When started in compat configuration of SynIC, e.g.
qemu-system-x86_64 -machine pc-i440fx-2.10,accel=kvm \
-cpu host,-vmx,hv-relaxed,hv_spinlocks=0x1fff,hv-vpindex,hv-synic
or explicitly
qemu-system-x86_64 -enable-kvm -cpu host,hv-synic,x-hv-synic-kvm-only=on
QEMU crashes in hyperv_synic_reset() trying to access the non-present
qobject for SynIC.
Add the missing check for NULL.
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reported-by: Igor Mammedov <imammedo@redhat.com>
Fixes: 9b4cf107b0
Fixes: 4a93722f9c
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20181126152836.25379-1-rkagan@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
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>
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>
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>
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>
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>
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>
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>
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>
