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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D162DC433EF for ; Thu, 28 Oct 2021 01:40:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE5B661107 for ; Thu, 28 Oct 2021 01:40:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229614AbhJ1Bmh (ORCPT ); Wed, 27 Oct 2021 21:42:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:57640 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229515AbhJ1Bmg (ORCPT ); Wed, 27 Oct 2021 21:42:36 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6090461100; Thu, 28 Oct 2021 01:40:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1635385210; bh=X288Vb/CllN4w89yrsjxckKoO24AoOFwTC+Y1bZLW54=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=dLx+k5vKHRPbn9SEh146uGicFOvuXY5hlgq84dMgd0XlKDUkNwmGh745Eyvj4Tlkx pHv0CQlLN2Fidfqzl0WpeQDhbO/RBotviUoP2VDpTIdNCIX7X8A4m4X08HkZJALyWI 7ivVD1MqmiC1bJTRItBaeEKM+7Nk8Ko5TgySx/QtN4O1PvNkY/keYwy69+VKQ1sATC arysC86WNTzxHzO7S/sZSF6w+99XpzZQPSoGRAf1TTPnCRy06usB4DGmBn7YSNCElT k1qmQvsrlO6vu7CUGNmLhuL+jRnU1WkrW0f8w540sMVT99qapAMoKKqkrpxrjQjV1B cAKl+pORy1r9A== Date: Wed, 27 Oct 2021 18:40:09 -0700 (PDT) From: Stefano Stabellini X-X-Sender: sstabellini@sstabellini-ThinkPad-T480s To: Oleksandr Tyshchenko cc: xen-devel@lists.xenproject.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Oleksandr Tyshchenko , Stefano Stabellini , Russell King , Boris Ostrovsky , Juergen Gross , Julien Grall Subject: Re: [PATCH V2 4/4] arm/xen: Read extended regions from DT and init Xen resource In-Reply-To: <1635264312-3796-5-git-send-email-olekstysh@gmail.com> Message-ID: References: <1635264312-3796-1-git-send-email-olekstysh@gmail.com> <1635264312-3796-5-git-send-email-olekstysh@gmail.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: multipart/mixed; BOUNDARY="8323329-800219594-1635384450=:20134" Content-ID: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-800219594-1635384450=:20134 Content-Type: text/plain; CHARSET=UTF-8 Content-Transfer-Encoding: 8BIT Content-ID: On Tue, 26 Oct 2021, Oleksandr Tyshchenko wrote: > 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 passed 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 > --- > Changes RFC -> V2: > - new patch, instead of > "[RFC PATCH 2/2] xen/unpopulated-alloc: Query hypervisor to provide unallocated space" > --- > arch/arm/xen/enlighten.c | 112 +++++++++++++++++++++++++++++++++++++++++++++++ > drivers/xen/Kconfig | 2 +- > 2 files changed, 113 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c > index dea46ec..1a1e0d3 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 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 +304,117 @@ static void __init xen_acpi_guest_init(void) > #endif > } > > +#ifdef CONFIG_XEN_UNPOPULATED_ALLOC > +int 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; > + struct range mhp_range; > + int rc; > + > + if (!xen_domain()) > + 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; > + } > + > + /* Check whether the resource range is within the hotpluggable range */ > + mhp_range = mhp_get_pluggable_range(true); > + if (min_gpaddr < mhp_range.start) > + min_gpaddr = mhp_range.start; > + if (max_gpaddr > mhp_range.end) > + max_gpaddr = mhp_range.end; > + > + res->start = min_gpaddr; > + res->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; > + > + start = regs[i - 1].end + 1; > + end = regs[i].start - 1; > + > + if (start > (end + 1)) { Should this be: if (start >= end) ? > + rc = -EINVAL; > + goto err; > + } > + > + /* There is no hole between regions */ > + if (start == (end + 1)) Also here, shouldn't it be: if (start == end) ? I think I am missing again something in termination accounting :-) > + continue; > + > + /* Check whether the hole range is within the resource range */ > + if (start < res->start || end > res->end) { By definition I don't think this check is necessary as either condition is impossible? > + if (start < res->start) > + start = res->start; > + if (end > res->end) > + end = res->end; > + > + if (start >= (end + 1)) > + continue; > + } > + > + 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; Do we need to set any flags so that the system can reuse the memory in the hole, e.g. IORESOURCE_MEM? Or is it not necessary? > + rc = insert_resource(res, tmp_res); > + if (rc) { > + pr_err("Cannot insert resource [%llx - %llx] %d\n", > + tmp_res->start, tmp_res->end, rc); Although it is impossible to enable XEN_UNPOPULATED_ALLOC on arm32 due to unmet dependencies, I would like to keep the implementation of arch_xen_unpopulated_init 32bit clean. I am getting build errors like (by forcing arch_xen_unpopulated_init to compile on arm32): ./include/linux/kern_levels.h:5:18: warning: format ‘%llx’ expects argument of type ‘long long unsigned int’, but argument 3 has type ‘resource_size_t {aka unsigned int}’ [-Wformat=] > + kfree(tmp_res); > + goto err; > + } > + } > + > +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 