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 22E69C433FE for ; Mon, 7 Mar 2022 14:51:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243439AbiCGOwT (ORCPT ); Mon, 7 Mar 2022 09:52:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243503AbiCGOvy (ORCPT ); Mon, 7 Mar 2022 09:51:54 -0500 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 BC25F90268 for ; Mon, 7 Mar 2022 06:50:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1646664650; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0tDVPG+cSC0wZSZXXfWO0Gv51YvV+L3gtZb8BmeIrIg=; b=CjoPQYGtjdOsk/O8Z1zMrFLhY1LrAFeVBvjIIid6ztpRxVWVUHbBCrdg4K3AoTII2mdk/+ +O5L8rOC4SgDiokdmlNFWSQo3c1MUuynE7ZPtSTQb8TvbyhM/LR7RUsjcpYrEhHSunbRN0 yp+pSo8v8ShTaESTc1ZDkSyqUZCbWn8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-280-YLL5bB4BMGKzBhyImxwLwg-1; Mon, 07 Mar 2022 09:50:49 -0500 X-MC-Unique: YLL5bB4BMGKzBhyImxwLwg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7C97C5218; Mon, 7 Mar 2022 14:50:48 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.193.244]) by smtp.corp.redhat.com (Postfix) with ESMTP id 201B67F0D6; Mon, 7 Mar 2022 14:50:45 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org Cc: Paolo Bonzini , Sean Christopherson , Wanpeng Li , Jim Mattson , linux-hyperv@vger.kernel.org, Siddharth Chandrasekaran , linux-kernel@vger.kernel.org Subject: [PATCH RFC 08/19] KVM: x86: hyper-v: Use preallocated buffer in 'struct kvm_vcpu_hv' instead of on-stack 'sparse_banks' Date: Mon, 7 Mar 2022 15:50:12 +0100 Message-Id: <20220307145023.1913205-9-vkuznets@redhat.com> In-Reply-To: <20220307145023.1913205-1-vkuznets@redhat.com> References: <20220307145023.1913205-1-vkuznets@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To make kvm_hv_flush_tlb() ready to handle Direct TLB flush request KVM needs to allow for all 64 sparse vCPU banks regardless of KVM_MAX_VCPUs as L1 may use vCPU overcommit for L2. To avoid growing on-stack allocation, make 'sparse_banks' part of per-vCPU 'struct kvm_vcpu_hv' which is allocated dynamically. Note: sparse_set_to_vcpu_mask() keeps using on-stack allocation as it won't be used to handle Direct TLB flush requests. Signed-off-by: Vitaly Kuznetsov --- arch/x86/include/asm/kvm_host.h | 3 +++ arch/x86/kvm/hyperv.c | 6 ++++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 750ac4055d0c..1fce8232a2e9 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -615,6 +615,9 @@ struct kvm_vcpu_hv { /* Two rings for regular Hyper-V TLB flush and Direct TLB flush */ struct kvm_vcpu_hv_tlbflush_ring tlb_flush_ring[2]; + + /* Preallocated buffer for handling hypercalls passing sparse vCPU set */ + u64 sparse_banks[64]; }; /* Xen HVM per vcpu emulation context */ diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 9dfc122d5eca..b88e44a126b8 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1969,13 +1969,14 @@ void kvm_hv_vcpu_flush_tlb(struct kvm_vcpu *vcpu) static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) { + struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu); + u64 *sparse_banks = hv_vcpu->sparse_banks; struct kvm *kvm = vcpu->kvm; struct hv_tlb_flush_ex flush_ex; struct hv_tlb_flush flush; DECLARE_BITMAP(vcpu_mask, KVM_MAX_VCPUS); u64 entries[KVM_HV_TLB_FLUSH_RING_SIZE - 2]; u64 valid_bank_mask; - u64 sparse_banks[KVM_HV_MAX_SPARSE_VCPU_SET_BITS]; struct kvm_vcpu *v; unsigned long i; bool all_cpus, all_addr; @@ -2127,11 +2128,12 @@ static void kvm_hv_send_ipi_to_many(struct kvm *kvm, u32 vector, static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) { + struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu); + u64 *sparse_banks = hv_vcpu->sparse_banks; struct kvm *kvm = vcpu->kvm; struct hv_send_ipi_ex send_ipi_ex; struct hv_send_ipi send_ipi; unsigned long valid_bank_mask; - u64 sparse_banks[KVM_HV_MAX_SPARSE_VCPU_SET_BITS]; u32 vector; bool all_cpus; -- 2.35.1