From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: Re: [RFC PATCH 00/45] KVM: arm/arm64: Rework virtual GIC emulation Date: Wed, 30 Mar 2016 21:55:55 +0200 Message-ID: <20160330195555.GL4126@cbox> References: <1458871508-17279-1-git-send-email-andre.przywara@arm.com> <56FA7F29.4060005@arm.com> <56FBBBC2.6010602@arm.com> <56FBC16A.7040404@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Vladimir Murzin , Andre Przywara , Eric Auger , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org To: Marc Zyngier Return-path: Received: from mail-wm0-f47.google.com ([74.125.82.47]:33701 "EHLO mail-wm0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753481AbcC3Tz4 (ORCPT ); Wed, 30 Mar 2016 15:55:56 -0400 Received: by mail-wm0-f47.google.com with SMTP id r72so113480115wmg.0 for ; Wed, 30 Mar 2016 12:55:55 -0700 (PDT) Content-Disposition: inline In-Reply-To: <56FBC16A.7040404@arm.com> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Mar 30, 2016 at 01:07:06PM +0100, Marc Zyngier wrote: > On 30/03/16 12:42, Vladimir Murzin wrote: > > On 29/03/16 14:12, Vladimir Murzin wrote: > >> Hi Andre, > >> > >> On 25/03/16 02:04, Andre Przywara wrote: > >>> Please have a look at the series, review it and give the code some > >>> serious testing (and possibly debugging). All feedback is appreciated. > >> > >> I see that with the new vgic implementation kvmtool starts throwing: > >> > >> kvm [1273]: Unable to register VGICv3 redist MMIO regions > >> > > > > It comes from kvm_io_bus_register_dev() > > > > if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1) > > return -ENOSPC; > > > > with bus->dev_count being 1000 > > Ouch. That's a consequence of having one "device" per actual register > set, I believe. So either we bump this limit up by a factor 10 (at > least), or we switch back to the old way of handling access to the GIC > regions (big "catch-all", and further demuxing). > > Thoughts? > Since we have to have code to iterate through the individual register regions for the userland MMIO accesses anyway, I think we should just revert back to the old way. -Christoffer From mboxrd@z Thu Jan 1 00:00:00 1970 From: christoffer.dall@linaro.org (Christoffer Dall) Date: Wed, 30 Mar 2016 21:55:55 +0200 Subject: [RFC PATCH 00/45] KVM: arm/arm64: Rework virtual GIC emulation In-Reply-To: <56FBC16A.7040404@arm.com> References: <1458871508-17279-1-git-send-email-andre.przywara@arm.com> <56FA7F29.4060005@arm.com> <56FBBBC2.6010602@arm.com> <56FBC16A.7040404@arm.com> Message-ID: <20160330195555.GL4126@cbox> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Mar 30, 2016 at 01:07:06PM +0100, Marc Zyngier wrote: > On 30/03/16 12:42, Vladimir Murzin wrote: > > On 29/03/16 14:12, Vladimir Murzin wrote: > >> Hi Andre, > >> > >> On 25/03/16 02:04, Andre Przywara wrote: > >>> Please have a look at the series, review it and give the code some > >>> serious testing (and possibly debugging). All feedback is appreciated. > >> > >> I see that with the new vgic implementation kvmtool starts throwing: > >> > >> kvm [1273]: Unable to register VGICv3 redist MMIO regions > >> > > > > It comes from kvm_io_bus_register_dev() > > > > if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1) > > return -ENOSPC; > > > > with bus->dev_count being 1000 > > Ouch. That's a consequence of having one "device" per actual register > set, I believe. So either we bump this limit up by a factor 10 (at > least), or we switch back to the old way of handling access to the GIC > regions (big "catch-all", and further demuxing). > > Thoughts? > Since we have to have code to iterate through the individual register regions for the userland MMIO accesses anyway, I think we should just revert back to the old way. -Christoffer