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authorZheyun Shen <szy0127@sjtu.edu.cn>2025-05-22 16:37:28 -0700
committerBorislav Petkov (AMD) <bp@alien8.de>2025-07-10 13:30:17 +0200
commit4fdc3431e03b9c11803f399f91837fca487029a1 (patch)
tree2ba967143c85a0e076f974a5945c11c9fc07806e
parent07f99c3fbe6e322bdb222fbfd59f708ced799cc5 (diff)
x86/lib: Add WBINVD and WBNOINVD helpers to target multiple CPUs
Extract KVM's open-coded calls to do writeback caches on multiple CPUs to common library helpers for both WBINVD and WBNOINVD (KVM will use both). Put the onus on the caller to check for a non-empty mask to simplify the SMP=n implementation, e.g. so that it doesn't need to check that the one and only CPU in the system is present in the mask. [sean: move to lib, add SMP=n helpers, clarify usage] Signed-off-by: Zheyun Shen <szy0127@sjtu.edu.cn> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Acked-by: Kai Huang <kai.huang@intel.com> Link: https://lore.kernel.org/r/20250128015345.7929-2-szy0127@sjtu.edu.cn Link: https://lore.kernel.org/20250522233733.3176144-5-seanjc@google.com
-rw-r--r--arch/x86/include/asm/smp.h12
-rw-r--r--arch/x86/kvm/x86.c3
-rw-r--r--arch/x86/lib/cache-smp.c12
3 files changed, 25 insertions, 2 deletions
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index e08f1ae25401..22bfebe6776d 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -113,7 +113,9 @@ void native_play_dead(void);
void play_dead_common(void);
void wbinvd_on_cpu(int cpu);
void wbinvd_on_all_cpus(void);
+void wbinvd_on_cpus_mask(struct cpumask *cpus);
void wbnoinvd_on_all_cpus(void);
+void wbnoinvd_on_cpus_mask(struct cpumask *cpus);
void smp_kick_mwait_play_dead(void);
void __noreturn mwait_play_dead(unsigned int eax_hint);
@@ -154,11 +156,21 @@ static inline void wbinvd_on_all_cpus(void)
wbinvd();
}
+static inline void wbinvd_on_cpus_mask(struct cpumask *cpus)
+{
+ wbinvd();
+}
+
static inline void wbnoinvd_on_all_cpus(void)
{
wbnoinvd();
}
+static inline void wbnoinvd_on_cpus_mask(struct cpumask *cpus)
+{
+ wbnoinvd();
+}
+
static inline struct cpumask *cpu_llc_shared_mask(int cpu)
{
return (struct cpumask *)cpumask_of(0);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a9d992d5652f..5a2160f449e0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8289,8 +8289,7 @@ static int kvm_emulate_wbinvd_noskip(struct kvm_vcpu *vcpu)
int cpu = get_cpu();
cpumask_set_cpu(cpu, vcpu->arch.wbinvd_dirty_mask);
- on_each_cpu_mask(vcpu->arch.wbinvd_dirty_mask,
- wbinvd_ipi, NULL, 1);
+ wbinvd_on_cpus_mask(vcpu->arch.wbinvd_dirty_mask);
put_cpu();
cpumask_clear(vcpu->arch.wbinvd_dirty_mask);
} else
diff --git a/arch/x86/lib/cache-smp.c b/arch/x86/lib/cache-smp.c
index 74e0d5ba867d..c5c60d07308c 100644
--- a/arch/x86/lib/cache-smp.c
+++ b/arch/x86/lib/cache-smp.c
@@ -20,6 +20,12 @@ void wbinvd_on_all_cpus(void)
}
EXPORT_SYMBOL(wbinvd_on_all_cpus);
+void wbinvd_on_cpus_mask(struct cpumask *cpus)
+{
+ on_each_cpu_mask(cpus, __wbinvd, NULL, 1);
+}
+EXPORT_SYMBOL_GPL(wbinvd_on_cpus_mask);
+
static void __wbnoinvd(void *dummy)
{
wbnoinvd();
@@ -30,3 +36,9 @@ void wbnoinvd_on_all_cpus(void)
on_each_cpu(__wbnoinvd, NULL, 1);
}
EXPORT_SYMBOL_GPL(wbnoinvd_on_all_cpus);
+
+void wbnoinvd_on_cpus_mask(struct cpumask *cpus)
+{
+ on_each_cpu_mask(cpus, __wbnoinvd, NULL, 1);
+}
+EXPORT_SYMBOL_GPL(wbnoinvd_on_cpus_mask);