Re: [Xen-devel] [PATCH V3] x86/vm_event: block interrupt injection for sync vm_events

[Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx>]

On 12/25/18 4:29 AM, Tian, Kevin wrote:
> > From: Razvan Cojocaru [mailto:rcojocaru@xxxxxxxxxxxxxxx]
> > Sent: Friday, December 14, 2018 7:50 PM
> >
> > Block interrupts (in vmx_intr_assist()) for the duration of
> > processing a sync vm_event (similarly to the strategy
> > currently used for single-stepping). Otherwise, attempting
> > to emulate an instruction when requested by a vm_event
> > reply may legitimately need to call e.g.
> > hvm_inject_page_fault(), which then overwrites the active
> > interrupt in the VMCS.
> >
> > The sync vm_event handling path on x86/VMX is (roughly):
> > monitor_traps() -> process vm_event -> vmx_intr_assist()
> > (possibly writing VM_ENTRY_INTR_INFO) ->
> > hvm_vm_event_do_resume() -> hvm_emulate_one_vm_event()
> > (possibly overwriting the VM_ENTRY_INTR_INFO value).
> >
> > This patch may also be helpful for the future removal
> > of may_defer in hvm_set_cr{0,3,4} and hvm_set_msr().
> >
> > Signed-off-by: Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx>
> Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Ping?


Thanks,
Razvan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel