In kvm_lapic_sync_from_vapic and kvm_lapic_sync_to_vapic there is the
potential to corrupt kernel memory if userspace provides an address that
is at the end of a page.  This patches concerts those functions to use
kvm_write_guest_cached and kvm_read_guest_cached.  It also checks the
vapic_address specified by userspace during ioctl processing and returns
an error to userspace if the address is not a valid GPA.

This is generally not guest triggerable, because the required write is
done by firmware that runs before the guest.  Also, it only affects AMD
processors and oldish Intel that do not have the FlexPriority feature
(unless you disable FlexPriority, of course; then newer processors are
also affected).

Fixes: b93463aa ('KVM: Accelerated apic support')
Reported-by: NAndrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: NAndrew Honig <ahonig@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This reverts most of the f1ed0450. After
the commit kvm_apic_set_irq() no longer returns accurate information
about interrupt injection status if injection is done into disabled
APIC. RTC interrupt coalescing tracking relies on the information to be
accurate and cannot recover if it is not.
Signed-off-by: NGleb Natapov <gleb@redhat.com>

Since the arrival of posted interrupt support we can no longer guarantee
that coalesced IRQs are always reported to the IRQ source. Moreover,
accumulated APIC timer events could cause a busy loop when a VCPU should
rather be halted. The consensus is to remove coalesced tracking from the
LAPIC.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Acked-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

Only deliver the posted interrupt when target vcpu is running
and there is no previous interrupt pending in pir.
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

We already know the trigger mode of a given interrupt when programming
the ioapice entry. So it's not necessary to set it in each interrupt
delivery.
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

restore rtc_status from migration or save/restore
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Add a new parameter to know vcpus who received the interrupt.
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

For a given vcpu, kvm_apic_match_dest() will tell you whether
the vcpu in the destination list quickly. Drop kvm_calculate_eoi_exitmap()
and use kvm_apic_match_dest() instead.
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

A VCPU sending INIT or SIPI to some other VCPU races for setting the
remote VCPU's mp_state. When we were unlucky, KVM_MP_STATE_INIT_RECEIVED
was overwritten by kvm_emulate_halt and, thus, got lost.

This introduces APIC events for those two signals, keeping them in
kvm_apic until kvm_apic_accept_events is run over the target vcpu
context. kvm_apic_has_events reports to kvm_arch_vcpu_runnable if there
are pending events, thus if vcpu blocking should end.

The patch comes with the side effect of effectively obsoleting
KVM_MP_STATE_SIPI_RECEIVED. We still accept it from user space, but
immediately translate it to KVM_MP_STATE_INIT_RECEIVED + KVM_APIC_SIPI.
The vcpu itself will no longer enter the KVM_MP_STATE_SIPI_RECEIVED
state. That also means we no longer exit to user space after receiving a
SIPI event.

Furthermore, we already reset the VCPU on INIT, only fixing up the code
segment later on when SIPI arrives. Moreover, we fix INIT handling for
the BSP: it never enter wait-for-SIPI but directly starts over on INIT.
Tested-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

Virtual interrupt delivery avoids KVM to inject vAPIC interrupts
manually, which is fully taken care of by the hardware. This needs
some special awareness into existing interrupr injection path:

- for pending interrupt, instead of direct injection, we may need
  update architecture specific indicators before resuming to guest.

- A pending interrupt, which is masked by ISR, should be also
  considered in above update action, since hardware will decide
  when to inject it at right time. Current has_interrupt and
  get_interrupt only returns a valid vector from injection p.o.v.
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NKevin Tian <kevin.tian@intel.com>
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

basically to benefit from apicv, we need to enable virtualized x2apic mode.
Currently, we only enable it when guest is really using x2apic.

Also, clear MSR bitmap for corresponding x2apic MSRs when guest enabled x2apic:
0x800 - 0x8ff: no read intercept for apicv register virtualization,
               except APIC ID and TMCCT which need software's assistance to
               get right value.
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NKevin Tian <kevin.tian@intel.com>
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

- APIC read doesn't cause VM-Exit
- APIC write becomes trap-like
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NKevin Tian <kevin.tian@intel.com>
Signed-off-by: NYang Zhang <yang.z.zhang@intel.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

Most interrupt are delivered to only one vcpu. Use pre-build tables to
find interrupt destination instead of looping through all vcpus. In case
of logical mode loop only through vcpus in a logical cluster irq is sent
to.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

For apic_set_spiv() to track APIC SW state correctly it needs to see
previous and next values of the spurious vector register, but currently
memset() overwrite the old value before apic_set_spiv() get a chance to
do tracking. Fix it by calling apic_set_spiv() before overwriting old
value.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Those functions are used during interrupt injection. When inlined they
become nops on the fast path.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Usually all APICs are HW enabled so the check can be optimized out.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

'reinject' is never initialized
't_ops' only serves as indirection to lapic_is_periodic; call that directly
   instead
'kvm' is never used
'vcpu' can be derived via container_of

Remove these fields.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

kvm_timer_fn(), the sole inhabitant of timer.c, is only used by lapic.c. Move
it there to make it easier to hack on it.

struct kvm_timer is a thin wrapper around hrtimer, and only adds obfuscation.
Move near its two users (with different names) to prepare for simplification.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Implementation of PV EOI using shared memory.
This reduces the number of exits an interrupt
causes as much as by half.

