Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2859C433EF for ; Thu, 9 Dec 2021 20:05:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231582AbhLIUJY (ORCPT ); Thu, 9 Dec 2021 15:09:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231483AbhLIUJU (ORCPT ); Thu, 9 Dec 2021 15:09:20 -0500 Received: from mail-lf1-x130.google.com (mail-lf1-x130.google.com [IPv6:2a00:1450:4864:20::130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 681A9C061746 for ; Thu, 9 Dec 2021 12:05:46 -0800 (PST) Received: by mail-lf1-x130.google.com with SMTP id b40so14117408lfv.10 for ; Thu, 09 Dec 2021 12:05:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=S5p+2FMTZ9me3f7MgyffrybzDu1cB0H0WkSIssxF4tQ=; b=L+12IgIWe9epXxHZEYZ6HgwZbTEbj/L3wLIDxUpfg2E1xfGiWQMCwOe4aBrheOaE0z wACfBvNIMkXEf+nya8oleo9e8liD3Up08GRb4Pf37/nVLwjUKrMltKBaKTIRQizuPTHa kiB2eeFQVyRO63kGFUo/eHdq51GIFL/uNXEQrwXCo/A+hV/HCtFwDoXNyGsTEKlu6OmK enU+r1Tg1ZYL1MEeX5Ui3wMAW53n6E8DRTyEXCbfwpJxJDVvdGA6r445ekgReyO47/KG 4eMBCsKkqlUsop0XMggtfAv6ao4oSO6uuSiJshxVb2O+ztOTDIWehgeVPb4vaQXzfM9s kn+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=S5p+2FMTZ9me3f7MgyffrybzDu1cB0H0WkSIssxF4tQ=; b=kwQ0TvdJi0J1ZE1Wzg2QRp1Naqzo61JEoNuUqCfrfBIuKePQlmTy5rAWn+//maoJkY K+9ibKzrg6NN+U9NnExAEV22jT4m6pYyswbrbBZQHASWvgN2b+X/tfWYMZM2WBi0FAbv 6ntK6ceWIBW8Znel1IdW/dB72VDg62a2fcE+awu3va+qSW4hrRGbzVjhsIn0VkUQAUO1 K0vJHXBDV2sDeZL6smhaGoPcOGojKYYhiD2TVxBhCksJxkNYQfz5M8QYiUZTLCUTBzpY JFtLhbccj5vHeK5MckNhUmHCLoq8IjSJHKO3RUp2yTH4CvNPEi0MEuUOqXMrqngRX32T gCsg== X-Gm-Message-State: AOAM531MBtpsHYh+uH7Wsk1HFk+8nzA7z/XxtaEINaPq8E1WLol4rkWB oEA+2i97bWv47wvRbc+yYY4= X-Google-Smtp-Source: ABdhPJzXmNpIc4USAluGA5qsH7ufiWxU3sy77PqmbLRlZ2c4zMxbHDRyt5AvEYyGUnPsWWW7TFMqdg== X-Received: by 2002:a05:6512:3052:: with SMTP id b18mr8189605lfb.424.1639080344638; Thu, 09 Dec 2021 12:05:44 -0800 (PST) Received: from otyshchenko.router ([212.22.223.21]) by smtp.gmail.com with ESMTPSA id o12sm87371lft.134.2021.12.09.12.05.43 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 09 Dec 2021 12:05:44 -0800 (PST) From: Oleksandr Tyshchenko To: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Cc: Oleksandr Tyshchenko , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , Julien Grall Subject: [PATCH V4 3/6] xen/balloon: Bring alloc(free)_xenballooned_pages helpers back Date: Thu, 9 Dec 2021 22:05:33 +0200 Message-Id: <1639080336-26573-4-git-send-email-olekstysh@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1639080336-26573-1-git-send-email-olekstysh@gmail.com> References: <1639080336-26573-1-git-send-email-olekstysh@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Oleksandr Tyshchenko This patch rolls back some of the changes introduced by commit 121f2faca2c0a "xen/balloon: rename alloc/free_xenballooned_pages" in order to make possible to still allocate xenballooned pages if CONFIG_XEN_UNPOPULATED_ALLOC is enabled. On Arm the unpopulated pages will be allocated on top of extended regions provided by Xen via device-tree (the subsequent patches will add required bits to support unpopulated-alloc feature on Arm). The problem is that extended regions feature has been introduced into Xen quite recently (during 4.16 release cycle). So this effectively means that Linux must only use unpopulated-alloc on Arm if it is running on "new Xen" which advertises these regions. But, it will only be known after parsing the "hypervisor" node at boot time, so before doing that we cannot assume anything. In order to keep working if CONFIG_XEN_UNPOPULATED_ALLOC is enabled and the extended regions are not advertised (Linux is running on "old Xen", etc) we need the fallback to alloc_xenballooned_pages(). This way we wouldn't reduce the amount of memory usable (wasting RAM pages) for any of the external mappings anymore (and eliminate XSA-300) with "new Xen", but would be still functional ballooning out RAM pages with "old Xen". Also rename alloc(free)_xenballooned_pages to xen_alloc(free)_ballooned_pages and make xen_alloc(free)_unpopulated_pages static inline in xen.h if CONFIG_XEN_UNPOPULATED_ALLOC is disabled. Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini --- Changes V2 -> V3: - new patch Changes V3 -> V4: - no changes --- drivers/xen/balloon.c | 20 +++++++++----------- include/xen/balloon.h | 3 +++ include/xen/xen.h | 14 ++++++++++++++ 3 files changed, 26 insertions(+), 11 deletions(-) diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index ba2ea11..a2c4fc49 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -581,7 +581,6 @@ void balloon_set_new_target(unsigned long target) } EXPORT_SYMBOL_GPL(balloon_set_new_target); -#ifndef CONFIG_XEN_UNPOPULATED_ALLOC static int add_ballooned_pages(unsigned int nr_pages) { enum bp_state st; @@ -610,12 +609,12 @@ static int add_ballooned_pages(unsigned int nr_pages) } /** - * xen_alloc_unpopulated_pages - get pages that have been ballooned out + * xen_alloc_ballooned_pages - get pages that have been ballooned out * @nr_pages: Number of pages to get * @pages: pages returned * @return 0 on success, error otherwise */ -int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages) +int xen_alloc_ballooned_pages(unsigned int nr_pages, struct page **pages) { unsigned int pgno = 0; struct page *page; @@ -652,23 +651,23 @@ int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages) return 0; out_undo: mutex_unlock(&balloon_mutex); - xen_free_unpopulated_pages(pgno, pages); + xen_free_ballooned_pages(pgno, pages); /* - * NB: free_xenballooned_pages will only subtract pgno pages, but since + * NB: xen_free_ballooned_pages will only subtract pgno pages, but since * target_unpopulated is incremented with nr_pages at the start we need * to remove the remaining ones also, or accounting will be screwed. */ balloon_stats.target_unpopulated -= nr_pages - pgno; return ret; } -EXPORT_SYMBOL(xen_alloc_unpopulated_pages); +EXPORT_SYMBOL(xen_alloc_ballooned_pages); /** - * xen_free_unpopulated_pages - return pages retrieved with get_ballooned_pages + * xen_free_ballooned_pages - return pages retrieved with get_ballooned_pages * @nr_pages: Number of pages * @pages: pages to return */ -void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages) +void xen_free_ballooned_pages(unsigned int nr_pages, struct page **pages) { unsigned int i; @@ -687,9 +686,9 @@ void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages) mutex_unlock(&balloon_mutex); } -EXPORT_SYMBOL(xen_free_unpopulated_pages); +EXPORT_SYMBOL(xen_free_ballooned_pages); -#if defined(CONFIG_XEN_PV) +#if defined(CONFIG_XEN_PV) && !defined(CONFIG_XEN_UNPOPULATED_ALLOC) static void __init balloon_add_region(unsigned long start_pfn, unsigned long pages) { @@ -712,7 +711,6 @@ static void __init balloon_add_region(unsigned long start_pfn, balloon_stats.total_pages += extra_pfn_end - start_pfn; } #endif -#endif static int __init balloon_init(void) { diff --git a/include/xen/balloon.h b/include/xen/balloon.h index e93d4f0..f78a6cc 100644 --- a/include/xen/balloon.h +++ b/include/xen/balloon.h @@ -26,6 +26,9 @@ extern struct balloon_stats balloon_stats; void balloon_set_new_target(unsigned long target); +int xen_alloc_ballooned_pages(unsigned int nr_pages, struct page **pages); +void xen_free_ballooned_pages(unsigned int nr_pages, struct page **pages); + #ifdef CONFIG_XEN_BALLOON void xen_balloon_init(void); #else diff --git a/include/xen/xen.h b/include/xen/xen.h index 9f031b5..86c5b37 100644 --- a/include/xen/xen.h +++ b/include/xen/xen.h @@ -52,7 +52,21 @@ bool xen_biovec_phys_mergeable(const struct bio_vec *vec1, extern u64 xen_saved_max_mem_size; #endif +#ifdef CONFIG_XEN_UNPOPULATED_ALLOC int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages); void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages); +#else +#include +static inline int xen_alloc_unpopulated_pages(unsigned int nr_pages, + struct page **pages) +{ + return xen_alloc_ballooned_pages(nr_pages, pages); +} +static inline void xen_free_unpopulated_pages(unsigned int nr_pages, + struct page **pages) +{ + xen_free_ballooned_pages(nr_pages, pages); +} +#endif #endif /* _XEN_XEN_H */ -- 2.7.4