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 3801F79DF; Sat, 22 Jun 2024 08:35:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719045306; cv=none; b=aZiTbiB90RvSFRvPkKwAJYW4dID+HrdeuPKQMNUHfjhO7hlUlnbp3nddn7BfFN4NrXXWEYorLm/JkTdIqsPL8vWQFmbICgAS7ytKlCQLUdHgeFP6evD3w76a/1AF3uJ2VrLFuTrXf53sr1OpI76q30f1sn8OLatVLoKy4whvg0g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719045306; c=relaxed/simple; bh=8jlN+9cmsrdbwvuoH5q2v8dvcPqa2p/E5So6Wqd8YDo=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=hZ6zu2G5PGHS9UxMTBfUOQ8gMx9rgBO3iW6TmLwpd4A+WXSreyPcKvV7QaDkJOR7gOvX+DJn5O3UZ/1g3aOQR2CJLJl3Wls+KvHPzM4d2hsh/sVjKD/flFGjYwglF8cK1gt/Jf6dBdwS/FISLJxW5EcSVfFUSeELD0iy5IeN2sU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IkzXs6VI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IkzXs6VI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BFD62C32781; Sat, 22 Jun 2024 08:35:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719045305; bh=8jlN+9cmsrdbwvuoH5q2v8dvcPqa2p/E5So6Wqd8YDo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=IkzXs6VIWffYvSMZ0DNf8czJo/DwdBBEUzxUGM3rYPmsHVnfWaOlOBQxi8Q4iZ1jr wZ0utq7FzngXFZRVDhcpqWYbdn0+5C9meJTYE8oGM1NhQMiXcMOO/W+2+kW5lYsj82 H8I/nu8995oDQCoagnhANfmyyJ2v1Kt2c+sCGdToCms9zmFSGOMyeqoRWE9MbgwERw 6slA7pZAHcN6WbaPWjDi18lztPSxGtEuotBJOIR3clgIjtytgXZnM/IfsUpieEMtco ftp3th7thIezv4Fbx+5zaw/V8GuqbZhU9hSQgd7ezdQQoggjrb6BaToC4IOiGlek/z o8BTN3+40AK7Q== 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 1sKwD9-006LNv-IJ; Sat, 22 Jun 2024 09:35:03 +0100 Date: Sat, 22 Jun 2024 09:35:02 +0100 Message-ID: <86zfrdide1.wl-maz@kernel.org> From: Marc Zyngier To: Oliver Upton Cc: kvmarm@lists.linux.dev, James Morse , Suzuki K Poulose , Zenghui Yu , kvm@vger.kernel.org Subject: Re: [PATCH] KVM: arm64: nv: Unfudge ID_AA64PFR0_EL1 masking In-Reply-To: <20240621224044.2465901-1-oliver.upton@linux.dev> References: <20240621224044.2465901-1-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/29.2 (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, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, kvm@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Fri, 21 Jun 2024 23:40:44 +0100, Oliver Upton wrote: > > Marc reports that L1 VMs aren't booting with the NV series applied to > today's kvmarm/next. After bisecting the issue, it appears that > 44241f34fac9 ("KVM: arm64: nv: Use accessors for modifying ID > registers") is to blame. > > Poking around at the issue a bit further, it'd appear that the value for > ID_AA64PFR0_EL1 is complete garbage, as 'val' still contains the value > we set ID_AA64ISAR1_EL1 to. > > Fix the read-modify-write pattern to actually use ID_AA64PFR0_EL1 as the > starting point. Excuse me as I return to my shame cube. > > Reported-by: Marc Zyngier > Fixes: 44241f34fac9 ("KVM: arm64: nv: Use accessors for modifying ID registers") > Signed-off-by: Oliver Upton Confirmed, we're back in business. Acked-by: Marc Zyngier Tested-by: Marc Zyngier Thanks, M. -- Without deviation from the norm, progress is not possible.