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Commit faff8758 authored by Junaid Shahid's avatar Junaid Shahid Committed by Paolo Bonzini
Browse files

kvm: x86: Flush only affected TLB entries in kvm_mmu_invlpg* 



This needs a minor bug fix. The updated patch is as follows.

Thanks,
Junaid

------------------------------------------------------------------------------

kvm_mmu_invlpg() and kvm_mmu_invpcid_gva() only need to flush the TLB
entries for the specific guest virtual address, instead of flushing all
TLB entries associated with the VM.

Signed-off-by: default avatarJunaid Shahid <junaids@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 956bf353

arch/x86/include/asm/kvm_host.h

+8 −0
Original line number Diff line number Diff line
@@ -985,6 +985,14 @@ struct kvm_x86_ops { 


	void (*tlb_flush)(struct kvm_vcpu *vcpu, bool invalidate_gpa);



	/*

	 * Flush any TLB entries associated with the given GVA.

	 * Does not need to flush GPA->HPA mappings.

	 * Can potentially get non-canonical addresses through INVLPGs, which

	 * the implementation may choose to ignore if appropriate.

	 */

	void (*tlb_flush_gva)(struct kvm_vcpu *vcpu, gva_t addr);



	void (*run)(struct kvm_vcpu *vcpu);

	int (*handle_exit)(struct kvm_vcpu *vcpu);

	void (*skip_emulated_instruction)(struct kvm_vcpu *vcpu);

arch/x86/kvm/mmu.c

+11 −3
Original line number Diff line number Diff line
@@ -5226,6 +5226,10 @@ void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 
{

	struct kvm_mmu *mmu = &vcpu->arch.mmu;



	/* INVLPG on a * non-canonical address is a NOP according to the SDM.  */

	if (is_noncanonical_address(gva, vcpu))

		return;



	mmu->invlpg(vcpu, gva, mmu->root_hpa);



	/*
@@ -5242,7 +5246,7 @@ void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) 
	if (VALID_PAGE(mmu->prev_root.hpa))

		mmu->invlpg(vcpu, gva, mmu->prev_root.hpa);



	kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);

	kvm_x86_ops->tlb_flush_gva(vcpu, gva);

	++vcpu->stat.invlpg;

}

EXPORT_SYMBOL_GPL(kvm_mmu_invlpg);
@@ -5250,18 +5254,22 @@ EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); 
void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid)

{

	struct kvm_mmu *mmu = &vcpu->arch.mmu;

	bool tlb_flush = false;



	if (pcid == kvm_get_active_pcid(vcpu)) {

		mmu->invlpg(vcpu, gva, mmu->root_hpa);

		kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);

		tlb_flush = true;

	}



	if (VALID_PAGE(mmu->prev_root.hpa) &&

	    pcid == kvm_get_pcid(vcpu, mmu->prev_root.cr3)) {

		mmu->invlpg(vcpu, gva, mmu->prev_root.hpa);

		kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);

		tlb_flush = true;

	}



	if (tlb_flush)

		kvm_x86_ops->tlb_flush_gva(vcpu, gva);



	++vcpu->stat.invlpg;



	/*

arch/x86/kvm/svm.c

+8 −0
Original line number Diff line number Diff line
@@ -5434,6 +5434,13 @@ static void svm_flush_tlb(struct kvm_vcpu *vcpu, bool invalidate_gpa) 
		svm->asid_generation--;

}



static void svm_flush_tlb_gva(struct kvm_vcpu *vcpu, gva_t gva)

{

	struct vcpu_svm *svm = to_svm(vcpu);



	invlpga(gva, svm->vmcb->control.asid);

}



static void svm_prepare_guest_switch(struct kvm_vcpu *vcpu)

{

}
@@ -7086,6 +7093,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = { 
	.set_rflags = svm_set_rflags,



	.tlb_flush = svm_flush_tlb,

	.tlb_flush_gva = svm_flush_tlb_gva,



	.run = svm_vcpu_run,

	.handle_exit = handle_exit,

arch/x86/kvm/vmx.c

+28 −0
Original line number Diff line number Diff line
@@ -1992,6 +1992,19 @@ static void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs) 
			 __loaded_vmcs_clear, loaded_vmcs, 1);

}



static inline bool vpid_sync_vcpu_addr(int vpid, gva_t addr)

{

	if (vpid == 0)

		return true;



	if (cpu_has_vmx_invvpid_individual_addr()) {

		__invvpid(VMX_VPID_EXTENT_INDIVIDUAL_ADDR, vpid, addr);

		return true;

	}



	return false;

}



static inline void vpid_sync_vcpu_single(int vpid)

{

	if (vpid == 0)
@@ -4833,6 +4846,20 @@ static void vmx_flush_tlb(struct kvm_vcpu *vcpu, bool invalidate_gpa) 
	__vmx_flush_tlb(vcpu, to_vmx(vcpu)->vpid, invalidate_gpa);

}



static void vmx_flush_tlb_gva(struct kvm_vcpu *vcpu, gva_t addr)

{

	int vpid = to_vmx(vcpu)->vpid;



	if (!vpid_sync_vcpu_addr(vpid, addr))

		vpid_sync_context(vpid);



	/*

	 * If VPIDs are not supported or enabled, then the above is a no-op.

	 * But we don't really need a TLB flush in that case anyway, because

	 * each VM entry/exit includes an implicit flush when VPID is 0.

	 */

}



static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu)

{

	ulong cr0_guest_owned_bits = vcpu->arch.cr0_guest_owned_bits;
@@ -13603,6 +13630,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = { 
	.set_rflags = vmx_set_rflags,



	.tlb_flush = vmx_flush_tlb,

	.tlb_flush_gva = vmx_flush_tlb_gva,



	.run = vmx_vcpu_run,

	.handle_exit = vmx_handle_exit,