From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=217.140.110.172 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793122189; b=CU8YIvmFu4AKcMkF6IZ5ngDpTGKRND9rykP4cCenufXlURTgC89vrL4fcqlaXO4YsXWC xIl8pCyJ9JhK4Fzy5qCGVTiPvF76MenynRSlUiRdW5xHe9frg410vqShwyAgbE3OmmYcE nusRWvs379Iin/M1qGY24f+WPVHhCHXSRztf5tWyLzLJUe1gpDPDn+hmjrqzEyDbxjWct xFldj5Zf8dozF2Ia3iTwN/rNJTxMlNVW4i714TWrA2+tJ5lqnSnypbHUclhmeP7v1vF4C 2AOmHnkhx5egj3FeqT79doQ3BF8stYm7knFpigLopP6CgU/W9lDi9JbUBiybdU35rUw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793122189; h=DMARC-Filter:Received:Received:DKIM-Signature:Date:From:To:Cc: Subject:Message-ID:References:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; bh=BnI1ypDPlmui1Fn2L3S4sqAodoDBEGGvrnjTOR08vd0=; b=H8R3tOSu9zfPPyhRmLMaUFO4nnLrOiJJ4QyheV+2MWqRDq8REudTrUfraWu4sISbvJF9 d9AGwUcetI6ib6wowUsP3IZAYtftadYULn4OAs9QlE0tKUgRbAH85yHFLYBVAom4btW5D h6MNdtb1k7AxM3NVb4+Q7OzyTCUBpEZwWFYQ4U4+tiRJ2OnV7G9XtsQzPcU+Ic/w4/u2X 6M+XhR38Dka8+86l1abFbJdUthITQMM1jbMpBtmUibsEc2hyxSs8DPtB3w2wZDglk44SS UR9wmwHJx9jcJILaySGJ0xI+hydZ6vQEU4y6C/n2Hoy5tPA25a2/OxgDC/0WH1b/jVg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=JnukGCmU; arc=none smtp.remote-ip=217.140.110.172 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7DE12606A31D for ; Tue, 27 Oct 2026 17:29:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 7DE12606A31D Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=JnukGCmU Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 76CB01650; Tue, 27 Oct 2026 10:29:44 -0700 (PDT) Received: from arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 03EA93F7B4; Tue, 27 Oct 2026 10:29:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1793122187; bh=Px2Eb/FcnI3Ov0Mt8j5f3nVtsWHdzfl3d+dvv9q4c3w=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JnukGCmUw/pTUGbxSJRJln9Shqph1UdbZJ11e8Rw/XWFSYh2PALvpdxDCrDVUdYar LzIMetk442+RLA1OwGDhiPXdCEN11FcDbAV7sW3W6KSaRWtPR5IOK52cwHFsvOA4lN FVsMGnDA/gqePHcu3rFELPNmZ5TUvTU4GXnL+wus= Date: Tue, 27 Oct 2026 17:29:43 +0000 From: Catalin Marinas To: Marc Zyngier Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, Steffen Eiden , Joey Gouly , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Fuad Tabba , Will Deacon , Mark Rutland Subject: Re: [PATCH 0/2] KVM: arm64: Reenable MTE on VHE guest exit Message-ID: References: <20261026082305.2515705-1-maz@kernel.org> X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261026082305.2515705-1-maz@kernel.org> On Mon, Oct 26, 2026 at 08:23:03AM +0000, Marc Zyngier wrote: > Upton taking an exception, the CPU sets PSTATE.TCO to ensure that no > tag fault can be taken while handling the exception. It is SW's job to > eventually clear it when it is safe to do so. > > It appears that when MTE is enabled and that the kernel is running > VHE, nothing eventually clears TCO when we come back from the guest, > so things such as KASAN_HW_TAGS will not work until the next exit to > userspace. > > This series aims at fixing this. This is not a stable candidate, as > KASAN is only a debug option. > > Marc Zyngier (2): > arm64: Add return value to mte_disable_tco_entry() > KVM: arm64: Reenable MTE tag checking on exit from guest when running > VHE > > arch/arm64/include/asm/mte.h | 10 +++++++--- > arch/arm64/kvm/hyp/vhe/switch.c | 7 +++++++ > 2 files changed, 14 insertions(+), 3 deletions(-) For both patches: Reviewed-by: Catalin Marinas