From nobody Mon Feb 9 20:12:35 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=fail(p=none dis=none) header.from=arm.com Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1655701933672874.0720068375339; Sun, 19 Jun 2022 22:12:13 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.352315.579110 (Exim 4.92) (envelope-from ) id 1o39hb-00031S-RO; Mon, 20 Jun 2022 05:11:55 +0000 Received: by outflank-mailman (output) from mailman id 352315.579110; Mon, 20 Jun 2022 05:11:55 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1o39hb-00031C-N4; Mon, 20 Jun 2022 05:11:55 +0000 Received: by outflank-mailman (input) for mailman id 352315; Mon, 20 Jun 2022 05:11:55 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1o39hb-0000ky-9q for xen-devel@lists.xenproject.org; Mon, 20 Jun 2022 05:11:55 +0000 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by se1-gles-sth1.inumbo.com (Halon) with ESMTP id 7f794c26-f057-11ec-bd2d-47488cf2e6aa; Mon, 20 Jun 2022 07:11:53 +0200 (CEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2BACE1042; Sun, 19 Jun 2022 22:11:53 -0700 (PDT) Received: from a011292.shanghai.arm.com (a011292.shanghai.arm.com [10.169.190.94]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 307DB3F7D7; Sun, 19 Jun 2022 22:11:49 -0700 (PDT) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 7f794c26-f057-11ec-bd2d-47488cf2e6aa From: Penny Zheng To: xen-devel@lists.xenproject.org Cc: wei.chen@arm.com, Penny Zheng , Stefano Stabellini , Julien Grall , Bertrand Marquis , Volodymyr Babchuk , Penny Zheng Subject: [PATCH v5 7/8] xen/arm: create shared memory nodes in guest device tree Date: Mon, 20 Jun 2022 13:11:13 +0800 Message-Id: <20220620051114.210118-8-Penny.Zheng@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220620051114.210118-1-Penny.Zheng@arm.com> References: <20220620051114.210118-1-Penny.Zheng@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZM-MESSAGEID: 1655701935185100015 Content-Type: text/plain; charset="utf-8" We expose the shared memory to the domU using the "xen,shared-memory-v1" reserved-memory binding. See Documentation/devicetree/bindings/reserved-memory/xen,shared-memory.txt in Linux for the corresponding device tree binding. To save the cost of re-parsing shared memory device tree configuration when creating shared memory nodes in guest device tree, this commit adds new fie= ld "shm_mem" to store shm-info per domain. For each shared memory region, a range is exposed under the /reserved-memory node as a child node. Each range sub-node is named xen-shmem@
and has the following properties: - compatible: compatible =3D "xen,shared-memory-v1" - reg: the base guest physical address and size of the shared memory region - xen,id: a string that identifies the shared memory region. Signed-off-by: Penny Zheng Reviewed-by: Stefano Stabellini --- v5 change: - no change --- v4 change: - no change --- v3 change: - move field "shm_mem" to kernel_info --- v2 change: - using xzalloc - shm_id should be uint8_t - make reg a local variable - add #address-cells and #size-cells properties - fix alignment --- xen/arch/arm/domain_build.c | 143 +++++++++++++++++++++++++++++- xen/arch/arm/include/asm/kernel.h | 1 + xen/arch/arm/include/asm/setup.h | 1 + 3 files changed, 143 insertions(+), 2 deletions(-) diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c index 1584e6c2ce..4d62440a0e 100644 --- a/xen/arch/arm/domain_build.c +++ b/xen/arch/arm/domain_build.c @@ -900,7 +900,22 @@ static int __init allocate_shared_memory(struct domain= *d, return ret; } =20 -static int __init process_shm(struct domain *d, +static int __init append_shm_bank_to_domain(struct kernel_info *kinfo, + paddr_t start, paddr_t size, + u32 shm_id) +{ + if ( (kinfo->shm_mem.nr_banks + 1) > NR_MEM_BANKS ) + return -ENOMEM; + + kinfo->shm_mem.bank[kinfo->shm_mem.nr_banks].start =3D start; + kinfo->shm_mem.bank[kinfo->shm_mem.nr_banks].size =3D size; + kinfo->shm_mem.bank[kinfo->shm_mem.nr_banks].shm_id =3D shm_id; + kinfo->shm_mem.nr_banks++; + + return 0; +} + +static int __init process_shm(struct domain *d, struct kernel_info *kinfo, const struct dt_device_node *node) { struct dt_device_node *shm_node; @@ -971,6 +986,14 @@ static int __init process_shm(struct domain *d, if ( ret ) return ret; } + + /* + * Record static shared memory region info for later setting + * up shm-node in guest device tree. + */ + ret =3D append_shm_bank_to_domain(kinfo, gbase, psize, shm_id); + if ( ret ) + return ret; } =20 return 0; @@ -1301,6 +1324,117 @@ static int __init make_memory_node(const struct dom= ain *d, return res; } =20 +#ifdef CONFIG_STATIC_SHM +static int __init make_shm_memory_node(const struct domain *d, + void *fdt, + int addrcells, int sizecells, + struct meminfo *mem) +{ + unsigned long i =3D 0; + int res =3D 0; + + if ( mem->nr_banks =3D=3D 0 ) + return -ENOENT; + + /* + * For each shared memory region, a range is exposed under + * the /reserved-memory node as a child node. Each range sub-node is + * named xen-shmem@
