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 02052C433EF for ; Wed, 30 Mar 2022 00:07:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241397AbiC3AIw (ORCPT ); Tue, 29 Mar 2022 20:08:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241388AbiC3AIu (ORCPT ); Tue, 29 Mar 2022 20:08:50 -0400 Received: from mail-pf1-x42f.google.com (mail-pf1-x42f.google.com [IPv6:2607:f8b0:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1D6B343493 for ; Tue, 29 Mar 2022 17:07:06 -0700 (PDT) Received: by mail-pf1-x42f.google.com with SMTP id p8so17321249pfh.8 for ; Tue, 29 Mar 2022 17:07:06 -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=Y2rRhw4flc97ksCHOd8D6zj8TKfoieAVBtd70rXcpQs=; b=o9HHTHEYnmATJjpdZ+6at7qnwRTprPUxz44HrTkQVZVnCOrEgYVmZWSnp4gUPhisJv Rmiu/9OTD/qceAnczy4elXmZYfqCtOJj96eJQMuVW9Lc1lYOGiX8XPbzl8WSTIsAt0FI 9afhf33i8d59GFe3+3rYaQygWjErHAhbVZIako5ZoRr5T0a8YW9Q16JqV/pxo4oBHHo/ UEXCoV5RfVH/960ntKzVVEko47A4lLAAUFSwvWxPfrN0Y8SkBw/e1ZrQUnG2NqnubIrO RzIPQAd1lEWZL6FPCSVd745Vy6Zx7A2+ckbidrCyQzYqyMtumppulGgHbvCydajf90TS nKtQ== 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=Y2rRhw4flc97ksCHOd8D6zj8TKfoieAVBtd70rXcpQs=; b=BzrjLbHnKhWK75ktUKmuZiCKZsFhbE+4QZiSCWC+60gx4i5PX8Mib20aanD9UoqF4L g9sbU0o61Ml++dt+2vdpQXXWmoIO5sEoor1qTMr2yXnSh25F9cKXGQnvpGeDmNjNK9J2 hF5sTQWbj6kcR1WCnAcB3MmmjORn39I0F0Z3RUbDK7kn1V6xnVF9VOkvgq5QndKBXYfG enDQAYCLrXKA9MooqT62oFHK1SZmLCsN6Y8ZpkjTzXMCQOrvcHqVkI+R2q6ciXdO1j3S mrIgsKpI0CfX/kVzMIfIaL3eTdZA6pI54ZROdY/GPxlnlqYakEUzyUqwZKtFBJCzX5qc 6Muw== X-Gm-Message-State: AOAM532+iq7AwW6XpNKEWUO+jXJjaljQpsgGctKiThECUq1ELWzBgkVL s+v2ePyuu7VPCaMI3lAeeY0wIA== X-Google-Smtp-Source: ABdhPJxUppfMa3o7A5xAfew/ErKXOffjoVHzpxNp8qP8IaCknbYo1DmmtfVP+XIrltUTJl/gsv4W0g== X-Received: by 2002:a63:dd47:0:b0:381:2bb3:86ba with SMTP id g7-20020a63dd47000000b003812bb386bamr3899371pgj.381.1648598825402; Tue, 29 Mar 2022 17:07:05 -0700 (PDT) Received: from google.com (157.214.185.35.bc.googleusercontent.com. [35.185.214.157]) by smtp.gmail.com with ESMTPSA id f20-20020a056a00229400b004fb16860af6sm17208497pfe.195.2022.03.29.17.07.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Mar 2022 17:07:04 -0700 (PDT) Date: Wed, 30 Mar 2022 00:07:01 +0000 From: Sean Christopherson To: Wanpeng Li Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel Subject: Re: [PATCH RESEND 3/5] KVM: X86: Boost vCPU which is in critical section Message-ID: References: <1648216709-44755-1-git-send-email-wanpengli@tencent.com> <1648216709-44755-4-git-send-email-wanpengli@tencent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1648216709-44755-4-git-send-email-wanpengli@tencent.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Mar 25, 2022, Wanpeng Li wrote: > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 425fd7f38fa9..6b300496bbd0 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -10375,6 +10375,28 @@ static int vcpu_run(struct kvm_vcpu *vcpu) > return r; > } > > +static int kvm_vcpu_non_preemptable(struct kvm_vcpu *vcpu) s/preemtable/preemptible And I'd recommend inverting the return, and also return a bool, i.e. static bool kvm_vcpu_is_preemptible(struct kvm_vcpu *vcpu) > +{ > + int count; > + > + if (!vcpu->arch.pv_pc.preempt_count_enabled) > + return 0; > + > + if (!kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_pc.preempt_count_cache, > + &count, sizeof(int))) > + return (count & ~PREEMPT_NEED_RESCHED); This cements PREEMPT_NEED_RESCHED into KVM's guest/host ABI. I doubt the sched folks will be happy with that. > + > + return 0; > +} > +