From owner-freebsd-virtualization@freebsd.org Fri May 21 14:09:17 2021 Return-Path: Delivered-To: freebsd-virtualization@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 13A366338B8 for ; Fri, 21 May 2021 14:09:17 +0000 (UTC) (envelope-from freebsd@omnilan.de) Received: from mx0.gentlemail.de (mx0.gentlemail.de [IPv6:2a00:e10:2800::a130]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "CN", Issuer "CN" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4FmpPm2Wxyz3Nhy for ; Fri, 21 May 2021 14:09:15 +0000 (UTC) (envelope-from freebsd@omnilan.de) Received: from mh0.gentlemail.de (mh0.gentlemail.de [IPv6:2a00:e10:2800:0:0:0:0:a135]) by mx0.gentlemail.de (8.15.2/8.15.2) with ESMTP id 14LE9AxH053576; Fri, 21 May 2021 16:09:12 +0200 (CEST) (envelope-from freebsd@omnilan.de) Received: from titan.inop.mo1.omnilan.net (s1.omnilan.de [217.91.127.234]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mh0.gentlemail.de (Postfix) with ESMTPSA id C4B378FA; Fri, 21 May 2021 16:09:10 +0200 (CEST) Subject: Re: FreeBSD 12.1 i386 on Hyper-V Fails to Mount Root From: Harry Schmalzbauer To: Konstantin Belousov , Wei Hu Cc: "freebsd-virtualization@freebsd.org" References: <22bbe4cd-82ed-b826-9ac0-05ef8aceba0e@omnilan.de> <7986b561-dd26-a134-e76d-530900363deb@omnilan.de> Organization: OmniLAN Message-ID: Date: Fri, 21 May 2021 16:09:10 +0200 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Greylist: inspected by milter-greylist-4.6.2 (mx0.gentlemail.de [IPv6:2a00:e10:2800:0:0:0:0:a130]); Fri, 21 May 2021 16:09:14 +0200 (CEST) for IP:'2a00:e10:2800::a135' DOMAIN:'mh0.gentlemail.de' HELO:'mh0.gentlemail.de' FROM:'freebsd@omnilan.de' RCPT:'' X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx0.gentlemail.de [IPv6:2a00:e10:2800:0:0:0:0:a130]); Fri, 21 May 2021 16:09:14 +0200 (CEST) X-Rspamd-Queue-Id: 4FmpPm2Wxyz3Nhy X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of freebsd@omnilan.de designates 2a00:e10:2800::a130 as permitted sender) smtp.mailfrom=freebsd@omnilan.de X-Spamd-Result: default: False [-2.80 / 15.00]; TO_DN_EQ_ADDR_SOME(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+mx]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[omnilan.de]; ARC_NA(0.00)[]; HAS_ORG_HEADER(0.00)[]; RCVD_COUNT_THREE(0.00)[3]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RBL_DBL_DONT_QUERY_IPS(0.00)[2a00:e10:2800::a130:from]; NEURAL_HAM_LONG(-0.98)[-0.980]; NEURAL_HAM_SHORT(-1.00)[-1.000]; SPAMHAUS_ZRD(0.00)[2a00:e10:2800::a130:from:127.0.2.255]; NEURAL_HAM_MEDIUM(-0.52)[-0.516]; FREEMAIL_TO(0.00)[gmail.com,microsoft.com]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:61157, ipnet:2a00:e10:2800::/38, country:DE]; RCVD_TLS_LAST(0.00)[]; MAILMAN_DEST(0.00)[freebsd-virtualization] X-BeenThere: freebsd-virtualization@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: "Discussion of various virtualization techniques FreeBSD supports." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 May 2021 14:09:17 -0000 Am 21.05.2021 um 14:50 schrieb Harry Schmalzbauer: > Am 19.05.2021 um 13:26 schrieb Harry Schmalzbauer: > > ... >> I can just assure that I tracked it down to the single r332489 >> committ which makes vmbus(4) failing on i386. >> Verification done: >> - built/installed world&kernel on i386 HyV guest with r332488 >>   reboot fine. >> - built/installed kernel on the same vm after svnlite up -r 332489 >>   reboot fails with "vmbus0: cannot find free IDT vector" >> - loaded kernel.old/kernel, did revert 332489, by 'svnlite up -r >> 332488' and compiled/reinstalled kernel (again r332488) >>   reboot fine. > > While having hard time catching up with x86 basics, I found another > oddity: > On Hyper-V gen1, the maximum ammount of RAM I can assign a FreeBSD > guest beeing able to boot i386 is 3914MB, startring with r332489. > As soon as I configure the guest to have 3916MB or more, FreeBSD-i386 > r332489 booting leads to guest reset.  Loader starts kernel, machine > reboots. > Either reverting to r332488 or reducing guest-RAM solves this. > > The most interesting fact here is that I couldn't reproduce it on ESXi. > I ducplicated the Hyper-V HDD and started the exactly same code on > ESXi(v6) guest, where it doesn't crash!  I can boot FreeBSD-i386 > r332489 with any ammount of guest-RAM on ESXi. > (speaking for GENERIC, non-PAE) Now that I have a living r332489 i386 available, I checked some sysctl. It seems on ESXi and i386, large page mappings aren't used anymore, or is it just wrong indicating? These valueas are suspicious to my eyes: kern.version: FreeBSD 12.0-CURRENT #0 r332489: Fri May 21 15:32:35 CEST 2021     root@esxtest:/usr/obj/altroot/usr/src/i386.i386/sys/GENERIC hw.pagesizes: 4096 0 hw.realmem: 0 vm.min_kernel_address: 0 vm.max_kernel_address: 4286578688 vm.kvm_free: -549453824 vm.kvm_size: -16777216 vm.pmap.pg_ps_enabled: 0 kern.version: FreeBSD 12.0-CURRENT #1 r332488: Fri May 21 17:35:58 CEST 2021     root@esxtest:/usr/obj/altroot/usr/src/i386.i386/sys/GENERIC hw.pagesizes: 4096 4194304 hw.realmem: 0 vm.min_kernel_address: 3220172800 vm.max_kernel_address: 4294963200 vm.kvm_free: 624947200 vm.kvm_size: 1073737728 vm.pmap.pg_ps_enabled: 1 Thanks for any hints, -harry