Re: [Qemu-devel] [PATCH] pci: add standard bridge device

[Wen Congyang]

At 07/04/2011 05:43 PM, Michael S. Tsirkin Write:
> This adds support for a standard pci to pci bridge,
> enabling support for more than 32 PCI devices in the system.
> To use, specify the device id as a 'bus' option.
> Example:
>       -device pci-bridge,id=bridge1 \
>       -netdev user,id=u \
>       -device ne2k_pci,id=net2,bus=bridge1,netdev=u
> 
> TODO: device hotplug support.

I try this patch, and found that when I use pci bridge, qemu will core dump.

Here is my command line:
/usr/local2/bin/qemu-system-x86_64 -M pc-0.14 -enable-kvm -m 512 -name vm1 
-drive 
file=/var/lib/libvirt/images/vm1.img,if=none,id=drive-ide0-0-0,format=qcow2,cache=writethrough
 -device 
ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1 -vnc 
0.0.0.0:1 -device pci-bridge,id=bridge1,bus=pci.0,addr=0x08.0x0 -netdev 
user,id=u -device ne2k_pci,id=net2,bus=bridge1,netdev=u

Here is the backtrace:
Core was generated by `/usr/local2/bin/qemu-system-x86_64 -M pc-0.14 
-enable-kvm -m 512 -name vm1 -dri'.
Program terminated with signal 11, Segmentation fault.
#0  0x0000000000438e34 in memory_region_add_subregion_common (mr=0x0, 
offset=49152, subregion=0x1de5d58) at /home/wency/source/qemu/memory.c:1152
1152        QTAILQ_FOREACH(other, &mr->subregions, subregions_link) {
Missing separate debuginfos, use: debuginfo-install SDL-1.2.14-2.el6.x86_64 
celt051-0.5.1.3-0.el6.x86_64 cyrus-sasl-gssapi-2.1.23-8.el6.x86_64 
cyrus-sasl-lib-2.1.23-8.el6.x86_64 cyrus-sasl-md5-2.1.23-8.el6.x86_64 
cyrus-sasl-plain-2.1.23-8.el6.x86_64 db4-4.7.25-16.el6.x86_64 
glib2-2.22.5-6.el6.x86_64 glibc-2.12-1.25.el6.x86_64 
keyutils-libs-1.4-1.el6.x86_64 krb5-libs-1.9-9.el6.x86_64 
libX11-1.3-2.el6.x86_64 libXau-1.0.5-1.el6.x86_64 libaio-0.3.107-10.el6.x86_64 
libattr-2.4.44-4.el6.x86_64 libcom_err-1.41.12-7.el6.x86_64 
libcurl-7.19.7-26.el6.x86_64 libgcrypt-1.4.5-5.el6.x86_64 
libgpg-error-1.7-3.el6.x86_64 libidn-1.18-2.el6.x86_64 libjpeg-6b-46.el6.x86_64 
libpng-1.2.44-1.el6.x86_64 libselinux-2.0.94-5.el6.x86_64 
libssh2-1.2.2-7.el6.x86_64 libtasn1-2.3-3.el6.x86_64 
libuuid-2.17.2-12.el6.x86_64 libxcb-1.5-1.el6.x86_64 
ncurses-libs-5.7-3.20090208.el6.x86_64 nspr-4.8.7-1.el6.x86_64 
nss-3.12.9-9.el6.x86_64 nss-softokn-freebl-3.12.9-3.el6.x86_64 
nss-util-3.12.9-1.el6.x86_64 openldap
-2.4.23-15.el6.x86_64 openssl-1.0.0-10.el6.x86_64 
pixman-0.18.4-1.el6_0.1.x86_64 spice-server-0.8.0-1.el6.x86_64 
zlib-1.2.3-25.el6.x86_64
(gdb) bt
#0  0x0000000000438e34 in memory_region_add_subregion_common (mr=0x0, 
offset=49152, subregion=0x1de5d58) at /home/wency/source/qemu/memory.c:1152
#1  0x0000000000439090 in memory_region_add_subregion_overlap (mr=0x0, 
offset=49152, subregion=0x1de5d58, priority=1) at 
/home/wency/source/qemu/memory.c:1194
#2  0x00000000005c55fe in pci_update_mappings (d=0x1de5900) at 
/home/wency/source/qemu/hw/pci.c:1063
#3  0x00000000005c5982 in pci_default_write_config (d=0x1de5900, addr=4, val=0, 
l=2) at /home/wency/source/qemu/hw/pci.c:1121
#4  0x00000000005cbfbf in pci_host_config_write_common (pci_dev=0x1de5900, 
addr=4, limit=256, val=1, len=2) at /home/wency/source/qemu/hw/pci_host.c:54
#5  0x00000000005cc0d1 in pci_data_write (s=0x1da2b90, addr=2147549188, val=1, 
len=2) at /home/wency/source/qemu/hw/pci_host.c:75
#6  0x00000000005cc2b1 in pci_host_data_write (handler=0x1da2b60, addr=3324, 
val=1, len=2) at /home/wency/source/qemu/hw/pci_host.c:125
#7  0x000000000042c884 in ioport_simple_writew (opaque=0x1da2b60, addr=3324, 
value=1) at /home/wency/source/qemu/rwhandler.c:50
#8  0x0000000000499e85 in ioport_write (index=1, address=3324, data=1) at 
ioport.c:81
#9  0x000000000049a8e1 in cpu_outw (addr=3324, val=1) at ioport.c:280
#10 0x0000000000433c5d in kvm_handle_io (port=3324, data=0x7f0b30f86000, 
direction=1, size=2, count=1) at /home/wency/source/qemu/kvm-all.c:837
#11 0x00000000004341c8 in kvm_cpu_exec (env=0x1b7fc70) at 
/home/wency/source/qemu/kvm-all.c:976
#12 0x000000000040da99 in cpu_exec_all () at /home/wency/source/qemu/cpus.c:1102
#13 0x00000000005b60c4 in main_loop () at /home/wency/source/qemu/vl.c:1392
#14 0x00000000005baa49 in main (argc=20, argv=0x7ffffa6b5a38, 
envp=0x7ffffa6b5ae0) at /home/wency/source/qemu/vl.c:3356

