Let's add a new mode and set it while we create the irqchip via
KVM_CREATE_IRQCHIP and KVM_CAP_SPLIT_IRQCHIP.

This mode will be used later to test if adding routes
(in kvm_set_routing_entry()) is already allowed.
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

We don't treat kvm->arch.vpic specially anymore, so the setup can look
like ioapic.  This gets a bit more information out of return values.
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

irqchip_in_kernel() tried to save a bit by reusing pic_irqchip(), but it
just complicated the code.
Add a separate state for the irqchip mode.
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
[Used Paolo's version of condition in irqchip_in_kernel().]
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

kvm_setup_default_irq_routing and kvm_setup_empty_irq_routing are
not used by generic code. So let's move the declarations in x86 irq.h
header instead of kvm_host.h.
Signed-off-by: NEric Auger <eric.auger@redhat.com>
Suggested-by: NAndre Przywara <andre.przywara@arm.com>
Acked-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Different pieces of code checked for vcpu->arch.apic being (non-)NULL,
or used kvm_vcpu_has_lapic (more optimized) or lapic_in_kernel.
Replace everything with lapic_in_kernel's name and kvm_vcpu_has_lapic's
implementation.
Reviewed-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

In order to enable userspace PIC support, the userspace PIC needs to
be able to inject local interrupts even when the APICs are in the
kernel.

KVM_INTERRUPT now supports sending local interrupts to an APIC when
APICs are in the kernel.

The ready_for_interrupt_request flag is now only set when the CPU/APIC
will immediately accept and inject an interrupt (i.e. APIC has not
masked the PIC).

When the PIC wishes to initiate an INTA cycle with, say, CPU0, it
kicks CPU0 out of the guest, and renedezvous with CPU0 once it arrives
in userspace.

When the CPU/APIC unmasks the PIC, a KVM_EXIT_IRQ_WINDOW_OPEN is
triggered, so that userspace has a chance to inject a PIC interrupt
if it had been pending.

Overall, this design can lead to a small number of spurious userspace
renedezvous. In particular, whenever the PIC transistions from low to
high while it is masked and whenever the PIC becomes unmasked while
it is low.

Note: this does not buffer more than one local interrupt in the
kernel, so the VMM needs to enter the guest in order to complete
interrupt injection before injecting an additional interrupt.

Compiles for x86.

Can pass the KVM Unit Tests.
Signed-off-by: NSteve Rutherford <srutherford@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

First patch in a series which enables the relocation of the
PIC/IOAPIC to userspace.

Adds capability KVM_CAP_SPLIT_IRQCHIP;

KVM_CAP_SPLIT_IRQCHIP enables the construction of LAPICs without the
rest of the irqchip.

Compile tested for x86.
Signed-off-by: NSteve Rutherford <srutherford@google.com>
Suggested-by: NAndrew Honig <ahonig@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Avoid pointer chasing and memory barriers, and simplify the code
when split irqchip (LAPIC in kernel, IOAPIC/PIC in userspace)
is introduced.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The memory barriers are trying to protect against concurrent RCU-based
interrupt injection, but the IRQ routing table is not valid at the time
kvm->arch.vpic is written.  Fix this by writing kvm->arch.vpic last.
kvm_destroy_pic then need not set kvm->arch.vpic to NULL; modify it
to take a struct kvm_pic* and reuse it if the IOAPIC creation fails.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

iodev.h contains definitions for the kvm_io_bus framework. This is
needed both by the generic KVM code in virt/kvm as well as by
architecture specific code under arch/. Putting the header file in
virt/kvm and using local includes in the architecture part seems at
least dodgy to me, so let's move the file into include/kvm, so that a
more natural "#include <kvm/iodev.h>" can be used by all of the code.
This also solves a problem later when using struct kvm_io_device
in arm_vgic.h.
Fixing up the FSF address in the GPL header and a wrong include path
on the way.
Signed-off-by: NAndre Przywara <andre.przywara@arm.com>
Acked-by: NChristoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: NMarc Zyngier <marc.zyngier@arm.com>
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Use PIC_NUM_PINS instead of hard-coded 16 for pic pins.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Currently the method of dealing with an IO operation on a bus (PIO/MMIO)
is to call the read or write callback for each device registered
on the bus until we find a device which handles it.

Since the number of devices on a bus can be significant due to ioeventfds
and coalesced MMIO zones, this leads to a lot of overhead on each IO
operation.

Instead of registering devices, we now register ranges which points to
a device. Lookup is done using an efficient bsearch instead of a linear
search.

Performance test was conducted by comparing exit count per second with
200 ioeventfds created on one byte and the guest is trying to access a
different byte continuously (triggering usermode exits).
Before the patch the guest has achieved 259k exits per second, after the
patch the guest does 274k exits per second.

Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NSasha Levin <levinsasha928@gmail.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Just remove useless function define kvm_pic_clear_isr_ack() and
pit_has_pending_timer()

Signed-off-by: Duan Jiong<djduanjiong@gmail.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The PIC code used to be called from preempt_disable() context, which
wasn't very good for PREEMPT_RT.  That is no longer the case, so move
back from raw_spinlock_t to spinlock_t.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Top of kvm_kpic_state structure should have the same memory layout as
kvm_pic_state since it is copied by memcpy.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Part of the i8259 code pretends it isn't part of kvm, but we know better.
Reduce excessive abstraction, eliminating callbacks and void pointers.
Signed-off-by: NAvi Kivity <avi@redhat.com>

This restores the deferred VCPU kicking before 956f97cf. We need this
over -rt as wake_up* requires non-atomic context in this configuration.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The i8254/i8259 locks need to be real spinlocks on preempt-rt. Convert
them to raw_spinlock. No change for !RT kernels.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

If we fail to init ioapic device or the fail to setup the default irq
routing, the device register by kvm_create_pic() and kvm_ioapic_init()
remain unregister. This patch fixed to do this.
Signed-off-by: NWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Otherwise kvm will leak memory on multiple KVM_CREATE_IRQCHIP.
Also serialize multiple accesses with kvm->lock.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This removes assumptions that max GSIs is smaller than number of pins.
Sharing is tracked on pin level not GSI level.

