From patchwork Mon Jun 13 13:39:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12879856 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 A0560CCA47B for ; Mon, 13 Jun 2022 18:00:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241222AbiFMSA1 (ORCPT ); Mon, 13 Jun 2022 14:00:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243580AbiFMR4l (ORCPT ); Mon, 13 Jun 2022 13:56:41 -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 729DE3DA7D for ; Mon, 13 Jun 2022 06:40:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1655127632; 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=+XbqM7qHi7EitckiOKedUNIRm0xdJ7+RlVUJPO0Gap0=; b=RpT4NiSdAOIf+z4fdZlPld8i/VBdnH4qUsLPbEHiCSuLGBCtmPJrvW3iQC0vqd2H/OIoE0 BRuxKnhXq40qKhMWnII793zePLRke/WIA2jkfm5Nv3MjOx+UpbWpyTedHL5dECR35dxD69 sp6wqyt4XI3LY0GTj2xwI7isCMDNUX8= 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-191-MwuYQlIkMH-ntovpgC6tLQ-1; Mon, 13 Jun 2022 09:40:27 -0400 X-MC-Unique: MwuYQlIkMH-ntovpgC6tLQ-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E04C029AA385; Mon, 13 Jun 2022 13:40:26 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.194.60]) by smtp.corp.redhat.com (Postfix) with ESMTP id C2601492CA2; Mon, 13 Jun 2022 13:40:24 +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 , Yuan Yao , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v7 22/39] KVM: nSVM: hyper-v: Enable L2 TLB flush Date: Mon, 13 Jun 2022 15:39:05 +0200 Message-Id: <20220613133922.2875594-23-vkuznets@redhat.com> In-Reply-To: <20220613133922.2875594-1-vkuznets@redhat.com> References: <20220613133922.2875594-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.85 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: kvm@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 VP 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. Note: VP assist page is cached in 'struct kvm_vcpu_hv' so recalc_intercepts() doesn't need to read from guest's memory. KVM needs to update the case upon each VMRUN and after svm_set_nested_state (svm_get_nested_state_pages()) to handle the case when the guest got migrated while L2 was running. Reviewed-by: Maxim Levitsky Signed-off-by: Vitaly Kuznetsov --- arch/x86/kvm/svm/hyperv.c | 7 +++++++ arch/x86/kvm/svm/hyperv.h | 30 ++++++++++++++++++++++++++++++ arch/x86/kvm/svm/nested.c | 36 ++++++++++++++++++++++++++++++++++-- 3 files changed, 71 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..7b01722838bf 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 +51,33 @@ 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_hv_update_vp_assist(struct kvm_vcpu *vcpu) +{ + if (!to_hv_vcpu(vcpu)) + return true; + + if (!kvm_hv_assist_page_enabled(vcpu)) + return true; + + return kvm_hv_get_assist_page(vcpu); +} + +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 kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu); + + if (!hv_vcpu) + return false; + + if (!hve->hv_enlightenments_control.nested_flush_hypercall) + return false; + + return hv_vcpu->vp_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 c43ba5b39288..dd4fc1081e2e 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]; @@ -489,6 +493,17 @@ 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: @@ -835,6 +850,12 @@ int nested_svm_vmrun(struct kvm_vcpu *vcpu) return 1; } + /* This fails when VP assist page is enabled but the supplied GPA is bogus */ + if (!nested_svm_hv_update_vp_assist(vcpu)) { + kvm_inject_gp(vcpu, 0); + return 1; + } + vmcb12_gpa = svm->vmcb->save.rax; ret = kvm_vcpu_map(vcpu, gpa_to_gfn(vmcb12_gpa), &map); if (ret == -EINVAL) { @@ -1412,6 +1433,7 @@ 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: @@ -1430,6 +1452,13 @@ 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; } @@ -1710,6 +1739,9 @@ static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu) return false; } + if (!nested_svm_hv_update_vp_assist(vcpu)) + return false; + return true; }