From patchwork Wed Sep 21 15:24:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12983834 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 463DCC6FA82 for ; Wed, 21 Sep 2022 15:26:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230386AbiIUP0X (ORCPT ); Wed, 21 Sep 2022 11:26:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231229AbiIUPZb (ORCPT ); Wed, 21 Sep 2022 11:25:31 -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 ESMTPS id 653657C1B1 for ; Wed, 21 Sep 2022 08:25:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1663773917; 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=N56sSL74TA1po1fXZiXcu/R2uNbfnItoPDl5bLdotsk=; b=L1ppUtIBcOllaXnP3qgDSKAaquo24FMuMa98muBg58NMBPUoznMqMf8Qymv0ShsqzcxXgJ MaNjTV56OMRtTAQ0xUQGjasLtYt0Z2HBsO05gwrreSjlWvDhPTmR9x6tuwB8W5icWIhwwS IrRw1cSK2M1APjEBaiZJevrIxATDqKQ= 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-60-1PnywtPsNPyw-oHI1T-Kww-1; Wed, 21 Sep 2022 11:25:12 -0400 X-MC-Unique: 1PnywtPsNPyw-oHI1T-Kww-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 75F1E381A727; Wed, 21 Sep 2022 15:25:11 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.194.159]) by smtp.corp.redhat.com (Postfix) with ESMTP id 050872166B26; Wed, 21 Sep 2022 15:25:08 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Michael Kelley , Siddharth Chandrasekaran , Yuan Yao , Maxim Levitsky , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v10 11/39] KVM: x86: hyper-v: Create a separate fifo for L2 TLB flush Date: Wed, 21 Sep 2022 17:24:08 +0200 Message-Id: <20220921152436.3673454-12-vkuznets@redhat.com> In-Reply-To: <20220921152436.3673454-1-vkuznets@redhat.com> References: <20220921152436.3673454-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org To handle L2 TLB flush requests, KVM needs to use a separate fifo from regular (L1) Hyper-V TLB flush requests: e.g. when a request to flush something in L2 is made, the target vCPU can transition from L2 to L1, receive a request to flush a GVA for L1 and then try to enter L2 back. The first request needs to be processed at this point. Similarly, requests to flush GVAs in L1 must wait until L2 exits to L1. No functional change as KVM doesn't handle L2 TLB flush requests from L2 yet. Signed-off-by: Vitaly Kuznetsov --- arch/x86/include/asm/kvm_host.h | 8 +++++++- arch/x86/kvm/hyperv.c | 11 +++++++---- arch/x86/kvm/hyperv.h | 18 +++++++++++++++--- 3 files changed, 29 insertions(+), 8 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index c97161436a9d..add0718798c1 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -612,6 +612,12 @@ struct kvm_vcpu_hv_synic { */ #define KVM_HV_TLB_FLUSHALL_ENTRY ((u64)-1) +enum hv_tlb_flush_fifos { + HV_L1_TLB_FLUSH_FIFO, + HV_L2_TLB_FLUSH_FIFO, + HV_NR_TLB_FLUSH_FIFOS, +}; + struct kvm_vcpu_hv_tlb_flush_fifo { spinlock_t write_lock; DECLARE_KFIFO(entries, u64, KVM_HV_TLB_FLUSH_FIFO_SIZE); @@ -639,7 +645,7 @@ struct kvm_vcpu_hv { u32 nested_ebx; /* HYPERV_CPUID_NESTED_FEATURES.EBX */ } cpuid_cache; - struct kvm_vcpu_hv_tlb_flush_fifo tlb_flush_fifo; + struct kvm_vcpu_hv_tlb_flush_fifo tlb_flush_fifo[HV_NR_TLB_FLUSH_FIFOS]; }; /* Xen HVM per vcpu emulation context */ diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 9764ebb7fd5f..23eb139b2936 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -956,8 +956,10 @@ int kvm_hv_vcpu_init(struct kvm_vcpu *vcpu) hv_vcpu->vp_index = vcpu->vcpu_idx; - INIT_KFIFO(hv_vcpu->tlb_flush_fifo.entries); - spin_lock_init(&hv_vcpu->tlb_flush_fifo.write_lock); + for (i = 0; i < HV_NR_TLB_FLUSH_FIFOS; i++) { + INIT_KFIFO(hv_vcpu->tlb_flush_fifo[i].entries); + spin_lock_init(&hv_vcpu->tlb_flush_fifo[i].write_lock); + } return 0; } @@ -1837,7 +1839,8 @@ static void hv_tlb_flush_enqueue(struct kvm_vcpu *vcpu, u64 *entries, int count) if (!hv_vcpu) return; - tlb_flush_fifo = &hv_vcpu->tlb_flush_fifo; + /* kvm_hv_flush_tlb() is not ready to handle requests for L2s yet */ + tlb_flush_fifo = &hv_vcpu->tlb_flush_fifo[HV_L1_TLB_FLUSH_FIFO]; spin_lock_irqsave(&tlb_flush_fifo->write_lock, flags); @@ -1874,7 +1877,7 @@ void kvm_hv_vcpu_flush_tlb(struct kvm_vcpu *vcpu) return; } - tlb_flush_fifo = &hv_vcpu->tlb_flush_fifo; + tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(vcpu, is_guest_mode(vcpu)); count = kfifo_out(&tlb_flush_fifo->entries, entries, KVM_HV_TLB_FLUSH_FIFO_SIZE); diff --git a/arch/x86/kvm/hyperv.h b/arch/x86/kvm/hyperv.h index ac30091ab346..ca7f1d2c134e 100644 --- a/arch/x86/kvm/hyperv.h +++ b/arch/x86/kvm/hyperv.h @@ -22,6 +22,7 @@ #define __ARCH_X86_KVM_HYPERV_H__ #include +#include "x86.h" /* "Hv#1" signature */ #define HYPERV_CPUID_SIGNATURE_EAX 0x31237648 @@ -151,16 +152,27 @@ int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args); int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, struct kvm_cpuid_entry2 __user *entries); +static inline struct kvm_vcpu_hv_tlb_flush_fifo *kvm_hv_get_tlb_flush_fifo(struct kvm_vcpu *vcpu, + bool is_guest_mode) +{ + struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu); + int i = is_guest_mode ? HV_L2_TLB_FLUSH_FIFO : + HV_L1_TLB_FLUSH_FIFO; + + /* KVM does not handle L2 TLB flush requests yet */ + WARN_ON_ONCE(i != HV_L1_TLB_FLUSH_FIFO); + + return &hv_vcpu->tlb_flush_fifo[i]; +} static inline void kvm_hv_vcpu_empty_flush_tlb(struct kvm_vcpu *vcpu) { struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo; - struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu); - if (!hv_vcpu || !kvm_check_request(KVM_REQ_HV_TLB_FLUSH, vcpu)) + if (!to_hv_vcpu(vcpu) || !kvm_check_request(KVM_REQ_HV_TLB_FLUSH, vcpu)) return; - tlb_flush_fifo = &hv_vcpu->tlb_flush_fifo; + tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(vcpu, is_guest_mode(vcpu)); kfifo_reset_out(&tlb_flush_fifo->entries); }