From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755200AbeDTNvQ (ORCPT ); Fri, 20 Apr 2018 09:51:16 -0400 Received: from mail-oi0-f66.google.com ([209.85.218.66]:40409 "EHLO mail-oi0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754888AbeDTNvO (ORCPT ); Fri, 20 Apr 2018 09:51:14 -0400 X-Google-Smtp-Source: AIpwx49prTuZErN425Q+0zAJCjfR+KW2eP2TApn/TWurroknT3X6gRVGSXJ3vZw42GPK0QBPs8+rSZcEBXJLZ4NkQrA= MIME-Version: 1.0 In-Reply-To: <20180420091537.1c6cb06b.cohuck@redhat.com> References: <1524185248-51744-1-git-send-email-wanpengli@tencent.com> <20180420091537.1c6cb06b.cohuck@redhat.com> From: Wanpeng Li Date: Fri, 20 Apr 2018 21:51:13 +0800 Message-ID: Subject: Re: [PATCH v2] KVM: Extend MAX_IRQ_ROUTES to 4096 for all archs To: Cornelia Huck Cc: LKML , kvm , Paolo Bonzini , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Tonny Lu , Christian Borntraeger , Janosch Frank Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id w3KDpLlE028262 2018-04-20 15:15 GMT+08:00 Cornelia Huck : > On Thu, 19 Apr 2018 17:47:28 -0700 > Wanpeng Li wrote: > >> From: Wanpeng Li >> >> Our virtual machines make use of device assignment by configuring >> 12 NVMe disks for high I/O performance. Each NVMe device has 129 >> MSI-X Table entries: >> Capabilities: [50] MSI-X: Enable+ Count=129 Masked-Vector table: BAR=0 offset=00002000 >> The windows virtual machines fail to boot since they will map the number of >> MSI-table entries that the NVMe hardware reported to the bus to msi routing >> table, this will exceed the 1024. This patch extends MAX_IRQ_ROUTES to 4096 >> for all archs, in the future this might be extended again if needed. >> >> Cc: Paolo Bonzini >> Cc: Radim Krčmář >> Cc: Tonny Lu >> Cc: Cornelia Huck >> Signed-off-by: Wanpeng Li >> Signed-off-by: Tonny Lu >> --- >> v1 -> v2: >> * extend MAX_IRQ_ROUTES to 4096 for all archs >> >> include/linux/kvm_host.h | 6 ------ >> 1 file changed, 6 deletions(-) >> >> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h >> index 6930c63..0a5c299 100644 >> --- a/include/linux/kvm_host.h >> +++ b/include/linux/kvm_host.h >> @@ -1045,13 +1045,7 @@ static inline int mmu_notifier_retry(struct kvm *kvm, unsigned long mmu_seq) >> >> #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING >> >> -#ifdef CONFIG_S390 >> #define KVM_MAX_IRQ_ROUTES 4096 //FIXME: we can have more than that... > > What about /* might need extension/rework in the future */ instead of > the FIXME? Yeah, I guess the maintainers can help to fix it when applying. :) > > As far as I understand, 4096 should cover most architectures and the > sane end of s390 configurations, but will not be enough at the scarier > end of s390. (I'm not sure how much it matters in practice.) > > Do we want to make this a tuneable in the future? Do some kind of > dynamic allocation? Not sure whether it is worth the trouble. I think keep as it is currently. Regards, Wanpeng Li