From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46287) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fLFz5-0000Yq-1T for qemu-devel@nongnu.org; Tue, 22 May 2018 18:42:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fLFz1-000889-Up for qemu-devel@nongnu.org; Tue, 22 May 2018 18:42:23 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:47370 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fLFz1-00087P-Ps for qemu-devel@nongnu.org; Tue, 22 May 2018 18:42:19 -0400 From: Laszlo Ersek References: <1526801333-30613-1-git-send-email-whois.zihan.yang@gmail.com> <1526801333-30613-4-git-send-email-whois.zihan.yang@gmail.com> <17a3765f-b835-2d45-e8b9-ffd4aff909f9@redhat.com> Message-ID: Date: Wed, 23 May 2018 00:42:09 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC 3/3] acpi-build: allocate mcfg for multiple host bridges List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Marcel Apfelbaum , Zihan Yang , qemu-devel@nongnu.org Cc: "Michael S. Tsirkin" , Igor Mammedov , Alex Williamson , Eric Auger , Drew Jones , Wei Huang Hold on, On 05/22/18 21:51, Laszlo Ersek wrote: > It had taken years until the edk2 core gained a universal > PciHostBridgeDxe driver with a well-defined platform customization > interface, and that interface doesn't support multiple domains / > segments. after doing a bit more research: I was wrong about this. What I remembered was not the current state. Edk2 does seem to support multiple domains, with different segment numbers, ECAM base addresses, and bus number ranges. If we figure out a placement strategy or an easy to consume representation of these data for the firmware, it might be possible for OVMF to hook them into the edk2 core (although not in the earliest firmware phases, such as SEC and PEI). In retrospect, I'm honestly surprised that so much multi-segment support has been upstreamed to the edk2 core. Sorry about the FUD. (My general points remain valid, for the record... But perhaps they no longer matter for this discussion.) (I meant to send this message soon after , but my internet connection had to die right then.) Thanks Laszlo