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Re: [Qemu-devel] -device xen-platform crashes
From: |
Markus Armbruster |
Subject: |
Re: [Qemu-devel] -device xen-platform crashes |
Date: |
Mon, 02 Feb 2015 10:24:15 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) |
Stefano Stabellini <address@hidden> writes:
> On Fri, 30 Jan 2015, Markus Armbruster wrote:
>> Stefano Stabellini <address@hidden> writes:
>>
>> > On Thu, 29 Jan 2015, Markus Armbruster wrote:
>> >> Stefano Stabellini <address@hidden> writes:
>> >>
>> >> > 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) ?
>> >>
>> >> Fixes the crash for me.
>> >>
>> >> Should Xen-only devices fail to realize when !xen_enabled()?
>> >
>> > Accelerators are configured after device registration unfortunately.
>>
>> Realization happens even later, doesn't it?
>
> Yes, you are right.
>
>
>> With this patch:
>>
>> @@ -389,6 +393,11 @@ static int xen_platform_initfn(PCIDevice *dev)
>> PCIXenPlatformState *d = XEN_PLATFORM(dev);
>> uint8_t *pci_conf;
>>
>> + if (!xen_enabled()) {
>> + error_report("Nope");
>> + return -1;
>> + }
>> +
>> pci_conf = dev->config;
>>
>> pci_set_word(pci_conf + PCI_COMMAND, PCI_COMMAND_IO |
>> PCI_COMMAND_MEMORY);
>>
>> I get:
>>
>> $ upstream-qemu -nodefaults -S -display none -device xen-platform
>> upstream-qemu: -device xen-platform: Nope
>> upstream-qemu: -device xen-platform: Device initialization failed.
>> upstream-qemu: -device xen-platform: Device 'xen-platform' could not be
>> initialized
>> [Exit 1 ]
>>
>> Note that error_report() is a bit problematic in init methods. The best
>> solution is to convert the device to realize (requires my "pci: Partial
>> conversion to realize" series) and use error_setg().
>
> I agree that this is much better than breaking at runtime for no clear
> reason. Are you going to submit a proper patch?
Can do. Best for all the xen-only PCI devices, not just this one.
I'd prefer to do it on top of a conversion to realize. Makes the task
depend on [PATCH 00/10] pci: Partial conversion to realize.
- Re: [Qemu-devel] -device xen-platform crashes,
Markus Armbruster <=