From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3C93E1775B for ; Fri, 27 Oct 2023 10:12:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EdCJQYAl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1926C433C8; Fri, 27 Oct 2023 10:12:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1698401520; bh=3dyAvGXo5VWGuv1+ZfV3qG1K/Sr93QPZJ0sQcLRtlwc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=EdCJQYAlQhGsi7ISmydVz7oM+X2cevcXgyucgnUe6rSuCgzaPYvMn+VEXDURfWHkN jkNZkaSzKN+Ylan/IOYNf81v9TLoV2zW7IWK8eZUR/YEGBQUdFcVfKWT7VrPiRHLOO ZqAJKAGI5eQv9yG6LL1Jon22CIN0Tkp8FnVMDoW/Z6XG9l0vAxjtLrRjeoKiZE65eV dNqNQAsnTC4/DNyN1kmJbWeYU7M34+jcBMiwmo2ch8zBVVZT337rmkb1nqGXGquE5D c+msGe3zbCjFQDglFVodO7SwpdVqc+l+jjzfs60zY9U2eQRbcpss9iHUB3hRCp/Obu 32FyaPH8F0x1w== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1qwJos-0089Ok-6F; Fri, 27 Oct 2023 11:11:58 +0100 Date: Fri, 27 Oct 2023 11:11:57 +0100 Message-ID: <867cn84bo2.wl-maz@kernel.org> From: Marc Zyngier To: Oliver Upton Cc: kvmarm@lists.linux.dev, kvm@vger.kernel.org, James Morse , Suzuki K Poulose , Zenghui Yu Subject: Re: [PATCH v2] KVM: arm64: Add tracepoint for MMIO accesses where ISV==0 In-Reply-To: <20231026205306.3045075-1-oliver.upton@linux.dev> References: <20231026205306.3045075-1-oliver.upton@linux.dev> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/29.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: oliver.upton@linux.dev, kvmarm@lists.linux.dev, kvm@vger.kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Thu, 26 Oct 2023 21:53:06 +0100, Oliver Upton wrote: > > It is a pretty well known fact that KVM does not support MMIO emulation > without valid instruction syndrome information (ESR_EL2.ISV == 0). The > current kvm_pr_unimpl() is pretty useless, as it contains zero context > to relate the event to a vCPU. > > Replace it with a precise tracepoint that dumps the relevant context > so the user can make sense of what the guest is doing. > > Signed-off-by: Oliver Upton Acked-by: Marc Zyngier Thanks for going the extra mile on this! M. -- Without deviation from the norm, progress is not possible.