The idea is simple: there's a bit, per APIC, in guest memory,
that tells the guest that it does not need EOI.
We set it before injecting an interrupt and clear
before injecting a nested one. Guest tests it using
a test and clear operation - this is necessary
so that host can detect interrupt nesting -
and if set, it can skip the EOI MSR.

There's a new MSR to set the address of said register
in guest memory. Otherwise not much changed:
- Guest EOI is not required
- Register is tested & ISR is automatically cleared on exit

For testing results see description of previous patch
'kvm_para: guest side for eoi avoidance'.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We perform ISR lookups twice: during interrupt
injection and on EOI. Typical workloads only have
a single bit set there. So we can avoid ISR scans by
1. counting bits as we set/clear them in ISR
2. on set, caching the injected vector number
3. on clear, invalidating the cache

The real purpose of this is enabling PV EOI
which needs to quickly validate the vector.
But non PV guests also benefit: with this patch,
and without interrupt nesting, apic_find_highest_isr
will always return immediately without scanning ISR.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Needed to deliver performance monitoring interrupts.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This patch emulate lapic tsc deadline timer for guest:
Enumerate tsc deadline timer capability by CPUID;
Enable tsc deadline timer mode by lapic MMIO;
Start tsc deadline timer by WRMSR;

[jan: use do_div()]
[avi: fix for !irqchip_in_kernel()]
[marcelo: another fix for !irqchip_in_kernel()]
Signed-off-by: NLiu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Instruction emulation for EOI writes can be skipped, since sane
guest simply uses MOV instead of string operations. This is a nice
improvement when guest doesn't support x2apic or hyper-V EOI
support.

a single VM bandwidth is observed with ~8% bandwidth improvement
(7.4Gbps->8Gbps), by saving ~5% cycles from EOI emulation.
Signed-off-by: NKevin Tian <kevin.tian@intel.com>
<Based on earlier work from>:
Signed-off-by: NEddie Dong <eddie.dong@intel.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Access to this page is mostly done through the regs member which holds
the address to this page.  The exceptions are in vmx_vcpu_reset() and
kvm_free_lapic() and these both can easily be converted to using regs.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Implement HYPER-V apic MSRs. Spec defines three MSRs that speed-up
access to EOI/TPR/ICR apic registers for PV guests.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NVadim Rozenfeld <vrozenfe@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This patch implements MSR interface to local apic as defines by x2apic
Intel specification.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Directed EOI is specified by x2APIC, but is available even when lapic is
in xAPIC mode.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Most of the time IRR is empty, so instead of scanning the whole IRR on
each VM entry keep a variable that tells us if IRR is not empty. IRR
will have to be scanned twice on each IRQ delivery, but this is much
more rare than VM entry.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Deliver interrupt during destination matching loop.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Acked-by: NXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Use kvm_apic_match_dest() in kvm_get_intr_delivery_bitmask() instead
of duplicating the same code. Use kvm_get_intr_delivery_bitmask() in
apic_send_ipi() to figure out ipi destination instead of reimplementing
the logic.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Get rid of ioapic_inj_irq() and ioapic_inj_nmi() functions.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Hide the internals of vcpu awakening / injection from the in-kernel
emulated timers. This makes future changes in this logic easier and
decreases the distance to more generic timer handling.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@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>

Noticed by sparse:
arch/x86/kvm/vmx.c:1583:6: warning: symbol 'vmx_disable_intercept_for_msr' was not declared. Should it be static?
arch/x86/kvm/x86.c:3406:5: warning: symbol 'kvm_task_switch_16' was not declared. Should it be static?
arch/x86/kvm/x86.c:3429:5: warning: symbol 'kvm_task_switch_32' was not declared. Should it be static?
arch/x86/kvm/mmu.c:1968:6: warning: symbol 'kvm_mmu_remove_one_alloc_mmu_page' was not declared. Should it be static?
arch/x86/kvm/mmu.c:2014:6: warning: symbol 'mmu_destroy_caches' was not declared. Should it be static?
arch/x86/kvm/lapic.c:862:5: warning: symbol 'kvm_lapic_get_base' was not declared. Should it be static?
arch/x86/kvm/i8254.c:94:5: warning: symbol 'pit_get_gate' was not declared. Should it be static?
arch/x86/kvm/i8254.c:196:5: warning: symbol '__pit_timer_fn' was not declared. Should it be static?
arch/x86/kvm/i8254.c:561:6: warning: symbol '__inject_pit_timer_intr' was not declared. Should it be static?
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This adds a mechanism for exposing the virtual apic tpr to the guest, and a
protocol for letting the guest update the tpr without causing a vmexit if
conditions allow (e.g. there is no interrupt pending with a higher priority
than the new tpr).
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>