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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 9FFD9C432C3 for ; Fri, 15 Nov 2019 06:22:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E05320801 for ; Fri, 15 Nov 2019 06:22:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573798937; bh=pCATTbiF5NuP+y+tN0vyFUdJXhwdFoHoBkoltCfJUlg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=l3VWDq4/cAMjqJptponkWJoxm09n53FzJ3QQuQUDbdpsUkg0yIyhDMyCV2IG5bh/H ik2mT/I6BLKeKZpkbauUUdxW8mo2RUf4vKMkUXhbiSFnNd5s5Ne4hGCqbeakGQMwOq nd9fP0fetlFzkoVsH12/Ct5FZ7ni0nPGLO12K/WQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727641AbfKOGWQ (ORCPT ); Fri, 15 Nov 2019 01:22:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:51470 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727629AbfKOGWP (ORCPT ); Fri, 15 Nov 2019 01:22:15 -0500 Received: from localhost (unknown [104.132.150.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CFE8820728; Fri, 15 Nov 2019 06:22:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573798934; bh=pCATTbiF5NuP+y+tN0vyFUdJXhwdFoHoBkoltCfJUlg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Dg0OInXCeh50cIRb9Za/fr2AXMpImcmjTKZ65142G8vaV/B95uA5C5IGHDXxiPBOs 13OOn/1P+L90bRkq6b7ii8abooz0Y9R3AWAU4stQqZdQb9O9TN/10kjCLtbLoyxe7v fFTD7rSxc1iVuzQZyX9HevMSvvsxHcB5x6tXO9hY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Junaid Shahid , Paolo Bonzini , Ben Hutchings Subject: [PATCH 4.9 18/31] kvm: Convert kvm_lock to a mutex Date: Fri, 15 Nov 2019 14:20:47 +0800 Message-Id: <20191115062017.228649452@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191115062009.813108457@linuxfoundation.org> References: <20191115062009.813108457@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Junaid Shahid commit 0d9ce162cf46c99628cc5da9510b959c7976735b upstream. It doesn't seem as if there is any particular need for kvm_lock to be a spinlock, so convert the lock to a mutex so that sleepable functions (in particular cond_resched()) can be called while holding it. Signed-off-by: Junaid Shahid Signed-off-by: Paolo Bonzini [bwh: Backported to 4.9: - Drop changes in kvm_hyperv_tsc_notifier(), vm_stat_clear(), vcpu_stat_clear(), kvm_uevent_notify_change() - Adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- Documentation/virtual/kvm/locking.txt | 6 +++--- arch/s390/kvm/kvm-s390.c | 4 ++-- arch/x86/kvm/mmu.c | 4 ++-- arch/x86/kvm/x86.c | 10 +++++----- include/linux/kvm_host.h | 2 +- virt/kvm/kvm_main.c | 18 +++++++++--------- 6 files changed, 22 insertions(+), 22 deletions(-) --- a/Documentation/virtual/kvm/locking.txt +++ b/Documentation/virtual/kvm/locking.txt @@ -13,8 +13,8 @@ The acquisition orders for mutexes are a - kvm->slots_lock is taken outside kvm->irq_lock, though acquiring them together is quite rare. -For spinlocks, kvm_lock is taken outside kvm->mmu_lock. Everything -else is a leaf: no other lock is taken inside the critical sections. +Everything else is a leaf: no other lock is taken inside the critical +sections. 2: Exception ------------ @@ -142,7 +142,7 @@ See the comments in spte_has_volatile_bi ------------ Name: kvm_lock -Type: spinlock_t +Type: mutex Arch: any Protects: - vm_list --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -1422,13 +1422,13 @@ int kvm_arch_init_vm(struct kvm *kvm, un kvm->arch.sca = (struct bsca_block *) get_zeroed_page(alloc_flags); if (!kvm->arch.sca) goto out_err; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); sca_offset += 16; if (sca_offset + sizeof(struct bsca_block) > PAGE_SIZE) sca_offset = 0; kvm->arch.sca = (struct bsca_block *) ((char *) kvm->arch.sca + sca_offset); - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); sprintf(debug_name, "kvm-%u", current->pid); --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -4979,7 +4979,7 @@ mmu_shrink_scan(struct shrinker *shrink, int nr_to_scan = sc->nr_to_scan; unsigned long freed = 0; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { int idx; @@ -5029,7 +5029,7 @@ unlock: break; } - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); return freed; } --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5978,17 +5978,17 @@ static int kvmclock_cpufreq_notifier(str smp_call_function_single(freq->cpu, tsc_khz_changed, freq, 1); - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { kvm_for_each_vcpu(i, vcpu, kvm) { if (vcpu->cpu != freq->cpu) continue; kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); - if (vcpu->cpu != smp_processor_id()) + if (vcpu->cpu != raw_smp_processor_id()) send_ipi = 1; } } - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); if (freq->old < freq->new && send_ipi) { /* @@ -6126,12 +6126,12 @@ static void pvclock_gtod_update_fn(struc struct kvm_vcpu *vcpu; int i; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) kvm_for_each_vcpu(i, vcpu, kvm) kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu); atomic_set(&kvm_guest_has_master_clock, 0); - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); } static DECLARE_WORK(pvclock_gtod_work, pvclock_gtod_update_fn); --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -129,7 +129,7 @@ static inline bool is_error_page(struct extern struct kmem_cache *kvm_vcpu_cache; -extern spinlock_t kvm_lock; +extern struct mutex kvm_lock; extern struct list_head vm_list; struct kvm_io_range { --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -87,7 +87,7 @@ module_param(halt_poll_ns_shrink, uint, * kvm->lock --> kvm->slots_lock --> kvm->irq_lock */ -DEFINE_SPINLOCK(kvm_lock); +DEFINE_MUTEX(kvm_lock); static DEFINE_RAW_SPINLOCK(kvm_count_lock); LIST_HEAD(vm_list); @@ -666,9 +666,9 @@ static struct kvm *kvm_create_vm(unsigne if (r) goto out_err; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_add(&kvm->vm_list, &vm_list); - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); preempt_notifier_inc(); @@ -724,9 +724,9 @@ static void kvm_destroy_vm(struct kvm *k kvm_destroy_vm_debugfs(kvm); kvm_arch_sync_events(kvm); - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_del(&kvm->vm_list); - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); kvm_free_irq_routing(kvm); for (i = 0; i < KVM_NR_BUSES; i++) { if (kvm->buses[i]) @@ -3752,13 +3752,13 @@ static int vm_stat_get(void *_offset, u6 u64 tmp_val; *val = 0; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { stat_tmp.kvm = kvm; vm_stat_get_per_vm((void *)&stat_tmp, &tmp_val); *val += tmp_val; } - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); return 0; } @@ -3772,13 +3772,13 @@ static int vcpu_stat_get(void *_offset, u64 tmp_val; *val = 0; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { stat_tmp.kvm = kvm; vcpu_stat_get_per_vm((void *)&stat_tmp, &tmp_val); *val += tmp_val; } - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); return 0; }