From patchwork Wed Nov 24 20:53:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksandr Tyshchenko X-Patchwork-Id: 12693585 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0F744C433EF for ; Wed, 24 Nov 2021 20:55:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=S5w6+NJmQ/PIN0vzFbjKSKjXnV5BQqO5OBeFnuO2sCg=; b=k0C2YJfh7FmnZJ wxKBUNRVH7qXBhZ/Eh6LaYBrAx8SCQty6MPSMMwPXyMwYE6taK52lyMqSEycpKRNK9wzw8y2fPZFp V01ycppUlk9TxUkvdsudPM1WdPtlTEQckd2pujGOG5xGGp8FeQj4XS1/hqCTJOSoK66OEcSdjfRrt F3fqIdp5pqJEfmc73JrvpCUtjGcFVfqSGzIt/mxZeZilV7OOMqKdFZ9a98/TCDsldtdMO/Kq1fjZd 0vxMlIV8pyQo2BRudaZabCUKpc7RKFGNEtdhIEU40Ew9MXuyvVFrbgnwi004jC5B8J/CFpx9lzFq6 Ij6yMBJBPjKKsHlMo11w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mpzHO-005p7d-CB; Wed, 24 Nov 2021 20:54:10 +0000 Received: from mail-lf1-x134.google.com ([2a00:1450:4864:20::134]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mpzHA-005p4Y-Vf for linux-arm-kernel@lists.infradead.org; Wed, 24 Nov 2021 20:53:58 +0000 Received: by mail-lf1-x134.google.com with SMTP id bi37so10547184lfb.5 for ; Wed, 24 Nov 2021 12:53:56 -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=I5Ua+XOo9ED8QtDOWHq4o6dMZ+6zt8B38QrRs94d3jQ=; b=N719U68AvD57cSsDPqL5VUMkg/l6W7dFaBn0ds0pOblImoqD4O8SZtTVbiKUWXvfVM QwgG8Z6Ro3SdIlXgsHzI0FIZjBoGs6sAhbvkMgKp55HqgPCIvBZ/bDrqp+nLkExXIDXk 85VfW8+LD7yFAUgUpvJ/2m018THtiaHbBxWJqD8iahLuB6p5h86QVJOti4p/Vko/73Z+ qaK9Vh/scmIZQ9BMI7l50DJ1kbaNGmaBXek6irskc4a0CJq/yZOsKvS2cCwp3ouJixdO l2ac3Q50aoO+804982jn926QvZK1sKU0l7f4bskWWYtjonKnDPp3c5jE7tbHdbSGR8QN +RFg== 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=I5Ua+XOo9ED8QtDOWHq4o6dMZ+6zt8B38QrRs94d3jQ=; b=P4FPLdCFbv/kLzx9ntNE+XF5fay/y3QGsky/t9Amo5vjLZ4SkHwpbejCVbIlcluf9b 08oOJ1e3qS8AHChwgbkQEQq1fTHzfyxJSun084djflQHYMjbjpJIyb1RAZ05TQYUWlsw ZvlT6lCCrURKlBJRg1reB0Tr0xQlWRYJ1Y6I5068VJnUK+D1oYL/3ikUecHYSzDnCgz2 UY5OW8NOxpAfDgppIfjWN3FZMy/Yd8KPr29GqE/b2fN9VT2jjnHi/230X12ga4+RtUnD HoEgFTIdg4iiBY5G2//T3X9nU/gPr0iikIsSOuv6fZ4Fxoc3KDdeL1X6nYLX3uF9YCYT Ui4A== X-Gm-Message-State: AOAM532IHm3k7I2iRncBMN2joBETwELm65o3HPNvYgI+3mHKtajriaYj kxaFIy0N/N5XZkNlr/Mq5uE= X-Google-Smtp-Source: ABdhPJwpqCkahz5EbzD+MVB6XyFKIyWyAaQlqRXN5qpJziSHo0yhzGV2dme1YXtZkarUALEtZaAUbg== X-Received: by 2002:a05:6512:20d4:: with SMTP id u20mr18715939lfr.339.1637787235341; Wed, 24 Nov 2021 12:53:55 -0800 (PST) Received: from otyshchenko.router ([212.22.223.21]) by smtp.gmail.com with ESMTPSA id j11sm97608ljc.9.2021.11.24.12.53.54 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 24 Nov 2021 12:53:55 -0800 (PST) From: Oleksandr Tyshchenko To: xen-devel@lists.xenproject.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Oleksandr Tyshchenko , Stefano Stabellini , Russell King , Julien Grall Subject: [PATCH V3 2/6] arm/xen: Switch to use gnttab_setup_auto_xlat_frames() for DT Date: Wed, 24 Nov 2021 22:53:39 +0200 Message-Id: <1637787223-21129-3-git-send-email-olekstysh@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1637787223-21129-1-git-send-email-olekstysh@gmail.com> References: <1637787223-21129-1-git-send-email-olekstysh@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211124_125357_048159_88BE235C X-CRM114-Status: GOOD ( 21.18 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Oleksandr Tyshchenko Read the start address of the grant table space from DT (region 0). This patch mostly restores behaviour before commit 3cf4095d7446 ("arm/xen: Use xen_xlate_map_ballooned_pages to setup grant table") but trying not to break the ACPI support added after that commit. So the patch touches DT part only and leaves the ACPI part with xen_xlate_map_ballooned_pages(). Also in order to make a code more resilient use a fallback to xen_xlate_map_ballooned_pages() if grant table region wasn't found. This is a preparation for using Xen extended region feature where unused regions of guest physical address space (provided by the hypervisor) will