From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52366) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dSORD-0006sC-03 for qemu-devel@nongnu.org; Tue, 04 Jul 2017 10:04:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dSOR9-0000pN-0X for qemu-devel@nongnu.org; Tue, 04 Jul 2017 10:04:23 -0400 References: <20170704135454.13467-1-david@gibson.dropbear.id.au> From: Thomas Huth Message-ID: <417cce4a-de1e-e8f5-96a9-a73d0fbe3446@redhat.com> Date: Tue, 4 Jul 2017 16:04:13 +0200 MIME-Version: 1.0 In-Reply-To: <20170704135454.13467-1-david@gibson.dropbear.id.au> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] spapr: Only report host/guest IOMMU page size mismatches on KVM List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Gibson , peter.maydell@linaro.org, agraf@suse.de, aik@ozlabs.ru Cc: qemu-devel@nongnu.org, qemu-ppc@nongnu.org On 04.07.2017 15:54, David Gibson wrote: > We print a warning if the spapr IOMMU isn't configured to support a page > size matching the host page size backing RAM. When that's the case we need > more complex logic to translate VFIO mappings, which is slower. > > But, it's not so slow that it would be at all noticeable against the > general slowness of TCG. So, only warn when using KVM. This removes some > noisy and unhelpful warnings from make check on hosts with page sizes > which typically differ from those on POWER (e.g. Sparc). > > Reported-by: Peter Maydell > Signed-off-by: David Gibson > --- > hw/ppc/spapr_pci.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c > index cc1588d..a52dcf8 100644 > --- a/hw/ppc/spapr_pci.c > +++ b/hw/ppc/spapr_pci.c > @@ -1745,7 +1745,8 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp) > } > > /* DMA setup */ > - if ((sphb->page_size_mask & qemu_getrampagesize()) == 0) { > + if (((sphb->page_size_mask & qemu_getrampagesize()) == 0) > + && kvm_enabled()) { Since you've put me on CC: ... too much parenthesis for my taste ;-) Apart from that, Reviewed-by: Thomas Huth