Re: [Qemu-devel] -device xen-platform crashes

[Stefano Stabellini]

On Thu, 29 Jan 2015, Markus Armbruster wrote:
> Reproducer: qemu -nodefaults -S -display none -device xen-platform
> 
> Yes, xen-platform makes no sense without Xen, but it shouldn't crash.

Is it just a matter of doing the following?

diff --git a/hw/i386/xen/xen_platform.c b/hw/i386/xen/xen_platform.c
index 28b324a..40ae1f3 100644
--- a/hw/i386/xen/xen_platform.c
+++ b/hw/i386/xen/xen_platform.c
@@ -177,6 +177,10 @@ static void platform_fixed_ioport_writeb(void *opaque, 
uint32_t addr, uint32_t v
 {
     PCIXenPlatformState *s = opaque;
 
+    if (!xen_enabled()) {
+        return;
+    }
+
     switch (addr) {
     case 0: /* Platform flags */ {
         hvmmem_type_t mem_type = (val & PFFLAG_ROM_LOCK) ?

> Backtrace:
> 
> #0  0x00007fffef5a677c in hypercall_buffer_cache_lock ()
>    from /lib64/libxenctrl.so.4.3
> #1  0x00007fffef5a68f1 in xc.hypercall_buffer_alloc_pages ()
>    from /lib64/libxenctrl.so.4.3
> #2  0x00007fffef5a6a61 in xc.hypercall_buffer_alloc ()
>    from /lib64/libxenctrl.so.4.3
> #3  0x00007fffef59da54 in xc_hvm_set_mem_type () from /lib64/libxenctrl.so.4.3
> #4  0x00005555556d5bcd in platform_fixed_ioport_writeb 
> (opaque=0x5555564713b0, 
>     addr=0, val=0) at /work/armbru/qemu/hw/i386/xen/xen_platform.c:184
> #5  0x00005555556d5ca4 in platform_fixed_ioport_reset (opaque=0x5555564713b0)
>     at /work/armbru/qemu/hw/i386/xen/xen_platform.c:238
> #6  0x00005555556d608c in platform_reset (dev=0x5555564713b0)
>     at /work/armbru/qemu/hw/i386/xen/xen_platform.c:417
> #7  0x00005555557e915b in device_reset (dev=0x5555564713b0)
>     at /work/armbru/qemu/hw/core/qdev.c:1269
> #8  0x00005555557e6a7b in qdev_reset_one (dev=0x5555564713b0, opaque=0x0)
>     at /work/armbru/qemu/hw/core/qdev.c:329
> #9  0x00005555557e7608 in qdev_walk_children (dev=0x5555564713b0, 
>     pre_devfn=0x0, pre_busfn=0x0, post_devfn=0x5555557e6a5f <qdev_reset_one>, 
>     post_busfn=0x5555557e6a82 <qbus_reset_one>, opaque=0x0)
>     at /work/armbru/qemu/hw/core/qdev.c:643
> #10 0x00005555557e74fb in qbus_walk_children (bus=0x5555563b1f00, 
>     pre_devfn=0x0, pre_busfn=0x0, post_devfn=0x5555557e6a5f <qdev_reset_one>, 
>     post_busfn=0x5555557e6a82 <qbus_reset_one>, opaque=0x0)
>     at /work/armbru/qemu/hw/core/qdev.c:601
> #11 0x00005555557e75cc in qdev_walk_children (dev=0x5555563d67d0, 
>     pre_devfn=0x0, pre_busfn=0x0, post_devfn=0x5555557e6a5f <qdev_reset_one>, 
>     post_busfn=0x5555557e6a82 <qbus_reset_one>, opaque=0x0)
>     at /work/armbru/qemu/hw/core/qdev.c:635
> #12 0x00005555557e74fb in qbus_walk_children (bus=0x5555563bd3c0, 
>     pre_devfn=0x0, pre_busfn=0x0, post_devfn=0x5555557e6a5f <qdev_reset_one>, 
>     post_busfn=0x5555557e6a82 <qbus_reset_one>, opaque=0x0)
>     at /work/armbru/qemu/hw/core/qdev.c:601
> #13 0x00005555557e6b57 in qbus_reset_all (bus=0x5555563bd3c0)
>     at /work/armbru/qemu/hw/core/qdev.c:350
> #14 0x00005555557e6b79 in qbus_reset_all_fn (opaque=0x5555563bd3c0)
>     at /work/armbru/qemu/hw/core/qdev.c:356
> #15 0x00005555557587b9 in qemu_devices_reset () at /work/armbru/qemu/vl.c:1614
> #16 0x0000555555758845 in qemu_system_reset (report=false)
>     at /work/armbru/qemu/vl.c:1627
> #17 0x0000555555760739 in main (argc=7, argv=0x7fffffffe0f8, 
>     envp=0x7fffffffe138) at /work/armbru/qemu/vl.c:4315
> 
> Sorry, no libxenctrl symbols installed.
>