On Tue, 19 Jul 2016 15:38:23 +0800
Zhou Jie <zhoujie2...@cn.fujitsu.com> wrote:
> From: Chen Fan <chen.fan.f...@cn.fujitsu.com>
>
> When assigning a vfio device with AER enabled, we must check whether
> the device supports a host bus reset (ie. hot reset) as this may be
> used by the guest OS in order to recover the device from an AER
> error. QEMU must therefore have the ability to perform a physical
> host bus reset using the existing vfio APIs in response to a virtual
> bus reset in the VM. A physical bus reset affects all of the devices
> on the host bus, therefore we place a few simplifying configuration
> restriction on the VM:
>
> - All physical devices affected by a bus reset must be assigned to
> the VM with AER enabled on each and be configured on the same
> virtual bus in the VM.
>
> - No devices unaffected by the bus reset, be they physical, emulated,
> or paravirtual may be configured on the same virtual bus as a
> device supporting AER signaling through vfio.
>
> In other words users wishing to enable AER on a multifunction device
> need to assign all functions of the device to the same virtual bus
> and enable AER support for each device. The easiest way to
> accomplish this is to identity map the physical functions to virtual
> functions with multifunction enabled on the virtual device.
Why am I able to start the following VM with aer=on for the vfio-pci
devices?
# lspci -tv
-[0000:00]-+-00.0 Intel Corporation 82G33/G31/P35/P31 Express DRAM Controller
+-01.0 Device 1234:1111
+-1c.0-[01]--
+-1d.0-[02]--+-01.0 Intel Corporation 82576 Gigabit Network
Connection
| \-01.1 Intel Corporation 82576 Gigabit Network
Connection
...
# lspci -vvv -s 1d.0
00:1d.0 PCI bridge: Red Hat, Inc. QEMU PCI-PCI bridge (prog-if 00 [Normal
decode])
The devices are behind a PCIe-to-PCI bridge, so shouldn't specifying
aer=on for the vfio-pci devices cause a configuration error?
commandline:
/home/alwillia/local/bin/qemu-system-x86_64 -name
guest=rhel7-q35,debug-threads=on -S -object
secret,id=masterKey0,format=raw,file=/var/lib/libvirt/qemu/domain-11-rhel7-q35/master-key.aes
-machine pc-q35-2.7,accel=kvm,usb=off,vmport=off -cpu IvyBridge -m 8192
-realtime mlock=off -smp 6,sockets=1,cores=6,threads=1 -uuid
b20b28b4-9304-4e11-9ffa-0367aeb44afb -no-user-config -nodefaults -chardev
socket,id=charmonitor,path=/var/lib/libvirt/qemu/domain-11-rhel7-q35/monitor.sock,server,nowait
-mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc,driftfix=slew
-global kvm-pit.lost_tick_policy=discard -no-hpet -no-shutdown -global
ICH9-LPC.disable_s3=1 -global ICH9-LPC.disable_s4=1 -boot strict=on -device
i82801b11-bridge,id=pci.1,bus=pcie.0,addr=0x1e -device
pci-bridge,chassis_nr=2,id=pci.2,bus=pci.1,addr=0x1 -device
pci-bridge,chassis_nr=3,id=pci.3,bus=pcie.0,addr=0x1d -device
ioh3420,port=0xe0,chassis=4,id=pci.4,bus=pcie.0,addr=0x1c -device
ich9-usb-ehci1,id=usb,bus=pci.2!
,addr=0x3.0x7 -device
ich9-usb-uhci1,masterbus=usb.0,firstport=0,bus=pci.2,multifunction=on,addr=0x3
-device ich9-usb-uhci2,masterbus=usb.0,firstport=2,bus=pci.2,addr=0x3.0x1
-device ich9-usb-uhci3,masterbus=usb.0,firstport=4,bus=pci.2,addr=0x3.0x2
-drive
file=/dev/rhel/rhel7-q35,format=raw,if=none,id=drive-virtio-disk0,cache=none,aio=native
-device
virtio-blk-pci,scsi=off,bus=pci.2,addr=0x5,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1
-netdev tap,fd=26,id=hostnet0,vhost=on,vhostfd=28 -device
virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:50:ec:0d,bus=pci.2,addr=0x1
-chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0
-device usb-tablet,id=input0,bus=usb.0,port=1 -vnc 127.0.0.1:0 -device
VGA,id=video0,vgamem_mb=16,bus=pcie.0,addr=0x1 -device
intel-hda,id=sound0,bus=pci.2,addr=0x2 -device
hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0 -device
vfio-pci,aer=on,host=07:00.0,id=hostdev0,bus=pci.3,multifunction=on,addr=0x1
-device vfio-pci,ae!
