From mboxrd@z Thu Jan 1 00:00:00 1970 From: Radim =?utf-8?B?S3LEjW3DocWZ?= Subject: Re: [PATCH 2/2] KVM: VMX: Use just one page for I/O permission bitmaps Date: Tue, 5 Dec 2017 22:26:40 +0100 Message-ID: <20171205212639.GD20099@flask> References: <20171201182110.7143-1-jmattson@google.com> <20171201182110.7143-2-jmattson@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, P J P To: Jim Mattson Return-path: Received: from mx1.redhat.com ([209.132.183.28]:37860 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751208AbdLEV0n (ORCPT ); Tue, 5 Dec 2017 16:26:43 -0500 Content-Disposition: inline In-Reply-To: <20171201182110.7143-2-jmattson@google.com> Sender: kvm-owner@vger.kernel.org List-ID: 2017-12-01 10:21-0800, Jim Mattson: > Since we no longer allow any I/O ports to be passed through to the guest, > we can use the same page for I/O bitmap A and I/O bitmap B. I think we can disable the feature and save the second page as well: diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index e25c55ea2eb7..80859a7cdf6d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3624,7 +3624,7 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf) #endif CPU_BASED_CR3_LOAD_EXITING | CPU_BASED_CR3_STORE_EXITING | - CPU_BASED_USE_IO_BITMAPS | + CPU_BASED_UNCOND_IO_EXITING | CPU_BASED_MOV_DR_EXITING | CPU_BASED_USE_TSC_OFFSETING | CPU_BASED_INVLPG_EXITING |