Re: [Qemu-devel] [BUGFIX][PATCH for 2.2 v3 1/1] -machine vmport=auto: Fix handling of VMWare ioport emulation for xen

[Don Slutz <dslutz@verizon.com>]

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On 11/20/14 01:04, Paolo Bonzini wrote:
>
> On 20/11/2014 01:58, Eduardo Habkost wrote:
>>      if (pc_machine->vmport == VMPORT_AUTO) {
>>            no_vmport = xen_enabled();
>>      } else {
>>            no_vmport = (pc_machine->vmport == VMPORT_ON);
>>      }
> I'm still not sure why the configuration should differ for "-M pc"
> depending on whether xen is enabled.
>
> Paolo

The key reason is that with current xen, if vmport is enabled QEMU will 
crash:


-------- Forwarded Message --------
Subject: 	Re: [Qemu-devel] qemu 2.2 crash on linux hvm domU (full 
backtrace included)
Date: 	Wed, 19 Nov 2014 15:04:58 +0100
From: 	Fabio Fantoni <fabio.fantoni@m2r.biz>
To: 	xen-devel <xen-devel@lists.xensource.com>, qemu-devel@nongnu.org 
<qemu-devel@nongnu.org>, spice-devel@lists.freedesktop.org
CC: 	anthony PERARD <anthony.perard@citrix.com>, dslutz@verizon.com, 
Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>



Il 14/11/2014 12:25, Fabio Fantoni ha scritto:
> dom0 xen-unstable from staging git with "x86/hvm: Extend HVM cpuid
> leaf with vcpu id" and "x86/hvm: Add per-vcpu evtchn upcalls" patches,
> and qemu 2.2 from spice git (spice/next commit
> e779fa0a715530311e6f59fc8adb0f6eca914a89):
> https://github.com/Fantu/Xen/commits/rebase/m2r-staging

I tried with qemu  tag v2.2.0-rc2 and crash still happen, here the full
backtrace of latest test:
> Program received signal SIGSEGV, Segmentation fault.
> 0x0000555555689b07 in vmport_ioport_read (opaque=0x5555564443a0, addr=0,
>     size=4) at /mnt/vm/xen/Xen/tools/qemu-xen-dir/hw/misc/vmport.c:73
> 73          eax = env->regs[R_EAX];
> (gdb) bt full
> #0  0x0000555555689b07 in vmport_ioport_read (opaque=0x5555564443a0,
> addr=0,
>     size=4) at /mnt/vm/xen/Xen/tools/qemu-xen-dir/hw/misc/vmport.c:73
>         s = 0x5555564443a0
>         cs = 0x0
>         cpu = 0x0
>         __func__ = "vmport_ioport_read"
>         env = 0x8250
>         command = 0 '\000'
>         eax = 0
> #1  0x0000555555655fc4 in memory_region_read_accessor (mr=0x555556444428,
>     addr=0, value=0x7fffffffd8d0, size=4, shift=0, mask=4294967295)
>     at /mnt/vm/xen/Xen/tools/qemu-xen-dir/memory.c:410
>         tmp = 0
> #2  0x00005555556562b7 in access_with_adjusted_size (addr=0,
>     value=0x7fffffffd8d0, size=4, access_size_min=4, access_size_max=4,
>     access=0x555555655f62 <memory_region_read_accessor>,
> mr=0x555556444428)
>     at /mnt/vm/xen/Xen/tools/qemu-xen-dir/memory.c:480
>         access_mask = 4294967295
>         access_size = 4
>         i = 0
> #3  0x00005555556590e9 in memory_region_dispatch_read1
> (mr=0x555556444428,
>     addr=0, size=4) at /mnt/vm/xen/Xen/tools/qemu-xen-dir/memory.c:1077
>         data = 0
> #4  0x00005555556591b1 in memory_region_dispatch_read (mr=0x555556444428,
>     addr=0, pval=0x7fffffffd9a8, size=4)
> ---Type <return> to continue, or q <return> to quit---
>     at /mnt/vm/xen/Xen/tools/qemu-xen-dir/memory.c:1099
> No locals.

...

and in QEMU 2.1 and older it just xen_enabled().

    -Don Slutz

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