Re: [PATCH 1/3] Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus hardening

[Wei Liu]

On Mon, Jun 29, 2020 at 06:19:46PM +0000, Andres Beltran wrote:
[...]
> > >  EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);
> > > +
> > > +/*
> > > + * vmbus_next_request_id - Returns a new request id. It is also
> > > + * the index at which the guest memory address is stored.
> > > + * Uses a spin lock to avoid race conditions.
> > > + * @rqstor: Pointer to the requestor struct
> > > + * @rqst_add: Guest memory address to be stored in the array
> > > + */
> > > +u64 vmbus_next_request_id(struct vmbus_requestor *rqstor, u64 rqst_addr)
> > > +{
> > > +	unsigned long flags;
> > > +	u64 current_id;
> > > +
> > > +	spin_lock_irqsave(&rqstor->req_lock, flags);
> > 
> > Do you really need the irqsave variant here? I.e. is there really a
> > chance this code is reachable from an interrupt handler?
> 
> Other VMBus drivers will also need to use this functionality, and
> some of them will be called with interrupts disabled. So, I think
> we should keep the irqsave variant here.
> 

Okay. This makes sense.

Wei.