From patchwork Mon Mar 20 00:12:47 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haozhong Zhang X-Patchwork-Id: 9632855 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 213BA6020B for ; Mon, 20 Mar 2017 00:13:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 12F9927F8C for ; Mon, 20 Mar 2017 00:13:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 04B4E27FBC; Mon, 20 Mar 2017 00:13:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 8B41927F8C for ; Mon, 20 Mar 2017 00:13:45 +0000 (UTC) Received: from localhost ([::1]:58634 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cpkxE-0005Er-JD for patchwork-qemu-devel@patchwork.kernel.org; Sun, 19 Mar 2017 20:13:44 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58270) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cpkwp-0005CB-Ad for qemu-devel@nongnu.org; Sun, 19 Mar 2017 20:13:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cpkwn-0004xg-Si for qemu-devel@nongnu.org; Sun, 19 Mar 2017 20:13:19 -0400 Received: from mga03.intel.com ([134.134.136.65]:51743) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cpkwn-0004uJ-GD for qemu-devel@nongnu.org; Sun, 19 Mar 2017 20:13:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=intel.com; i=@intel.com; q=dns/txt; s=intel; t=1489968797; x=1521504797; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=rmEggL8vJa7ZDBS4MRqbDpIbryfmCDV6TheDSCuuqGo=; b=ss8a5AaVwhyF/vkeHZmvJTIGxIRaVUlHX84IdRhQaYCBfsBiaq2snjQs XViIH+wfhiZ2SK7MMR14vb+wybzyuQ==; Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Mar 2017 17:13:17 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,191,1486454400"; d="scan'208";a="78799198" Received: from hz-desktop.sh.intel.com (HELO localhost) ([10.239.159.153]) by fmsmga006.fm.intel.com with ESMTP; 19 Mar 2017 17:13:15 -0700 From: Haozhong Zhang To: qemu-devel@nongnu.org, xen-devel@lists.xen.org Date: Mon, 20 Mar 2017 08:12:47 +0800 Message-Id: <20170320001249.25521-9-haozhong.zhang@intel.com> X-Mailer: git-send-email 2.10.1 In-Reply-To: <20170320001249.25521-1-haozhong.zhang@intel.com> References: <20170320001249.25521-1-haozhong.zhang@intel.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.65 Subject: [Qemu-devel] [RFC QEMU PATCH v2 08/10] hostmem: add a host memory backend for Xen X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Haozhong Zhang , Eduardo Habkost , "Michael S. Tsirkin" , Igor Mammedov , Konrad Rzeszutek Wilk , Dan Williams Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Some virtual devices (e.g. NVDIMM) use the host memory backend to map its backend resources to the guest. When those devices are used on Xen, the mapping has to be managed out of QEMU. In order to reuse other parts of the implementation of those devices, we introduce a host memory backend for Xen (memory-backend-xen) which is mostly a placeholder that only creates an empty memory region and does not actually allocate and map the resource. Following is an example of a vNVDIMM device backed by a host pmem namespace, -object memory-backend-xen,id=mem1,mem-path=/dev/pmem0,size=4G -device nvdimm,id=nvdimm1,memdev=mem1 Signed-off-by: Haozhong Zhang --- Cc: Eduardo Habkost Cc: Igor Mammedov Cc: "Michael S. Tsirkin" --- backends/Makefile.objs | 1 + backends/hostmem-xen.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++++ backends/hostmem.c | 8 ++++ hw/mem/pc-dimm.c | 5 +- 4 files changed, 134 insertions(+), 1 deletion(-) create mode 100644 backends/hostmem-xen.c diff --git a/backends/Makefile.objs b/backends/Makefile.objs index 0e0f1567b2..11dcaa4d0e 100644 --- a/backends/Makefile.objs +++ b/backends/Makefile.objs @@ -9,6 +9,7 @@ common-obj-$(CONFIG_TPM) += tpm.o common-obj-y += hostmem.o hostmem-ram.o common-obj-$(CONFIG_LINUX) += hostmem-file.o +common-obj-${CONFIG_XEN_BACKEND} += hostmem-xen.o common-obj-y += cryptodev.o common-obj-y += cryptodev-builtin.o diff --git a/backends/hostmem-xen.c b/backends/hostmem-xen.c new file mode 100644 index 0000000000..b1b446766d --- /dev/null +++ b/backends/hostmem-xen.c @@ -0,0 +1,121 @@ +/* + * QEMU Host Memory Backend for Xen + * + * Copyright(C) 2017 Intel Corporation. + * + * Author: + * Haozhong Zhang + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see + */ + +#include "qemu/osdep.h" +#include "qemu/mmap-alloc.h" +#include "sysemu/hostmem.h" +#include "qapi/error.h" +#include "qom/object_interfaces.h" + + +#define TYPE_MEMORY_BACKEND_XEN "memory-backend-xen" + +#define MEMORY_BACKEND_XEN(obj) \ + OBJECT_CHECK(HostMemoryBackendXen, (obj), TYPE_MEMORY_BACKEND_XEN) + +typedef struct HostMemoryBackendXen HostMemoryBackendXen; + +struct HostMemoryBackendXen { + HostMemoryBackend parent_obj; + + char *mem_path; +}; + +static void xen_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) +{ + HostMemoryBackendXen *db = MEMORY_BACKEND_XEN(backend); + int fd; + size_t page_size; + + if (!backend->size) { + error_setg(errp, "can't create backend with size 0"); + return; + } + memory_region_init(&backend->mr, + OBJECT(backend), db->mem_path, backend->size); + + fd = open(db->mem_path, O_RDONLY); + if (!fd) { + error_setg(errp, "can't open file %s, err %d", db->mem_path, errno); + return; + } + page_size = qemu_fd_getpagesize(fd); + backend->mr.align = MAX(page_size, QEMU_VMALLOC_ALIGN); + close(fd); +} + +static void xen_backend_class_init(ObjectClass *oc, void *data) +{ + HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc); + + bc->alloc = xen_backend_memory_alloc; +} + +static char *get_mem_path(Object *o, Error **errp) +{ + HostMemoryBackendXen *db = MEMORY_BACKEND_XEN(o); + + return g_strdup(db->mem_path); +} + +static void set_mem_path(Object *o, const char *str, Error **errp) +{ + HostMemoryBackend *backend = MEMORY_BACKEND(o); + HostMemoryBackendXen *db = MEMORY_BACKEND_XEN(o); + + if (memory_region_size(&backend->mr)) { + error_setg(errp, "cannot change property value"); + return; + } + g_free(db->mem_path); + db->mem_path = g_strdup(str); +} + +static void +xen_backend_instance_init(Object *o) +{ + object_property_add_str(o, "mem-path", get_mem_path, + set_mem_path, NULL); +} + +static void xen_backend_instance_finalize(Object *o) +{ + HostMemoryBackendXen *db = MEMORY_BACKEND_XEN(o); + + g_free(db->mem_path); +} + +static const TypeInfo xen_backend_info = { + .name = TYPE_MEMORY_BACKEND_XEN, + .parent = TYPE_MEMORY_BACKEND, + .class_init = xen_backend_class_init, + .instance_init = xen_backend_instance_init, + .instance_finalize = xen_backend_instance_finalize, + .instance_size = sizeof(HostMemoryBackendXen), +}; + +static void register_types(void) +{ + type_register_static(&xen_backend_info); +} + +type_init(register_types); diff --git a/backends/hostmem.c b/backends/hostmem.c index 7f5de70609..ee5e59c133 100644 --- a/backends/hostmem.c +++ b/backends/hostmem.c @@ -18,6 +18,7 @@ #include "qapi-visit.h" #include "qemu/config-file.h" #include "qom/object_interfaces.h" +#include "hw/xen/xen.h" #ifdef CONFIG_NUMA #include @@ -274,6 +275,13 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp) goto out; } + /* The backend storage of MEMORY_BACKEND_XEN is managed by Xen, + * so no further work in this function is needed. + */ + if (xen_enabled() && !backend->mr.ram_block) { + goto out; + } + ptr = memory_region_get_ram_ptr(&backend->mr); sz = memory_region_size(&backend->mr); diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c index 9e8dab0e89..69c5784252 100644 --- a/hw/mem/pc-dimm.c +++ b/hw/mem/pc-dimm.c @@ -28,6 +28,7 @@ #include "sysemu/kvm.h" #include "trace.h" #include "hw/virtio/vhost.h" +#include "hw/xen/xen.h" typedef struct pc_dimms_capacity { uint64_t size; @@ -107,7 +108,9 @@ void pc_dimm_memory_plug(DeviceState *dev, MemoryHotplugState *hpms, } memory_region_add_subregion(&hpms->mr, addr - hpms->base, mr); - vmstate_register_ram(vmstate_mr, dev); + if (!xen_enabled()) { + vmstate_register_ram(vmstate_mr, dev); + } numa_set_mem_node_id(addr, memory_region_size(mr), dimm->node); out: