From patchwork Thu Sep 8 13:55:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Penny Zheng X-Patchwork-Id: 12970353 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 0B2ADC6FA86 for ; Thu, 8 Sep 2022 16:39:17 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.403511.645657 (Exim 4.92) (envelope-from ) id 1oWKYX-0005bt-L0; Thu, 08 Sep 2022 16:39:09 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 403511.645657; Thu, 08 Sep 2022 16:39:09 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1oWKYX-0005bm-HQ; Thu, 08 Sep 2022 16:39:09 +0000 Received: by outflank-mailman (input) for mailman id 403511; Thu, 08 Sep 2022 16:39:08 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1oWKSp-0002V6-PH for xen-devel@lists.xenproject.org; Thu, 08 Sep 2022 16:33:15 +0000 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by se1-gles-flk1.inumbo.com (Halon) with ESMTP id dcef5faa-2f7d-11ed-9760-273f2230c3a0; Thu, 08 Sep 2022 15:55:14 +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 44DA2106F; Thu, 8 Sep 2022 06:55:54 -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 5FE743F7B4; Thu, 8 Sep 2022 06:55:45 -0700 (PDT) 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: dcef5faa-2f7d-11ed-9760-273f2230c3a0 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 v8 7/9] xen/arm: create shared memory nodes in guest device tree Date: Thu, 8 Sep 2022 21:55:11 +0800 Message-Id: <20220908135513.1800511-8-Penny.Zheng@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220908135513.1800511-1-Penny.Zheng@arm.com> References: <20220908135513.1800511-1-Penny.Zheng@arm.com> MIME-Version: 1.0 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 field "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 = "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. - xen,offset: (borrower VMs only) 64 bit integer offset within the owner virtual machine's shared memory region used for the mapping in the borrower VM. Currently, we provide "xen,offset=<0x0>" as a temprary placeholder. Signed-off-by: Penny Zheng Reviewed-by: Stefano Stabellini Reviewed-by: Bertrand Marquis --- v8 changes: - Fix missing property "xen,offset" for borrower VMs by temporarily adding "xen,offset=<0x0>" - use >= to avoid thinking about the overflow case for nr_banks - check the return value of dt_property_read_string() for parsing shm_id - struct meminfo *mem and char resvbuf[16] = "reserved-memory" could be const - change "__be32 reg[4]" to "__be32 reg[GUEST_ROOT_ADDRESS_CELLS + GUEST_ROOT_SIZE_CELLS]" --- v7 changes: - allocate reg for worst case addrcells + sizecells - replace assert() with BUG_ON() since it is init code --- v6 change: - change "struct meminfo *mem" to "const struct meminfo *mem" - change "unsigned long i" to "unsigned int i" to match the type of nr_banks. - accroding to the Linux binding, "xen,id" is meant to be a string, not an integer --- 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 | 160 +++++++++++++++++++++++++++++- xen/arch/arm/include/asm/kernel.h | 1 + 2 files changed, 159 insertions(+), 2 deletions(-) diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c index a10d07266b..cd03370b38 100644 --- a/xen/arch/arm/domain_build.c +++ b/xen/arch/arm/domain_build.c @@ -914,7 +914,22 @@ static int __init assign_shared_memory(struct domain *d, return ret; } -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, + const char *shm_id) +{ + if ( kinfo->shm_mem.nr_banks >= NR_MEM_BANKS ) + return -ENOMEM; + + kinfo->shm_mem.bank[kinfo->shm_mem.nr_banks].start = start; + kinfo->shm_mem.bank[kinfo->shm_mem.nr_banks].size = size; + safe_strcpy(kinfo->shm_mem.bank[kinfo->shm_mem.nr_banks].shm_id, 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; @@ -928,6 +943,7 @@ static int __init process_shm(struct domain *d, int ret = 0; unsigned int i; const char *role_str; + const char *shm_id; bool owner_dom_io = true; if ( !dt_device_is_compatible(shm_node, "xen,domain-shared-memory-v1") ) @@ -972,6 +988,13 @@ static int __init process_shm(struct domain *d, if ( dt_property_read_string(shm_node, "role", &role_str) == 0 ) owner_dom_io = false; + if ( dt_property_read_string(shm_node, "xen,shm-id", &shm_id) ) + { + printk("%pd: invalid \"xen,shm-id\" property", d); + return -EINVAL; + } + BUG_ON((strlen(shm_id) <= 0) || (strlen(shm_id) >= MAX_SHM_ID_LENGTH)); + /* * DOMID_IO is a fake domain and is not described in the Device-Tree. * Therefore when the owner of the shared region is DOMID_IO, we will @@ -999,6 +1022,14 @@ 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 = append_shm_bank_to_domain(kinfo, gbase, psize, shm_id); + if ( ret ) + return ret; } return 0; @@ -1331,6 +1362,126 @@ static int __init make_memory_node(const struct domain *d, return res; } +#ifdef CONFIG_STATIC_SHM +static int __init make_shm_memory_node(const struct domain *d, + void *fdt, + int addrcells, int sizecells, + const struct meminfo *mem) +{ + unsigned int i = 0; + int res = 0; + + if ( mem->nr_banks == 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 = mem->bank[i].start; + uint64_t size = mem->bank[i].size; + /* Placeholder for xen-shmem@ + a 64-bit number + \0 */ + char buf[27]; + const char compat[] = "xen,shared-memory-v1"; + /* Worst case addrcells + sizecells */ + __be32 reg[GUEST_ROOT_ADDRESS_CELLS + GUEST_ROOT_SIZE_CELLS]; + __be32 *cells; + unsigned int len = (addrcells + sizecells) * sizeof(__be32); + + snprintf(buf, sizeof(buf), "xen-shmem@%"PRIx64, mem->bank[i].start); + res = fdt_begin_node(fdt, buf); + if ( res ) + return res; + + res = fdt_property(fdt, "compatible", compat, sizeof(compat)); + if ( res ) + return res; + + cells = reg; + dt_child_set_range(&cells, addrcells, sizecells, start, size); + + res = fdt_property(fdt, "reg", reg, len); + if ( res ) + return res; + + dt_dprintk("Shared memory bank %u: %#"PRIx64"->%#"PRIx64"\n", + i, start, start + size); + + res = fdt_property_string(fdt, "xen,id", mem->bank[i].shm_id); + if ( res ) + return res; + + /* TODO: + * - xen,offset: (borrower VMs only) + * 64 bit integer offset within the owner virtual machine's shared + * memory region used for the mapping in the borrower VM + */ + res = fdt_property_u64(fdt, "xen,offset", 0); + if ( res ) + return res; + + res = 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, + const struct meminfo *mem) +{ + ASSERT_UNREACHABLE(); +} +#endif + +static int __init make_resv_memory_node(const struct domain *d, + void *fdt, + int addrcells, int sizecells, + const struct meminfo *mem) +{ + int res = 0; + /* Placeholder for reserved-memory\0 */ + const char resvbuf[16] = "reserved-memory"; + + if ( mem->nr_banks == 0 ) + /* No shared memory provided. */ + return 0; + + dt_dprintk("Create reserved-memory node\n"); + + res = fdt_begin_node(fdt, resvbuf); + if ( res ) + return res; + + res = fdt_property(fdt, "ranges", NULL, 0); + if ( res ) + return res; + + res = fdt_property_cell(fdt, "#address-cells", addrcells); + if ( res ) + return res; + + res = fdt_property_cell(fdt, "#size-cells", sizecells); + if ( res ) + return res; + + res = make_shm_memory_node(d, fdt, addrcells, sizecells, mem); + if ( res ) + return res; + + res = fdt_end_node(fdt); + + return res; +} + static int __init add_ext_regions(unsigned long s, unsigned long e, void *data) { struct meminfo *ext_regions = data; @@ -3108,6 +3259,11 @@ static int __init prepare_dtb_domU(struct domain *d, struct kernel_info *kinfo) if ( ret ) goto err; + ret = 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 @@ -3484,7 +3640,7 @@ static int __init construct_domU(struct domain *d, assign_static_memory_11(d, &kinfo, node); #ifdef CONFIG_STATIC_SHM - rc = process_shm(d, node); + rc = 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/kernel.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; /* kernel entry point */ paddr_t entry;