1b2c3ac..e6031fc 100644 > --- a/drivers/xen/Kconfig > +++ b/drivers/xen/Kconfig > @@ -297,7 +297,7 @@ 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 --8323329-800219594-1635384450=:20134-- 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C091C43219 for ; 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b=dLx+k5vKHRPbn9SEh146uGicFOvuXY5hlgq84dMgd0XlKDUkNwmGh745Eyvj4Tlkx pHv0CQlLN2Fidfqzl0WpeQDhbO/RBotviUoP2VDpTIdNCIX7X8A4m4X08HkZJALyWI 7ivVD1MqmiC1bJTRItBaeEKM+7Nk8Ko5TgySx/QtN4O1PvNkY/keYwy69+VKQ1sATC arysC86WNTzxHzO7S/sZSF6w+99XpzZQPSoGRAf1TTPnCRy06usB4DGmBn7YSNCElT k1qmQvsrlO6vu7CUGNmLhuL+jRnU1WkrW0f8w540sMVT99qapAMoKKqkrpxrjQjV1B cAKl+pORy1r9A== Date: Wed, 27 Oct 2021 18:40:09 -0700 (PDT) From: Stefano Stabellini X-X-Sender: sstabellini@sstabellini-ThinkPad-T480s To: Oleksandr Tyshchenko cc: xen-devel@lists.xenproject.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Oleksandr Tyshchenko , Stefano Stabellini , Russell King , Boris Ostrovsky , Juergen Gross , Julien Grall Subject: Re: [PATCH V2 4/4] arm/xen: Read extended regions from DT and init Xen resource In-Reply-To: <1635264312-3796-5-git-send-email-olekstysh@gmail.com> Message-ID: References: <1635264312-3796-1-git-send-email-olekstysh@gmail.com> <1635264312-3796-5-git-send-email-olekstysh@gmail.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: multipart/mixed; BOUNDARY="8323329-800219594-1635384450=:20134" Content-ID: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211027_184011_354001_07C90695 X-CRM114-Status: GOOD ( 38.84 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-800219594-1635384450=:20134 Content-Type: text/plain; CHARSET=UTF-8 Content-Transfer-Encoding: 8BIT Content-ID: On Tue, 26 Oct 2021, Oleksandr Tyshchenko wrote: > 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 passed 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 > --- > Changes RFC -> V2: > - new patch, instead of > "[RFC PATCH 2/2] xen/unpopulated-alloc: Query hypervisor to provide unallocated space" > --- > arch/arm/xen/enlighten.c | 112 +++++++++++++++++++++++++++++++++++++++++++++++ > drivers/xen/Kconfig | 2 +- > 2 files changed, 113 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c > index dea46ec..1a1e0d3 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 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 +304,117 @@ static void __init xen_acpi_guest_init(void) > #endif > } > > +#ifdef CONFIG_XEN_UNPOPULATED_ALLOC > +int 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; > + struct range mhp_range; > + int rc; > + > + if (!xen_domain()) > + 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; > + } > + > + /* Check whether the resource range is within the hotpluggable range */ > + mhp_range = mhp_get_pluggable_range(true); > + if (min_gpaddr < mhp_range.start) > + min_gpaddr = mhp_range.start; > + if (max_gpaddr > mhp_range.end) > + max_gpaddr = mhp_range.end; > + > + res->start = min_gpaddr; > + res->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; > + > + start = regs[i - 1].end + 1; > + end = regs[i].start - 1; > + > + if (start > (end + 1)) { Should this be: if (start >= end) ? > + rc = -EINVAL; > + goto err; > + } > + > + /* There is no hole between regions */ > + if (start == (end + 1)) Also here, shouldn't it be: if (start == end) ? I think I am missing again something in termination accounting :-) > + continue; > + > + /* Check whether the hole range is within the resource range */ > + if (start < res->start || end > res->end) { By definition I don't think this check is necessary as either condition is impossible? > + if (start < res->start) > + start = res->start; > + if (end > res->end) > + end = res->end; > + > + if (start >= (end + 1)) > + continue; > + } > + > + 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; Do we need to set any flags so that the system can reuse the memory in the hole, e.g. IORESOURCE_MEM? Or is it not necessary? > + rc = insert_resource(res, tmp_res); > + if (rc) { > + pr_err("Cannot insert resource [%llx - %llx] %d\n", > + tmp_res->start, tmp_res->end, rc); Although it is impossible to enable XEN_UNPOPULATED_ALLOC on arm32 due to unmet dependencies, I would like to keep the implementation of arch_xen_unpopulated_init 32bit clean. I am getting build errors like (by forcing arch_xen_unpopulated_init to compile on arm32): ./include/linux/kern_levels.h:5:18: warning: format ‘%llx’ expects argument of type ‘long long unsigned int’, but argument 3 has type ‘resource_size_t {aka unsigned int}’ [-Wformat=] > + kfree(tmp_res); > + goto err; > + } > + } > + > +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 1b2c3ac..e6031fc 100644 > --- a/drivers/xen/Kconfig > +++ b/drivers/xen/Kconfig > @@ -297,7 +297,7 @@ 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 --8323329-800219594-1635384450=:20134 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --8323329-800219594-1635384450=:20134--