Commit b08660e5 authored by Tianyu Lan's avatar Tianyu Lan Committed by Paolo Bonzini
Browse files

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: default avatarLan Tianyu <Tianyu.Lan@microsoft.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 60cfce4c

arch/x86/include/asm/kvm_host.h

+11 −0
Original line number Diff line number Diff line
@@ -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);

include/linux/kvm_host.h

+7 −0
Original line number Diff line number Diff line
@@ -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);

virt/kvm/kvm_main.c

+2 −1
Original line number Diff line number Diff line
@@ -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);

}