From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55084) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gNEzF-0008B4-2o for qemu-devel@nongnu.org; Thu, 15 Nov 2018 05:35:08 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gNEz8-00056K-02 for qemu-devel@nongnu.org; Thu, 15 Nov 2018 05:34:58 -0500 Received: from mail-wr1-f45.google.com ([209.85.221.45]:44615) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gNEz7-00054Y-PZ for qemu-devel@nongnu.org; Thu, 15 Nov 2018 05:34:53 -0500 Received: by mail-wr1-f45.google.com with SMTP id j17-v6so20602232wrq.11 for ; Thu, 15 Nov 2018 02:34:50 -0800 (PST) References: From: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= Message-ID: <975c044d-f44f-ca85-5ea8-28bce1cc6e40@redhat.com> Date: Thu, 15 Nov 2018 11:34:47 +0100 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [OVMF+VIFO+QEMU] Large VM RAM allocation = Long Boot Times List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: A Z , edk2-devel@lists.01.org, QEMU Developers Cc'ing qemu-devel@ On 15/11/18 6:58, A Z wrote: > This is an issue that involves a combination of different software > packages, so my apologies in advance if this is the wrong list to post on. > > I'm experiencing terrible boot times when I assign a large amount of RAM to > a VM when used in combination with VIFO/PCI-passthrough. > > On a VM with a Nvidia GTX 970 + USB controller and 24GiB of RAM assigned, > the time to the TianoCore splash screen is ~5 minutes. It's then ~30 > seconds before Windows 10 begins to boot (spinning dots). During this time, > the QEMU CPU core threads are 100% busy. > > According to `perf`, the QMU CPU core threads are spending most of their > time waiting on a spinlock over kvm->mmu_lock that's created by > kvm_zap_gfn_range. > > I'm fairly certain that ~1 year ago (if not longer) the same configuration > didn't take this long to boot. > > Regards, > Adam