Commit afe828d1 authored by Junaid Shahid's avatar Junaid Shahid Committed by Paolo Bonzini
Browse files

kvm: x86: Add ability to skip TLB flush when switching CR3 



Remove the implicit flush from the set_cr3 handlers, so that the
callers are able to decide whether to flush the TLB or not.

Signed-off-by: default avatarJunaid Shahid <junaids@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 50c28f21

arch/x86/kvm/mmu.c

+2 −0
Original line number Diff line number Diff line
@@ -4070,6 +4070,7 @@ static bool fast_cr3_switch(struct kvm_vcpu *vcpu, gpa_t new_cr3, 


			kvm_make_request(KVM_REQ_LOAD_CR3, vcpu);

			kvm_make_request(KVM_REQ_MMU_SYNC, vcpu);

			kvm_x86_ops->tlb_flush(vcpu, true);

			__clear_sp_write_flooding_count(

				page_header(mmu->root_hpa));
@@ -4851,6 +4852,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu) 
	if (r)

		goto out;

	kvm_mmu_load_cr3(vcpu);

	kvm_x86_ops->tlb_flush(vcpu, true);

out:

	return r;

}

arch/x86/kvm/mmu.h

+0 −1
Original line number Diff line number Diff line
@@ -88,7 +88,6 @@ static inline int kvm_mmu_reload(struct kvm_vcpu *vcpu) 


static inline void kvm_mmu_load_cr3(struct kvm_vcpu *vcpu)

{

	/* set_cr3() should ensure TLB has been flushed */

	if (VALID_PAGE(vcpu->arch.mmu.root_hpa))

		vcpu->arch.mmu.set_cr3(vcpu, vcpu->arch.mmu.root_hpa);

}

arch/x86/kvm/svm.c

+0 −4
Original line number Diff line number Diff line
@@ -2884,7 +2884,6 @@ static void nested_svm_set_tdp_cr3(struct kvm_vcpu *vcpu, 


	svm->vmcb->control.nested_cr3 = __sme_set(root);

	mark_dirty(svm->vmcb, VMCB_NPT);

	svm_flush_tlb(vcpu, true);

}



static void nested_svm_inject_npf_exit(struct kvm_vcpu *vcpu,
@@ -5766,7 +5765,6 @@ static void svm_set_cr3(struct kvm_vcpu *vcpu, unsigned long root) 


	svm->vmcb->save.cr3 = __sme_set(root);

	mark_dirty(svm->vmcb, VMCB_CR);

	svm_flush_tlb(vcpu, true);

}



static void set_tdp_cr3(struct kvm_vcpu *vcpu, unsigned long root)
@@ -5779,8 +5777,6 @@ static void set_tdp_cr3(struct kvm_vcpu *vcpu, unsigned long root) 
	/* Also sync guest cr3 here in case we live migrate */

	svm->vmcb->save.cr3 = kvm_read_cr3(vcpu);

	mark_dirty(svm->vmcb, VMCB_CR);



	svm_flush_tlb(vcpu, true);

}



static int is_disabled(void)

arch/x86/kvm/vmx.c

+0 −1
Original line number Diff line number Diff line
@@ -5029,7 +5029,6 @@ static void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) 
		ept_load_pdptrs(vcpu);

	}



	vmx_flush_tlb(vcpu, true);

	vmcs_writel(GUEST_CR3, guest_cr3);

}