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 29281D0E6C8 for ; Tue, 25 Nov 2025 11:26:19 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vNrB5-0002pk-1y; Tue, 25 Nov 2025 06:25:47 -0500 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 1vNrAr-0002me-Qz for qemu-devel@nongnu.org; Tue, 25 Nov 2025 06:25:36 -0500 Received: from linux.microsoft.com ([13.77.154.182]) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vNrAp-0005zx-1P for qemu-devel@nongnu.org; Tue, 25 Nov 2025 06:25:32 -0500 Received: from example.com (unknown [167.220.208.65]) by linux.microsoft.com (Postfix) with ESMTPSA id 9C6F12120E8F; Tue, 25 Nov 2025 03:25:24 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 9C6F12120E8F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1764069925; bh=od8ZsCDDKmFt5JQQcLKQ2rzSmGilHXZWjhvv8NxuMII=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Ot5WpxCxJP57+6Rl2nofyLt9FfAHva4lurJAsx8+RIY4XX3EzadA5eChZR9bK3bth Ir/Czw/z0M/n63/OZKAxE5amuRIqipApE9fv4eEDSItHePbAh1KOSYfXavhYAS1yhN 5ZEU53fiV2M1+dQAd0cFibjBv6jVfCM7Df0xJixE= Date: Tue, 25 Nov 2025 12:25:22 +0100 From: Magnus Kulke To: Bernhard Beschow Cc: qemu-devel@nongnu.org, Paolo Bonzini Subject: Re: [PULL 28/35] target/i386/mshv: Implement mshv_vcpu_run() Message-ID: References: <20251009075026.505715-1-pbonzini@redhat.com> <20251009075026.505715-29-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Received-SPF: pass client-ip=13.77.154.182; envelope-from=magnuskulke@linux.microsoft.com; helo=linux.microsoft.com X-Spam_score_int: -19 X-Spam_score: -2.0 X-Spam_bar: -- X-Spam_report: (-2.0 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 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 On Sun, Nov 09, 2025 at 01:10:50PM +0000, Bernhard Beschow wrote: > >+static int read_memory(const CPUState *cpu, uint64_t initial_gva, > >+ uint64_t initial_gpa, uint64_t gva, uint8_t *data, > >+ size_t len) > >+{ > >+ int ret; > >+ uint64_t gpa, flags; > >+ > >+ if (gva == initial_gva) { > >+ gpa = initial_gpa; > > This assignment is never read and this branch leaves `data` untouched... > > >+ } else { > >+ flags = HV_TRANSLATE_GVA_VALIDATE_READ; > >+ ret = translate_gva(cpu, gva, &gpa, flags); > >+ if (ret < 0) { > >+ return -1; > >+ } > >+ > > while this block: > > >+ ret = mshv_guest_mem_read(gpa, data, len, false, false); > >+ if (ret < 0) { > >+ error_report("failed to read guest mem"); > >+ return -1; > >+ } > > is only executed in the else branch which is inconsistent to write_memory(). Is that intended? If so, do we really need the unused assignment above? > > Best regards, > Bernhard > Thank you for spotting this Bernhard, this is a remnant from an attempt to optimize gva=>gpa translations, but currently it's dead code. I'll send a patch. best, magnus