From patchwork Wed May 8 18:29:49 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13659044 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 BAA8C130A64 for ; Wed, 8 May 2024 18:30:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715193020; cv=none; b=AhR/gbK/HIruFg8DS9I3jQ6G7IxEcAfQyI8gWOGgAKKqSPJJUuZKhOCQfyy0rlMVx/jzpgfLX7JEyrZ1TOJHvMx0834NaThwiQQf5NovvkUM51eY4k0QbsHdxAKaH22MZ/z8RT270UJFHtq9/TFrveyKBj2lvJ5GP5zHk3mruqA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715193020; c=relaxed/simple; bh=9cMxw+0FUPFscli9SRIp15T5tvpY7n1JYHRqVPxhLQ8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BHdNdsGjM/aQUvLGpL2Gis0ZOcVOFFnYFg+VHqR+S01YIOrWda7evxKiCLyYZGX2UjouGoLsWlKvjdK9f3K61seQQk2ZfITSgGJSNMcm2gxtMJA06Y9IpfDxtES6gDHZbji4nSP8HFzYYZ2hzj1zMp+DYaG5HCX6U1+Mn+3kQh8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=aqolmFLy; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="aqolmFLy" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1715193018; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=MYWABkGxV8MYRWHh8nd3DHUSmm6awTOHiljU31Nr1kM=; b=aqolmFLyiCKur/L8AxnNt7vvV6YIHoBrTVtSLIpEZqiLVpTbxnz4hICnBwvcbSBJexjrtt XKstOWPl0Shpieuq4lE6LuejB43JdxmOFPTp62p+fFRbPMd1C+8VNvPywqVQE4yAcuE/hK AHqMUQKh/afMPXJ3NCT4DNOl0Xz+5/Q= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-628-C9cFn8fZOBah3jYfTssNEg-1; Wed, 08 May 2024 14:30:13 -0400 X-MC-Unique: C9cFn8fZOBah3jYfTssNEg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id CD905800262; Wed, 8 May 2024 18:30:12 +0000 (UTC) Received: from t14s.fritz.box (unknown [10.39.192.63]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5545C1000DB4; Wed, 8 May 2024 18:30:09 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, David Hildenbrand , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Janosch Frank , Claudio Imbrenda , Gerald Schaefer , Matthew Wilcox , Thomas Huth Subject: [PATCH v3 04/10] s390/uv: convert PG_arch_1 users to only work on small folios Date: Wed, 8 May 2024 20:29:49 +0200 Message-ID: <20240508182955.358628-5-david@redhat.com> In-Reply-To: <20240508182955.358628-1-david@redhat.com> References: <20240508182955.358628-1-david@redhat.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 Now that make_folio_secure() may only set PG_arch_1 for small folios, let's convert relevant remaining UV code to only work on (small) folios and simply reject large folios early. This way, we'll never end up touching PG_arch_1 on tail pages of a large folio in UV code. The folio_get()/folio_put() for functions that are documented to already hold a folio reference look weird; likely they are required to make concurrent gmap_make_secure() back off because the caller might only hold an implicit reference due to the page mapping. So leave that alone for now. Reviewed-by: Claudio Imbrenda Signed-off-by: David Hildenbrand --- arch/s390/include/asm/page.h | 2 ++ arch/s390/kernel/uv.c | 41 ++++++++++++++++++++++-------------- 2 files changed, 27 insertions(+), 16 deletions(-) diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h index 224ff9d433ea..ecbf4b626f46 100644 --- a/arch/s390/include/asm/page.h +++ b/arch/s390/include/asm/page.h @@ -247,7 +247,9 @@ static inline unsigned long __phys_addr(unsigned long x, bool is_31bit) #define pfn_to_phys(pfn) ((pfn) << PAGE_SHIFT) #define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys)) +#define phys_to_folio(phys) page_folio(phys_to_page(phys)) #define page_to_phys(page) pfn_to_phys(page_to_pfn(page)) +#define folio_to_phys(page) pfn_to_phys(folio_pfn(folio)) static inline void *pfn_to_virt(unsigned long pfn) { diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c index 3c6d86e3e828..914dcec27329 100644 --- a/arch/s390/kernel/uv.c +++ b/arch/s390/kernel/uv.c @@ -135,14 +135,18 @@ static int uv_destroy_page(unsigned long paddr) */ int uv_destroy_owned_page(unsigned long paddr) { - struct page *page = phys_to_page(paddr); + struct folio *folio = phys_to_folio(paddr); int rc; - get_page(page); + /* See gmap_make_secure(): large folios cannot be secure */ + if (unlikely(folio_test_large(folio))) + return 0; + + folio_get(folio); rc = uv_destroy_page(paddr); if (!rc) - clear_bit(PG_arch_1, &page->flags); - put_page(page); + clear_bit(PG_arch_1, &folio->flags); + folio_put(folio); return rc; } @@ -170,14 +174,18 @@ int uv_convert_from_secure(unsigned long paddr) */ int uv_convert_owned_from_secure(unsigned long paddr) { - struct page *page = phys_to_page(paddr); + struct folio *folio = phys_to_folio(paddr); int rc; - get_page(page); + /* See gmap_make_secure(): large folios cannot be secure */ + if (unlikely(folio_test_large(folio))) + return 0; + + folio_get(folio); rc = uv_convert_from_secure(paddr); if (!rc) - clear_bit(PG_arch_1, &page->flags); - put_page(page); + clear_bit(PG_arch_1, &folio->flags); + folio_put(folio); return rc; } @@ -479,33 +487,34 @@ EXPORT_SYMBOL_GPL(gmap_destroy_page); */ int arch_make_page_accessible(struct page *page) { + struct folio *folio = page_folio(page); int rc = 0; - /* Hugepage cannot be protected, so nothing to do */ - if (PageHuge(page)) + /* See gmap_make_secure(): large folios cannot be secure */ + if (unlikely(folio_test_large(folio))) return 0; /* * PG_arch_1 is used in 3 places: * 1. for kernel page tables during early boot * 2. for storage keys of huge pages and KVM - * 3. As an indication that this page might be secure. This can + * 3. As an indication that this small folio might be secure. This can * overindicate, e.g. we set the bit before calling * convert_to_secure. * As secure pages are never huge, all 3 variants can co-exists. */ - if (!test_bit(PG_arch_1, &page->flags)) + if (!test_bit(PG_arch_1, &folio->flags)) return 0; - rc = uv_pin_shared(page_to_phys(page)); + rc = uv_pin_shared(folio_to_phys(folio)); if (!rc) { - clear_bit(PG_arch_1, &page->flags); + clear_bit(PG_arch_1, &folio->flags); return 0; } - rc = uv_convert_from_secure(page_to_phys(page)); + rc = uv_convert_from_secure(folio_to_phys(folio)); if (!rc) { - clear_bit(PG_arch_1, &page->flags); + clear_bit(PG_arch_1, &folio->flags); return 0; }