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authorLongpeng(Mike) <longpeng2@huawei.com>2017-08-08 12:05:32 +0800
committerPaolo Bonzini <pbonzini@redhat.com>2017-08-08 10:57:43 +0200
commit199b5763d329b43c88f6ad539db8a6c6b42f8edb (patch)
tree224f4ebeb9e58c43ea1916e63e813452f81dd45a /arch/mips/kvm
parent1b4d56b86a370a3785a33eba23e2e3009f5a03af (diff)
downloadlinux-199b5763d329b43c88f6ad539db8a6c6b42f8edb.tar.bz2
KVM: add spinlock optimization framework
If a vcpu exits due to request a user mode spinlock, then the spinlock-holder may be preempted in user mode or kernel mode. (Note that not all architectures trap spin loops in user mode, only AMD x86 and ARM/ARM64 currently do). But if a vcpu exits in kernel mode, then the holder must be preempted in kernel mode, so we should choose a vcpu in kernel mode as a more likely candidate for the lock holder. This introduces kvm_arch_vcpu_in_kernel() to decide whether the vcpu is in kernel-mode when it's preempted. kvm_vcpu_on_spin's new argument says the same of the spinning VCPU. Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/mips/kvm')
-rw-r--r--arch/mips/kvm/mips.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index d4b2ad18eef2..bce2a6431430 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -98,6 +98,11 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
return !!(vcpu->arch.pending_exceptions);
}
+bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
+{
+ return false;
+}
+
int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
{
return 1;