From mboxrd@z Thu Jan 1 00:00:00 1970 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 B83DCC433EF for ; Tue, 17 May 2022 18:06:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236820AbiEQSFu (ORCPT ); Tue, 17 May 2022 14:05:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351931AbiEQSF1 (ORCPT ); Tue, 17 May 2022 14:05:27 -0400 Received: from mail-wm1-x32a.google.com (mail-wm1-x32a.google.com [IPv6:2a00:1450:4864:20::32a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C8B8E5158D for ; Tue, 17 May 2022 11:04:33 -0700 (PDT) Received: by mail-wm1-x32a.google.com with SMTP id p5-20020a1c2905000000b003970dd5404dso1694989wmp.0 for ; Tue, 17 May 2022 11:04:33 -0700 (PDT) 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=xUxnvY0wWYvQFwVkkKnZ0hYzB77/1hWqL1wilzE489c=; b=kb8ddVNGcr5cVeafnyHPeYNXQERd/qF31HFkfUdq2R0uWdYsIrV5qJc5rqOLz8AJ2R LeqlzPakVREbISyj+rzFqGHtWdSCexiQvfb3BzQZY4Gb6WIGH1gnWvSpBsaSAoOAgJPw Y2gQVbghkdgpguWD5R6ZUeT1mykXPwp1lsXvUamDbQaFqmfp7ZJs19gwZMPPJzKo2yI5 qsxQdCIXfE44XW+Ui9ZV8j0XprUOYnEv+bHcF2+ibhH3I9NCtjxHxMwKRYDXdrArzigQ AkB6D1SgJLfFBjy+aEuoy/qrUgNvZwQus2tAbvnVgDGakrkC9Xvt3cWzsnYci380bHt5 MjFQ== 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=xUxnvY0wWYvQFwVkkKnZ0hYzB77/1hWqL1wilzE489c=; b=rJ3sRgpdWQjRsPrMVGIVDDw9mAyP62EFJA32M0pAF+iewIGG6150dKGjar9oerkoju DhDYxAq40E2gi+c3eKytSpPR+/7AimuK9YClA+M7mTsKTKodEu90mFf9KzyLVDiyBc8X PvnBJkW3BXiR/G2yueRzWCSeb2DJF1S7+V8oOs5aO8WY0JoQSHx6AVNDHlPvMsnM0DSa rvx7lhdMtEwquvJMM5awP6lF6G5bQ1M05NW+MSqphvv58MD6KMw3qeCy0BNS0FaYp+m4 lZq63t5ej8c5VlYOun/iqhaJ3PEzSBHLpwvRlYB5Im2+5+Of14Pp2oRGUwYKwEJ3aWQq p3sQ== X-Gm-Message-State: AOAM5334ui9/7PAXtpZU/icfmRfXVwG45gYFXhxGgEfI/K9POYSAWkSt eXK+dDxQtX25fg3VJUiANQE= X-Google-Smtp-Source: ABdhPJzy8So6LUCbbqsaVyGqZpkGWh1nIJifHTvsH6tXSl1Cxhg/tQhSmkYmww8KULDXmX3Xv/O7fQ== X-Received: by 2002:a05:600c:1989:b0:394:8dc0:b57f with SMTP id t9-20020a05600c198900b003948dc0b57fmr33101152wmq.110.1652810672320; Tue, 17 May 2022 11:04:32 -0700 (PDT) Received: from otyshchenko.router ([212.22.223.21]) by smtp.gmail.com with ESMTPSA id c3-20020adfc6c3000000b0020c5253d8dasm12978625wrh.38.2022.05.17.11.04.31 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 17 May 2022 11:04:31 -0700 (PDT) From: Oleksandr Tyshchenko To: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Cc: Oleksandr Tyshchenko , Stefano Stabellini , Boris Ostrovsky , Juergen Gross , Julien Grall Subject: [RFC PATCH 2/2] xen/grant-table: Use unpopulated DMAable pages instead of real RAM ones Date: Tue, 17 May 2022 21:04:18 +0300 Message-Id: <1652810658-27810-3-git-send-email-olekstysh@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1652810658-27810-1-git-send-email-olekstysh@gmail.com> References: <1652810658-27810-1-git-send-email-olekstysh@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Oleksandr Tyshchenko Depends on CONFIG_XEN_UNPOPULATED_ALLOC. If enabled then unpopulated DMAable (contiguous) pages will be allocated for grant mapping into instead of ballooning out real RAM pages. TODO: Fallback to real RAM pages if xen_alloc_unpopulated_dma_pages() fails. Signed-off-by: Oleksandr Tyshchenko --- drivers/xen/grant-table.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 8ccccac..2bb4392 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -864,6 +864,25 @@ EXPORT_SYMBOL_GPL(gnttab_free_pages); */ int gnttab_dma_alloc_pages(struct gnttab_dma_alloc_args *args) { +#ifdef CONFIG_XEN_UNPOPULATED_ALLOC + int ret; + + ret = xen_alloc_unpopulated_dma_pages(args->dev, args->nr_pages, + args->pages); + if (ret < 0) + return ret; + + ret = gnttab_pages_set_private(args->nr_pages, args->pages); + if (ret < 0) { + gnttab_dma_free_pages(args); + return ret; + } + + args->vaddr = page_to_virt(args->pages[0]); + args->dev_bus_addr = page_to_phys(args->pages[0]); + + return ret; +#else unsigned long pfn, start_pfn; size_t size; int i, ret; @@ -910,6 +929,7 @@ int gnttab_dma_alloc_pages(struct gnttab_dma_alloc_args *args) fail: gnttab_dma_free_pages(args); return ret; +#endif } EXPORT_SYMBOL_GPL(gnttab_dma_alloc_pages); @@ -919,6 +939,12 @@ EXPORT_SYMBOL_GPL(gnttab_dma_alloc_pages); */ int gnttab_dma_free_pages(struct gnttab_dma_alloc_args *args) { +#ifdef CONFIG_XEN_UNPOPULATED_ALLOC + gnttab_pages_clear_private(args->nr_pages, args->pages); + xen_free_unpopulated_dma_pages(args->dev, args->nr_pages, args->pages); + + return 0; +#else size_t size; int i, ret; @@ -946,6 +972,7 @@ int gnttab_dma_free_pages(struct gnttab_dma_alloc_args *args) dma_free_wc(args->dev, size, args->vaddr, args->dev_bus_addr); return ret; +#endif } EXPORT_SYMBOL_GPL(gnttab_dma_free_pages); #endif -- 2.7.4