From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01B43C433EF for ; Thu, 31 Mar 2022 22:00:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242194AbiCaWCe (ORCPT ); Thu, 31 Mar 2022 18:02:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58546 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230257AbiCaWCd (ORCPT ); Thu, 31 Mar 2022 18:02:33 -0400 Received: from mail-pl1-x634.google.com (mail-pl1-x634.google.com [IPv6:2607:f8b0:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F0B51107EC for ; Thu, 31 Mar 2022 15:00:45 -0700 (PDT) Received: by mail-pl1-x634.google.com with SMTP id j13so800741plj.8 for ; Thu, 31 Mar 2022 15:00:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=xdDHp8DZv62+tC1QpF06xU//55Uv53QsP+VwWvx7yKA=; b=EIWeMACFP4jLGYR2cBqX0EnEcdQE/UAi5wgZaLvKnjpAg/Buj6Lo83ST7MK6tOkMYw kRH74cPPb3v1iG73l1LNJJA0CGbfykkoyj4j7nqrk+hsmYuLq3tTsW4ByFj7IRk7vPHB DJ5ZxUkYx7xQ8yJ9S/3YkhYeutJi+8qh6U77T3WrtdbxhnFuDqULsk3BHrSCarE6dsAq EeV1B3qVaS3NRcq5KQO5GlxNLakQbAHUR/NziCSq9TzoTuhfxS5kAHrcHH4v2EHDAosp KlJWuYEqRDSNAZ3GimiSa70ZD3rv5XS7YEeZWO9pLkSQi54edf2uCsc88gi76sB/5Cwe +uNw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=xdDHp8DZv62+tC1QpF06xU//55Uv53QsP+VwWvx7yKA=; b=bl+gswViGltAz4G4pb8iVP4qOyrqRxtilUrm5ePNYidmE4tT81BQOvYcrzPaL1+ZTF ldjhU+A3dzqHjfrxqV2GEnRh73Kg6Fs35dhuR5ZQw08OHlcjUoZKwpd9ojhhnap7mFDx IBTKNy0jS9oGjijE6ACmAmNJtw1D4pZ2d/5FwZZYmZbKFpydjuVStFfmT8m9EoBOXc6h UmODH98UJppmMzC3F7RulxdfZ4CEZ7kvdwrhSG6e3s9DGBZioRVMQTromS+i+11iKNXy azGUqQxvq0TuolcXM9ejtc4hXPTSoJUSkJm1NlQ4Xcj2yUmrzP57fO+3u8Wrvg2tjOPq nHrQ== X-Gm-Message-State: AOAM533hHD4DJCJAZMcp0zyP+u7Nf2m02iQV1iXN3PIvySLs+rMjoJ+C +ECO0klm2x+vNwMcOPnH2BasOQ== X-Google-Smtp-Source: ABdhPJz1IGynAVRKqq2sYcpKslDVnp2bEwrTzO0FDG5XYcRu+u38Lvvd1DQheCE7tkhG9mNJ54bvKw== X-Received: by 2002:a17:90a:728f:b0:1c9:dbf2:591b with SMTP id e15-20020a17090a728f00b001c9dbf2591bmr8277572pjg.172.1648764044464; Thu, 31 Mar 2022 15:00:44 -0700 (PDT) Received: from google.com (157.214.185.35.bc.googleusercontent.com. [35.185.214.157]) by smtp.gmail.com with ESMTPSA id z7-20020a056a00240700b004e1cde37bc1sm453873pfh.84.2022.03.31.15.00.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 31 Mar 2022 15:00:43 -0700 (PDT) Date: Thu, 31 Mar 2022 22:00:40 +0000 From: Sean Christopherson To: Wanpeng Li Cc: LKML , kvm , Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel Subject: Re: [PATCH RESEND 2/5] KVM: X86: Add guest interrupt disable state support Message-ID: References: <1648216709-44755-1-git-send-email-wanpengli@tencent.com> <1648216709-44755-3-git-send-email-wanpengli@tencent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, Mar 30, 2022, Wanpeng Li wrote: > On Wed, 30 Mar 2022 at 08:04, Sean Christopherson wrote: > > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > > > index 50f011a7445a..8e05cbfa9827 100644 > > > --- a/arch/x86/include/asm/kvm_host.h > > > +++ b/arch/x86/include/asm/kvm_host.h > > > @@ -861,6 +861,7 @@ struct kvm_vcpu_arch { > > > bool preempt_count_enabled; > > > struct gfn_to_hva_cache preempt_count_cache; > > > } pv_pc; > > > + bool irq_disabled; > > > > This is going to at best be confusing, and at worst lead to bugs The flag is > > valid if and only if the vCPU is not loaded. I don't have a clever answer, but > > this needs to have some form of guard to (a) clarify when it's valid and (b) actively > > prevent misuse. > > How about renaming it to last_guest_irq_disabled and comments as /* > Guest irq disabled state, valid iff the vCPU is not loaded */ What about usurping vcpu->run->if_flag? Userspace could manipulate the data, but that should be fine since the data is already guest-controlled.