be used to create grant/foreign/whatever mappings instead of wasting real RAM pages from the domain memory for establishing these mappings. The immediate benefit of this change: - Avoid superpage shattering in Xen P2M when establishing stage-2 mapping (GFN <-> MFN) for the grant table space - Avoid wasting real RAM pages (reducing the amount of memory usuable) for mapping grant table space - The grant table space is always mapped at the exact same place (region 0 is reserved for the grant table) Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini --- Changes RFC -> V2: - new patch Changes V2 -> V3: - add __read_mostly specifier to xen_grant_frames - retain a fallback to xen_xlate_map_ballooned_pages() if xen_grant_frames is invalid - process xen_events_irq before xen_grant_frames in xen_dt_guest_init() - update patch description --- arch/arm/xen/enlighten.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 7619fbf..3fb3384 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -59,6 +59,9 @@ unsigned long xen_released_pages; struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata; static __read_mostly unsigned int xen_events_irq; +static __read_mostly phys_addr_t xen_grant_frames; + +#define GRANT_TABLE_INDEX 0 uint32_t xen_start_flags; EXPORT_SYMBOL(xen_start_flags); @@ -303,6 +306,7 @@ static void __init xen_acpi_guest_init(void) static void __init xen_dt_guest_init(void) { struct device_node *xen_node; + struct resource res; xen_node = of_find_compatible_node(NULL, NULL, "xen,xen"); if (!xen_node) { @@ -311,13 +315,19 @@ static void __init xen_dt_guest_init(void) } xen_events_irq = irq_of_parse_and_map(xen_node, 0); + + if (of_address_to_resource(xen_node, GRANT_TABLE_INDEX, &res)) { + pr_err("Xen grant table region is not found\n"); + return; + } + xen_grant_frames = res.start; } static int __init xen_guest_init(void) { struct xen_add_to_physmap xatp; struct shared_info *shared_info_page = NULL; - int cpu; + int rc, cpu; if (!xen_domain()) return 0; @@ -370,12 +380,16 @@ static int __init xen_guest_init(void) for_each_possible_cpu(cpu) per_cpu(xen_vcpu_id, cpu) = cpu; - xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames(); - if (xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn, - &xen_auto_xlat_grant_frames.vaddr, - xen_auto_xlat_grant_frames.count)) { + if (!acpi_disabled || !xen_grant_frames) { + xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames(); + rc = xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn, + &xen_auto_xlat_grant_frames.vaddr, + xen_auto_xlat_grant_frames.count); + } else + rc = gnttab_setup_auto_xlat_frames(xen_grant_frames); + if (rc) { free_percpu(xen_vcpu_info); - return -ENOMEM; + return rc; } gnttab_init(); From patchwork Wed Nov 24 20:53:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksandr Tyshchenko X-Patchwork-Id: 12693587 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2E7F2C433F5 for ; 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The extended region (safe range) is a region of guest physical address space which is unused and could be safely used to create grant/foreign mappings instead of wasting real RAM pages from the domain memory for establishing these mappings. The extended regions are chosen by the hypervisor at the domain creation time and advertised to it via "reg" property under hypervisor node in the guest device-tree. As region 0 is reserved for grant table space (always present), the indexes for extended regions are 1...N. If arch_xen_unpopulated_init() fails for some reason the default behaviour will be restored (allocate xenballooned pages). This patch also removes XEN_UNPOPULATED_ALLOC dependency on x86. Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini --- Changes RFC -> V2: - new patch, instead of "[RFC PATCH 2/2] xen/unpopulated-alloc: Query hypervisor to provide unallocated space" Changes V2 -> V3: - update comments in code - drop the checks that a region is within the hotpluggable range, now the common code takes care of - update arch_xen_unpopulated_init() according to interface change, move xen_resource here, etc - use %pR specifier in error message - bait out in arch_xen_unpopulated_init() if !acpi_disabled - update checks in second loop in arch_xen_unpopulated_init() for the sake of clarity --- arch/arm/xen/enlighten.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++ drivers/xen/Kconfig | 2 +- 2 files changed, 107 insertions(+), 1 deletion(-) diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 3fb3384..019caa6 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -62,6 +62,7 @@ static __read_mostly unsigned int xen_events_irq; static __read_mostly phys_addr_t xen_grant_frames; #define GRANT_TABLE_INDEX 0 +#define EXT_REGION_INDEX 1 uint32_t xen_start_flags; EXPORT_SYMBOL(xen_start_flags); @@ -303,6 +304,111 @@ static void __init xen_acpi_guest_init(void) #endif } +#ifdef CONFIG_XEN_UNPOPULATED_ALLOC +/* + * A type-less specific Xen resource which contains extended regions + * (unused regions of guest physical address space provided by the hypervisor). + */ +static struct resource xen_resource = { + .name = "Xen unused space", +}; + +int __init arch_xen_unpopulated_init(struct resource **res) +{ + struct device_node *np; + struct resource *regs, *tmp_res; + uint64_t min_gpaddr = -1, max_gpaddr = 0; + unsigned int i, nr_reg = 0; + int rc; + + if (!xen_domain()) + return -ENODEV; + + if (!acpi_disabled) + return -ENODEV; + + np = of_find_compatible_node(NULL, NULL, "xen,xen"); + if (WARN_ON(!np)) + return -ENODEV; + + /* Skip region 0 which is reserved for grant table space */ + while (of_get_address(np, nr_reg + EXT_REGION_INDEX, NULL, NULL)) + nr_reg++; + + if (!nr_reg) { + pr_err("No extended regions are found\n"); + return -EINVAL; + } + + regs = kcalloc(nr_reg, sizeof(*regs), GFP_KERNEL); + if (!regs) + return -ENOMEM; + + /* + * Create resource from extended regions provided by the hypervisor to be + * used as unused address space for Xen scratch pages. + */ + for (i = 0; i < nr_reg; i++) { + rc = of_address_to_resource(np, i + EXT_REGION_INDEX, ®s[i]); + if (rc) + goto err; + + if (max_gpaddr < regs[i].end) + max_gpaddr = regs[i].end; + if (min_gpaddr > regs[i].start) + min_gpaddr = regs[i].start; + } + + xen_resource.start = min_gpaddr; + xen_resource.end = max_gpaddr; + + /* + * Mark holes between extended regions as unavailable. The rest of that + * address space will be available for the allocation. + */ + for (i = 1; i < nr_reg; i++) { + resource_size_t start, end; + + /* There is an overlap between regions */ + if (regs[i - 1].end + 1 > regs[i].start) { + rc = -EINVAL; + goto err; + } + + /* There is no hole between regions */ + if (regs[i - 1].end + 1 == regs[i].start) + continue; + + start = regs[i - 1].end + 1; + end = regs[i].start - 1; + + tmp_res = kzalloc(sizeof(*tmp_res), GFP_KERNEL); + if (!tmp_res) { + rc = -ENOMEM; + goto err; + } + + tmp_res->name = "Unavailable space"; + tmp_res->start = start; + tmp_res->end = end; + + rc = insert_resource(&xen_resource, tmp_res); + if (rc) { + pr_err("Cannot insert resource %pR (%d)\n", tmp_res, rc); + kfree(tmp_res); + goto err; + } + } + + *res = &xen_resource; + +err: + kfree(regs); + + return rc; +} +#endif + static void __init xen_dt_guest_init(void) { struct device_node *xen_node; diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index a1b11c62..553b614 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -321,7 +321,7 @@ config XEN_FRONT_PGDIR_SHBUF config XEN_UNPOPULATED_ALLOC bool "Use unpopulated memory ranges for guest mappings" - depends on X86 && ZONE_DEVICE + depends on ZONE_DEVICE default XEN_BACKEND || XEN_GNTDEV || XEN_DOM0 help Use unpopulated memory ranges in order to create mappings for guest