Hi Marc,
On 8/5/2020 8:13 PM, Marc Zyngier wrote:
On 2020-08-05 12:54, Jingyi Wang wrote:
Hi all,
Currently, kvm-unit-tests only support GICv3 vLPI injection. May I ask
is there any plan or suggestion on constructing irq bypass mechanism
to test vLPI direct injection in kvm-unit-tests?
I'm not sure what you are asking for here. VLPIs are only delivered
from a HW device, and the offloading mechanism isn't visible from
userspace (you either have an enabled GICv4 implementation, or
you don't).
There are ways to *trigger* device MSIs from userspace and inject
them in a guest, but that's only a debug feature, which shouldn't
be enabled on a production system.
M.
Sorry for the late reply.
As I mentioned before, we want to add vLPI direct injection test
in KUT, meanwhile measure the latency of hardware vLPI injection.
Sure, vLPI is triggered by hardware. Since kernel supports sending
ITS INT command in guest to trigger vLPI, I wonder if it is possible
to add an extra interface to make a vLPI hardware-offload(just as
kvm_vgic_v4_set_forwarding() does). If so, vgic_its_trigger_msi()
can inject vLPI directly instead of using LR.
Thanks,
Jingyi
