Commit 83b20b28 authored Sep 07, 2018 by Wei Yang Committed by Paolo Bonzini Sep 20, 2018

KVM: x86: don't reset root in kvm_mmu_setup()



Here is the code path which shows kvm_mmu_setup() is invoked after
kvm_mmu_create(). Since kvm_mmu_setup() is only invoked in this code path,
this means the root_hpa and prev_roots are guaranteed to be invalid. And
it is not necessary to reset it again.

    kvm_vm_ioctl_create_vcpu()
        kvm_arch_vcpu_create()
            vmx_create_vcpu()
                kvm_vcpu_init()
                    kvm_arch_vcpu_init()
                        kvm_mmu_create()
        kvm_arch_vcpu_setup()
            kvm_mmu_setup()
                kvm_init_mmu()

This patch set reset_roots to false in kmv_mmu_setup().

Fixes: 50c28f21
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent d35b34a9

arch/x86/kvm/mmu.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -5417,7 +5417,12 @@ void kvm_mmu_setup(struct kvm_vcpu *vcpu)
		{
		MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu.root_hpa));

		kvm_init_mmu(vcpu, true);
		/*
		* kvm_mmu_setup() is called only on vCPU initialization.
		* Therefore, no need to reset mmu roots as they are not yet
		* initialized.
		*/
		kvm_init_mmu(vcpu, false);
		}

		static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm,