From patchwork Thu Dec 9 20:05:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksandr Tyshchenko X-Patchwork-Id: 12695513 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 2AB1BC433EF for ; Thu, 9 Dec 2021 20:07:25 +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=92T24p6NytptmLuB5OnjT1gVp7cQTdnnYXHEI0tARR8=; b=QfIa+mZLBM9D17 /wYL28vNBvmabIuh4PFZwN1neja3ISNZ9isrSsiMbFOEIpzfyEcIVSsmOm2hFVj64dmEW7lJ+M7Cr DAgbYYue57Lu/UQPz8VNkIOJ6AIJ7dbrdjh0C4wc9jLnIjcXc0oNziRooouGcKhxfyU/yWpdnaFAg ghuT/dqvn4DPG9HKWHcKyYeQjz3oCmer22i6thF6LpuRs8y4EFRlweoPNz7RGGwlAWVTi7c6w50Hn zuRBQRoi0Ts7qbAbrAuzqL9Xt2H5FawSo9tvMmNWzCWKPWmorMRrjlTaZSXO+wXJoV5PSyD/JfIqr 7abPq7+ovRBylNykBumg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mvPg0-00HQkc-7k; Thu, 09 Dec 2021 20:06:00 +0000 Received: from mail-lj1-x230.google.com ([2a00:1450:4864:20::230]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mvPfl-00HQfw-Ml for linux-arm-kernel@lists.infradead.org; Thu, 09 Dec 2021 20:05:47 +0000 Received: by mail-lj1-x230.google.com with SMTP id l7so10726042lja.2 for ; Thu, 09 Dec 2021 12:05:45 -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=XoEU3DaXUqalCs6jzwcHq5Z2kR7REX3RsrqKMfGCo2w=; b=GlM2t+eQRjThRQMjBZpSdxLnDWzEbjJWVwRDusOaEx3MeX4FketF3biTqFzeEnAVU0 VhfKGEcuQp52HiEpPpvacBbuQwd87JvMTehJYvdAXf7KeOioUXb3WO3fCLID1qKZ7UBZ UTgdjk7vrs0SFE8l7HuLKFHyLrmDTcAD9cNMgKBWyA2U3xnLfBw1azVxQh+7gf79/OoO 1dQ4RbzOz6pbkTfeB0WK3PC7JrQpMMkPLByBqimCV2s9g1epLNijcmYesEuTP320tf69 StZYm2luPMAgllAQQSpglOUobSo4Wx1O+YEknSkfIltx1nSkiZfvAJ+J+cQWzBjsQ1vZ FzVg== 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=XoEU3DaXUqalCs6jzwcHq5Z2kR7REX3RsrqKMfGCo2w=; b=acwnaxlPEFA1p+c4OWOZoqbshyvFzwTQBR2SdNp2gCYwX/LUNV+xgcb4rrBHaa91Vz CyVo4OSPr1RdxuwQXCUoyalHQTmqCp1+3HQDnVKNet2AMci4vevzmDNATWDP+OMo88UD KUtjFDy++ct3Fwb72Qa2eJpsmAaF9MixY3Cvujm9G+Uf4XmuzgPZ0Gvkv8mIUXR8OUBw 4jTW5ojNlfQkBUUlTB4AKBhlBHrnRc3wXr5JPOT23ivXqepNa+kKgEOeB6PI0MUQGI3e DJAqIoWBlDe22pmGNeIL1KMNfG0bNIpG+Nic6e8uxLZUo//bzpbWJRDca0wDsYeRuk0i HbrA== X-Gm-Message-State: AOAM530z4nCJLb1JEGpCQyQZIqNsjZroBmXyaYLj3Kce/i8QqvO8DdVO 0nIttnVK7c6CjGypP9+KSsk= X-Google-Smtp-Source: ABdhPJwRwGnN2HYDLn4/ya4vANtMy2LFN1OiYbe33DChi+j/uEDELzNOeHtrWCUSzf5Mr+Zxr7NNrA== X-Received: by 2002:a2e:8ec7:: with SMTP id e7mr8517097ljl.430.1639080343851; Thu, 09 Dec 2021 12:05:43 -0800 (PST) Received: from otyshchenko.router ([212.22.223.21]) by smtp.gmail.com with ESMTPSA id o12sm87371lft.134.2021.12.09.12.05.42 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 09 Dec 2021 12:05:42 -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 V4 2/6] arm/xen: Switch to use gnttab_setup_auto_xlat_frames() for DT Date: Thu, 9 Dec 2021 22:05:32 +0200 Message-Id: <1639080336-26573-3-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> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211209_120545_803346_1AF37003 X-CRM114-Status: GOOD ( 21.13 ) 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 Changes V3 -> V4: - add Stefano's R-b - remove first condition in "if (!acpi_disabled || !xen_grant_frames)" --- 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..49bb675 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 (!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 Thu Dec 9 20:05:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksandr Tyshchenko X-Patchwork-Id: 12695514 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 2FFADC433F5 for ; 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Thu, 09 Dec 2021 12:05:45 -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 , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , Russell King , Julien Grall Subject: [PATCH V4 5/6] arm/xen: Read extended regions from DT and init Xen resource Date: Thu, 9 Dec 2021 22:05:35 +0200 Message-Id: <1639080336-26573-6-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> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211209_120547_730450_3EB20C89 X-CRM114-Status: GOOD ( 25.61 ) 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 This patch implements arch_xen_unpopulated_init() on Arm where the extended regions (if any) are gathered from DT and inserted into specific Xen resource to be used as unused address space for Xen scratch pages by unpopulated-alloc code. 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 Changes V3 -> V4: - add Stefano's R-b --- 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 49bb675..ec5b082 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 33e941e..120d32f 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -327,7 +327,7 @@ 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