From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D0BBD606A31C for ; Wed, 11 Nov 2026 03:43:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=mTm0px9h Received: by kanga.kvack.org (Postfix) id CCECC6B00EF; Tue, 10 Nov 2026 22:43:49 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CA5C16B05B0; Tue, 10 Nov 2026 22:43:49 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BBBC76B05B1; Tue, 10 Nov 2026 22:43:49 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 7E4436B00EF for ; Tue, 10 Nov 2026 22:43:49 -0500 (EST) Received: from smtpin05.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 5CE221C1556 for ; Wed, 11 Nov 2026 03:43:47 +0000 (UTC) X-FDA: 85421444094.05.79A2E0D Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf10.hostedemail.com (Postfix) with ESMTP id A2E81C0005 for ; Wed, 11 Nov 2026 03:43:45 +0000 (UTC) Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=mTm0px9h; spf=pass (imf10.hostedemail.com: domain of sashiko-bot@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=sashiko-bot@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1794368625; h=from:from:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=S+rqQqYrT9yFpTdM21Tx4bknM2pwbSO2Dwgz2+bmKog=; b=deT/p+mtxEXs6ySUyclFvw+pzoiHgK9hFxv8DFPkCOSFDyLt3Qtq584AFWzDMXVVYZaSm4 m0AyFnhuL6AnzIE64BJ041VdkCYI24CMHfHJWEByDC1o68Gbgv2BP+G0UE+vCEuuMh1mP/ dY+TFRDM5wxwo7AmzP75TfMLdG3RlrI= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1794368625; b=MlsI4WB8dSChjRoyyQBhsS1lHTTAS1U+Ki+42JijfEm7owCyw+xvKhKpURC6KOYWNlXBHi 9PKtHj71AB6zyFsJjSnjUo3LcKvZ1WJMsggWEWs9ysc+gaB60kI/aafnLuAuwJ2gHYf+69 kkVhKGNUVAKjpj65thXNMbm9AGYHprw= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=mTm0px9h; spf=pass (imf10.hostedemail.com: domain of sashiko-bot@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=sashiko-bot@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 0EC4040894; Wed, 11 Nov 2026 03:43:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9FE351F00A0A; Wed, 11 Nov 2026 03:43:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794368623; bh=S+rqQqYrT9yFpTdM21Tx4bknM2pwbSO2Dwgz2+bmKog=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=mTm0px9hQxukgifXp/JR9YAFwSumMQuU4O2vZnNFuCDy9G7jEh633U/ahLzje1qhi /Y1RGJDd70YEKPY/zKEpxd90Aj27ARyV3AWuhtt2bi3w2DFDO0ZNIgK1mr12pNJQiO piURHjrf8TxXswtFrObGuO92q51LXHzt05Hfs8T+A+lL1p18+R9YI8awvdswGHohcB 1t15pahnoQ4v1P99Ytx302h0I6mC0JqTpcmXx5+lKZkJ7PNC8JdBA/Ol2wrM/ydrAg jVvZlxafRdR2grK5cJ0YbJv1pmEYrvWTXZv0a1IXVTPfWDE0kdz6u+Mhvxv+ipMBTH 3kCrxnAcUdVxA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [RFC PATCH v2 22/25] net/gve: Use PISA memory for RX buffers Reply-To: sashiko-reviews@lists.linux.dev To: "Luigi Rizzo" , "Luigi Rizzo" , "Joerg Roedel" , "Will Deacon" , "Robin Murphy" , "Christoph Hellwig" , "Marek Szyprowski" , "Andrew Morton" , "Vlastimil Babka" , "David Hildenbrand" , "Jens Axboe" , "David S . Miller" , "Eric Dumazet" , "Jakub Kicinski" , "Paolo Abeni" Cc: "Greg Kroah-Hartman" , "Rafael J . Wysocki" , "Danilo Krummrich" , "Jonathan Corbet" , "Matthew Wilcox" , "Lorenzo Stoakes" , "Jesper Dangaard Brouer" , "Ilias Apalodimas" , "Willem de Bruijn" , "Kuniyuki Iwashima" , "Joshua Washington" , "Harshitha Ramamurthy" , "Alexander Lobakin" , linux-mm@kvack.org In-Reply-To: <20261109182533.3594984-23-lrizzo@google.com> References: <20261003212241.3432303-1-lrizzo@google.com> <20261109182533.3594984-23-lrizzo@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 11 Nov 2026 03:43:42 +0000 X-Stat-Signature: gtkd4u54f1qng3z4ud7nxfbqkin99dzs X-Rspamd-Queue-Id: A2E81C0005 X-Rspam-User: X-Rspamd-Server: rspam08 X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-HE-Tag: 1794368625-592865 X-HE-Meta: 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 /rsSqrCv 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 X-Archived-By: Thank you for your contribution! Sashiko AI review found 2 potential issues to consider: - [High] net/gve: wrong GFP flags in gve_rx_alloc_buffer() via gve_get_napi_enabled() - [Medium] net/gve: uninitialized new_info.can_flip copied in gve_rx_refill_buffers() -- commit 58fd34b0315f121e3fcc6437dac09650326d6a54 Author: Luigi Rizzo net/gve: Use PISA memory for RX buffers This commit allocates GQI-RDA RX packet buffers with pisa_rx_gfp(dev) when PISA RX buffers are enabled, and replaces plain pages when free PISA RX blocks are available. > diff --git a/drivers/net/ethernet/google/gve/gve_rx.c b/drivers/net/ether= net/google/gve/gve_rx.c > index 89f287b678bf0..85c243bbdeb33 