Re: [PATCH v3 4/7] x86/vmx: add do_vmtrace_op

["Michał Leszczyński" <michal.leszczynski@cert.pl>]

----- 23 cze 2020 o 13:54, Andrew Cooper andrew.cooper3@citrix.com napisał(a):
> Overall, the moving parts of this series needs to split out into rather
> more patches.
> 
> First, in patch 3, the hvm_funcs.pt_supported isn't the place for that
> to live.  You want a global "bool vmtrace_supported" in common/domain.c
> which vmx_init_vmcs_config() sets, and the ARM code can set in the
> future when CoreSight is added.
> 
> Next, you want a patch in isolation which adds vmtrace_pt_size (or
> whatever it ends up being) to createdomain, where all
> allocation/deallocation logic lives in common/domain.c.  The spinlock
> (if its needed, but I don't think it is) wants initialising early in
> domain_create(), alongside d->pbuf_lock, and you also need an extra
> clause in sanitise_domain_config() which rejects a vmtrace setting if
> vmtrace isn't supported.  You'll need to put the struct page_info *
> pointer to the memory allocation in struct vcpu, and adjust the vcpu
> create/destroy logic appropriately.
> 
> Next, you want a patch doing the acquire resource logic for userspace to
> map the buffers.
> 
> Next, you want a patch to introduce a domctl with the various runtime
> enable/disable settings which were in an hvmop here.
> 
> Next, you want a patch to do the VMX plumbing, both at create, and runtime.
> 
> This ought to lay the logic out in a way which is extendable to x86 PV
> guests and ARM CoreSight, and oughtn't to explode when creating guests
> on non-Intel hardware.
> 
> Thanks,
> 
> ~Andrew


Thanks for your review, I'm almost done addressing all these remarks.
I've converted HVMOP to DOMCTL and splitted patches to smaller pieces.

I will send v4 soon.


Best regards,
Michał Leszczyński