From patchwork Tue Nov 1 14:53:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 13027047 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 A6089C433FE for ; Tue, 1 Nov 2022 14:57:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231146AbiKAO5G (ORCPT ); Tue, 1 Nov 2022 10:57:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231134AbiKAO4Y (ORCPT ); Tue, 1 Nov 2022 10:56:24 -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 ESMTPS id D52C710FEF for ; Tue, 1 Nov 2022 07:55:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1667314520; 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=j/oauzu6LgWIUbAnrnyqdVHkJDsV2keOHJMa4/XTYmQ=; b=BLQqDq59clNY26Qoyyzh4YZtGJNiSzVuR+6ToMH/iY3F0DPnRGMccPS1fjcUiEJ+wBfcB0 ytwRp3JjGPGiGh5aBAjFWbb9VmKid4Dl30XAyQS0cs4HYa3CqO95rivJf3/0VWl/N+S24+ VIFfcfXTGdekVtf5I700e3KcbhQtmBE= 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-103-z3uWEmTXO7muHE8AjRufpg-1; Tue, 01 Nov 2022 10:55:16 -0400 X-MC-Unique: z3uWEmTXO7muHE8AjRufpg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 60AB11C16EA4; Tue, 1 Nov 2022 14:55:15 +0000 (UTC) Received: from ovpn-194-149.brq.redhat.com (ovpn-194-149.brq.redhat.com [10.40.194.149]) by smtp.corp.redhat.com (Postfix) with ESMTP id 61FD3C15BA5; Tue, 1 Nov 2022 14:55:13 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini , Sean Christopherson Cc: Wanpeng Li , Jim Mattson , Michael Kelley , Siddharth Chandrasekaran , Yuan Yao , Maxim Levitsky , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v13 17/48] KVM: x86: hyper-v: Create a separate fifo for L2 TLB flush Date: Tue, 1 Nov 2022 15:53:55 +0100 Message-Id: <20221101145426.251680-18-vkuznets@redhat.com> In-Reply-To: <20221101145426.251680-1-vkuznets@redhat.com> References: <20221101145426.251680-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 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. Reviewed-by: Sean Christopherson Signed-off-by: Vitaly Kuznetsov --- arch/x86/include/asm/kvm_host.h | 8 +++++++- arch/x86/kvm/hyperv.c | 11 +++++++---- arch/x86/kvm/hyperv.h | 19 ++++++++++++++++--- 3 files changed, 30 insertions(+), 8 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index f8ee72dd8660..6ebcf78368d1 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 0bfa59838e0a..989846310303 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; } @@ -1839,7 +1841,8 @@ 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(&tlb_flush_fifo->write_lock); @@ -1874,7 +1877,7 @@ int kvm_hv_vcpu_flush_tlb(struct kvm_vcpu *vcpu) if (!tdp_enabled || !hv_vcpu) return -EINVAL; - 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 f79edf9234cd..8942e8c6c912 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 @@ -151,15 +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_purge_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); }