From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 367813B1A4; Tue, 29 Apr 2025 14:46:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745938011; cv=none; b=LaQShacy5NDlH5OxM0sA8nslJhT0tecLPUXxT736ro86ec2K6Sb1E4cAgmUacX9vwB+FYKEaYcZ1QRhv5WT1aCbi1hqw1nbIeyvq5lzqw3Pcognt8GPR/C/2csafrfE6NrOIZJb8UxjVbs5um2yOFMMxAhstmnUZFgbW2UIgIsE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745938011; c=relaxed/simple; bh=vg3hLhxa0BT1lWtJ0wGlClMnOrlCg2NBvt6huItHUVI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HSkqekv8j08pmtzkkBs+zOt5NETHYeRO9mt0pQj4dcPkqUEGoEKC8PL8+Z7KaGWceCOE6IiDU1KU13SubvTJCXvF/osGQ/rv8ax0PY69XFUntTGF0t0mB9xNHLQOYWwcZwzu+87gDf7GC54ohuV3OqrKZtvTbP285l2ZClTidrE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=it0iWgin; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="it0iWgin" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=wb8yKBSDCNd+wK+Tsc/EBbJclD6fbaVvRfrOmBDAvfg=; b=it0iWgingi7xBwddoimoLQmsC8 P1qAwKNqpnUT+k+Oq1/EnY2+drj48W4KhIqm0UtjfhuV4TC75P9XnisekHhjPnMUrqDraqOqH5e75 fr7NrtYVqMB8/NY/ibTmdfc69swXp3Lm7ZYNhQ6jGzXnYHk1u320d7RMzOhOv269gP4h+b9IsFGGx K2aG4+fnJIFiD6DHGh6t1Pgal1j8P/KDpUeXf4uVwKFBHzlQQ+NnnZkYjGpym44+aeON7V/Usrsff 0paTYLzK+CMmamTcDvI5K2R9l28N0VW+2HmOu6MjWnJtgSPhqxGypqTFyY8IqgtRJph5lDNViPhLJ qtNfYOVA==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1u9mED-0000000HWLz-0Zv5; Tue, 29 Apr 2025 14:46:33 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id A9315300777; Tue, 29 Apr 2025 16:46:31 +0200 (CEST) Date: Tue, 29 Apr 2025 16:46:31 +0200 From: Peter Zijlstra To: Sean Christopherson Cc: Josh Poimboeuf , x86@kernel.org, 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, hpa@zytor.com, pawan.kumar.gupta@linux.intel.com, pbonzini@redhat.com, ardb@kernel.org, kees@kernel.org, Arnd Bergmann , gregkh@linuxfoundation.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-efi@vger.kernel.org, samitolvanen@google.com, ojeda@kernel.org, shuah@kernel.org Subject: Re: [PATCH 3/6] x86/kvm/emulate: Avoid RET for fastops Message-ID: <20250429144631.GI4198@noisy.programming.kicks-ass.net> References: <20250414111140.586315004@infradead.org> <20250414113754.172767741@infradead.org> <7vfbchsyhlsvdl4hszdtmapdghw32nrj2qd652f3pjzg3yb6vn@po3bsa54b6ta> <20250415074421.GI5600@noisy.programming.kicks-ass.net> <20250416083859.GH4031@noisy.programming.kicks-ass.net> <20250426100134.GB4198@noisy.programming.kicks-ass.net> <20250429100919.GH4198@noisy.programming.kicks-ass.net> 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 Tue, Apr 29, 2025 at 07:05:35AM -0700, Sean Christopherson wrote: > On Tue, Apr 29, 2025, Peter Zijlstra wrote: > > On Mon, Apr 28, 2025 at 10:13:31AM -0700, Sean Christopherson wrote: > > > On Sat, Apr 26, 2025, Peter Zijlstra wrote: > > > > On Wed, Apr 16, 2025 at 10:38:59AM +0200, Peter Zijlstra wrote: > > > > > > > > > Yeah, I finally got there. I'll go cook up something else. > > > > > > > > Sean, Paolo, can I once again ask how best to test this fastop crud? > > > > > > Apply the below, build KVM selftests, > > > > Patch applied, my own hackery applied, host kernel built and booted, > > foce_emulation_prefix set, but now I'm stuck at this seemingly simple > > step.. > > > > $ cd tools/testing/selftests/kvm/ > > $ make > > ... metric ton of fail ... > > > > Clearly I'm doing something wrong :/ > > Did you install headers in the top level directory? I.e. make headers_install. No, of course not :-) I don't use the top directory to build anything, ever. All my builds are into build directories, using make O=foo. This allows me to do parallel builds for multiple architectures etc. Also, much easier to wipe a complete build directory than it is to clean out the top level dir. > The selftests build system was change a while back to require users to manually > install headers (I forget why, but it is indeed annoying). Bah, I remember NAK-ing that. Clearly the selftest people don't want selftests to be usable :-( Anyway, mingo build me a copy of the fastop selftest, and aside from a few stupid mistakes, I seem to now pass it \o/ I'll attempt a Changelog and update the hyper-v patches and then post the lot.