Re: [Xen-devel] [PATCH] x86/HVM: Merge HVM and PVH hypercall tables

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 11.12.15 at 17:50, <boris.ostrovsky@xxxxxxxxxx> wrote:
> On 12/10/2015 11:53 AM, Boris Ostrovsky wrote:
>> Especially given that PVH dom0 is not booting for me, as I just found 
>> out:
>>
>> ...
>> (XEN) d0v0 EPT violation 0x1aa (-w-/r-x) gpa 0x000000c0008116 mfn 
>> 0xc0008 type 5
>> (XEN) d0v0 Walking EPT tables for GFN c0008:
>> (XEN) d0v0  epte 800000082bf50007
>> (XEN) d0v0  epte 800000082bf19007
>> (XEN) d0v0  epte 800000043c6f9007
>> (XEN) d0v0  epte 80500000c0008805
>> (XEN) d0v0  --- GLA 0xffffc90020008116
>> (XEN) domain_crash called from vmx.c:2816
>> (XEN) Domain 0 (vcpu#0) crashed on cpu#0:
>> (XEN) ----[ Xen-4.7-unstable  x86_64  debug=y  Tainted:    C ]----
>> (XEN) CPU:    0
>> (XEN) RIP:    0010:[<ffffffff816150dc>]
>> (XEN) RFLAGS: 0000000000010046   CONTEXT: hvm guest (d0v0)
>> (XEN) rax: 000000000000001d   rbx: 0000000000000000   rcx: 
>> ffff88014700f9b8
>> (XEN) rdx: 00000000000000ff   rsi: 0000000000000000   rdi: 
>> 0000000000000000
>> (XEN) rbp: ffff88014700fa18   rsp: ffff88014700f9e8   r8: 
>> ffff88014700f9c0
>> (XEN) r9:  000000000000001d   r10: ffffffff8189c7f0   r11: 
>> 0000000000000000
>> (XEN) r12: ffffc90020008000   r13: ffffc90020008116   r14: 
>> 0000000000000002
>> (XEN) r15: 000000000000001d   cr0: 0000000080050033   cr4: 
>> 00000000000406f0
>> (XEN) cr3: 0000000001c0e000   cr2: 0000000000000000
>> (XEN) ds: 0000   es: 0000   fs: 0000   gs: 0000   ss: 0000   cs: 0010
>> (XEN) Guest stack trace from rsp=ffff88014700f9e8:
>> (XEN)   Fault while accessing guest memory.
>> (XEN) Hardware Dom0 crashed: rebooting machine in 5 seconds.
>>
>>
>> We haven't been running regression tests for PVH dom0 so I don't know 
>> how long this has been broken.
> 
> 
> This is broken by 9256f66c1606 ("x86/PCI: intercept all PV Dom0 MMCFG 
> writes").

Well, I can't find any hookup of the write emulation logic for PVH
at all in ept_handle_violation() or hvm_hap_nested_page_fault(),
i.e. it looks to me as if this was broken already before, just that
for the limited set of devices that had their MMCFG space marked
r/o this went unnoticed (iow perhaps a missing FIXME annotation).
I'll see to find time to look into this, but I can't really predict when
I might get around to it.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel