RE: [PATCH] Clear unplug keys if Active device is not the Vendor device

[Paul Durrant <xadimgnik@xxxxxxxxx>]

> -----Original Message-----
> From: win-pv-devel <win-pv-devel-bounces@xxxxxxxxxxxxxxxxxxxx> On Behalf Of 
> Owen Smith
> Sent: 16 July 2020 09:38
> To: win-pv-devel@xxxxxxxxxxxxxxxxxxxx
> Cc: Owen Smith <owen.smith@xxxxxxxxxx>
> Subject: [PATCH] Clear unplug keys if Active device is not the Vendor device
> 
> If the Vendor device is distributed by Windows Update, the update
> process will queue a reboot.

Well, the device is not distributed by Windows Update. Do you mean "If a 
version of XENBUS supporting a vendor device"? (Bear in
mind there could theoretically be vendor devices other than the Citrix one).

> If the vendor device is not the active
> device, then the unplug keys will not be removed before the next reboot.
> The reboot will also replace the driver on the active device which
> requires rebinding child devices, which cannot happen during the early
> boot phase. This will lead to a 7B bugcheck because XenVbd has not been
> rebound to the new version of XenBus

What is *supposed* to happen is that the, when a vendor device appears in the 
system necessitating a new XENBUS binding, the
co-installer clears the unplug keys because the PDOs beneath the non-vendor 
device will disappear at next boot because XENBUS's
active device will change. This could equally happen if a vendor device 
subsequently disappears, which I don't think this patch
covers.

  Paul

> 
> Signed-off-by: Owen Smith <owen.smith@xxxxxxxxxx>
> ---
>  src/coinst/coinst.c | 25 ++++++++++++++++++++++---
>  1 file changed, 22 insertions(+), 3 deletions(-)
> 
> diff --git a/src/coinst/coinst.c b/src/coinst/coinst.c
> index 7b96f59..8e57a10 100644
> --- a/src/coinst/coinst.c
> +++ b/src/coinst/coinst.c
> @@ -1361,7 +1361,8 @@ static BOOLEAN
>  IsActiveDevice(
>      IN  HDEVINFO            DeviceInfoSet,
>      IN  PSP_DEVINFO_DATA    DeviceInfoData,
> -    OUT PBOOLEAN            ActiveDevice
> +    OUT PBOOLEAN            ActiveDevice,
> +    OUT PBOOLEAN            VendorIsActive
>      )
>  {
>      PTCHAR                  ActiveDeviceID;
> @@ -1392,6 +1393,20 @@ IsActiveDevice(
>          TRUE :
>          FALSE;
> 
> +#ifdef VENDOR_DEVICE_ID_STR
> +
> +#define DRIVER_VENDOR_DEVICE_ID "PCI\\VEN_5853&DEV_" ## VENDOR_DEVICE_ID_STR 
> ##
> "&SUBSYS_C0005853&REV_01"
> +
> +    *VendorIsActive = (_stricmp(ActiveDeviceID, DRIVER_VENDOR_DEVICE_ID) == 
> 0) ?
> +        TRUE :
> +        FALSE;
> +
> +#undef DRIVER_VENDOR_DEVICE_ID
> +
> +#else
> +    *VendorIsActive = FALSE;
> +#endif
> +
>      free(DeviceID);
>      free(InstanceID);
> 
> @@ -1778,21 +1793,25 @@ DifInstallPostProcess(
>  {
>      BOOLEAN                         NewBinding;
>      BOOLEAN                         Active;
> +    BOOLEAN                         VendorIsActive;
> 
>      Log("====>");
> 
>      NewBinding = (BOOLEAN)(ULONG_PTR)Context->PrivateData;
> 
>      Active = TRUE;
> +    VendorIsActive = FALSE;
> 
>      (VOID) IsActiveDevice(DeviceInfoSet,
>                            DeviceInfoData,
> -                          &Active);
> +                          &Active,
> +                          &VendorIsActive);
> 
>      Log("Active = %s", Active ? "TRUE" : "FALSE");
>      Log("NewBinding = %s", NewBinding ? "TRUE" : "FALSE");
> 
> -    if (Active && NewBinding) {
> +    if ((Active && NewBinding) ||
> +        !VendorIsActive) {
>          (VOID) ClearUnplugRequest("DISKS");
>          (VOID) ClearUnplugRequest("NICS");
>      }
> --
> 2.16.2.windows.1
>