Hi James,
On 2019/6/12 20:48, James Morse wrote:
Hi,
On 12/06/2019 10:08, Zenghui Yu wrote:
In current KVM/ARM code, no one will invoke trace_kvm_mmio_emulate().
Remove this TRACE_EVENT definition.
Oooer. We can't just go removing these things, they are visible to user-space.
I recall an article on this: https://lwn.net/Articles/737530/
"Another attempt to address the tracepoint ABI problem"
I agree this is orphaned, it was added by commit 45e96ea6b369 ("KVM: ARM: Handle I/O
aborts"), but there never was a caller.
The problem with removing it is /sys/kernel/debug/tracing/events/kvm/kvm_mmio_emulate
disappears. Any program relying on that being present (but useless) is now broken.
Thanks for the reminder.
It turned out that I knew little about the tracepoint ABI :( .
I'm OK to just drop this patch in next version.
Thanks,
zenghui
.
