From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7CC641C29 for ; Fri, 22 Sep 2023 18:42:40 +0000 (UTC) Received: from mail-pl1-f179.google.com (mail-pl1-f179.google.com [209.85.214.179]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 815DAA9; Fri, 22 Sep 2023 11:42:39 -0700 (PDT) Received: by mail-pl1-f179.google.com with SMTP id d9443c01a7336-1c3cbfa40d6so22975025ad.1; Fri, 22 Sep 2023 11:42:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695408159; x=1696012959; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=uy4Qx3oAlemzZ68pG10cO3ool7kPh2NALLfQXvvFL/M=; b=H2pbrAMvmp8v/KmbukUu/IxvsRmZB1t7TwZCQVN0Sc8XFsyqE7dt6JE1po/DS2Ht5A AOKOflk+ncq6YqNGDxLBxE+HMcyBJFrTqRTVBErAGZFVG3GEkRH+b9MKT+U0jgQ31jGJ Uwbi7f6INYV7AuRzCSifMjtZCZsETV4rbKAj6yVRpvcSt9VuhqiCtHSLuj3kjktOW2/d OB7nHh+1pFnn5AzyKa+I8UPrjMU2h55G8/4eCS5VVzZ6R5w1mv9Mjdagol/nas0ZLrlM v4HJRvOnF0t/gM+HarXQrUy9qIC3WTGgGl1L1/KZXvE8zLkJKTCcF2k5zlqtw0YQ/59B ndBg== X-Gm-Message-State: AOJu0YyEGHIzEJ6N8s+UFqelRvTEURXeVp3GZm1mseFkHCpHEo6zySPG nvgbiNivJA6csWnifL4NBnfEHjyCOME= X-Google-Smtp-Source: AGHT+IE8Zjcqr0VIt3JGl7z6pVgiqpImUuwwkhyrlyBkP+oL46ew3ySJ0QlB4eTQ9I7Qsih5vWVmCg== X-Received: by 2002:a17:903:120a:b0:1c4:2641:7744 with SMTP id l10-20020a170903120a00b001c426417744mr332698plh.25.1695408158778; Fri, 22 Sep 2023 11:42:38 -0700 (PDT) Received: from liuwe-devbox-debian-v2 ([20.69.120.36]) by smtp.gmail.com with ESMTPSA id l20-20020a170903005400b001bc18e579aesm3831240pla.101.2023.09.22.11.42.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 22 Sep 2023 11:42:38 -0700 (PDT) Date: Fri, 22 Sep 2023 18:41:55 +0000 From: Wei Liu To: Saurabh Sengar Cc: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, mikelley@microsoft.com, vkuznets@redhat.com, ssengar@microsoft.com Subject: Re: [PATCH v3] x86/hyperv: Restrict get_vtl to only VTL platforms Message-ID: References: <1695182675-13405-1-git-send-email-ssengar@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1695182675-13405-1-git-send-email-ssengar@linux.microsoft.com> X-Spam-Status: No, score=-1.4 required=5.0 tests=BAYES_00, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Tue, Sep 19, 2023 at 09:04:35PM -0700, Saurabh Sengar wrote: > When Linux runs in a non-default VTL (CONFIG_HYPERV_VTL_MODE=y), > get_vtl() must never fail as its return value is used in negotiations > with the host. In the more generic case, (CONFIG_HYPERV_VTL_MODE=n) the > VTL is always zero so there's no need to do the hypercall. > > Make get_vtl() BUG() in case of failure and put the implementation under > "if IS_ENABLED(CONFIG_HYPERV_VTL_MODE)" to avoid the call altogether in > the most generic use case. > > Signed-off-by: Saurabh Sengar > Reviewed-by: Vitaly Kuznetsov Applied to hyperv-fixes. Thanks.