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authorTianyu Lan <Tianyu.Lan@microsoft.com>2018-07-19 08:40:17 +0000
committerPaolo Bonzini <pbonzini@redhat.com>2018-08-06 17:59:06 +0200
commitb08660e59dbdb600c55953787ed2265a0b510f77 (patch)
tree3016620245ab6babe9c65babdcff9730f2578072
parent60cfce4c4f6f6741882032ee6f895e835533a16b (diff)
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KVM: x86: Add tlb remote flush callback in kvm_x86_ops.
This patch is to provide a way for platforms to register hv tlb remote flush callback and this helps to optimize operation of tlb flush among vcpus for nested virtualization case. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/include/asm/kvm_host.h11
-rw-r--r--include/linux/kvm_host.h7
-rw-r--r--virt/kvm/kvm_main.c3
3 files changed, 20 insertions, 1 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 75ab578c3f6a..150937e64f63 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -985,6 +985,7 @@ struct kvm_x86_ops {
void (*set_rflags)(struct kvm_vcpu *vcpu, unsigned long rflags);
void (*tlb_flush)(struct kvm_vcpu *vcpu, bool invalidate_gpa);
+ int (*tlb_remote_flush)(struct kvm *kvm);
/*
* Flush any TLB entries associated with the given GVA.
@@ -1145,6 +1146,16 @@ static inline void kvm_arch_free_vm(struct kvm *kvm)
return kvm_x86_ops->vm_free(kvm);
}
+#define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLB
+static inline int kvm_arch_flush_remote_tlb(struct kvm *kvm)
+{
+ if (kvm_x86_ops->tlb_remote_flush &&
+ !kvm_x86_ops->tlb_remote_flush(kvm))
+ return 0;
+ else
+ return -ENOTSUPP;
+}
+
int kvm_mmu_module_init(void);
void kvm_mmu_module_exit(void);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 2840ac74a3d7..7c7362dd2faa 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -834,6 +834,13 @@ static inline void kvm_arch_free_vm(struct kvm *kvm)
}
#endif
+#ifndef __KVM_HAVE_ARCH_FLUSH_REMOTE_TLB
+static inline int kvm_arch_flush_remote_tlb(struct kvm *kvm)
+{
+ return -ENOTSUPP;
+}
+#endif
+
#ifdef __KVM_HAVE_ARCH_NONCOHERENT_DMA
void kvm_arch_register_noncoherent_dma(struct kvm *kvm);
void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 8f461e0ed382..74544d20bbf8 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -273,7 +273,8 @@ void kvm_flush_remote_tlbs(struct kvm *kvm)
* kvm_make_all_cpus_request() reads vcpu->mode. We reuse that
* barrier here.
*/
- if (kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
+ if (!kvm_arch_flush_remote_tlb(kvm)
+ || kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
++kvm->stat.remote_tlb_flush;
cmpxchg(&kvm->tlbs_dirty, dirty_count, 0);
}