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 X-Spam-Level: X-Spam-Status: No, score=-16.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D0458C432BE for ; Wed, 11 Aug 2021 10:24:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B37C860EB9 for ; Wed, 11 Aug 2021 10:24:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237158AbhHKKY1 (ORCPT ); Wed, 11 Aug 2021 06:24:27 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:41811 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237150AbhHKKYZ (ORCPT ); Wed, 11 Aug 2021 06:24:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1628677441; 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=Wjib2CaoBoKQ960V8nb3t6a1/GwcD38v7ydXMlMNTLw=; b=gaKUGVkcRCO/BXK4rUgbzzcvPsWsAGQYNjHRjGfdPFnpDRai1WP0GOOzkta/+9EftNcFBx 0o1YD5goyFrxgiE1V9IKTh71PKZgFjGX8JJzeC/nVSHu1jfhIQ/NxNY28M2TK7aws9qWP8 milCzZMHKdDfUUenG+DcpqG15Wp5R1g= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-556-A1WSQEExOHuemxTFuC2LLA-1; Wed, 11 Aug 2021 06:24:00 -0400 X-MC-Unique: A1WSQEExOHuemxTFuC2LLA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7478A101C8A0; Wed, 11 Aug 2021 10:23:59 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id EE7625D9C6; Wed, 11 Aug 2021 10:23:58 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: vkuznets@redhat.com, mtosatti@redhat.com Subject: [PATCH 2/2] kvm: x86: abstract locking around pvclock_update_vm_gtod_copy Date: Wed, 11 Aug 2021 06:23:56 -0400 Message-Id: <20210811102356.3406687-3-pbonzini@redhat.com> In-Reply-To: <20210811102356.3406687-1-pbonzini@redhat.com> References: <20210811102356.3406687-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Updates to the kvmclock parameters needs to do a complicated dance of KVM_REQ_MCLOCK_INPROGRESS and KVM_REQ_CLOCK_UPDATE in addition to taking pvclock_gtod_sync_lock. Place that in two functions that can be called on all of master clock update, KVM_SET_CLOCK, and Hyper-V reenlightenment. Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_host.h | 1 - arch/x86/kvm/x86.c | 66 +++++++++++++-------------------- 2 files changed, 26 insertions(+), 41 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index bc6157677753..c54f9da91f99 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1839,7 +1839,6 @@ u64 kvm_calc_nested_tsc_multiplier(u64 l1_multiplier, u64 l2_multiplier); unsigned long kvm_get_linear_rip(struct kvm_vcpu *vcpu); bool kvm_is_linear_rip(struct kvm_vcpu *vcpu, unsigned long linear_rip); -void kvm_make_mclock_inprogress_request(struct kvm *kvm); void kvm_make_scan_ioapic_request(struct kvm *kvm); void kvm_make_scan_ioapic_request_mask(struct kvm *kvm, unsigned long *vcpu_bitmap); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 284afaa1db86..8f96cdfcf364 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2757,35 +2757,36 @@ static void pvclock_update_vm_gtod_copy(struct kvm *kvm) #endif } -void kvm_make_mclock_inprogress_request(struct kvm *kvm) +static void kvm_start_pvclock_update(struct kvm *kvm) { + struct kvm_arch *ka = &kvm->arch; kvm_make_all_cpus_request(kvm, KVM_REQ_MCLOCK_INPROGRESS); + + /* no guest entries from this point */ + spin_lock_irq(&ka->pvclock_gtod_sync_lock); } -static void kvm_gen_update_masterclock(struct kvm *kvm) +static void kvm_end_pvclock_update(struct kvm *kvm) { -#ifdef CONFIG_X86_64 - int i; - struct kvm_vcpu *vcpu; struct kvm_arch *ka = &kvm->arch; - unsigned long flags; - - kvm_hv_invalidate_tsc_page(kvm); - - kvm_make_mclock_inprogress_request(kvm); - - /* no guest entries from this point */ - spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags); - pvclock_update_vm_gtod_copy(kvm); - spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags); + struct kvm_vcpu *vcpu; + int i; + spin_unlock_irq(&ka->pvclock_gtod_sync_lock); kvm_for_each_vcpu(i, vcpu, kvm) kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); /* guest entries allowed */ kvm_for_each_vcpu(i, vcpu, kvm) kvm_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu); -#endif +} + +static void kvm_update_masterclock(struct kvm *kvm) +{ + kvm_hv_invalidate_tsc_page(kvm); + kvm_start_pvclock_update(kvm); + pvclock_update_vm_gtod_copy(kvm); + kvm_end_pvclock_update(kvm); } u64 get_kvmclock_ns(struct kvm *kvm) @@ -6077,12 +6078,10 @@ long kvm_arch_vm_ioctl(struct file *filp, goto out; r = 0; - /* - * TODO: userspace has to take care of races with VCPU_RUN, so - * kvm_gen_update_masterclock() can be cut down to locked - * pvclock_update_vm_gtod_copy(). - */ - kvm_gen_update_masterclock(kvm); + + kvm_hv_invalidate_tsc_page(kvm); + kvm_start_pvclock_update(kvm); + pvclock_update_vm_gtod_copy(kvm); /* * This pairs with kvm_guest_time_update(): when masterclock is @@ -6091,15 +6090,12 @@ long kvm_arch_vm_ioctl(struct file *filp, * is slightly ahead) here we risk going negative on unsigned * 'system_time' when 'user_ns.clock' is very small. */ - spin_lock_irq(&ka->pvclock_gtod_sync_lock); if (kvm->arch.use_master_clock) now_ns = ka->master_kernel_ns; else now_ns = get_kvmclock_base_ns(); ka->kvmclock_offset = user_ns.clock - now_ns; - spin_unlock_irq(&ka->pvclock_gtod_sync_lock); - - kvm_make_all_cpus_request(kvm, KVM_REQ_CLOCK_UPDATE); + kvm_end_pvclock_update(kvm); break; } case KVM_GET_CLOCK: { @@ -8105,9 +8101,7 @@ static void tsc_khz_changed(void *data) static void kvm_hyperv_tsc_notifier(void) { struct kvm *kvm; - struct kvm_vcpu *vcpu; int cpu; - unsigned long flags; mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) @@ -8121,19 +8115,11 @@ static void kvm_hyperv_tsc_notifier(void) kvm_max_guest_tsc_khz = tsc_khz; list_for_each_entry(kvm, &vm_list, vm_list) { - struct kvm_arch *ka = &kvm->arch; - - kvm_make_mclock_inprogress_request(kvm); - spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags); + kvm_start_pvclock_update(kvm); pvclock_update_vm_gtod_copy(kvm); - spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags); - - kvm_for_each_vcpu(cpu, vcpu, kvm) - kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); - - kvm_for_each_vcpu(cpu, vcpu, kvm) - kvm_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu); + kvm_end_pvclock_update(kvm); } + mutex_unlock(&kvm_lock); } #endif @@ -9413,7 +9399,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) if (kvm_check_request(KVM_REQ_MIGRATE_TIMER, vcpu)) __kvm_migrate_timers(vcpu); if (kvm_check_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu)) - kvm_gen_update_masterclock(vcpu->kvm); + kvm_update_masterclock(vcpu->kvm); if (kvm_check_request(KVM_REQ_GLOBAL_CLOCK_UPDATE, vcpu)) kvm_gen_kvmclock_update(vcpu); if (kvm_check_request(KVM_REQ_CLOCK_UPDATE, vcpu)) { -- 2.27.0