Re: [Qemu-devel] [PULL 2/2] xen-platform: Ensure xen is enabled when initializing

[Paolo Bonzini <pbonzini@redhat.com>]

On 19/10/2015 12:23, Stefano Stabellini wrote:
> The xen-platform code crashes on reset if the xen backend is not
> initialized, because it calls xc_hvm_set_mem_type(). Ensure xen-platform
> won't be created without initializing the xen backend.
> 
> The assert can't be triggered by the user because the device is not
> hotpluggable, and the only code creating it (at pc_xen_hvm_init())
> already checks xen_enabled().

The device is not hotpluggable, but it is accessible with -device.  This
is by design because IIUC, we want -M xenfv to be phased out in favor of
the PC machines plus -device xen-platform.

Thus, k->init should be changed to k->realize instead.  I guess it can
be done on top of this pull request, so I'm not blocking it.

Paolo

> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  hw/i386/xen/xen_platform.c |    3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/hw/i386/xen/xen_platform.c b/hw/i386/xen/xen_platform.c
> index ee45f03..8682c42 100644
> --- a/hw/i386/xen/xen_platform.c
> +++ b/hw/i386/xen/xen_platform.c
> @@ -387,6 +387,9 @@ static int xen_platform_initfn(PCIDevice *dev)
>      PCIXenPlatformState *d = XEN_PLATFORM(dev);
>      uint8_t *pci_conf;
>  
> +    /* Device will crash on reset if xen is not initialized */
> +    assert(xen_enabled());
> +