Re: [PATCH v3 4/7] KVM: x86/xen: Extract delivery of event to vCPU into a separate helper

[David Woodhouse]

On Thu, 2026-08-06 at 12:00 +0200, David Woodhouse wrote:
> 
> Hm, it probably wants to live before the RCU part. I think the plan
> should be to first send these in parallel as they don't conflict:
> 
>  • Patch 1 from this series (the syzbot races).
>  • The updated xen series.
> 
> Separately, we can remove the non_block_start() from the OOM reaper
> path (patch 2 of this series), marking it as fixing the existing KVM
> mn_invalidate_lock splat under RT¹.
> 
> The actual conversion to RCU (which fixes the GPC RT issues) can be
> rebased on top of all of the above, and wait in the wings for a little
> while longer until they've landed.
> 
> I'll build a 'xen-rcu' branch with that all in a single linear set, and
> redo all the testing.

Pushed to
https://git.infradead.org/?p=users/dwmw2/linux.git;a=shortlog;h=refs/heads/xen-rcu

I'm not going to spam yet another patch series just yet; I'll wait for
Sean to opine. There's an extra SRCU fix that's tacked on to the end of
the xen series, which showed up in testing. 

bfc8471128bb (xen-rcu) KVM: x86: Use gfn_to_pfn_cache for steal time / preempted status
641309005314 KVM: x86: Request the guest TLB flush from record_steal_time()
f36625fcee41 KVM: x86/xen: Don't dirty track "vCPU info" page
ee5a6622c42d KVM: x86/xen: Explicitly tag "shared info" page as never being dirty tracked
77cf50babaa2 KVM: x86/xen: Extract delivery of event to vCPU into a separate helper
5435b60f92ad KVM: pfncache: Use RCU for readers instead of a rwlock
bee88a71959c mm/mmu_notifier: Remove non_block_start/end() from notifier invocation
c3b0e9347be8 (syzbot) KVM: pfncache: use a dedicated invalidation sequence for cache refresh
e8c3b5bdc2b1 (xen-v2) KVM: x86/xen: Take kvm->srcu in __kvm_xen_has_interrupt()
bc35ad561196 KVM: x86/xen: Use atomic*() APIs instead of open coded equivalents
b363d2ca18aa KVM: x86/xen: Use 32-bit atomics if vCPU's evtchn_pending_sel isn't aligned
da38f64bd735 KVM: x86/xen: Use 32-bit locked bts for vcpu_info evtchn_pending_sel
725a62d774ea KVM: x86/xen: Enforce 4-byte alignment of vcpu_info registration
0267ff414f71 KVM: x86/xen: Latch shinfo mode in kvm_xen_schedop_poll()
6ceac154447d KVM: x86/xen: Latch shinfo mode in kvm_xen_set_evtchn_fast()
3300e2ca471e KVM: x86/xen: Rename max_evtchn_port() to kvm_max_evtchn_port()
e8b7e8ae6de8 KVM: x86/xen: Introduce kvm_xen_has_64bit_shinfo() macro
9643c9d83837 KVM: x86/xen: Rename 'longmode' to 'is_64bit' in hypercall handling

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