From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: [patch 2/4] KVM: move coalesced_mmio locking to its own device Date: Mon, 18 May 2009 13:56:03 -0300 Message-ID: <20090518170855.346048603@localhost.localdomain> References: <20090518165601.747763120@localhost.localdomain> Cc: Marcelo Tosatti To: kvm@vger.kernel.org Return-path: Received: from mx2.redhat.com ([66.187.237.31]:55602 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750930AbZERRLu (ORCPT ); Mon, 18 May 2009 13:11:50 -0400 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id n4IHBqtV010266 for ; Mon, 18 May 2009 13:11:52 -0400 Content-Disposition: inline; filename=coalesced-mmio-lock Sender: kvm-owner@vger.kernel.org List-ID: Signed-off-by: Marcelo Tosatti Index: kvm/virt/kvm/coalesced_mmio.c =================================================================== --- kvm.orig/virt/kvm/coalesced_mmio.c +++ kvm/virt/kvm/coalesced_mmio.c @@ -26,9 +26,10 @@ static int coalesced_mmio_in_range(struc if (!is_write) return 0; - /* kvm->lock is taken by the caller and must be not released before - * dev.read/write - */ + /* + * dev->lock must not be released before coalesced_mmio_write. + */ + mutex_lock(&dev->lock); /* Are we able to batch it ? */ @@ -41,6 +42,7 @@ static int coalesced_mmio_in_range(struc KVM_COALESCED_MMIO_MAX; if (next == dev->kvm->coalesced_mmio_ring->first) { /* full */ + mutex_unlock(&dev->lock); return 0; } @@ -57,6 +59,7 @@ static int coalesced_mmio_in_range(struc addr + len <= zone->addr + zone->size) return 1; } + mutex_unlock(&dev->lock); return 0; } @@ -67,8 +70,6 @@ static void coalesced_mmio_write(struct (struct kvm_coalesced_mmio_dev*)this->private; struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring; - /* kvm->lock must be taken by caller before call to in_range()*/ - /* copy data in first free entry of the ring */ ring->coalesced_mmio[ring->last].phys_addr = addr; @@ -76,6 +77,7 @@ static void coalesced_mmio_write(struct memcpy(ring->coalesced_mmio[ring->last].data, val, len); smp_wmb(); ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX; + mutex_unlock(&dev->lock); } static void coalesced_mmio_destructor(struct kvm_io_device *this) @@ -90,6 +92,8 @@ int kvm_coalesced_mmio_init(struct kvm * dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL); if (!dev) return -ENOMEM; + mutex_init(&dev->lock); + dev->dev.write = coalesced_mmio_write; dev->dev.in_range = coalesced_mmio_in_range; dev->dev.destructor = coalesced_mmio_destructor; @@ -109,16 +113,16 @@ int kvm_vm_ioctl_register_coalesced_mmio if (dev == NULL) return -EINVAL; - mutex_lock(&kvm->lock); + mutex_lock(&dev->lock); if (dev->nb_zones >= KVM_COALESCED_MMIO_ZONE_MAX) { - mutex_unlock(&kvm->lock); + mutex_unlock(&dev->lock); return -ENOBUFS; } dev->zone[dev->nb_zones] = *zone; dev->nb_zones++; - mutex_unlock(&kvm->lock); + mutex_unlock(&dev->lock); return 0; } @@ -132,7 +136,7 @@ int kvm_vm_ioctl_unregister_coalesced_mm if (dev == NULL) return -EINVAL; - mutex_lock(&kvm->lock); + mutex_lock(&dev->lock); i = dev->nb_zones; while(i) { @@ -150,7 +154,7 @@ int kvm_vm_ioctl_unregister_coalesced_mm i--; } - mutex_unlock(&kvm->lock); + mutex_unlock(&dev->lock); return 0; } Index: kvm/virt/kvm/coalesced_mmio.h =================================================================== --- kvm.orig/virt/kvm/coalesced_mmio.h +++ kvm/virt/kvm/coalesced_mmio.h @@ -12,6 +12,7 @@ struct kvm_coalesced_mmio_dev { struct kvm_io_device dev; struct kvm *kvm; + struct mutex lock; int nb_zones; struct kvm_coalesced_mmio_zone zone[KVM_COALESCED_MMIO_ZONE_MAX]; }; --