100644 > --- a/drivers/net/ethernet/google/gve/gve_rx.c > +++ b/drivers/net/ethernet/google/gve/gve_rx.c > @@ -4,6 +4,7 @@ > * Copyright (C) 2015-2021 Google, Inc. > */ > =20 > +#include > #include "gve.h" > #include "gve_adminq.h" > #include "gve_utils.h" > @@ -170,6 +171,8 @@ static int gve_rx_alloc_buffer(struct gve_priv *priv,= struct device *dev, > dma_addr_t dma; > int err; > =20 > + if (rx->data.raw_addressing) > + gfp |=3D pisa_rx_gfp(dev); > err =3D gve_alloc_page(priv, dev, &page, &dma, DMA_FROM_DEVICE, gfp); > if (err) { > u64_stats_update_begin(&rx->statss); > @@ -499,13 +502,19 @@ static void gve_rx_flip_buff(struct gve_rx_slot_pag= e_info *page_info, __be64 *sl > *(slot_addr) ^=3D offset; > } > =20 > -static int gve_rx_can_recycle_buffer(struct gve_rx_slot_page_info *page_= info) > +static int gve_rx_can_recycle_buffer(struct gve_rx_ring *rx, > + struct gve_rx_slot_page_info *page_info) > { > int pagecount =3D page_count(page_info->page); > =20 > /* This page is not being used by any SKBs - reuse */ > - if (pagecount =3D=3D page_info->pagecnt_bias) > + if (pagecount =3D=3D page_info->pagecnt_bias) { > + if (rx && rx->data.raw_addressing && > + !is_pisa_page(page_info->page) && > + pisa_has_free_blocks_rx(&rx->gve->pdev->dev, 0, rx->gve->numa_node= )) > + return 0; > return 1; > + } [Severity: High] Can gve_rx_alloc_buffer() sleep in softirq context or pass GFP_ATOMIC in process context when selecting GFP flags via gve_get_napi_enabled(priv)? In gve_turnup(), NAPI is enabled, IRQs are unmasked, and napi_schedule() is called on all RX queues before gve_set_napi_enabled(priv) runs: drivers/net/ethernet/google/gve/gve_main.c:gve_turnup() { ... napi_enable_locked(&block->napi); netif_queue_set_napi(priv->dev, idx, NETDEV_QUEUE_TYPE_RX, &block->napi); ... mb(); napi_schedule(&block->napi); } if (priv->tx_cfg.num_xdp_queues && gve_supports_xdp_xmit(priv)) xdp_features_set_redirect_target_locked(priv->dev, false); gve_set_napi_enabled(priv); } With gve_rx_can_recycle_buffer() returning 0 to evict non-PISA pages even when pagecount =3D=3D pagecnt_bias, a NAPI poll running before gve_set_napi_enabled(priv) reaches gve_rx_refill_buffers() -> gve_rx_alloc_buffer() while gve_get_napi_enabled(priv) is still false. That passes GFP_KERNEL | __GFP_PISA_RW in softirq context, allowing the page allocator or PISA metadata initialization and page decryption to sleep in atomic context. Conversely, gve_adjust_config() -> gve_queues_mem_alloc() and gve_rx_queue_mem_alloc() pre-fill new RX rings in process context while the interface is up and gve_get_napi_enabled(priv) is true, passing GFP_ATOMIC | __GFP_PISA_RW and preventing PISA from blocking to initialize metadata or decrypt pages. Passing an explicit gfp_t parameter from gve_rx_prefill_pages() (GFP_KERNEL) and gve_rx_refill_buffers() (GFP_ATOMIC) into gve_rx_alloc_buffer() would avoid relying on gve_get_napi_enabled(priv). [ ... ] > @@ -987,12 +996,15 @@ static bool gve_rx_refill_buffers(struct gve_priv *= priv, struct gve_rx_ring *rx) > union gve_rx_data_slot *data_slot =3D > &rx->data.data_ring[idx]; > struct device *dev =3D &priv->pdev->dev; > - gve_rx_free_buffer(dev, page_info, data_slot); > - page_info->page =3D NULL; > - if (gve_rx_alloc_buffer(priv, dev, page_info, > - data_slot, rx)) { > + struct gve_rx_slot_page_info new_info; > + union gve_rx_data_slot new_slot; > + > + if (gve_rx_alloc_buffer(priv, dev, &new_info, > + &new_slot, rx)) > break; > - } > + gve_rx_free_buffer(dev, page_info, data_slot); > + *page_info =3D new_info; > + *data_slot =3D new_slot; > } > } > fill_cnt++; [Severity: Medium] Does copying new_info into *page_info overwrite page_info->can_flip with uninitialized stack memory? new_info is declared on the stack without initialization, and gve_rx_alloc_buffer() -> gve_setup_rx_buffer() only initializes page, page_offset, page_address, buf_size, and pagecnt_bias, leaving can_flip (and pad) untouched. Previously, page_info was zero-allocated and this branch was only entered when page_info->can_flip was 0. When the next packet received into this slot takes the copybreak path in gve_rx_skb(), a non-XDP_PASS verdict, or a drop path in gve_rx(), page_info->can_flip is not updated, so the following gve_rx_refill_buffers() pass checks an uninitialized page_info->can_flip and can spuriously flip the buffer instead of checking whether it can be recycled. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261109182533.3594= 984-1-lrizzo@google.com?part=3D22