From nobody Tue Feb 10 01:34:23 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1486645105045529.7073651910921; Thu, 9 Feb 2017 04:58:25 -0800 (PST) Received: from localhost ([::1]:37452 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cboIp-0006fa-UD for importer@patchew.org; Thu, 09 Feb 2017 07:58:23 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59203) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cboDz-0002c0-Fn for qemu-devel@nongnu.org; Thu, 09 Feb 2017 07:53:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cboDy-0007QS-GS for qemu-devel@nongnu.org; Thu, 09 Feb 2017 07:53:23 -0500 Received: from mx2.suse.de ([195.135.220.15]:54704) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cboDs-0007O0-74; Thu, 09 Feb 2017 07:53:16 -0500 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id D4471AD63; Thu, 9 Feb 2017 12:53:14 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de From: Alexander Graf To: qemu-devel@nongnu.org Date: Thu, 9 Feb 2017 13:53:27 +0100 Message-Id: <1486644810-33181-2-git-send-email-agraf@suse.de> X-Mailer: git-send-email 1.8.5.6 In-Reply-To: <1486644810-33181-1-git-send-email-agraf@suse.de> References: <1486644810-33181-1-git-send-email-agraf@suse.de> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x (no timestamps) [generic] [fuzzy] X-Received-From: 195.135.220.15 Subject: [Qemu-devel] [PATCH v2 1/4] target-arm: Declare virtio-mmio as dma-coherent in dt 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: Ard Biesheuvel , qemu-arm@nongnu.org, Laszlo Ersek , Shannon Zhao , mst@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" QEMU emulated hardware is always dma coherent with its guest. We do annotate that correctly on the PCI host controller, but left out virtio-mmio. Recent kernels have started to interpret that flag rather than take dma coherency as granted with virtio-mmio. While that is considered a kernel bug, as it breaks previously working systems, it showed that our dt description is incomplete. This patch adds the respective marker that allows guest OSs to evaluate that our virtio-mmio devices are indeed cache coherent. Signed-off-by: Alexander Graf --- hw/arm/vexpress.c | 1 + hw/arm/virt.c | 1 + 2 files changed, 2 insertions(+) diff --git a/hw/arm/vexpress.c b/hw/arm/vexpress.c index 58760f4..e057568 100644 --- a/hw/arm/vexpress.c +++ b/hw/arm/vexpress.c @@ -452,6 +452,7 @@ static int add_virtio_mmio_node(void *fdt, uint32_t ace= lls, uint32_t scells, acells, addr, scells, size); qemu_fdt_setprop_cells(fdt, nodename, "interrupt-parent", intc); qemu_fdt_setprop_cells(fdt, nodename, "interrupts", 0, irq, 1); + qemu_fdt_setprop(fdt, nodename, "dma-coherent", NULL, 0); g_free(nodename); if (rc) { return -1; diff --git a/hw/arm/virt.c b/hw/arm/virt.c index 1f216cf..14881fa 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -797,6 +797,7 @@ static void create_virtio_devices(const VirtMachineStat= e *vms, qemu_irq *pic) qemu_fdt_setprop_cells(vms->fdt, nodename, "interrupts", GIC_FDT_IRQ_TYPE_SPI, irq, GIC_FDT_IRQ_FLAGS_EDGE_LO_HI); + qemu_fdt_setprop(vms->fdt, nodename, "dma-coherent", NULL, 0); g_free(nodename); } } --=20 2.10.0