r=on,host=07:00.1,id=hostdev1,bus=pci.3,addr=0x1.0x1 -msg timestamp=on
Thanks,
Alex
> Signed-off-by: Chen Fan <chen.fan.f...@cn.fujitsu.com>
> ---
> hw/vfio/pci.c | 278
> +++++++++++++++++++++++++++++++++++++++++++++++++++++-----
> hw/vfio/pci.h | 1 +
> 2 files changed, 256 insertions(+), 23 deletions(-)
>
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 21fd801..242c1e4 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -1693,6 +1693,42 @@ static void vfio_check_af_flr(VFIOPCIDevice *vdev,
> uint8_t pos)
> }
> }
>
> +static int vfio_pci_name_to_addr(const char *name, PCIHostDeviceAddress
> *addr)
> +{
> + if (strlen(name) != 12 ||
> + sscanf(name, "%04x:%02x:%02x.%1x", &addr->domain,
> + &addr->bus, &addr->slot, &addr->function) != 4) {
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static bool vfio_pci_host_match(PCIHostDeviceAddress *addr, const char *name)
> +{
> + PCIHostDeviceAddress tmp;
> +
> + if (vfio_pci_name_to_addr(name, &tmp)) {
> + return false;
> + }
> +
> + return (tmp.domain == addr->domain && tmp.bus == addr->bus &&
> + tmp.slot == addr->slot && tmp.function == addr->function);
> +}
> +
> +static bool vfio_pci_host_match_slot(PCIHostDeviceAddress *addr,
> + const char *name)
> +{
> + PCIHostDeviceAddress tmp;
> +
> + if (vfio_pci_name_to_addr(name, &tmp)) {
> + return false;
> + }
> +
> + return (tmp.domain == addr->domain && tmp.bus == addr->bus &&
> + tmp.slot == addr->slot);
> +}
> +
> /*
> * return negative with errno, return 0 on success.
> * if success, the point of ret_info fill with the affected device reset
> info.
> @@ -1854,6 +1890,200 @@ static int vfio_add_std_cap(VFIOPCIDevice *vdev,
> uint8_t pos)
> return 0;
> }
>
> +static int vfio_device_range_limit(PCIBus *bus)
> +{
> + PCIDevice *br;
> +
> + br = pci_bridge_get_device(bus);
> + if (!br ||
> + !pci_is_express(br) ||
> + !(br->exp.exp_cap) ||
> + pcie_cap_is_arifwd_enabled(br)) {
> + return 255;
> + }
> +
> + return 8;
> +}
> +
> +static void vfio_check_hot_bus_reset(VFIOPCIDevice *vdev, Error **errp)
> +{
> + PCIBus *bus = vdev->pdev.bus;
> + struct vfio_pci_hot_reset_info *info = NULL;
> + struct vfio_pci_dependent_device *devices;
> + VFIOGroup *group;
> + int ret, i, devfn, range_limit;
> +
> + ret = vfio_get_hot_reset_info(vdev, &info);
> + if (ret) {
> + error_setg(errp, "vfio: Cannot enable AER for device %s,"
> + " device does not support hot reset.",
> + vdev->vbasedev.name);
> + return;
> + }
> +
> + /* List all affected devices by bus reset */
> + devices = &info->devices[0];
> +
> + /* Verify that we have all the groups required */
> + for (i = 0; i < info->count; i++) {
> + PCIHostDeviceAddress host;
> + VFIOPCIDevice *tmp;
> + VFIODevice *vbasedev_iter;
> + bool found = false;
> +
> + host.domain = devices[i].segment;
> + host.bus = devices[i].bus;
> + host.slot = PCI_SLOT(devices[i].devfn);
> + host.function = PCI_FUNC(devices[i].devfn);
> +
> + /* Skip the current device */
> + if (vfio_pci_host_match(&host, vdev->vbasedev.name)) {
> + continue;
> + }
> +
> + /* Ensure we own the group of the affected device */
> + QLIST_FOREACH(group, &vfio_group_list, next) {
> + if (group->groupid == devices[i].group_id) {
> + break;
> + }
> + }
> +
> + if (!group) {
