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 8762CC4332F for ; Tue, 22 Mar 2022 16:52:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239292AbiCVQxs (ORCPT ); Tue, 22 Mar 2022 12:53:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55212 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236614AbiCVQxo (ORCPT ); Tue, 22 Mar 2022 12:53:44 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 0F1658594A for ; Tue, 22 Mar 2022 09:52:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647967934; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=db1IMNfZ680sFvNInZ9xMoSKQytu/M0sDENAFmyTnBo=; b=iaTwla+iMBTQQL1A0pLL1D7BXPhKd/bs6qZqcF9AL8vnHo7FV6TfndkzQ1i0vRS19qBvNG So8xx+uRIuS1opup0SPLKtxJdWwgXy7xgp3KA1V7giZ5AjBmHgm/JCs+PDGQT8rECkOrI3 1Z51YurZeQndaDmzcthga+UT42SY+1A= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-443-PdXpRn9_PX6lYYxjLmGOQQ-1; Tue, 22 Mar 2022 12:52:11 -0400 X-MC-Unique: PdXpRn9_PX6lYYxjLmGOQQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4A2E985A5BE; Tue, 22 Mar 2022 16:52:10 +0000 (UTC) Received: from starship (unknown [10.40.194.231]) by smtp.corp.redhat.com (Postfix) with ESMTP id ECF8740CF900; Tue, 22 Mar 2022 16:52:06 +0000 (UTC) Message-ID: <5a63e5f2d88aa8a2caf84319c469b265ec430eb2.camel@redhat.com> Subject: Re: [PATCH v3 4/7] KVM: x86: nSVM: support PAUSE filter threshold and count when cpu_pm=on From: Maxim Levitsky To: Paolo Bonzini , kvm@vger.kernel.org Cc: Ingo Molnar , Dave Hansen , Sean Christopherson , Borislav Petkov , "H. Peter Anvin" , Thomas Gleixner , Jim Mattson , x86@kernel.org, Vitaly Kuznetsov , Joerg Roedel , linux-kernel@vger.kernel.org, Wanpeng Li Date: Tue, 22 Mar 2022 18:52:05 +0200 In-Reply-To: References: <20220301143650.143749-1-mlevitsk@redhat.com> <20220301143650.143749-5-mlevitsk@redhat.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2022-03-09 at 14:12 +0100, Paolo Bonzini wrote: > On 3/1/22 15:36, Maxim Levitsky wrote: > > Allow L1 to use these settings if L0 disables PAUSE interception > > (AKA cpu_pm=on) > > > > Signed-off-by: Maxim Levitsky > > --- > > arch/x86/kvm/svm/nested.c | 6 ++++++ > > arch/x86/kvm/svm/svm.c | 17 +++++++++++++++++ > > arch/x86/kvm/svm/svm.h | 2 ++ > > 3 files changed, 25 insertions(+) > > > > diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c > > index 37510cb206190..4cb0bc49986d5 100644 > > --- a/arch/x86/kvm/svm/nested.c > > +++ b/arch/x86/kvm/svm/nested.c > > @@ -664,6 +664,12 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm) > > if (!nested_vmcb_needs_vls_intercept(svm)) > > svm->vmcb->control.virt_ext |= VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK; > > > > + if (svm->pause_filter_enabled) > > + svm->vmcb->control.pause_filter_count = svm->nested.ctl.pause_filter_count; > > + > > + if (svm->pause_threshold_enabled) > > + svm->vmcb->control.pause_filter_thresh = svm->nested.ctl.pause_filter_thresh; > > I think this should be > > if (kvm_pause_in_guest(vcpu->kvm)) { > /* copy from VMCB12 if guest has CPUID, else set to 0 */ > } else { > /* copy from VMCB01, unconditionally */ > } > and likewise it should be copied back to VMCB01 unconditionally on > vmexit if !kvm_pause_in_guest(vcpu->kvm). I did something different in the next version of the patches. Please take a look. > > > nested_svm_transition_tlb_flush(vcpu); > > > > /* Enter Guest-Mode */ > > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c > > index 6a571eed32ef4..52198e63c5fc4 100644 > > --- a/arch/x86/kvm/svm/svm.c > > +++ b/arch/x86/kvm/svm/svm.c > > @@ -4008,6 +4008,17 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) > > > > svm->v_vmload_vmsave_enabled = vls && guest_cpuid_has(vcpu, X86_FEATURE_V_VMSAVE_VMLOAD); > > > > + if (kvm_pause_in_guest(vcpu->kvm)) { > > + svm->pause_filter_enabled = pause_filter_count > 0 && > > + guest_cpuid_has(vcpu, X86_FEATURE_PAUSEFILTER); > > + > > + svm->pause_threshold_enabled = pause_filter_thresh > 0 && > > + guest_cpuid_has(vcpu, X86_FEATURE_PFTHRESHOLD); > > Why only if the module parameters are >0? The module parameter is > unused if pause-in-guest is active. Agree, will do. > > > + } else { > > + svm->pause_filter_enabled = false; > > + svm->pause_threshold_enabled = false; > > + } > > + > > svm_recalc_instruction_intercepts(vcpu, svm); > > > > /* For sev guests, the memory encryption bit is not reserved in CR3. */ > > @@ -4763,6 +4774,12 @@ static __init void svm_set_cpu_caps(void) > > if (vls) > > kvm_cpu_cap_set(X86_FEATURE_V_VMSAVE_VMLOAD); > > > > + if (pause_filter_count) > > + kvm_cpu_cap_set(X86_FEATURE_PAUSEFILTER); > > + > > + if (pause_filter_thresh) > > + kvm_cpu_cap_set(X86_FEATURE_PFTHRESHOLD); > > Likewise, this should be set using just boot_cpu_has, not the module > parameters. Agree as well + the check above is wrong - it should have been inverted. > > Paolo > > > /* Nested VM can receive #VMEXIT instead of triggering #GP */ > > kvm_cpu_cap_set(X86_FEATURE_SVME_ADDR_CHK); > > } > > diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h > > index a3c93f9c02847..6fa81eb3ffb78 100644 > > --- a/arch/x86/kvm/svm/svm.h > > +++ b/arch/x86/kvm/svm/svm.h > > @@ -234,6 +234,8 @@ struct vcpu_svm { > > bool tsc_scaling_enabled : 1; > > bool lbrv_enabled : 1; > > bool v_vmload_vmsave_enabled : 1; > > + bool pause_filter_enabled : 1; > > + bool pause_threshold_enabled : 1; > > > > u32 ldr_reg; > > u32 dfr_reg; Thanks for the review! Best regards, Maxim Levitsky