From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 ABFF715B547; Fri, 6 Sep 2024 23:40:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725666000; cv=none; b=P1vtKJl07BGF+V9dGPivuxK7BQTk8nL3spf1T+oakge3OD7EAN1gaqYsW//xD1pi7dKgXsbQPrhNAFVkdiiBYr797LR+C9G231/2JVf2I/q/ZN1c3dznK1CZPaDaJ/LBPY3fzDaWQQExGIxPCwG/o8xnSJh7mVPKXlSM17Ytiz8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725666000; c=relaxed/simple; bh=hMcMMc3MkfFHqrQ2mnexr17azQHrRCKNkfzIhM20zq8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jV2qINie/a8LJG2F+lbt8yHWV/NjSzcEvjXxkCkGAPsFNA20vVotbMHbXvrRlHTnFqM9RfqpunA8ao1qbcSPe2cILu/4ixnfAUl8nxZ1wmQwEXnMHI5sb0gswaQ7KuiuM9jz3BF5//5jnoXfQ3alx6m2GjMG6RU5ls8gfvHe+V8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aUqxPU4e; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aUqxPU4e" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D7131C4CEC4; Fri, 6 Sep 2024 23:39:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725666000; bh=hMcMMc3MkfFHqrQ2mnexr17azQHrRCKNkfzIhM20zq8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=aUqxPU4eo+UHEB4+25Nsa3J5VXEiBtO5Zn0tIMvz//qNKqiAho6aoWjY8jdFqoloj ma3w7Kif0kWJ+/gL2mcybS3wbdygVhLFo+JZSgzwc4G55zKPc2q+BUFAs3fQOhpjCV WIixBSX0VXl4JPSPOl3JoUs0nInHCPMbdRcCGCMVIURvNtlxpBpvsUxFwDqQRkQZct NvgfWj9KLtxCuuRlRTLfKCfKrNi5PQgdMeFyVcE3pjeUaECTo/iYMJFRJ4KCIMxBaq 9rpL3XN+6vooaVe4raSjzHig0PX2RtjUN+vk8ZV+He8QCmU7R1ZTeTaAbn8/HxuoMs ozBD4iKyqtfUA== Date: Fri, 6 Sep 2024 16:39:58 -0700 From: Nathan Chancellor To: Linus Torvalds Cc: Paolo Bonzini , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [GIT PULL] KVM fixes for Linux 6.11-rc7 Message-ID: <20240906233958.GA1968981@thelio-3990X> References: <20240906154517.191976-1-pbonzini@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@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: On Fri, Sep 06, 2024 at 03:38:16PM -0700, Linus Torvalds wrote: > On Fri, 6 Sept 2024 at 08:45, Paolo Bonzini wrote: > > > > - Specialize return value of KVM_CHECK_EXTENSION(KVM_CAP_READONLY_MEM), > > based on VM type > > Grr. This actually causes a build warning with clang, but I didn't > notice in my "between pulls" build check, because that is with gcc. > > So now it's merged with this error: > > arch/x86/kvm/x86.c:4819:2: error: unannotated fall-through between > switch labels [-Werror,-Wimplicit-fallthrough] > > and I'm actually surprised that gcc didn't warn about this too. Yeah, GCC does not warn when falling through to a break or return, as I mention in the patch I sent for this (I was going to keep an eye out for the pull request and comment before it went in but looks like I missed it): https://lore.kernel.org/kvm/20240905-kvm-x86-avoid-clang-implicit-fallthrough-v1-1-f2e785f1aa45@kernel.org/ > We definitely enable -Wimplicit-fallthrough on gcc too, but apparently > it's not functional: falling through to a "break" statement seems to > not warn with gcc. Which is nonsensical, but whatever. This was brought up to GCC at one point and they considered its current behavior as working as intended from my understanding: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91432 Cheers, Nathan