From patchwork Tue Jan 10 11:35:11 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Herrenschmidt X-Patchwork-Id: 135208 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 5F826B6FC4 for ; Tue, 10 Jan 2012 22:35:38 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753918Ab2AJLfe (ORCPT ); Tue, 10 Jan 2012 06:35:34 -0500 Received: from gate.crashing.org ([63.228.1.57]:41321 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752659Ab2AJLfd (ORCPT ); Tue, 10 Jan 2012 06:35:33 -0500 Received: from [IPv6:::1] (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.13.8) with ESMTP id q0ABZCC9012949; Tue, 10 Jan 2012 05:35:13 -0600 Message-ID: <1326195311.23910.59.camel@pasglop> Subject: [PATCH] virtio-pci: Fix endianness of virtio config From: Benjamin Herrenschmidt To: "qemu-devel@nongnu.org" Cc: "kvm@vger.kernel.org" , kvm-ppc@vger.kernel.org, Alexander Graf , David Gibson Date: Tue, 10 Jan 2012 22:35:11 +1100 X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org The virtio config area in PIO space is a bit special. The initial header is little endian but the rest (device specific) is guest native endian. The PIO accessors for PCI on machines that don't have native IO ports assume that all PIO is little endian, which works fine for everything except the above. A complicated way to fix it would be to split the BAR into two memory regions with different endianess settings, but this isn't practical to do, besides, the PIO code doesn't honor region endianness anyway (I have a patch for that too but it isn't necessary at this stage). So I decided to go for the quick fix instead which consists of reverting the swap in virtio-pci in selected places, hoping that when we eventually do a "v2" of the virtio protocols, we sort that out once and for all using a fixed endian setting for everything. Unfortunately, that mean moving virtio-pci from Makefile.objs to Makefile.target so we can use TARGET_WORDS_BIGENDIAN which would otherwise be poisoned. Signed-off-by: Benjamin Herrenschmidt --- Makefile.objs | 1 - Makefile.target | 1 + hw/virtio-pci.c | 24 ++++++++++++++++++++++-- 3 files changed, 23 insertions(+), 3 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/Makefile.objs b/Makefile.objs index 4f6d26c..b721fca 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -186,7 +186,6 @@ hw-obj-y = hw-obj-y += vl.o loader.o hw-obj-$(CONFIG_VIRTIO) += virtio-console.o hw-obj-y += usb-libhw.o -hw-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o hw-obj-y += fw_cfg.o hw-obj-$(CONFIG_PCI) += pci.o pci_bridge.o hw-obj-$(CONFIG_PCI) += msix.o msi.o diff --git a/Makefile.target b/Makefile.target index ef6834b..03d44c3 100644 --- a/Makefile.target +++ b/Makefile.target @@ -191,6 +191,7 @@ obj-y = arch_init.o cpus.o monitor.o machine.o gdbstub.o balloon.o ioport.o # need to fix this properly obj-$(CONFIG_NO_PCI) += pci-stub.o obj-$(CONFIG_VIRTIO) += virtio.o virtio-blk.o virtio-balloon.o virtio-net.o virtio-serial-bus.o +obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o obj-y += vhost_net.o obj-$(CONFIG_VHOST_NET) += vhost.o obj-$(CONFIG_REALLY_VIRTFS) += 9pfs/virtio-9p-device.o diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c index 77b75bc..ca70e42 100644 --- a/hw/virtio-pci.c +++ b/hw/virtio-pci.c @@ -412,20 +412,34 @@ static uint32_t virtio_pci_config_readw(void *opaque, uint32_t addr) { VirtIOPCIProxy *proxy = opaque; uint32_t config = VIRTIO_PCI_CONFIG(&proxy->pci_dev); + uint16_t val; if (addr < config) return virtio_ioport_read(proxy, addr); addr -= config; - return virtio_config_readw(proxy->vdev, addr); + val = virtio_config_readw(proxy->vdev, addr); +#ifdef TARGET_WORDS_BIGENDIAN + /* virtio is odd, ioports are LE but config space is target native + * endian. However, in qemu, all PIO is LE, so we need to re-swap + * on BE targets + */ + val = bswap16(val); +#endif + return val; } static uint32_t virtio_pci_config_readl(void *opaque, uint32_t addr) { VirtIOPCIProxy *proxy = opaque; uint32_t config = VIRTIO_PCI_CONFIG(&proxy->pci_dev); + uint32_t val; if (addr < config) return virtio_ioport_read(proxy, addr); addr -= config; - return virtio_config_readl(proxy->vdev, addr); + val = virtio_config_readl(proxy->vdev, addr); +#ifdef TARGET_WORDS_BIGENDIAN + val = bswap32(val); +#endif + return val; } static void virtio_pci_config_writeb(void *opaque, uint32_t addr, uint32_t val) @@ -449,6 +463,9 @@ static void virtio_pci_config_writew(void *opaque, uint32_t addr, uint32_t val) return; } addr -= config; +#ifdef TARGET_WORDS_BIGENDIAN + val = bswap16(val); +#endif virtio_config_writew(proxy->vdev, addr, val); } @@ -461,6 +478,9 @@ static void virtio_pci_config_writel(void *opaque, uint32_t addr, uint32_t val) return; } addr -= config; +#ifdef TARGET_WORDS_BIGENDIAN + val = bswap32(val); +#endif virtio_config_writel(proxy->vdev, addr, val); }