[Bug 1924912] Re: VirtIO drivers don't work on Windows: "GLib: Too many handles to wait for!" crash

[Stefan Weil]

Did you build your own Windows binary based on the official sources? Or
did you use a precompiled binary? If yes, which one?

Please describe the exact steps to reproduce the issue.

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1924912

Title:
  VirtIO drivers don't work on Windows: "GLib: Too many handles to wait
  for!" crash

Status in QEMU:
  New

Bug description:
  I ran SerenityOS <https://github.com/SerenityOS/serenity> out of WSL2
  with native Windows QEMU. The system runs fine on the Linux QEMU (with
  Windows X-Server). However, with Windows QEMU I get a hard crash after
  the following output:

  ```
  [#0 colonel(0:0)]: Scheduler[0]: idle loop running
  [init_stage2(2:2)]: PCI [0000:00:00:00] PCI::ID [8086:1237]
  [init_stage2(2:2)]: PCI [0000:00:01:00] PCI::ID [8086:7000]
  [init_stage2(2:2)]: PCI [0000:00:01:01] PCI::ID [8086:7010]
  [init_stage2(2:2)]: PCI [0000:00:01:02] PCI::ID [8086:7020]
  [init_stage2(2:2)]: PCI [0000:00:01:03] PCI::ID [8086:7113]
  [init_stage2(2:2)]: PCI [0000:00:02:00] PCI::ID [1234:1111]
  [init_stage2(2:2)]: PCI [0000:00:03:00] PCI::ID [8086:2922]
  [init_stage2(2:2)]: PCI [0000:00:04:00] PCI::ID [1af4:1003]
  [init_stage2(2:2)]: PCI [0000:00:05:00] PCI::ID [1af4:1005]
  [init_stage2(2:2)]: PCI [0000:00:06:00] PCI::ID [8086:100e]
  [#0 init_stage2(2:2)]: BXVGA: framebuffer @ P0xf8000000
  [#0 init_stage2(2:2)]: BXVGADevice resolution set to 1024x768 (pitch=4096)
  [init_stage2(2:2)]: UHCI: Controller found PCI::ID [8086:7020] @ PCI 
[0000:00:01:02]
  [init_stage2(2:2)]: UHCI: I/O base IO c080
  [init_stage2(2:2)]: UHCI: Interrupt line: 11
  [#0 init_stage2(2:2)]: UHCI: Allocated framelist at physical address 
P0x00e40000
  [#0 init_stage2(2:2)]: UHCI: Framelist is at virtual address V0xc115d000
  [#0 init_stage2(2:2)]: UHCI: QH(0xc115f000) @ 14946304: link_ptr=14946338, 
element_link_ptr=1
  [#0 init_stage2(2:2)]: UHCI: QH(0xc115f020) @ 14946336: link_ptr=14946370, 
element_link_ptr=1
  [#0 init_stage2(2:2)]: UHCI: QH(0xc115f040) @ 14946368: link_ptr=14946402, 
element_link_ptr=1
  [#0 init_stage2(2:2)]: UHCI: QH(0xc115f060) @ 14946400: link_ptr=14946434, 
element_link_ptr=1
  [#0 init_stage2(2:2)]: UHCI: QH(0xc115f080) @ 14946432: link_ptr=14958593, 
element_link_ptr=1
  [#0 init_stage2(2:2)]: UHCI: Reset completed
  [#0 init_stage2(2:2)]: UHCI: Started
  [#0 init_stage2(2:2)]: DMIExpose: SMBIOS 32bit Entry point @ P0x000f5870
  [#0 init_stage2(2:2)]: DMIExpose: Data table @ P0x000f5890
  [#0 init_stage2(2:2)]: VirtIOConsole: Found @ PCI [0000:00:04:00]
  [#0 init_stage2(2:2)]: Trying to unregister unused handler (?)
  [#0 init_stage2(2:2)]: VirtIOConsole: Multi port is not yet supported!
  [#0 init_stage2(2:2)]: VirtIOConsole: cols: 0, rows: 0, max nr ports 0
  qemu-system-i386.exe: warning: GLib: Too many handles to wait for!
  ```

  The lines starting with [ are SerenityOS output; QEMU warns "GLib: Too
  many handles to wait for!" and crashes right after (can't even Ctrl-C
  in the WSL command line, force-close in Windows necessary). A window
  is still spawned but as the OS already switched out of text mode, just
  a black screen is visible as QEMU crashes.

  I first thought this to be an issue with SerenityOS and reported it
  over there: <https://github.com/SerenityOS/serenity/issues/6422>. The
  kernel devs pointed out that this seems to be a VirtIO driver/device
  issue on the Windows build of QEMU, because the Serenity kernel tries
  to initialize VirtIO devices which apparently crashes QEMU. There will
  be mitigations from the SerenityOS side (by allowing to disable VirtIO
  on boot) but it would of course be great if QEMU handled this
  properly.

  Version info: Both QEMU 6.0.0-rc3 and 5.2.0 exhibit this issue.
  Windows release is 20H2, WSL2 is running Debian 10.9. SerenityOS has
  no proper version but it was reproduced on the most current commits as
  of 18/04/2021.

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1924912/+subscriptions