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 795C126F467; Mon, 24 Nov 2025 13:14:30 +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=1763990070; cv=none; b=hkV/VSOtfYM9Fob9CyLRYDkBply6w8HMZLA6WvBawtJBUmHp8nYVB5okP/0boQaAiu6jYB80opwSjA2gISwBnI7NnmjZKVOR0hj5RGYFikffTn4eOSDse72v1F6QfIFNFRHVCGxN8fz9IXz8Ydnqwr6xvpt2iqnA2NJO9QZ6XUs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763990070; c=relaxed/simple; bh=RkP3XoBrROfWxpPBrDgZoNSdZ6SM16qUrh12yE+95MM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=h9LyaVBK7znPWaAG2E8s2XYpEwuhz5m39EKcWhY0WHUijCSXQ/uTmV2W56k2UQzDTCJsjdwK3pof/GLOYJ3MDqq4UgvLNfQRayYhfEyrzI/aK7GJhRxOFz2ZsHILK02C+q+w/O5XU/6WghUNtKFYAfDsTuujkibJ9Chu67zNoZs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jmZ/16DT; 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="jmZ/16DT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E64EC116C6; Mon, 24 Nov 2025 13:14:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763990070; bh=RkP3XoBrROfWxpPBrDgZoNSdZ6SM16qUrh12yE+95MM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jmZ/16DT0AV5S1MN9ZABpryaAZ3eE5oVUK1vVTDTfYkNQzDDlagWodLtTcSEHSRHE bBx8CzXdWq6kmAoB0um7jWzu6RT21Mfp0Y3UUfrAI5iWePndMdFXpN7ipEpuY+4Xvg wUGWCymAWyCllQgPeKsZ8sBhc3U6xtF/RTRcQlBafh5TYS2ZCqC8fIh3Ys8LYgDJUW xYw++b6a0Eae2yMUU3qNcVzlRd20nTzHxqDqLVCgqcj6fbs1H77qJSk8OYmdc7VyP/ Hx1Yi91I9FhKM2ctMbelRoQU4RInZZX77QIz2CdYeKYKZ2up2tFxBslyS0aHGgWBZz S4d793LsYiBxg== Date: Mon, 24 Nov 2025 13:14:24 +0000 From: Will Deacon To: Suzuki K Poulose Cc: Mauro Carvalho Chehab , Jonathan Cameron , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, catalin.marinas@arm.com, gshan@redhat.com, aneesh.kumar@kernel.org, sami.mujawar@arm.com, sudeep.holla@arm.com, steven.price@arm.com, regressions@lists.linux.dev Subject: Re: [REGRESSION] GHES firmware can't be readonly - Was: Re: [PATCH v3 3/3] arm64: acpi: Enable ACPI CCEL support Message-ID: References: <20250918125618.2125733-1-suzuki.poulose@arm.com> <20250918125618.2125733-4-suzuki.poulose@arm.com> <20251121224611.07efa95a@foz.lan> <4a750da6-7883-4afa-94c1-4806677e61c2@arm.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4a750da6-7883-4afa-94c1-4806677e61c2@arm.com> On Mon, Nov 24, 2025 at 05:21:00AM +0000, Suzuki K Poulose wrote: > On 21/11/2025 21:46, Mauro Carvalho Chehab wrote: > > Hi, > > > > Em Thu, 18 Sep 2025 13:56:18 +0100 > > Suzuki K Poulose escreveu: > > > > > Add support for ACPI CCEL by handling the EfiACPIMemoryNVS type memory. > > > As per UEFI specifications NVS memory is reserved for Firmware use even > > > after exiting boot services. Thus map the region as read-only. > > > > > > Cc: Sami Mujawar > > > Cc: Will Deacon > > > Cc: Catalin Marinas > > > Cc: Aneesh Kumar K.V > > > Cc: Steven Price > > > Cc: Sudeep Holla > > > Cc: Gavin Shan > > > Reviewed-by: Gavin Shan > > > Tested-by: Sami Mujawar > > > Signed-off-by: Suzuki K Poulose > > > --- > > > arch/arm64/kernel/acpi.c | 10 ++++++++++ > > > 1 file changed, 10 insertions(+) > > > > > > diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c > > > index 4d529ff7ba51..b3195b3b895f 100644 > > > --- a/arch/arm64/kernel/acpi.c > > > +++ b/arch/arm64/kernel/acpi.c > > > @@ -357,6 +357,16 @@ void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size) > > > * as long as we take care not to create a writable > > > * mapping for executable code. > > > */ > > > + fallthrough; > > > + > > > + case EFI_ACPI_MEMORY_NVS: > > > + /* > > > + * ACPI NVS marks an area reserved for use by the > > > + * firmware, even after exiting the boot service. > > > + * This may be used by the firmware for sharing dynamic > > > + * tables/data (e.g., ACPI CCEL) with the OS. Map it > > > + * as read-only. > > > + */ > > > prot = PAGE_KERNEL_RO; > > > > Please revert this change. > > > > Making area reserved to be used by firmware breaks some APEI > > notification mechanisms: > > Thanks for the report. Clearly, we missed this case. I am happy for this > patch to be reverted and we can work out the handling of NVS later. I'll revert the change shortly. Will