From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cornelia Huck Subject: Re: [PATCH v2 3/5] KVM: s390: adapter interrupt sources Date: Fri, 21 Mar 2014 11:07:13 +0100 Message-ID: <20140321110713.4b2b29e8.cornelia.huck@de.ibm.com> References: <1395079899-29239-1-git-send-email-cornelia.huck@de.ibm.com> <1395079899-29239-4-git-send-email-cornelia.huck@de.ibm.com> <532C05CB.5010604@de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, qemu-devel@nongnu.org, agraf@suse.de, pbonzini@redhat.com, gleb@kernel.org To: Christian Borntraeger Return-path: Received: from e06smtp11.uk.ibm.com ([195.75.94.107]:45814 "EHLO e06smtp11.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760554AbaCUKHU (ORCPT ); Fri, 21 Mar 2014 06:07:20 -0400 Received: from /spool/local by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 21 Mar 2014 10:07:18 -0000 In-Reply-To: <532C05CB.5010604@de.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, 21 Mar 2014 10:26:35 +0100 Christian Borntraeger wrote: > On 17/03/14 19:11, Cornelia Huck wrote: > > Add a new interface to register/deregister sources of adapter interrupts > > identified by an unique id via the flic. Adapters may also be maskable > > and carry a list of pinned pages. > > > > These adapters will be used by irq routing later. > > > > Signed-off-by: Cornelia Huck > > [...] > > > +static int kvm_s390_adapter_map(struct kvm *kvm, unsigned int id, __u64 addr) > > +{ > > + struct s390_io_adapter *adapter = get_io_adapter(kvm, id); > > + struct s390_map_info *map; > > + int ret; > > + > > + if (!adapter || !addr) > > + return -EINVAL; > > + > > + map = kzalloc(sizeof(*map), GFP_KERNEL); > > + if (!map) { > > + ret = -ENOMEM; > > + goto out; > > + } > > + INIT_LIST_HEAD(&map->list); > > + map->addr = addr; > > + ret = get_user_pages_fast(addr, 1, 1, &map->page); > > + if (ret < 0) > > + goto out; > > + BUG_ON(ret != 1); > > + down_write(&adapter->maps_lock); > > + list_add_tail(&map->list, &adapter->maps); > > + up_write(&adapter->maps_lock); > > + ret = 0; > > Can you limit the amount of pinned pages to something sane, e.g. 1MB? > As far as I can see, QEMU will fall back to non-irqfd if the mapping fails. I'll introduce a counter for that. > > Otherwise looks good. > > Acked-by: Christian Borntraeger >