On Mon, Feb 24, 2025 at 03:55:39PM -0800, Sean Christopherson wrote:
> Don't load (and then put) a vCPU when unloading its MMU during VM
> destruction, as nothing in kvm_mmu_unload() accesses vCPU state beyond the
> root page/address of each MMU, i.e. can't possible need to run with the
> vCPU loaded.
>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
> arch/x86/kvm/x86.c | 9 +--------
> 1 file changed, 1 insertion(+), 8 deletions(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 045c61cc7e54..9978ed4c0917 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -12767,13 +12767,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
> return ret;
> }
>
> -static void kvm_unload_vcpu_mmu(struct kvm_vcpu *vcpu)
> -{
> - vcpu_load(vcpu);
> - kvm_mmu_unload(vcpu);
> - vcpu_put(vcpu);
> -}
> -
> static void kvm_unload_vcpu_mmus(struct kvm *kvm)
> {
> unsigned long i;
> @@ -12781,7 +12774,7 @@ static void kvm_unload_vcpu_mmus(struct kvm *kvm)
>
> kvm_for_each_vcpu(i, vcpu, kvm) {
> kvm_clear_async_pf_completion_queue(vcpu);
> - kvm_unload_vcpu_mmu(vcpu);
> + kvm_mmu_unload(vcpu);
What about just dropping kvm_unload_vcpu_mmu() here?
kvm_mmu_unload() will be invoked again in kvm_mmu_destroy().
kvm_arch_vcpu_destroy() --> kvm_mmu_destroy() --> kvm_mmu_unload().
> }
> }
>
> --
> 2.48.1.658.g4767266eb4-goog
>
