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 3970E4C8C54; Wed, 30 Sep 2026 12:22:52 +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=1790770974; cv=none; b=purHw+fzbTga5E0hwqCzaozhfH0exCI5cpib5ngYvXlV9iOtF2mAbr9noceaZMTgR4pDIabiCNEx4UIoAIhgrSGbNDYh2+UAEdSPZbByuiHglohxLexy7MS1rJRRSyrMxyGUpivsAz14qzgh7Ha6xWxrdPL1azO89EYSZwTYOQ4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790770974; c=relaxed/simple; bh=R0iufsfkkM+S0LEUEzWV9BMHm7KUVrqY2MjsW9zOOuw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=T8cUjpVtcBOfz9XOn5ehDfpKKvIUf3i7oxPKGUziIOSSmonZOiEP4oP4NQ0wFhNTXTaej8cVG8y1IN/cX9ROFbcufBHIsq5D/snxlakXkyyBG62PIqlvlK+oS1F37zuqAFFLmYM73GYcQXkKAZc7Bpd92h1xyKbnvyjFq/MziKk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=F0oRsWWX; 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="F0oRsWWX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5DCF61F000FF; Wed, 30 Sep 2026 12:22:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790770972; bh=e940AjQ0jQQWP5rvA/K+cI8JuO4iBqCxD/BwdAtAYs4=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=F0oRsWWXI7cbEARvdQkabseN2gp44WIpQVNuE/0AkzSDAGAgCZXFPcsVXdXOr+geq GGYwyMqQ9suXrzuHRYoXQTn4NOKC+ohlTrADPmXyMS2HtJ1Ht0XVvJbBu7+aquz7z5 cJzQu3XiOuJ+WN2nw/do4NQ17GWT0wnMy6nOjV87y3B1xVeaaYaKfQodMmx8qk9D// FBRbTLog09XQEzFfg63eT4h0npUi6RNaa9/M1uFzmZxO9SaBSkbXB+bcWPEZPGjCbE G8X4ej00Dsb/LGM7V82i3+ND78qecMiGc/J69Ru1VYwi2GlxFAOo/wcULsj3Ok8u3B zhhITKCmiPxSQ== Message-ID: <4d3be415-6d51-46f7-81ca-ab2dcf0f0f74@kernel.org> Date: Wed, 30 Sep 2026 14:22:43 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v20 9/9] firmware: arm_rmm: hotplug: Skip memory added to ZONE_MOVABLE To: Suzuki K Poulose , kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: maz@kernel.org, will@kernel.org, catalin.marinas@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, steven.price@arm.com, aneesh.kumar@kernel.org, oupton@kernel.org, gshan@redhat.com, joey.gouly@arm.com, tabba@google.com, yuzenghui@huawei.com, linux-coco@lists.linux.dev, gankulkarni@os.amperecomputing.com, sdonthineni@nvidia.com, alpergun@google.com, fj0570is@fujitsu.com, WeiLin.Chang@arm.com, lpieralisi@kernel.org, enju.kohei@fujitsu.com, sudeep.holla@arm.com, jonathan.cameron@oss.qualcomm.com References: <20260929221623.1342076-1-suzuki.poulose@arm.com> <20260929221623.1342076-10-suzuki.poulose@arm.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/30/26 00:16, Suzuki K Poulose wrote: > If the hotadded memory is in ZONE_MOVABLE, we could allow that to proceed > without the RMM having fine grained tracking, as we won't allocate pages > from there for guest-memfd or kernel allocation > > Cc: Catalin Marinas > Cc: David Hildenbrand (Arm) > Signed-off-by: Suzuki K Poulose > --- > Changes since v19: > - New patch in v20, keeping this at the tail to allow for the rest of the > series to proceed, while this patch gets discussed. > --- > drivers/firmware/arm_rmm/rmi.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/drivers/firmware/arm_rmm/rmi.c b/drivers/firmware/arm_rmm/rmi.c > index d4d098448e46e..ef0a171ba9677 100644 > --- a/drivers/firmware/arm_rmm/rmi.c > +++ b/drivers/firmware/arm_rmm/rmi.c > @@ -1043,6 +1043,18 @@ static int rmi_memory_notifier(struct notifier_block *nb, > start = PFN_PHYS(arg->start_pfn); > end = PFN_PHYS(arg->start_pfn + arg->nr_pages); > > + /* > + * If the hotplugged memory region is in ZONE_MOVABLE, neither the > + * guest-memfd nor the kernel allocations can come from there. So we are > + * fine to skip this. > + * For boot time memory, we don't allow this discount, as the > + * decision to move boot memory pages to ZONE_MOVABLE is purely > + * a kernel choice and the firmware must have decided what it covers. > + */ > + if (page_zonenum(pfn_to_page(arg->start_pfn)) == ZONE_MOVABLE && > + page_zonenum(pfn_to_page(arg->start_pfn + arg->nr_pages - 1)) == ZONE_MOVABLE) > + return NOTIFY_DONE; > + is_zone_movable_page(pfn_to_page(start_pfn) as used by virtio-mem should be sufficient. Checking only the start pfn is sufficient. -- Cheers, David