From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 17146C77B73 for ; Thu, 20 Apr 2023 18:20:36 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ppYt4-0001At-65; Thu, 20 Apr 2023 14:20:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ppYt3-0001Ag-3W; Thu, 20 Apr 2023 14:20:05 -0400 Received: from smtp-out2.suse.de ([2001:67c:2178:6::1d]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1ppYt0-0000S9-RW; Thu, 20 Apr 2023 14:20:04 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id CE9D51F88F; Thu, 20 Apr 2023 18:19:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1682014799; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=FSLE+q64VX9JLiXEWz3ddwog8BPvbLelHYNjuBFVRtA=; b=1f+swi1JgK0+6JaGqzzgPwY+nyTEfkbqdaOdRcDalCg8zMtmC9C5IymokEokJPT2cxGotp H01O9NauUbVsSQGNbDMH5949HMeiHivRrOznPi5kxWs6dSwe2z1fcd9U08TIHO100bIV/w T/B+yJADpehVtgh/krOfa/3YPWpmtVE= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1682014799; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=FSLE+q64VX9JLiXEWz3ddwog8BPvbLelHYNjuBFVRtA=; b=027XXH713Kg3gxsr2zW29xte7eLCQOBsBy244Phx5LvBWTZ39n8UjMdYJjG+CPlpjfsI3m 03HGhFP0zwkLiuBg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 5049713584; Thu, 20 Apr 2023 18:19:59 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 8zBaBk+CQWSoLwAAMHmgww (envelope-from ); Thu, 20 Apr 2023 18:19:59 +0000 From: Fabiano Rosas To: Narayana Murty N , danielhb413@gmail.com, clg@kaod.org, david@gibson.dropbear.id.au, groug@kaod.org Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org, npiggin@linux.ibm.com, vajain21@linux.ibm.com, harshpb@linux.ibm.com, sbhat@linux.ibm.com Subject: Re: [PATCH] target: ppc: Correctly initialize HILE in HID-0 for book3s processors In-Reply-To: <20230420145055.10196-1-nnmlinux@linux.ibm.com> References: <20230420145055.10196-1-nnmlinux@linux.ibm.com> Date: Thu, 20 Apr 2023 15:19:56 -0300 Message-ID: <87v8hq8lgz.fsf@suse.de> MIME-Version: 1.0 Content-Type: text/plain Received-SPF: pass client-ip=2001:67c:2178:6::1d; envelope-from=farosas@suse.de; helo=smtp-out2.suse.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Narayana Murty N writes: > On PPC64 the HILE(Hypervisor Interrupt Little Endian) bit in HID-0 > register needs to be initialized as per isa 3.0b[1] section > 2.10. This bit gets copied to the MSR_LE when handling interrupts that > are handled in HV mode to establish the Endianess mode of the interrupt > handler. > > Qemu's ppc_interrupts_little_endian() depends on HILE to determine Host > endianness which is then used to determine the endianess of the guest dump. > Not quite. We use the interrupt endianness as a proxy to guest endianness to avoid reading MSR_LE at an inopportune moment when the guest is switching endianness. This is not dependent on host endianness. The HILE check is used when taking a memory dump of a HV-capable machine such as the emulated powernv. I think the actual issue might be that we're calling ppc_interrupts_little_endian with hv=true for the dump. > Currently the HILE bit is never set in the HID0 register even if the > qemu is running in Little-Endian mode. This causes the guest dumps to be > always taken in Big-Endian byte ordering. A guest memory dump of a > Little-Endian guest running on Little-Endian qemu guest fails with the > crash tool as illustrated below: > Could you describe in more detail what is your setup? Specifically whether both guests are running TCG or KVM (info kvm) and the state of the nested-hv capability in QEMU command line.