If I do not attach any device on bus bridge1, qemu can work nice.

Thanks
Wen Congyang

> 
> Signed-off-by: Michael S. Tsirkin <address@hidden>
> ---
>  Makefile.objs       |    2 +-
>  hw/pci_bridge_dev.c |   70 
> +++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 71 insertions(+), 1 deletions(-)
>  create mode 100644 hw/pci_bridge_dev.c
> 
> diff --git a/Makefile.objs b/Makefile.objs
> index cea15e4..9e82b12 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -174,7 +174,7 @@ hw-obj-y += vl.o loader.o
>  hw-obj-$(CONFIG_VIRTIO) += virtio.o virtio-console.o
>  hw-obj-$(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) += pci.o pci_bridge.o pci_bridge_dev.o
>  hw-obj-$(CONFIG_PCI) += msix.o msi.o
>  hw-obj-$(CONFIG_PCI) += pci_host.o pcie_host.o
>  hw-obj-$(CONFIG_PCI) += ioh3420.o xio3130_upstream.o xio3130_downstream.o
> diff --git a/hw/pci_bridge_dev.c b/hw/pci_bridge_dev.c
> new file mode 100644
> index 0000000..c7ab5ad
> --- /dev/null
> +++ b/hw/pci_bridge_dev.c
> @@ -0,0 +1,70 @@
> +/*
> + * Standard PCI Bridge Device
> + *
> + * Copyright (c) 2011 Red Hat Inc. Author: Michael S. Tsirkin 
> <address@hidden>
> + *
> + * 
> http://www.pcisig.com/specifications/conventional/pci_to_pci_bridge_architecture/
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program 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 General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include "pci_bridge.h"
> +#include "pci_ids.h"
> +#include "pci_internals.h"
> +
> +#define REDHAT_PCI_VENDOR_ID 0x1b36
> +#define PCI_BRIDGE_DEV_VENDOR_ID REDHAT_PCI_VENDOR_ID
> +#define PCI_BRIDGE_DEV_DEVICE_ID 0x1
> +
> +/* Mapping mandated by PCI-to-PCI Bridge architecture specification,
> + * revision 1.2 */
> +/* Table 9-1: Interrupt Binding for Devices Behind a Bridge */
> +static int pci_bridge_dev_map_irq_fn(PCIDevice *dev, int irq_num)
> +{
> +    return (irq_num + PCI_SLOT(dev->devfn) + irq_num) % PCI_NUM_PINS;
> +}
> +
> +static int pci_bridge_dev_initfn(PCIDevice *dev)
> +{
> +    PCIBridge *br = DO_UPCAST(PCIBridge, dev, dev);
> +    br->map_irq = pci_bridge_dev_map_irq_fn;
> +    /* If we don't specify the name, the bus will be addressed as <id>.0, 
> where
> +     * id is the parent id.  But it seems more natural to address the bus 
> using
> +     * the parent device name. */
> +    if (dev->qdev.id && *dev->qdev.id) {
> +        br->bus_name = dev->qdev.id;
> +    }
> +    return pci_bridge_initfn(dev);
> +}
> +
> +static PCIDeviceInfo pci_bridge_dev_info = {
> +    .qdev.name = "pci-bridge",
> +    .qdev.desc = "Standard PCI Bridge",
> +    .qdev.size = sizeof(PCIBridge),
> +    .qdev.reset = pci_bridge_reset,
> +    .is_bridge = 1,
> +    .config_write = pci_bridge_write_config,
> +    .init = pci_bridge_dev_initfn,
> +    .exit = pci_bridge_exitfn,
> +    .vendor_id = PCI_BRIDGE_DEV_VENDOR_ID,
> +    .device_id = PCI_BRIDGE_DEV_DEVICE_ID,
> +    .class_id = PCI_CLASS_BRIDGE_PCI,
> +};
> +
> +static void pci_bridge_dev_register(void)
> +{
> +    pci_qdev_register(&pci_bridge_dev_info);
> +}
> +
> +device_init(pci_bridge_dev_register);