From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793984208; b=h02OhAMww7E7JSDqOqqkK1UF2JjwsJxss+asae0FBEJvIwCF1evPLE7e16z0ECIMrxPR z6NhBZKW0Uv1aSMAsfO2QwdPQuBcV/M6BG6M0F0xrw4ilpyIieg7D8O72TOP62KDrIIYk zqTnVtyO/B6zV86hGlB3fksTQwC9tkCRFo8g+r2dM7Vy5PQ0zgm1ORiwVcj+4erHyWVLg 7MlnTrL7SDX4PYsbzRP3KeJKStYOZ11n1xMMneNrPGnWZOTbHjWn5qx8qSrxErRRDNynG dZCTocH78LmgieToF+SFp4LHdM6/1oRvkt6s+7y3GINHmTJCDvNZcCGgbB+v3FLvyDA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793984208; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=UMoPahHv2EIHkQEJjh5Tshzm/BTxLvso7C8eR52i+G4=; b=xA1kLNUQZGsPNwOXJDs24jAEhnMbg+KwJTEC6eP6FLMiP1qvwND0Ko3/Kz5dOI0fF4s3 Ln78O38NQR1EiiUjqpDwWu1p1GSBKfpz9DdWq2wB7ZtuT7pbdAngfaxcMtpcP1PUAiy4H JDPtyjoFKst3LEWY5Z9WCCT1Z2Lzp95GUv9ETMfkFZ5KVtIPKOI9XCdq04nExn7HtwP1o Qb8Bzoi4o8cIYRhQsUrG/rsadTfH6WWhBcGnd7OeOjNMUW/Qg7RcD/hBkG05QdOBFwZvT Z8Qk3C/18CF2IZDhR/ZguMVAPff4dJeuPt6Nlc43Y/8H/6wJWAF9aQJLC1SyRm8tXZQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=AI1VXYlb; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A295A606A32C; Fri, 6 Nov 2026 16:56:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=AI1VXYlb Received: by smtp.kernel.org (Postfix) with ESMTPSA id B72DD1F0089F; Fri, 6 Nov 2026 16:56:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793984208; bh=UMoPahHv2EIHkQEJjh5Tshzm/BTxLvso7C8eR52i+G4=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=AI1VXYlbGHKHBSDeYRPa9IfNna+l0TQHpTzeMjjLxqEtHsr1KUrWx3LjcHDD2EsHG Yt2z+K3hQchT6TrSnr2E5e971gHRhO08bC1flVFfNKFN2BwCSojbig5o6XgMZ1xjJN QKS2nlzPe8fqTHeW+MRJ0cg0f+k9RZhUkismQhDXEQMSr6B6tr32DI4nkdvppZVSik jJdi3wftovQmwF2tl8gyrJ4K8RBaoICTVulwRxUuBsk5apX2nuI0AuNJ/rx+wAJ7cq 93KRStOvSJKCghD/E/i2SyXdr+rPUNNhbwLbwnA4qNgQp3M7Wu+h8FkLe4WVmmJ83a a/JcOXxrCyf3Q== Date: Fri, 6 Nov 2026 09:56:46 -0700 From: Keith Busch To: Shameer Kolothum Cc: kvm@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, alex@shazbot.org, jgg@ziepe.ca, kevin.tian@intel.com, kbusch@meta.com, michal.winiarski@intel.com, satyanarayana.k.v.p@intel.com, sonangp@nvidia.com, ankita@nvidia.com, nathanc@nvidia.com, mochs@nvidia.com Subject: Re: [RFC PATCH v2 00/16] vfio/pci: Handle PCI error recovery and report state to userspace Message-ID: References: <20260929173305.204856-1-skolothumtho@nvidia.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260929173305.204856-1-skolothumtho@nvidia.com> On Tue, Sep 29, 2026 at 06:32:49PM +0100, Shameer Kolothum wrote: > Hi, > > Currently, vfio-pci signals the error eventfd from error_detected() and > returns PCI_ERS_RESULT_CAN_RECOVER, including for permanent failure. It > has no slot_reset() or resume() callback, so userspace is not notified > when host recovery completes or whether the device was reset. > > This series adds opt-in host PCI error recovery for vfio-pci. It blocks > device access during recovery, restores device state after a host reset, > and reports recovery status to userspace. The kernel runs host recovery > and the VMM decides how to recover the guest. We've been experiementating with this recently. It turns out that doing a meaningful recovery on the user space side is a bit more difficult than initially thought, but we can at least get more deterministic behavior with these notifications and gracefully stop affected processes. I don't think there is much else the kernel side can do to make this go any better, so this series looks good to us. Acked-by: Keith Busch