i386/hvf: In kick_vcpu use hv_vcpu_interrupt to force exit

i386/hvf: In kick_vcpu use hv_vcpu_interrupt to force exit

When interrupting a vCPU thread, this patch actually tells the hypervisor to
stop running guest code on that vCPU.

Calling hv_vcpu_interrupt actually forces a vCPU exit, analogously to
hv_vcpus_exit on aarch64. Alternatively, if the vCPU thread
is not
running the VM, it will immediately cause an exit when it attempts
to do so.

Previously, hvf_kick_vcpu_thread relied upon hv_vcpu_run returning very
frequently, including many spurious exits, which made it less of a problem that
nothing was actively done to stop the vCPU thread running guest code.
The newer, more efficient hv_vcpu_run_until exits much more rarely, so a true
"kick" is needed before switching to that.

Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu>
Message-ID: <20240605112556.43193-6-phil@philjordan.eu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>