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)
@@ -110,7 +110,7 @@ static int __init haltpoll_init(void)
 		return -ENODEV;
 #endif
 
-	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