From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 9B20C364E84; Tue, 2 Jun 2026 17:49:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780422583; cv=none; b=CssIIQ0AvoMY/Xt7WC1xuPcdX42ogDcLzIIhciaGf85CvLbimc6lEmfQTPzY88DKPhrG81awO4vFsosLf4RWVDeNxrBSNKgwJg0xUJ00/7DnxC+VEhcqWlwn1U5ZUhTumOVoa7T1yUqzxe25QFemxRuZToCBt0hUe053HY+yTRk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780422583; c=relaxed/simple; bh=I5i1xfO+gv8CrjMPywVeoHFCAe/X53UHBxVwURlaVN4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=KiVBZ/wji7EaOj81qMv9NS3Q+w/FT+4ZBZlRgAX6IYQ+VWzC0B3ftMprKcfDk1sdQZPiXVl+An0xW0IIP48omEAji3R3vRPyXKLpjJ9XuimZwpQfhI1Ywaysq93Wcb0QCd4B0F4PlSRzoW1sVq4uJRMN4B8EckCcSromAzz6TJA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=THcXnvnh; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="THcXnvnh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 375831F00893; Tue, 2 Jun 2026 17:49:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780422582; bh=x3SSyL6XDPm0B1wSgJccpgK6c1F2MWcK3UMGOKWZ9yA=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=THcXnvnh6bAvtnE2NpOON27TvODIIYnWcLsKAgn+KY/kcro/zOo3a/xoP0wb/Kvl6 g07daCyMzMxmmu5y+VgVYU6hAfhwdtpRtio6OXCL2dnEdrfZme0srbziRhsaRkjzIk a7OuaqvL5FrPBrMlKPzTC9daOtEVWYcHrRjK5l9zZlPLbfWQZhzAiwLhaANRKtu03k 1g76msvXjZzSFueZUKcdX7zpvJdcSkDdA0NKhxtaPqRp+OrJeauRJe5uZXAe3MLjtK R0bSNeUCFGmCslHSNglwula4bcpSmrtZZ1CqTjzU3QR4g3LExcIWlfeebEXL6EeIwW qrzg/4Q/D1K1A== Date: Tue, 2 Jun 2026 10:49:41 -0700 From: Oliver Upton To: Marc Zyngier Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, Steffen Eiden , Joey Gouly , Suzuki K Poulose , Zenghui Yu Subject: Re: [PATCH 0/3] KVM: arm64: FEAT_{S1POE,ATS1A} support fixes Message-ID: References: <20260602155430.2088142-1-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: <20260602155430.2088142-1-maz@kernel.org> On Tue, Jun 02, 2026 at 04:54:26PM +0100, Marc Zyngier wrote: > Whilst working on a slightly unrelated feature (FEAT_NV3), I found out > that an L2 guest wouldn't boot if the host was exposed to FEAT_S1POE. > > Upon investigation (and hours wasted in a SW model), it became > apparent that while the AT S1E1A code was ready for action, it had > never been fully plugged in (blame the usual suspect...). > > This resulted in an extremely odd failure mode, with an L2 being > unable to make forward progress, but KVM at L1 not taking the hint > that something was really wrong. Additionally, an embarrassing typo > was spotted in the CPTR_EL2 handling. > > With this in, FEAT_S1POE no longer breaks our NV guests. > > Marc Zyngier (3): > KVM: arm64: Key CPTR_EL2.E0POE propagation on FEAT_S1POE > KVM: arm64: Wire AT S1E1A in the system instruction handling table > arm64: cpufeature: Expose ID_AA64ISAR2_EL1.ATS1A to KVM Reviewed-by: Oliver Upton Thanks, Oliver > arch/arm64/kernel/cpufeature.c | 1 + > arch/arm64/kvm/hyp/include/hyp/switch.h | 2 +- > arch/arm64/kvm/sys_regs.c | 1 + > 3 files changed, 3 insertions(+), 1 deletion(-) > > -- > 2.47.3 >