From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ED5D53ACF15 for ; Fri, 5 Jun 2026 18:27:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780684081; cv=none; b=BlV2PMVBG+Qp72ACWM7GxV0NUNq+szB3jQ3VIOu1JLkegdW4ypbsNYvWtO06Oq4AOS06lHj9d9JAMm4guBF2V4VbF7GTV4hv+XVPpL31ijFZZMruI3wu9bQ1W9rSGLeKfFG2lzMQo8UylnQH7ahapJjcGiF4TfJnF8jarQ9/cqE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780684081; c=relaxed/simple; bh=5jiFPb4shRixueM3EXqj7rLUUpc6Mvk/umob9LPRscI=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=EMZaDsFihAL9ZJiyPW8mIjxIk7vP0n9VN4eZYD3a9yqZFWwqV0hPfbOZfp3Iec8gBu4mtrnMzI2/COHkhCAqIXkzKvsBanflAyxptjQjTPkU6YAksAjNNAJjvsvbIwJrtLBjM9buRxwiX7vdkZvZZoPe3aXII2EruIWOdI66+OA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=e9yEA4mQ; arc=none smtp.client-ip=209.85.216.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="e9yEA4mQ" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-36d979441eeso2088167a91.0 for ; Fri, 05 Jun 2026 11:27:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1780684079; x=1781288879; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=Al0zDa4bN146O1R+FtGZtDttdy90kv7zGQH5evIcYPw=; b=e9yEA4mQM2lut0pEuCRQy3Ps8v9Hyu0Fb1uWNJ62pgvmh5CYZnF9CaZYEwUMxEUlm/ 8Azxab4UduI99UbxJyBd7805CWQsOCFsv4JaKlvMH59Y7Cs+QkZlEjZQII2EuW/mBvl+ E654i/X+2Q8W3amEZWXtyAubBNvVx1uFvWkQCXYiXnieAzgoTRL/MbVcCjEjU8sqx0P5 dvgaDa9D8TJAz2YY5WhxLFnWOBWMsxpQKRR5Mfaz95Yk+/6Nl9qtY4/rb4EjxDdkIe8X OJUyzKpW/ERHauokVrwmOBbq1m25UU927PjuKGYU2fRqejCMwr3Y+8WzcAOOPP1bdT2x 5WqQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780684079; x=1781288879; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Al0zDa4bN146O1R+FtGZtDttdy90kv7zGQH5evIcYPw=; b=nymy4ti2aSE3fHls8VebuerWOmp3E33mTouStvKX6mOwPzB7azYrWNsWVDj2FOqutL Ae/9IphwOpERkW5JGVpSSWjbUv+0fwBDMPHNhqbZMEa+lSj2kxfYM45LDQ5g2vkDVFsP IHz/364emTeyXKb2MWZrr2TUce98WMFgBc6lnnM0hCgTetxz83ZYED1gTs1hemruIp3F lDG1ieUzXEe3A1biCoHTcNU3soYy1BaDOroUI+i7z4WiG7GExnTioDp/jrhGJsc1bsrH SFJrV6cEh7Yw7KmK8/ziPlpNF2FicrZb9XlH/gCJxYZmnpjlhWeGLYh71JaPGnOap4Pk 8cCA== X-Forwarded-Encrypted: i=1; AFNElJ+/hNuQf4im+rijgySzBtyovYM3t52qfNVq/DhGlrVgzzAjbz6qWS3asjJwAO0hENovq7QQeePBIrGOULilWcAM9nY=@vger.kernel.org X-Gm-Message-State: AOJu0Yxo+tqsGQcgTQdcTAcIk4RBkJePVd1kgwY+WVLtHcARDBmzOYls gXZpQCIwG8Nh2zekifNsMbTD2sbCCrhHugCUP+OzA554CboNbzz7kXPA5L1R/fMNYuGy55jmaOr LAazqIA== X-Received: from pfwp41.prod.google.com ([2002:a05:6a00:26e9:b0:842:5fa6:3103]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:5210:b0:36a:1ed8:6fe6 with SMTP id 98e67ed59e1d1-370f0b58cefmr4684526a91.24.1780684078907; Fri, 05 Jun 2026 11:27:58 -0700 (PDT) Date: Fri, 5 Jun 2026 11:27:58 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260522-gmem-inplace-conversion-v7-0-2f0fae496530@google.com> Message-ID: Subject: Re: [PATCH v7 00/42] guest_memfd: In-place conversion support From: Sean Christopherson To: Ackerley Tng Cc: Ackerley Tng via B4 Relay , aik@amd.com, andrew.jones@linux.dev, binbin.wu@linux.intel.com, brauner@kernel.org, chao.p.peng@linux.intel.com, david@kernel.org, ira.weiny@intel.com, jmattson@google.com, jthoughton@google.com, michael.roth@amd.com, oupton@kernel.org, pankaj.gupta@amd.com, qperret@google.com, rick.p.edgecombe@intel.com, rientjes@google.com, shivankg@amd.com, steven.price@arm.com, tabba@google.com, willy@infradead.org, wyihan@google.com, yan.y.zhao@intel.com, forkloop@google.com, pratyush@kernel.org, suzuki.poulose@arm.com, aneesh.kumar@kernel.org, liam@infradead.org, Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , Shuah Khan , Vishal Annapurve , Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Jason Gunthorpe , Vlastimil Babka , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev Content-Type: text/plain; charset="us-ascii" On Thu, Jun 04, 2026, Ackerley Tng wrote: > Sean Christopherson writes: > >> + KVM: selftests: Test conversion with elevated page refcount > >> + Askar pointed out that soon vmsplice may not pin pages. Should I > >> pin pages through CONFIG_GUP_TEST like in [2]? I prefer not to > >> take a dependency on CONFIG_GUP_TEST. > > > > I'm not exactly excited about taking a dependency on CONFIG_GUP_TEST either, but > > it probably is the least awful choice. E.g. KVM also pins pages is certain flows, > > but we're _also_ actively working to remove the need to pin. > > > > Hmm, maybe IORING_REGISTER_PBUF_RING? AFAICT, it's almost literally a "pin user > > memory" syscall. > > > > Hmm that takes a dependency on io_uring, which isn't always compiled > in. Between CONFIG_IO_URING and CONFIG_GUP_TEST, I'd rather > CONFIG_GUP_TEST. Or try both? If it's not a ridiculous amount of work.