From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A2487C982E1 for ; Mon, 21 Sep 2026 11:42:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=KHVh8f+CDiS52n2nqmGCKgqcZPhJmTUHAloQj6QXyZ0=; b=EzZIKm5DidqNhBFvVhpLw0rCVL 9b1EnTOLJ9eK4vXTzMwO5T7dfxVG5VnHNsCC/LRzt8RdS8SyC6KO/RoPg3JU/mtUGc3dezr5cA1x/ 4/mOZ22kv18BBNEfLONFFQ/YcyWUu6uv028jvTU1jc9wI8zfETuQ5RHzMqrnn2k/tcDKoKdzDBxre 4RJWsNxViWtGTq+N1vlO+x2CKLgrp6teCuJOY2iZCcDrHAf15u1cGeE2cwwjHrQECYtdEbv7O5eYi IjRczLZHyOBEPvE9z8RPMrcImSBHYLMNO2kryzb4bH46tmeQi/KrJFT/EbjtoBv1jLETOgC6VSL6e gKbitgMg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x8cPp-00000001x88-1duw; Mon, 21 Sep 2026 11:42:33 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x8cPl-00000001x7Z-166k for linux-arm-kernel@lists.infradead.org; Mon, 21 Sep 2026 11:42:29 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 545D3600C8; Mon, 21 Sep 2026 11:42:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 09D0F1F000FF; Mon, 21 Sep 2026 11:42:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789990948; bh=KHVh8f+CDiS52n2nqmGCKgqcZPhJmTUHAloQj6QXyZ0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=YTnV8SbqTR/BakhRDkRQmybmJEwfKh9yeygyfrBF1/qxOzvFaK2suFVsN191DgMZJ +X6BOChoAvJtOJyUehk26jNgxpD1uG9vLhU6eh0wEpTJkxlhVtDO1z00JMCJu6wHcE TjmCy4wOAfMSN/A0wkRMY/5Md2QfRdY9QYLTpmy2IKKzRhfbUKj5w5Nf5Es3OBdV7r FbSY6kdl/7qqi2ZHeSN8sNiEw6+MfLmhEA8Xoi1j3CEO4Sd4sstfAXDOtxzQd0glzP XDetAxSsy0Ia54FdPWm2Qx9sHCeqAab8YVsAxP6M9D+7nQ9urPEyBqb6FNF4Mgw8YD ZVe56C9QpGADg== Date: Mon, 21 Sep 2026 12:42:22 +0100 From: "Lorenzo Stoakes (ARM)" To: Fuad Tabba Cc: Oliver Upton , Marc Zyngier , Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Will Deacon , Jack Thomson , kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] KVM: arm64: Restore the VM's feature bitmap when kvm_setup_vcpu() fails Message-ID: References: <20260921063718.1604533-1-fuad.tabba@linux.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Sep 21, 2026 at 08:24:56AM +0100, Fuad Tabba wrote: > Hi Oliver, > > On Mon, 21 Sep 2026 00:09:17 -0700, Oliver Upton wrote: > [...] > > > Nothing in the tree loads a vCPU whose init failed, so this is latent. > > > The upcoming series that enables KVM_PRE_FAULT_MEMORY for arm64 exposes > > > it: the generic kvm_vcpu_pre_fault_memory() calls vcpu_load() whether > > > or not the vCPU has been initialised. > > > > That's a bug, not a feature. We should require an initialized vcpu for > > the ioctl. > > That one is for Lorenzo then :) I'll reword the message so the stale > bitmap comes first and the pre-fault crash is just how it showed up. Let me dig into this. -- Cheers, Lorenzo