4cbaf3c133
Add infrastructure to deliver SynIC messages to the SynIC message page. Note that KVM may also want to deliver (SynIC timer) messages to the same message slot. The problem is that the access to a SynIC message slot is controlled by the value of its .msg_type field which indicates if the slot is being owned by the hypervisor (zero) or by the guest (non-zero). This leaves no room for synchronizing multiple concurrent producers. The simplest way to deal with this for both KVM and QEMU is to only deliver messages in the vcpu thread. KVM already does this; this patch makes it for QEMU, too. Specifically, - add a function for posting messages, which only copies the message into the staging buffer if its free, and schedules a work on the corresponding vcpu to actually deliver it to the guest slot; - instead of a sint ack callback, set up the sint route with a message status callback. This function is called in a bh whenever there are updates to the message slot status: either the vcpu made definitive progress delivering the message from the staging buffer (succeeded or failed) or the guest issued EOM; the status is passed as an argument to the callback. Signed-off-by: Roman Kagan <rkagan@virtuozzo.com> Message-Id: <20180921082217.29481-6-rkagan@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
||
|---|---|---|
| .. | ||
| hyperv_testdev.c | ||
| hyperv.c | ||
| Makefile.objs | ||