From nobody Thu Oct 2 11:57:50 2025 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 AA11727E040 for ; Wed, 17 Sep 2025 17:40:48 +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=1758130848; cv=none; b=oDoLUKw5ycaW+ctbfGylNKqJE+Uba4RcA1OBCET6/gP1BsfAzSKEPAl5JWTxdDsdb7J3nlKa2x0TVC8ef7xSt0ZmoyRi0UNBog4qWrD02qNpgfbPHNLlixuy33WMT7aHYzelF0WbzR480fgwRQgU35jXsJABN5XBoQW83U2zLjY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758130848; c=relaxed/simple; bh=q/t3uKKPwUDe/VS493c2y7ty/sgLNnbkDT1wsgUidLE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SuvaOagGvhioqSUZBxfWAvxjbRQ1zmChUrabOC4BW1y8SowvTG/tRmzTv5Y7hob5RU5RXwtpT3+AJwqq+8I/uzRp510X9MtyD55j80pUTMuMW+DM6PNIy5EW+f03/Xgncz3DB8ICzIJT2LdvPzDF2frUvsEHi9q8ZGCFlEv0djU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YWNVC2+N; 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="YWNVC2+N" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CD38C4CEE7; Wed, 17 Sep 2025 17:40:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758130848; bh=q/t3uKKPwUDe/VS493c2y7ty/sgLNnbkDT1wsgUidLE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YWNVC2+NhhjJf+hD1kotVftCFqdoDZkFLt5It7TUxiKYJRf3UOOfk0X3WW8ki+GiX KkU1fJdKFjt9BzSmWLeuCYwjt+e5EmLTt0jbv4eGIc44Ha62Nipr9/l+cYYwTIZ7pX tItwXA4/CVyvwh6t9CLCgV2Kao+l46eSUIVQisWIuqc2ovOv6znBhwjiRvCvTE7BGa W/bqshWp76kkI/KnmtBOrXYSUndLrW+96geZMRXLsVFn198LIzSNc1qw+8aBnnS/oX xEVuk4XZ9Jrn29sG+OgcUNu9/KuS4NoQpBVAWeqqZibjpWtG7MXZEQWmZkcdmZbwgC C0mR3JWJch7gQ== From: Mike Rapoport To: Andrew Morton Cc: Alexander Graf , Baoquan He , Changyuan Lyu , Chris Li , Jason Gunthorpe , Mike Rapoport , Pasha Tatashin , Pratyush Yadav , kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 2/4] kho: replace kho_preserve_phys() with kho_preserve_pages() Date: Wed, 17 Sep 2025 20:40:31 +0300 Message-ID: <20250917174033.3810435-3-rppt@kernel.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250917174033.3810435-1-rppt@kernel.org> References: <20250917174033.3810435-1-rppt@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Mike Rapoport (Microsoft)" to make it clear that KHO operates on pages rather than on a random physical address. The kho_preserve_pages() will be also used in upcoming support for vmalloc preservation. Signed-off-by: Mike Rapoport (Microsoft) --- include/linux/kexec_handover.h | 5 +++-- kernel/kexec_handover.c | 25 +++++++++++-------------- mm/memblock.c | 4 +++- 3 files changed, 17 insertions(+), 17 deletions(-) diff --git a/include/linux/kexec_handover.h b/include/linux/kexec_handover.h index 348844cffb13..cc5c49b0612b 100644 --- a/include/linux/kexec_handover.h +++ b/include/linux/kexec_handover.h @@ -18,6 +18,7 @@ enum kho_event { =20 struct folio; struct notifier_block; +struct page; =20 #define DECLARE_KHOSER_PTR(name, type) \ union { \ @@ -42,7 +43,7 @@ struct kho_serialization; bool kho_is_enabled(void); =20 int kho_preserve_folio(struct folio *folio); -int kho_preserve_phys(phys_addr_t phys, size_t size); +int kho_preserve_pages(struct page *page, unsigned int nr_pages); struct folio *kho_restore_folio(phys_addr_t phys); int kho_add_subtree(struct kho_serialization *ser, const char *name, void = *fdt); int kho_retrieve_subtree(const char *name, phys_addr_t *phys); @@ -65,7 +66,7 @@ static inline int kho_preserve_folio(struct folio *folio) return -EOPNOTSUPP; } =20 -static inline int kho_preserve_phys(phys_addr_t phys, size_t size) +static inline int kho_preserve_pages(struct page *page, unsigned int nr_pa= ges) { return -EOPNOTSUPP; } diff --git a/kernel/kexec_handover.c b/kernel/kexec_handover.c index f421acc58c1f..3ad59c5f9eaa 100644 --- a/kernel/kexec_handover.c +++ b/kernel/kexec_handover.c @@ -698,26 +698,23 @@ int kho_preserve_folio(struct folio *folio) EXPORT_SYMBOL_GPL(kho_preserve_folio); =20 /** - * kho_preserve_phys - preserve a physically contiguous range across kexec. - * @phys: physical address of the range. - * @size: size of the range. + * kho_preserve_pages - preserve contiguous pages across kexec + * @page: first page in the list. + * @nr_pages: number of pages. * - * Instructs KHO to preserve the memory range from @phys to @phys + @size - * across kexec. + * Preserve a contiguous list of order 0 pages. Must be restored using + * kho_restore_page() on each order 0 page. * * Return: 0 on success, error code on failure */ -int kho_preserve_phys(phys_addr_t phys, size_t size) +int kho_preserve_pages(struct page *page, unsigned int nr_pages) { - unsigned long pfn =3D PHYS_PFN(phys); + struct kho_mem_track *track =3D &kho_out.ser.track; + const unsigned long start_pfn =3D page_to_pfn(page); + const unsigned long end_pfn =3D start_pfn + nr_pages; + unsigned long pfn =3D start_pfn; unsigned long failed_pfn =3D 0; - const unsigned long start_pfn =3D pfn; - const unsigned long end_pfn =3D PHYS_PFN(phys + size); int err =3D 0; - struct kho_mem_track *track =3D &kho_out.ser.track; - - if (!PAGE_ALIGNED(phys) || !PAGE_ALIGNED(size)) - return -EINVAL; =20 while (pfn < end_pfn) { const unsigned int order =3D @@ -737,7 +734,7 @@ int kho_preserve_phys(phys_addr_t phys, size_t size) =20 return err; } -EXPORT_SYMBOL_GPL(kho_preserve_phys); +EXPORT_SYMBOL_GPL(kho_preserve_pages); =20 /* Handling for debug/kho/out */ =20 diff --git a/mm/memblock.c b/mm/memblock.c index 117d963e677c..6ec3eaa4e8d1 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -2516,8 +2516,10 @@ static int reserve_mem_kho_finalize(struct kho_seria= lization *ser) =20 for (i =3D 0; i < reserved_mem_count; i++) { struct reserve_mem_table *map =3D &reserved_mem_table[i]; + struct page *page =3D phys_to_page(map->start); + unsigned int nr_pages =3D map->size >> PAGE_SHIFT; =20 - err |=3D kho_preserve_phys(map->start, map->size); + err |=3D kho_preserve_pages(page, nr_pages); } =20 err |=3D kho_preserve_folio(page_folio(kho_fdt)); --=20 2.50.1