From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:40603 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751150AbbEBM0M (ORCPT ); Sat, 2 May 2015 08:26:12 -0400 Subject: Patch "KVM: s390: no need to hold the kvm->mutex for floating interrupts" has been added to the 3.19-stable tree To: borntraeger@de.ibm.com, cornelia.huck@de.ibm.com, gregkh@linuxfoundation.org, jfrei@linux.vnet.ibm.com Cc: , From: Date: Sat, 02 May 2015 14:25:36 +0200 Message-ID: <14305695361845@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled KVM: s390: no need to hold the kvm->mutex for floating interrupts to the 3.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-s390-no-need-to-hold-the-kvm-mutex-for-floating-interrupts.patch and it can be found in the queue-3.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 69a8d456263849152826542c7cb0a164b90e68a8 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Wed, 17 Dec 2014 10:36:04 +0100 Subject: KVM: s390: no need to hold the kvm->mutex for floating interrupts From: Christian Borntraeger commit 69a8d456263849152826542c7cb0a164b90e68a8 upstream. The kvm mutex was (probably) used to protect against cpu hotplug. The current code no longer needs to protect against that, as we only rely on CPU data structures that are guaranteed to be available if we can access the CPU. (e.g. vcpu_create will put the cpu in the array AFTER the cpu is ready). Signed-off-by: Christian Borntraeger Acked-by: Cornelia Huck Reviewed-by: Jens Freimann Signed-off-by: Greg Kroah-Hartman --- arch/s390/kvm/interrupt.c | 8 -------- 1 file changed, 8 deletions(-) --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -1131,7 +1131,6 @@ struct kvm_s390_interrupt_info *kvm_s390 if ((!schid && !cr6) || (schid && cr6)) return NULL; - mutex_lock(&kvm->lock); fi = &kvm->arch.float_int; spin_lock(&fi->lock); inti = NULL; @@ -1159,7 +1158,6 @@ struct kvm_s390_interrupt_info *kvm_s390 if (list_empty(&fi->list)) atomic_set(&fi->active, 0); spin_unlock(&fi->lock); - mutex_unlock(&kvm->lock); return inti; } @@ -1172,7 +1170,6 @@ static int __inject_vm(struct kvm *kvm, int sigcpu; int rc = 0; - mutex_lock(&kvm->lock); fi = &kvm->arch.float_int; spin_lock(&fi->lock); if (fi->irq_count >= KVM_S390_MAX_FLOAT_IRQS) { @@ -1225,7 +1222,6 @@ static int __inject_vm(struct kvm *kvm, kvm_s390_vcpu_wakeup(kvm_get_vcpu(kvm, sigcpu)); unlock_fi: spin_unlock(&fi->lock); - mutex_unlock(&kvm->lock); return rc; } @@ -1379,7 +1375,6 @@ void kvm_s390_clear_float_irqs(struct kv struct kvm_s390_float_interrupt *fi; struct kvm_s390_interrupt_info *n, *inti = NULL; - mutex_lock(&kvm->lock); fi = &kvm->arch.float_int; spin_lock(&fi->lock); list_for_each_entry_safe(inti, n, &fi->list, list) { @@ -1389,7 +1384,6 @@ void kvm_s390_clear_float_irqs(struct kv fi->irq_count = 0; atomic_set(&fi->active, 0); spin_unlock(&fi->lock); - mutex_unlock(&kvm->lock); } static inline int copy_irq_to_user(struct kvm_s390_interrupt_info *inti, @@ -1429,7 +1423,6 @@ static int get_all_floating_irqs(struct int ret = 0; int n = 0; - mutex_lock(&kvm->lock); fi = &kvm->arch.float_int; spin_lock(&fi->lock); @@ -1448,7 +1441,6 @@ static int get_all_floating_irqs(struct } spin_unlock(&fi->lock); - mutex_unlock(&kvm->lock); return ret < 0 ? ret : n; } Patches currently in stable-queue which might be from borntraeger@de.ibm.com are queue-3.19/kvm-s390-zero-out-current-vmdb-of-stsi-before-including-level3-data.patch queue-3.19/kvm-s390-reinjection-of-irqs-can-fail-in-the-tpi-handler.patch queue-3.19/kvm-s390-fix-get_all_floating_irqs.patch queue-3.19/kvm-s390-no-need-to-hold-the-kvm-mutex-for-floating-interrupts.patch queue-3.19/kvm-s390-fix-handling-of-write-errors-in-the-tpi-handler.patch