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 35B59CD6E60 for ; Tue, 2 Jun 2026 17:49:51 +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=x3SSyL6XDPm0B1wSgJccpgK6c1F2MWcK3UMGOKWZ9yA=; b=2D02SAQ/RaA1p3M3AmNPjls/d1 nmyddde5yECtDmv3jYCRCl+G2uXboDl9KwPYNPSzjN70nCKEsLNS/8OxJK1fRXWRAbdnbRekAwBKD DRd++sAxS1vM4+1wQjumqVYpEOxdMnX7VLeKIphElmeI1BQHsEszd1qrCNkI/1i8F99lhRXNEn6lu Q+6ig+Tu8X6n5b/6KSAwRNl3ZjawFbelCVhp5qohAXYtWAByXqJ97/wa/h6xfOPn50CBG2wdhrKv8 wTwAxrEVE6Q+r831XfLecI5s69fjdS/lm0TADAgGk9qNiu1QGmqacryB5nKcnPfRvnnt5d0LldUsO vCRA+hdg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wUTFI-0000000DbtN-3qRu; Tue, 02 Jun 2026 17:49:44 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wUTFH-0000000DbtD-1ZEg for linux-arm-kernel@lists.infradead.org; Tue, 02 Jun 2026 17:49:43 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 97F9960098; Tue, 2 Jun 2026 17:49:42 +0000 (UTC) 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260602155430.2088142-1-maz@kernel.org> 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 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 >