From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-183.mta0.migadu.com (out-183.mta0.migadu.com [91.218.175.183]) (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 142931BF54 for ; Tue, 27 Aug 2024 17:01:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.183 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724778076; cv=none; b=YgIjWO4R6k0ZulCvRmtjvC7Dl2M8X9NL6j27YMo6pR0B91dYNhhgNFui7M+8h8LSIRFuz10DTw09I+dZTx8WYQiEeCk9JJh318bSe6g/pds/DaJELQKpSHu2sH742i7NysLGhv2FoFy2kNkfwhhaxnsy6wCQ3a7ltVFYcQY9Ups= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724778076; c=relaxed/simple; bh=s+s49fN/FAiOcamtBM8CmOMVLJc/w0FfOuGGIjEMgkY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VAJZkFS1uXpzm7l6gnkya9PmyxJ+g6FoPVJKhkTy/J4w35mfVJzUQPyPvW+oaRmGyHNqoNcrF5pOeRBC7iUmfFghN5/wXjtns3zY6V/2Il/IH8/a7YOWTdJcpjRbeKDdAQjceQLvdMj9FXfzxa1+rOkakW7sYyuY3rSsM97i3fA= 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=PKS77+tp; arc=none smtp.client-ip=91.218.175.183 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="PKS77+tp" Date: Tue, 27 Aug 2024 10:01:02 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1724778072; 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=MV12ntjo4cxMXNDjQ7ec7Q6W3AL3teSESN1/QLqjjxw=; b=PKS77+tp3JM/UMvuFCxQQnisoTXR7DAgJVmkv+pcVUDEXyzMr29CfF79jnqKuIqnoYWAB2 b172WCEOzib9d3mSliGTuxS0y+aSTiWc0e0lbxebReSkwOXvX+plEEmwVJvPfFbc33z+Za MJ9Bm3AnZaUTqive9F/CmyPRkhz/VCk= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Marc Zyngier Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, James Morse , Suzuki K Poulose , Zenghui Yu , Alexander Potapenko Subject: Re: [PATCH v2 00/11] KVM: arm64: Handle the lack of GICv3 exposed to a guest Message-ID: References: <20240827152517.3909653-1-maz@kernel.org> 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: <20240827152517.3909653-1-maz@kernel.org> X-Migadu-Flow: FLOW_OUT On Tue, Aug 27, 2024 at 04:25:06PM +0100, Marc Zyngier wrote: > It recently appeared that, when running on a GICv3-equipped platform > (which is what non-ancient arm64 HW has), *not* configuring a GICv3 > for the guest could result in less than desirable outcomes. > > We have multiple issues to fix: > > - for registers that *always* trap (the SGI registers) or that *may* > trap (the SRE register), we need to check whether a GICv3 has been > instantiated before acting upon the trap. > > - for registers that only conditionally trap, we must actively trap > them even in the absence of a GICv3 being instantiated, and handle > those traps accordingly. > > - finally, ID registers must reflect the absence of a GICv3, so that > we are consistent. > > This series goes through all these requirements. The main complexity > here is to apply a GICv3 configuration on the host in the absence of a > GICv3 in the guest. This is pretty hackish, but I don't have a much > better solution so far. LGTM, thanks for respinning. Reviewed-by: Oliver Upton -- Thanks, Oliver