. + */ + dt_dprintk("Create xen-shmem node\n"); + + for ( ; i < mem->nr_banks; i++ ) + { + uint64_t start =3D mem->bank[i].start; + uint64_t size =3D mem->bank[i].size; + uint8_t shm_id =3D mem->bank[i].shm_id; + /* Placeholder for xen-shmem@ + a 64-bit number + \0 */ + char buf[27]; + const char compat[] =3D "xen,shared-memory-v1"; + __be32 reg[4]; + __be32 *cells; + unsigned int len =3D (addrcells + sizecells) * sizeof(__be32); + + snprintf(buf, sizeof(buf), "xen-shmem@%"PRIx64, mem->bank[i].start= ); + res =3D fdt_begin_node(fdt, buf); + if ( res ) + return res; + + res =3D fdt_property(fdt, "compatible", compat, sizeof(compat)); + if ( res ) + return res; + + cells =3D reg; + dt_child_set_range(&cells, addrcells, sizecells, start, size); + + res =3D fdt_property(fdt, "reg", reg, len); + if ( res ) + return res; + + dt_dprintk("Shared memory bank %lu: %#"PRIx64"->%#"PRIx64"\n", + i, start, start + size); + + res =3D fdt_property_cell(fdt, "xen,id", shm_id); + if ( res ) + return res; + + res =3D fdt_end_node(fdt); + if ( res ) + return res; + } + + return res; +} +#else +static int __init make_shm_memory_node(const struct domain *d, + void *fdt, + int addrcells, int sizecells, + struct meminfo *mem) +{ + ASSERT_UNREACHABLE(); +} +#endif + +static int __init make_resv_memory_node(const struct domain *d, + void *fdt, + int addrcells, int sizecells, + struct meminfo *mem) +{ + int res =3D 0; + /* Placeholder for reserved-memory\0 */ + char resvbuf[16] =3D "reserved-memory"; + + if ( mem->nr_banks =3D=3D 0 ) + /* No shared memory provided. */ + return 0; + + dt_dprintk("Create reserved-memory node\n"); + + res =3D fdt_begin_node(fdt, resvbuf); + if ( res ) + return res; + + res =3D fdt_property(fdt, "ranges", NULL, 0); + if ( res ) + return res; + + res =3D fdt_property_cell(fdt, "#address-cells", addrcells); + if ( res ) + return res; + + res =3D fdt_property_cell(fdt, "#size-cells", sizecells); + if ( res ) + return res; + + res =3D make_shm_memory_node(d, fdt, addrcells, sizecells, mem); + if ( res ) + return res; + + res =3D fdt_end_node(fdt); + + return res; +} + static int __init add_ext_regions(unsigned long s, unsigned long e, void *= data) { struct meminfo *ext_regions =3D data; @@ -3078,6 +3212,11 @@ static int __init prepare_dtb_domU(struct domain *d,= struct kernel_info *kinfo) if ( ret ) goto err; =20 + ret =3D make_resv_memory_node(d, kinfo->fdt, addrcells, sizecells, + &kinfo->shm_mem); + if ( ret ) + goto err; + /* * domain_handle_dtb_bootmodule has to be called before the rest of * the device tree is generated because it depends on the value of @@ -3454,7 +3593,7 @@ static int __init construct_domU(struct domain *d, assign_static_memory_11(d, &kinfo, node); =20 #ifdef CONFIG_STATIC_SHM - rc =3D process_shm(d, node); + rc =3D process_shm(d, &kinfo, node); if ( rc < 0 ) return rc; #endif diff --git a/xen/arch/arm/include/asm/kernel.h b/xen/arch/arm/include/asm/k= ernel.h index c4dc039b54..2cc506b100 100644 --- a/xen/arch/arm/include/asm/kernel.h +++ b/xen/arch/arm/include/asm/kernel.h @@ -19,6 +19,7 @@ struct kernel_info { void *fdt; /* flat device tree */ paddr_t unassigned_mem; /* RAM not (yet) assigned to a bank */ struct meminfo mem; + struct meminfo shm_mem; =20 /* kernel entry point */ paddr_t entry; diff --git a/xen/arch/arm/include/asm/setup.h b/xen/arch/arm/include/asm/se= tup.h index 5063e5d077..7497cc40aa 100644 --- a/xen/arch/arm/include/asm/setup.h +++ b/xen/arch/arm/include/asm/setup.h @@ -29,6 +29,7 @@ struct membank { bool xen_domain; /* whether the memory bank is bound to a Xen domain. = */ #ifdef CONFIG_STATIC_SHM unsigned int nr_shm_domain; + uint8_t shm_id ; /* ID identifier of a static shared memory bank. */ #endif }; =20 --=20 2.25.1