[avi: no PIC on ia64]
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

d5ecfdd25 moved it out because back than it was impossible to
call it inside spinlock. This restriction no longer exists.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

IRQ ack notifications assume an identity mapping between pin->gsi,
which might not be the case with, for example, HPET.

Translate before acking.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Acked-by: NGleb Natapov <gleb@redhat.com>

Simplify LAPIC TMCCT calculation by using hrtimer provided
function to query remaining time until expiration.

Fixes host hang with nested ESX.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

While most accesses to the i8259 are with the kvm mutex taken, the call
to kvm_pic_read_irq() is not.  We can't easily take the kvm mutex there
since the function is called with interrupts disabled.

Fix by adding a spinlock to the virtual interrupt controller.  Since we
can't send an IPI under the spinlock (we also take the same spinlock in
an irq disabled context), we defer the IPI until the spinlock is released.
Similarly, we defer irq ack notifications until after spinlock release to
avoid lock recursion.
Signed-off-by: NAvi Kivity <avi@redhat.com>

This patch refactors the NMI watchdog delivery patch, consolidating
tests and providing a proper API for delivering watchdog events.

An included micro-optimization is to check only for apic_hw_enabled in
kvm_apic_local_deliver (the test for LVT mask is covering the
soft-disabled case already).
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Acked-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

LINT0 of the LAPIC can be used to route PIT events as NMI watchdog ticks
into the guest. This patch aligns the in-kernel irqchip emulation with
the user space irqchip with already supports this feature. The trick is
to route PIT interrupts to all LAPIC's LVT0 lines.

Rebased and slightly polished patch originally posted by Sheng Yang.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NSheng Yang <sheng.yang@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Moving irq ack notification logic as common, and make
it shared with ia64 side.
Signed-off-by: NXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

The PIC code makes little effort to avoid kvm_vcpu_kick(), resulting in
unnecessary guest exits in some conditions.

For example, if the timer interrupt is routed through the IOAPIC, IRR
for IRQ 0 will get set but not cleared, since the APIC is handling the
acks.

This means that everytime an interrupt < 16 is triggered, the priority
logic will find IRQ0 pending and send an IPI to vcpu0 (in case IRQ0 is
not masked, which is Linux's case).

Introduce a new variable isr_ack to represent the IRQ's for which the
guest has been signalled / cleared the ISR. Use it to avoid more than
one IPI per trigger-ack cycle, in addition to the avoidance when ISR is
set in get_priority().
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Based on a patch from: Ben-Ami Yassour <benami@il.ibm.com>
which was based on a patch from: Amit Shah <amit.shah@qumranet.com>

Notify IRQ acking on PIC/APIC emulation. The previous patch missed two things:

- Edge triggered interrupts on IOAPIC
- PIC reset with IRR/ISR set should be equivalent to ack (LAPIC probably
needs something similar).
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
CC: Amit Shah <amit.shah@qumranet.com>
CC: Ben-Ami Yassour <benami@il.ibm.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This can be used by kvm subsystems that are interested in when
interrupts are acked, for example time drift compensation.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This function injects an interrupt into the guest given the kvm struct,
the (guest) irq number and the interrupt level.
Signed-off-by: NAmit Shah <amit.shah@qumranet.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Check that an injected pic irq is between 0 and 15.
Signed-off-by: NBen-Ami Yassour <benami@il.ibm.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Migrate the PIT timer to the physical CPU which vcpu0 is scheduled on,
similarly to what is done for the LAPIC timers, otherwise PIT interrupts
will be delayed until an unrelated event causes an exit.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Timers that fire between guest hlt and vcpu_block's add_wait_queue() are
ignored, possibly resulting in hangs.

Also make sure that atomic_inc and waitqueue_active tests happen in the
specified order, otherwise the following race is open:

CPU0                                        CPU1
                                            if (waitqueue_active(wq))
add_wait_queue()
if (!atomic_read(pit_timer->pending))
    schedule()
                                            atomic_inc(pit_timer->pending)
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Migrating the apic timer in the critical section is not very nice, and is
absolutely horrible with the real-time port.  Move migration to the regular
vcpu execution path, triggered by a new bitflag.

Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Moving kvm_vcpu_kick() to x86.c. Since it should be
common for all archs, put its declarations in <linux/kvm_host.h>
Signed-off-by: NZhang Xiantao <xiantao.zhang@intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This allows reuse of ioapic in ia64.
Signed-off-by: NZhang Xiantao <xiantao.zhang@intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This paves the way for multiple architecture support.  Note that while
ioapic.c could potentially be shared with ia64, it is also moved.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This patches moves two fields vpid and vioapic to kvm_arch
Signed-off-by: NZhang Xiantao <xiantao.zhang@intel.com>
Acked-by: NCarsten Otte <cotte@de.ibm.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>