[libvirt] [PATCH v2] nodedev: update mdev_types caps before dumpxml

[Erik Skultety]

On Mon, Jan 08, 2018 at 07:35:22PM +0800, Wu Zongyong wrote:
> In current implemention, mdev_types caps keep constant all
> the time. But, it is possible that a device capable of
> mdev_types sometime(for example:bind to proper driver) and
> incapable of mdev_types at other times(for example: unbind
> from its driver).
> We should keep the info of xml dumped out consistent with
> real status of the device.
>
> Signed-off-by: Wu Zongyong <cordius.wu at huawei.com>
> ---
>
> v2:
> - fix mistakes pointed out by Erik
>
>  src/node_device/node_device_linux_sysfs.c | 21 +++++++++++++++++++++
>  src/node_device/node_device_udev.c        | 29 +++++++++++++++++++++++++++++
>  src/node_device/node_device_udev.h        | 18 +++++++++++++-----
>  3 files changed, 63 insertions(+), 5 deletions(-)
>
> diff --git a/src/node_device/node_device_linux_sysfs.c b/src/node_device/node_device_linux_sysfs.c
> index 6f438e5..8b00aff 100644
> --- a/src/node_device/node_device_linux_sysfs.c
> +++ b/src/node_device/node_device_linux_sysfs.c
> @@ -29,6 +29,7 @@
>  #include "dirname.h"
>  #include "node_device_driver.h"
>  #include "node_device_hal.h"
> +#include "node_device_udev.h"
>  #include "node_device_linux_sysfs.h"
>  #include "virerror.h"
>  #include "viralloc.h"
> @@ -175,6 +176,24 @@ nodeDeviceSysfsGetPCIIOMMUGroupCaps(virNodeDevCapPCIDevPtr pci_dev)
>      return ret;
>  }
>
> +static int
> +nodeDeviceSysfsGetPCIMdevTypesCaps(const char *sysfsPath,
> +                                   virNodeDevCapPCIDevPtr pci_dev)
> +{
> +    size_t i;
> +
> +    /* this could be a refresh, so clear out the old data */
> +    for (i = 0; i < pci_dev->nmdev_types; i++)
> +        virNodeDevCapMdevTypeFree(pci_dev->mdev_types[i]);
> +    VIR_FREE(pci_dev->mdev_types);
> +    pci_dev->nmdev_types = 0;

You also need to clear the VIR_NODE_DEV_CAP_FLAG_PCI_MDEV flag, otherwise the
device:
1) is still listed as mdev_types capable using virsh nodedev-list --cap
mdev_types
2) formats an empty mdev_types element

> +
> +    if (udevPCISysfsGetMdevTypesCap(sysfsPath, pci_dev) < 0)
> +        return -1;
> +
> +    return 0;
> +}

Still leaking memory, because you didn't drop the old way of querying the
capabilities - there's udevPCIGetMdevTypesCap() at the end of udevProcessPCI
that has to be dropped.

> +
>
>  /* nodeDeviceSysfsGetPCIRelatedCaps() get info that is stored in sysfs
>   * about devices related to this device, i.e. things that can change
> @@ -190,6 +209,8 @@ nodeDeviceSysfsGetPCIRelatedDevCaps(const char *sysfsPath,
>          return -1;
>      if (nodeDeviceSysfsGetPCIIOMMUGroupCaps(pci_dev) < 0)
>          return -1;
> +    if (nodeDeviceSysfsGetPCIMdevTypesCaps(sysfsPath, pci_dev) < 0)
> +        return -1;
>      return 0;
>  }
>
> diff --git a/src/node_device/node_device_udev.c b/src/node_device/node_device_udev.c
> index e0fca61..781facf 100644
> --- a/src/node_device/node_device_udev.c
> +++ b/src/node_device/node_device_udev.c
> @@ -506,6 +506,35 @@ udevPCIGetMdevTypesCap(struct udev_device *device,
>  }
>
>
> +int
> +udevPCISysfsGetMdevTypesCap(const char *sysfsPath,
> +                            virNodeDevCapPCIDevPtr pci_dev)
> +{
> +    int ret = -1;
> +    udevEventDataPtr priv = NULL;

initialize @priv ^here...

> +    struct udev *udev = NULL;
> +    struct udev_device *device = NULL;
> +
> +    priv = driver->privateData;

rather than ^here...

you're missing virObjectLock(priv) here...

> +    udev = udev_monitor_get_udev(priv->udev_monitor);
> +    device = udev_device_new_from_syspath(udev, sysfsPath);

...and virObjectUnlock(priv) here...

> +    if (!device) {
> +        virReportError(VIR_ERR_INTERNAL_ERROR,
> +                       _("failed to create udev device from path %s"),
> +                       sysfsPath);
> +        goto cleanup;
> +    }
> +
> +    if (udevPCIGetMdevTypesCap(device, pci_dev) < 0)
> +        goto cleanup;
> +
> +    ret = 0;
> + cleanup:
> +    udev_device_unref(device);
> +    return ret;
> +}
> +
> +
>  static int
>  udevProcessPCI(struct udev_device *device,
>                 virNodeDeviceDefPtr def)
> diff --git a/src/node_device/node_device_udev.h b/src/node_device/node_device_udev.h
> index f15e520..bbdc70f 100644
> --- a/src/node_device/node_device_udev.h
> +++ b/src/node_device/node_device_udev.h
> @@ -19,10 +19,18 @@
>   *
>   * Author: Dave Allan <dallan at redhat.com>
>   */
> +#ifndef __VIR_NODE_DEVICE_UDEV_H__
> +# define __VIR_NODE_DEVICE_UDEV_H__
>
> -#include <libudev.h>
> -#include <stdint.h>
> +# include <libudev.h>
> +# include <stdint.h>
>
> -#define SYSFS_DATA_SIZE 4096
> -#define DMI_DEVPATH "/sys/devices/virtual/dmi/id"
> -#define DMI_DEVPATH_FALLBACK "/sys/class/dmi/id"
> +# define SYSFS_DATA_SIZE 4096
> +# define DMI_DEVPATH "/sys/devices/virtual/dmi/id"
> +# define DMI_DEVPATH_FALLBACK "/sys/class/dmi/id"
> +
> +int
> +udevPCISysfsGetMdevTypesCap(const char *sysfsPath, virNodeDevCapPCIDevPtr pci_dev);
> +
> +
> +#endif /* __VIR_NODE_DEVICE_UDEV_H__ */
> --

Now that I'm looking at this hunk, would you mind splitting the patch in 2 and
move this include guard-related change into a separate patch?

Thanks,
Erik