Re: [PATCH V2 02/10] KVM: X86: Synchronize the shadow pagetable before link it

[Paolo Bonzini <pbonzini@xxxxxxxxxx>]

On 18/09/21 02:56, Lai Jiangshan wrote:
> +			 * It also makes KVM_REQ_MMU_SYNC request if the @sp
> +			 * is linked on a different addr to expedite it.
> +			 */
> +			if (sp->unsync_children &&
> +			    mmu_sync_children(vcpu, sp, false)) {
> +				kvm_make_request(KVM_REQ_MMU_SYNC, vcpu);
> +				return RET_PF_RETRY;
> +			}
>   		}

I think we can put the sync in mmu_sync_children:

-			if (!can_yield)
+			if (!can_yield) {
+				/*
+				 * Some progress has been made so the caller
+				 * can simply retry, but we can expedite the
+				 * process by forcing a sync to happen.
+				 */
+				kvm_make_request(KVM_REQ_MMU_SYNC, vcpu);
 				return -EINTR;
+			}

Paolo