Commit Graph

9 Commits

Author SHA1 Message Date
Roman Kagan 6738ccfff0 hyperv_testdev: add SynIC message and event testmodes
Add testmodes for SynIC messages and events.  The message or event
connection setup / teardown is initiated by the guest via new control
codes written to the test device port.  Then the test connections bounce
the respective operations back to the guest, i.e. the incoming messages
are posted or the incoming events are signaled on the configured vCPUs.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-19 13:44:14 +02:00
Roman Kagan 76036a5fc7 hyperv: process POST_MESSAGE hypercall
Add handling of POST_MESSAGE hypercall.  For that, add an interface to
regsiter a handler for the messages arrived from the guest on a
particular connection id (IOW set up a message connection in Hyper-V
speak).

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-10-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-19 13:44:14 +02:00
Roman Kagan 8d3bc0b753 hyperv: add support for KVM_HYPERV_EVENTFD
When setting up a notifier for Hyper-V event connection, try to use the
KVM-assisted one first, and fall back to userspace handling of the
hypercall if the kernel doesn't provide the requested feature.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-9-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-19 13:44:14 +02:00
Roman Kagan e6ea9f45b7 hyperv: process SIGNAL_EVENT hypercall
Add handling of SIGNAL_EVENT hypercall.  For that, provide an interface
to associate an EventNotifier with an event connection number, so that
it's signaled when the SIGNAL_EVENT hypercall with the matching
connection ID is called by the guest.

Support for using KVM functionality for this will be added in a followup
patch.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-8-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-19 13:44:14 +02:00
Roman Kagan f5642f8b45 hyperv: add synic event flag signaling
Add infrastructure to signal SynIC event flags by atomically setting the
corresponding bit in the event flags page and firing a SINT if
necessary.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-7-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-19 13:44:14 +02:00
Roman Kagan 4cbaf3c133 hyperv: add synic message delivery
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>
2018-10-19 13:44:14 +02:00
Roman Kagan 267e071bd6 hyperv: make overlay pages for SynIC
Per Hyper-V spec, SynIC message and event flag pages are to be
implemented as so called overlay pages.  That is, they are owned by the
hypervisor and, when mapped into the guest physical address space,
overlay the guest physical pages such that

1) the overlaid guest page becomes invisible to the guest CPUs until the
   overlay page is turned off
2) the contents of the overlay page is preserved when it's turned off
   and back on, even at a different address; it's only zeroed at vcpu
   reset

This particular nature of SynIC message and event flag pages is ignored
in the current code, and guest physical pages are used directly instead.
This happens to (mostly) work because the actual guests seem not to
depend on the features listed above.

This patch implements those pages as the spec mandates.

Since the extra RAM regions, which introduce migration incompatibility,
are only added at SynIC object creation which only happens when
hyperv_synic_kvm_only == false, no extra compat logic is necessary.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-5-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-19 13:44:14 +02:00
Roman Kagan 606c34bfd5 hyperv: qom-ify SynIC
Make Hyper-V SynIC a device which is attached as a child to a CPU.  For
now it only makes SynIC visibile in the qom hierarchy, and maintains its
internal fields in sync with the respecitve msrs of the parent cpu (the
fields will be used in followup patches).

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-3-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-19 13:44:14 +02:00
Roman Kagan 701189e311 hyperv: factor out arch-independent API into hw/hyperv
A significant part of hyperv.c is not actually tied to x86, and can
be moved to hw/.

This will allow to maintain most of Hyper-V and VMBus
target-independent, and to avoid conflicts with inclusion of
arch-specific headers down the road in VMBus implementation.

Also this stuff can now be opt-out with CONFIG_HYPERV.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082041.29380-4-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-19 13:44:13 +02:00