From patchwork Mon Feb 29 18:40:45 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Markus Armbruster X-Patchwork-Id: 8457151 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 015BFC0554 for ; Mon, 29 Feb 2016 18:47:41 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 472EE20117 for ; Mon, 29 Feb 2016 18:47:40 +0000 (UTC) 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.kernel.org (Postfix) with ESMTPS id 2263E201FA for ; Mon, 29 Feb 2016 18:47:39 +0000 (UTC) Received: from localhost ([::1]:38421 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aaSr4-0004yy-E5 for patchwork-qemu-devel@patchwork.kernel.org; Mon, 29 Feb 2016 13:47:38 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59837) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aaSkk-00026r-EL for qemu-devel@nongnu.org; Mon, 29 Feb 2016 13:41:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aaSki-0007t9-Ip for qemu-devel@nongnu.org; Mon, 29 Feb 2016 13:41:06 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34049) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aaSki-0007sd-BH for qemu-devel@nongnu.org; Mon, 29 Feb 2016 13:41:04 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (Postfix) with ESMTPS id EA2F7AAA; Mon, 29 Feb 2016 18:41:03 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-22.ams2.redhat.com [10.36.116.22]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u1TIf0Rd004234 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 29 Feb 2016 13:41:02 -0500 Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 094CC30052FC; Mon, 29 Feb 2016 19:40:55 +0100 (CET) From: Markus Armbruster To: qemu-devel@nongnu.org Date: Mon, 29 Feb 2016 19:40:45 +0100 Message-Id: <1456771254-17511-30-git-send-email-armbru@redhat.com> In-Reply-To: <1456771254-17511-1-git-send-email-armbru@redhat.com> References: <1456771254-17511-1-git-send-email-armbru@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: claudio.fontana@huawei.com, cam@cs.ualberta.ca, mlureau@redhat.com, david.marchand@6wind.com, pbonzini@redhat.com Subject: [Qemu-devel] [PATCH 29/38] ivshmem: Implement shm=... with a memory backend X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP ivshmem has its very own code to create and map shared memory. Replace that with an implicitly created memory backend. Reduces the number of ways we create BAR 2 from three to two. Signed-off-by: Markus Armbruster --- hw/misc/ivshmem.c | 89 +++++++++++++++++++++---------------------------------- 1 file changed, 33 insertions(+), 56 deletions(-) diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index 8d54fa9..9931d5e 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -26,6 +26,7 @@ #include "migration/migration.h" #include "qemu/error-report.h" #include "qemu/event_notifier.h" +#include "qom/object_interfaces.h" #include "sysemu/char.h" #include "sysemu/hostmem.h" #include "qapi/visitor.h" @@ -369,31 +370,6 @@ static int check_shm_size(IVShmemState *s, int fd, Error **errp) } } -/* create the shared memory BAR when we are not using the server, so we can - * create the BAR and map the memory immediately */ -static int create_shared_memory_BAR(IVShmemState *s, int fd, uint8_t attr, - Error **errp) -{ - void * ptr; - - ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); - if (ptr == MAP_FAILED) { - error_setg_errno(errp, errno, "Failed to mmap shared memory"); - return -1; - } - - memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s), "ivshmem.bar2", - s->ivshmem_size, ptr); - qemu_set_ram_fd(s->ivshmem.ram_addr, fd); - vmstate_register_ram(&s->ivshmem, DEVICE(s)); - memory_region_add_subregion(&s->bar, 0, &s->ivshmem); - - /* region for shared memory */ - pci_register_bar(PCI_DEVICE(s), 2, attr, &s->bar); - - return 0; -} - static void ivshmem_add_eventfd(IVShmemState *s, int posn, int i) { memory_region_add_eventfd(&s->ivshmem_mmio, @@ -833,6 +809,33 @@ static void ivshmem_write_config(PCIDevice *pdev, uint32_t address, } } +static HostMemoryBackend *desugar_shm(const char *shm, size_t size) +{ + /* TODO avoid the detour through QemuOpts */ + static int counter; + QemuOpts *opts = qemu_opts_create(qemu_find_opts("object"), + NULL, 0, &error_abort); + char *path; + Object *obj; + + qemu_opt_set(opts, "qom-type", "memory-backend-file", + &error_abort); + /* FIXME need a better way to make up an ID */ + qemu_opts_set_id(opts, g_strdup_printf("ivshmem-backend-%d", counter++)); + path = g_strdup_printf("/dev/shm/%s", shm); + qemu_opt_set(opts, "mem-path", path, &error_abort); + qemu_opt_set_number(opts, "size", size, &error_abort); + qemu_opt_set_bool(opts, "share", true, &error_abort); + g_free(path); + + obj = user_creatable_add_opts(opts, &error_abort); + qemu_opts_del(opts); + + user_creatable_complete(obj, &error_abort); + + return MEMORY_BACKEND(obj); +} + static void pci_ivshmem_realize(PCIDevice *dev, Error **errp) { IVShmemState *s = IVSHMEM(dev); @@ -911,6 +914,10 @@ static void pci_ivshmem_realize(PCIDevice *dev, Error **errp) attr |= PCI_BASE_ADDRESS_MEM_TYPE_64; } + if (s->shmobj) { + s->hostmem = desugar_shm(s->shmobj, s->ivshmem_size); + } + if (s->hostmem != NULL) { MemoryRegion *mr; @@ -921,7 +928,7 @@ static void pci_ivshmem_realize(PCIDevice *dev, Error **errp) vmstate_register_ram(mr, DEVICE(s)); memory_region_add_subregion(&s->bar, 0, mr); pci_register_bar(PCI_DEVICE(s), 2, attr, &s->bar); - } else if (s->server_chr != NULL) { + } else { IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n", s->server_chr->filename); @@ -948,36 +955,6 @@ static void pci_ivshmem_realize(PCIDevice *dev, Error **errp) error_setg(errp, "failed to initialize interrupts"); return; } - } else { - /* just map the file immediately, we're not using a server */ - int fd; - - IVSHMEM_DPRINTF("using shm_open (shm object = %s)\n", s->shmobj); - - /* try opening with O_EXCL and if it succeeds zero the memory - * by truncating to 0 */ - if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR|O_EXCL, - S_IRWXU|S_IRWXG|S_IRWXO)) > 0) { - /* truncate file to length PCI device's memory */ - if (ftruncate(fd, s->ivshmem_size) != 0) { - error_report("could not truncate shared file"); - } - - } else if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR, - S_IRWXU|S_IRWXG|S_IRWXO)) < 0) { - error_setg(errp, "could not open shared file"); - return; - } - - if (check_shm_size(s, fd, errp) == -1) { - return; - } - - create_shared_memory_BAR(s, fd, attr, &err); - if (err) { - error_propagate(errp, err); - return; - } } if (s->role_val == IVSHMEM_PEER) {