Re: [Xen-devel] [PATCH] vm_event: consolidate hvm_event_fill_regs and p2m_vm_event_fill_regs

[Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx>]

On 02/11/2016 11:35 PM, Andrew Cooper wrote:
> On 11/02/2016 21:05, Tamas K Lengyel wrote:
> 
>> diff --git a/xen/arch/x86/vm_event.c b/xen/arch/x86/vm_event.c
>> index 08d678a..fa5d154 100644
>> --- a/xen/arch/x86/vm_event.c
>> +++ b/xen/arch/x86/vm_event.c
>> @@ -122,6 +122,64 @@ void vm_event_set_registers(struct vcpu *v, 
>> vm_event_response_t *rsp)
>>      v->arch.user_regs.eip = rsp->data.regs.x86.rip;
>>  }
>>  
>> +void vm_event_fill_regs(vm_event_request_t *req)
>> +{
>> +    const struct cpu_user_regs *regs = guest_cpu_user_regs();
>> +    struct segment_register seg;
>> +    struct hvm_hw_cpu ctxt;
>> +    struct vcpu *curr = current;
>> +
>> +    req->data.regs.x86.rax = regs->eax;
>> +    req->data.regs.x86.rcx = regs->ecx;
>> +    req->data.regs.x86.rdx = regs->edx;
>> +    req->data.regs.x86.rbx = regs->ebx;
>> +    req->data.regs.x86.rsp = regs->esp;
>> +    req->data.regs.x86.rbp = regs->ebp;
>> +    req->data.regs.x86.rsi = regs->esi;
>> +    req->data.regs.x86.rdi = regs->edi;
>> +
>> +    req->data.regs.x86.r8  = regs->r8;
>> +    req->data.regs.x86.r9  = regs->r9;
>> +    req->data.regs.x86.r10 = regs->r10;
>> +    req->data.regs.x86.r11 = regs->r11;
>> +    req->data.regs.x86.r12 = regs->r12;
>> +    req->data.regs.x86.r13 = regs->r13;
>> +    req->data.regs.x86.r14 = regs->r14;
>> +    req->data.regs.x86.r15 = regs->r15;
>> +
>> +    req->data.regs.x86.rflags = regs->eflags;
>> +    req->data.regs.x86.rip    = regs->eip;
>> +    req->data.regs.x86.dr7    = curr->arch.debugreg[7];
> 
> I think there is a %dr7 handling issue here.  For an HVM guests, this
> field is only valid when you are not in the context of the guest, as it
> lives in the vmcs/vmcs.  (PV guests keep it synchronously up to date)

Would this make it OK to use in p2m_vm_event_fill_regs() but not in
hvm_event_fill_regs(), as it currently is? Maybe this is the issue I'm
remembering.


Thanks,
Razvan

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