> + error_setg(errp, "vfio: Cannot enable AER for device %s, "
> + "depends on group %d which is not owned.",
> + vdev->vbasedev.name, devices[i].group_id);
> + goto out;
> + }
> +
> + /* Ensure affected devices for reset on the same bus */
> + QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
> + if (vbasedev_iter->type != VFIO_DEVICE_TYPE_PCI) {
> + continue;
> + }
> + tmp = container_of(vbasedev_iter, VFIOPCIDevice, vbasedev);
> + if (vfio_pci_host_match(&host, tmp->vbasedev.name)) {
> + /*
> + * AER errors may be broadcast to all functions of a multi-
> + * function endpoint. If any of those sibling functions are
> + * also assigned, they need to have AER enabled or else an
> + * error may continue to cause a vm_stop condition. IOW,
> + * AER setup of this function would be pointless.
> + */
> + if (vfio_pci_host_match_slot(&host, vdev->vbasedev.name) &&
> + !(tmp->features & VFIO_FEATURE_ENABLE_AER)) {
> + error_setg(errp, "vfio: Cannot enable AER for device %s,"
> + " on same slot the dependent device %s which"
> + " does not enable AER.",
> + vdev->vbasedev.name, tmp->vbasedev.name);
> + goto out;
> + }
> +
> + if (tmp->pdev.bus != bus) {
> + error_setg(errp, "vfio: Cannot enable AER for device %s,
> "
> + "the dependent device %s is not on the same
> bus",
> + vdev->vbasedev.name, tmp->vbasedev.name);
> + goto out;
> + }
> + found = true;
> + break;
> + }
> + }
> +
> + /* Ensure all affected devices assigned to VM */
> + if (!found) {
> + error_setg(errp, "vfio: Cannot enable AER for device %s, "
> + "the dependent device %04x:%02x:%02x.%x "
> + "is not assigned to VM.",
> + vdev->vbasedev.name, host.domain, host.bus,
> + host.slot, host.function);
> + goto out;
> + }
> + }
> +
> + /*
> + * The above code verified that all devices affected by a bus reset
> + * exist on the same bus in the VM. To further simplify, we also
> + * require that there are no additional devices beyond those existing on
> + * the VM bus.
> + */
> + range_limit = vfio_device_range_limit(bus);
> + for (devfn = 0; devfn < range_limit; devfn++) {
> + VFIOPCIDevice *tmp;
> + PCIDevice *dev;
> + bool found = false;
> +
> + dev = pci_find_device(bus, pci_bus_num(bus),
> + PCI_DEVFN(PCI_SLOT(vdev->pdev.devfn), devfn));
> +
> + if (!dev) {
> + continue;
> + }
> +
> + if (!object_dynamic_cast(OBJECT(dev), "vfio-pci")) {
> + error_setg(errp, "vfio: Cannot enable AER for device %s, device"
> + " %s: slot %d function%d cannot be configured"
> + " on the same virtual bus",
> + vdev->vbasedev.name, dev->name,
> + PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn));
> + goto out;
> + }
> +
> + tmp = DO_UPCAST(VFIOPCIDevice, pdev, dev);
> + for (i = 0; i < info->count; i++) {
> + PCIHostDeviceAddress host;
> +
> + host.domain = devices[i].segment;
> + host.bus = devices[i].bus;
> + host.slot = PCI_SLOT(devices[i].devfn);
> + host.function = PCI_FUNC(devices[i].devfn);
> +
> + if (vfio_pci_host_match(&host, tmp->vbasedev.name)) {
> + found = true;
> + break;
> + }
> + }
> +
> + if (!found) {
> + error_setg(errp, "vfio: Cannot enable AER for device %s,
> affected"
> + " device %s does not be configured on the same"
> + " virtual bus",
> + vdev->vbasedev.name, tmp->vbasedev.name);
> + goto out;
> + }
> + }
> +
> +out:
> + g_free(info);
> + return;
> +}
> +
> +static void vfio_aer_check_host_bus_reset(Error **errp)
> +{
> + VFIOGroup *group;
> + VFIODevice *vbasedev;
> + VFIOPCIDevice *vdev;
> + Error *local_err = NULL;
> +
> + /* Check All vfio-pci devices if have bus reset capability */
> + QLIST_FOREACH(group, &vfio_group_list, next) {
> + QLIST_FOREACH(vbasedev, &group->device_list, next) {
> + if (vbasedev->type != VFIO_DEVICE_TYPE_PCI) {
> + continue;
> + }
> + vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
> + if (vdev->features & VFIO_FEATURE_ENABLE_AER) {
> + vfio_check_hot_bus_reset(vdev, &local_err);
> + if (local_err) {
> + error_propagate(errp, local_err);
> + return;
> + }
> + }
> + }
> + }
> +
> + return;
> +}
> +
> static int vfio_setup_aer(VFIOPCIDevice *vdev, uint8_t cap_ver,
> int pos, uint16_t size)
> {
> @@ -2060,29 +2290,6 @@ static void vfio_pci_post_reset(VFIOPCIDevice *vdev)
> vfio_intx_enable(vdev);
> }
>
> -static int vfio_pci_name_to_addr(const char *name, PCIHostDeviceAddress
> *addr)
> -{
> - if (strlen(name) != 12 ||
> - sscanf(name, "%04x:%02x:%02x.%1x", &addr->domain,
> - &addr->bus, &addr->slot, &addr->function) != 4) {
> - return -EINVAL;
> - }
> -
> - return 0;
> -}
> -
> -static bool vfio_pci_host_match(PCIHostDeviceAddress *addr, const char *name)
> -{
> - PCIHostDeviceAddress tmp;
> -
> - if (vfio_pci_name_to_addr(name, &tmp)) {
> - return false;
> - }
> -
> - return (tmp.domain == addr->domain && tmp.bus == addr->bus &&
> - tmp.slot == addr->slot && tmp.function == addr->function);
> -}
> -
> static int vfio_pci_hot_reset(VFIOPCIDevice *vdev, bool single)
> {
> VFIOGroup *group;
> @@ -2608,6 +2815,22 @@ static void vfio_unregister_req_notifier(VFIOPCIDevice
> *vdev)
> vdev->req_enabled = false;
> }
>
> +static void vfio_pci_machine_done_notify(Notifier *notifier, void *unused)
> +{
> + Error *local_err = NULL;
> +
> + vfio_aer_check_host_bus_reset(&local_err);
> + if (local_err) {
> + fprintf(stderr, "%s\n", error_get_pretty(local_err));
> + error_free(local_err);
> + exit(1);
> + }
> +}
> +
> +static Notifier machine_notifier = {
> + .notify = vfio_pci_machine_done_notify,
> +};
> +
> static int vfio_initfn(PCIDevice *pdev)
> {
> VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
> @@ -3000,6 +3223,15 @@ static const TypeInfo vfio_pci_dev_info = {
> static void register_vfio_pci_dev_type(void)
> {
> type_register_static(&vfio_pci_dev_info);
> +
> + /*
> + * The AER configuration may depend on multiple devices, so we cannot
> + * validate consistency after each device is initialized. We can only
> + * depend on function initialization order (function 0 last) for hotplug
> + * devices, therefore a machine-init-done notifier is used to validate
> + * the configuration after all cold-plug devices are processed.
> + */
> + qemu_add_machine_init_done_notifier(&machine_notifier);
> }
>
> type_init(register_vfio_pci_dev_type)
> diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
> index 5483044..e2faffb 100644
> --- a/hw/vfio/pci.h
> +++ b/hw/vfio/pci.h
> @@ -15,6 +15,7 @@
> #include "qemu-common.h"
> #include "exec/memory.h"
> #include "hw/pci/pci.h"
> +#include "hw/pci/pci_bus.h"
> #include "hw/pci/pci_bridge.h"
> #include "hw/vfio/vfio-common.h"
> #include "qemu/event_notifier.h"
