>>> On 08.11.18 at 14:20, <[email protected]> wrote: > On Thu, Nov 08, 2018 at 06:04:11AM -0700, Jan Beulich wrote: >> >>> On 08.11.18 at 13:47, <[email protected]> wrote: >> > My point would be that on x86 I think the only way to have preemptible >> > long-running operations inside of Xen is to block the guest vCPU and >> > run them in a tasklet, or at least this seems the less invasive one. >> > >> > Do you still have objections to this patch/approach? >> >> Well, I still don't understand why you think you need to introduce >> a tasklet in the first place. That's because I still don't understand >> what you think is wrong with the current approach (leaving aside >> the exact placement of where the vpci hook needs to be called). > > The current approach doesn't prevent the vCPU from returning to guest > context with pending work. > > Placing the pending work hook (vpci_process_pending) in hvm_do_resume > is not going to solve this unless we raise and process a scheduler > softirq, and then this leads to the recursion problem.
Which recursion problem? I still haven't seen an outline taking into account what I have written in earlier replies. In particular I don't see a softirq handler itself calling do_softirq() anywhere. Jan _______________________________________________ Xen-devel mailing list [email protected] https://lists.xenproject.org/mailman/listinfo/xen-devel
