On 17/02/21 18:29, Sean Christopherson wrote:
All that being said, I'm pretty we can eliminate setting
inject_page_fault dynamically. I think that would yield more
maintainable code. Following these flows is a nightmare. The change
itself will be scarier, but I'm pretty sure the end result will be a lot
cleaner.
I had a similar reaction, though my proposal was different.
The only thing we're changing in complete_mmu_init is the page fault
callback for init_kvm_softmmu, so couldn't that be the callback directly
(i.e. something like context->inject_page_fault =
kvm_x86_ops.inject_softmmu_page_fault)? And then adding is_guest_mode
to the conditional that is already in vmx_inject_page_fault_nested and
svm_inject_page_fault_nested.
That said, I'm also rusty on _why_ this code is needed. Why isn't it
enough to inject the exception normally, and let
nested_vmx_check_exception decide whether to inject a vmexit to L1 or an
exception into L2?
Also, bonus question which should have been in the 5/7 changelog: are
there kvm-unit-tests testcases that fail with npt=0, and if not could we
write one? [Answer: the mode_switch testcase fails, but I haven't
checked why].
Paolo
