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 C5E23C433F5 for ; Wed, 25 May 2022 09:05:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240577AbiEYJF1 (ORCPT ); Wed, 25 May 2022 05:05:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49200 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239977AbiEYJEp (ORCPT ); Wed, 25 May 2022 05:04:45 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 991E69CF63 for ; Wed, 25 May 2022 02:03:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653469345; 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=KilInDwXSVF7+aga2/zZ4/KtDVLkGpwa7DByyzJGd/8=; b=HcfsGh+mBjK7nuQjGxy4Y+G4WdBmdxNoOPYCoNCtQNLKk7eflqgKXaQXvLv337Ot8mLsIK 6mRxVZUyjUFDT6RiZ7nwhH990CTeFqUlza6isJzV6O0ioGQcfXY0bjBu+EUlrxbScfHI9b 5KlAG0xdqlA3BJvLSXBlaEGeZLo5IwY= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-362-XahouciIP0qPp-Xn5q5YQg-1; Wed, 25 May 2022 05:02:21 -0400 X-MC-Unique: XahouciIP0qPp-Xn5q5YQg-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 0375E3C01D9B; Wed, 25 May 2022 09:02:21 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.194.186]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4ECA5405D4BF; Wed, 25 May 2022 09:02:19 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Maxim Levitsky , Wanpeng Li , Jim Mattson , Michael Kelley , Siddharth Chandrasekaran , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 21/37] KVM: nSVM: hyper-v: Enable L2 TLB flush Date: Wed, 25 May 2022 11:01:17 +0200 Message-Id: <20220525090133.1264239-22-vkuznets@redhat.com> In-Reply-To: <20220525090133.1264239-1-vkuznets@redhat.com> References: <20220525090133.1264239-1-vkuznets@redhat.com> MIME-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Implement Hyper-V L2 TLB flush for nSVM. The feature needs to be enabled both in extended 'nested controls' in VMCB and partition assist page. According to Hyper-V TLFS, synthetic vmexit to L1 is performed with - HV_SVM_EXITCODE_ENL exit_code. - HV_SVM_ENL_EXITCODE_TRAP_AFTER_FLUSH exit_info_1. Reviewed-by: Maxim Levitsky Signed-off-by: Vitaly Kuznetsov --- arch/x86/kvm/svm/hyperv.c | 7 +++++++ arch/x86/kvm/svm/hyperv.h | 19 +++++++++++++++++++ arch/x86/kvm/svm/nested.c | 27 +++++++++++++++++++++++++-- 3 files changed, 51 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/svm/hyperv.c b/arch/x86/kvm/svm/hyperv.c index 911f51021af1..088f6429b24c 100644 --- a/arch/x86/kvm/svm/hyperv.c +++ b/arch/x86/kvm/svm/hyperv.c @@ -8,4 +8,11 @@ void svm_hv_inject_synthetic_vmexit_post_tlb_flush(struct kvm_vcpu *vcpu) { + struct vcpu_svm *svm = to_svm(vcpu); + + svm->vmcb->control.exit_code = HV_SVM_EXITCODE_ENL; + svm->vmcb->control.exit_code_hi = 0; + svm->vmcb->control.exit_info_1 = HV_SVM_ENL_EXITCODE_TRAP_AFTER_FLUSH; + svm->vmcb->control.exit_info_2 = 0; + nested_svm_vmexit(svm); } diff --git a/arch/x86/kvm/svm/hyperv.h b/arch/x86/kvm/svm/hyperv.h index dd2e393f84a0..6ea78499e21b 100644 --- a/arch/x86/kvm/svm/hyperv.h +++ b/arch/x86/kvm/svm/hyperv.h @@ -33,6 +33,9 @@ struct hv_enlightenments { */ #define VMCB_HV_NESTED_ENLIGHTENMENTS VMCB_SW +#define HV_SVM_EXITCODE_ENL 0xF0000000 +#define HV_SVM_ENL_EXITCODE_TRAP_AFTER_FLUSH (1) + static inline void nested_svm_hv_update_vm_vp_ids(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); @@ -48,6 +51,22 @@ static inline void nested_svm_hv_update_vm_vp_ids(struct kvm_vcpu *vcpu) hv_vcpu->nested.vp_id = hve->hv_vp_id; } +static inline bool nested_svm_l2_tlb_flush_enabled(struct kvm_vcpu *vcpu) +{ + struct vcpu_svm *svm = to_svm(vcpu); + struct hv_enlightenments *hve = + (struct hv_enlightenments *)svm->nested.ctl.reserved_sw; + struct hv_vp_assist_page assist_page; + + if (unlikely(!kvm_hv_get_assist_page(vcpu, &assist_page))) + return false; + + if (!hve->hv_enlightenments_control.nested_flush_hypercall) + return false; + + return assist_page.nested_control.features.directhypercall; +} + void svm_hv_inject_synthetic_vmexit_post_tlb_flush(struct kvm_vcpu *vcpu); #endif /* __ARCH_X86_KVM_SVM_HYPERV_H__ */ diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 3b243abe0121..864d4690ded4 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -171,8 +171,12 @@ void recalc_intercepts(struct vcpu_svm *svm) vmcb_clr_intercept(c, INTERCEPT_VINTR); } - /* We don't want to see VMMCALLs from a nested guest */ - vmcb_clr_intercept(c, INTERCEPT_VMMCALL); + /* + * We want to see VMMCALLs from a nested guest only when Hyper-V L2 TLB + * flush feature is enabled. + */ + if (!nested_svm_l2_tlb_flush_enabled(&svm->vcpu)) + vmcb_clr_intercept(c, INTERCEPT_VMMCALL); for (i = 0; i < MAX_INTERCEPT; i++) c->intercepts[i] |= g->intercepts[i]; @@ -488,6 +492,17 @@ static void nested_save_pending_event_to_vmcb12(struct vcpu_svm *svm, static void nested_svm_transition_tlb_flush(struct kvm_vcpu *vcpu) { + /* + * KVM_REQ_HV_TLB_FLUSH flushes entries from either L1's VP_ID or + * L2's VP_ID upon request from the guest. Make sure we check for + * pending entries for the case when the request got misplaced (e.g. + * a transition from L2->L1 happened while processing L2 TLB flush + * request or vice versa). kvm_hv_vcpu_flush_tlb() will not flush + * anything if there are no requests in the corresponding buffer. + */ + if (to_hv_vcpu(vcpu)) + kvm_make_request(KVM_REQ_HV_TLB_FLUSH, vcpu); + /* * TODO: optimize unconditional TLB flush/MMU sync. A partial list of * things to fix before this can be conditional: @@ -1357,6 +1372,7 @@ static int svm_check_nested_events(struct kvm_vcpu *vcpu) int nested_svm_exit_special(struct vcpu_svm *svm) { u32 exit_code = svm->vmcb->control.exit_code; + struct kvm_vcpu *vcpu = &svm->vcpu; switch (exit_code) { case SVM_EXIT_INTR: @@ -1375,6 +1391,13 @@ int nested_svm_exit_special(struct vcpu_svm *svm) return NESTED_EXIT_HOST; break; } + case SVM_EXIT_VMMCALL: + /* Hyper-V L2 TLB flush hypercall is handled by L0 */ + if (guest_hv_cpuid_has_l2_tlb_flush(vcpu) && + nested_svm_l2_tlb_flush_enabled(vcpu) && + kvm_hv_is_tlb_flush_hcall(vcpu)) + return NESTED_EXIT_HOST; + break; default: break; } -- 2.35.3