From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-182.mta0.migadu.com (out-182.mta0.migadu.com [91.218.175.182]) (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 32AF21C2324 for ; Wed, 18 Jun 2025 23:24:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750289091; cv=none; b=jOsSR9NRXTf+0+SwapfuCxdI/O7PBoivVydaY5+929PomA+v0Ww/ItF2jIe0wRXspEmD+KehOjG2Rgrlcb4QHBo/7EE42tkjuFEE304RwO6K/pKPxqRKJZufOx58lXRlStmbZyJmM4BS4oMBJC6VYc5DcSVv7T+PIfFsDVNuGUA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750289091; c=relaxed/simple; bh=mpsyaZM6A/eruigZ3NSJqal62PMFICXzeTz3pckdd6c=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=uK+q9iVaqXVth0Lo+Rhe3dqqRZajd+2u1P89OCAevA+BABJhQ6BzFQ/A4stlfokB7EgGV374U9Fk/bSDdZ4K+LIuNwE6ArVhyE2RT2YJjQj9JqDbA+2CXroU8v1cSPDxL9TaMdBtr5F3gb2fYQcCg/z+FEQUkEoq/6YYnZL594E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=nOQhMYcg; arc=none smtp.client-ip=91.218.175.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="nOQhMYcg" Date: Wed, 18 Jun 2025 16:24:40 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1750289087; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=qrxD2n0/TPw17Uc8nkUtK6jXpsmer9Xjurk1Z29eM00=; b=nOQhMYcgxS/j4foBRzM8x72Ps/2vwu3podTsW2GdwB6L5WptAFrt2zoVmkn7ZjE2CtMxwI Ke3zJFXq2P7kMgU6W800fjEMmLCr8l1IMicqSUwXSi5dq+M0rO/X3yznPChqY0NlwTkFdL Qqvfl1RmsbEX+p3fnUWdHkfvrghENe4= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: James Houghton Cc: Paolo Bonzini , Sean Christopherson , Jonathan Corbet , Marc Zyngier , Yan Zhao , Nikita Kalyazin , Anish Moorthy , Peter Gonda , Peter Xu , David Matlack , wei.w.wang@intel.com, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev Subject: Re: [PATCH v3 00/15] KVM: Introduce KVM Userfault Message-ID: References: <20250618042424.330664-1-jthoughton@google.com> Precedence: bulk X-Mailing-List: kvm@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: <20250618042424.330664-1-jthoughton@google.com> X-Migadu-Flow: FLOW_OUT On Wed, Jun 18, 2025 at 04:24:09AM +0000, James Houghton wrote: > Hi Sean, Paolo, Oliver, + others, > > Here is a v3 of KVM Userfault. Thanks for all the feedback on the v2, > Sean. I realize it has been 6 months since the v2; I hope that isn't an > issue. Not one bit. The only thing I look for in patch frequency is the urgency with which the author wants to get something in. > I am working on the QEMU side of the changes as I get time. Let me know > if it's important for me to send those patches out for this series to be > merged. It'd be good to know we have line of sight on a functional implementation here, i.e. uffd-based handling of non-vCPU accesses. I'm not expecting surprises here, but patches always speak louder than words. Don't want to block the kernel pieces if that's a time sink though. And FWIW, besides the nitpicking I'm quite happy with the way this is shaping up. > Be aware that this series will have non-trivial conflicts with Fuad's > user mapping support for guest_memfd series[1]. For example, for the > arm64 change he is making, the newly introduced gmem_abort() would need > to be enlightened to handle KVM Userfault exits. Appreciate the heads up! Thanks, Oliver