Add pv tlb shootdown tracepoint.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Remove a few stale checks for non-NULL ops now that the ops in question
are implemented by both VMX and SVM.

Note, this is **not** stable material, the Fixes tags are there purely
to show when a particular op was first supported by both VMX and SVM.

Fixes: 74f16909 ("kvm/svm: Setup MCG_CAP on AMD properly")
Fixes: b31c114b ("KVM: X86: Provide a capability to disable PAUSE intercepts")
Fixes: 411b44ba ("svm: Implements update_pi_irte hook to setup posted interrupt")
Cc: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Rename "access" to "mmio_access" to match the other MMIO cache members
and to make it more obvious that it's tracking the access permissions
for the MMIO cache.
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

To avoid hardcoding xsetbv length to '3' we need to support decoding it in
the emulator.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

When doing x86_emulate_instruction(EMULTYPE_SKIP) interrupt shadow has to
be cleared if and only if the skipping is successful.

There are two immediate issues:
- In SVM skip_emulated_instruction() we are not zapping interrupt shadow
  in case kvm_emulate_instruction(EMULTYPE_SKIP) is used to advance RIP
  (!nrpip_save).
- In VMX handle_ept_misconfig() when running as a nested hypervisor we
  (static_cpu_has(X86_FEATURE_HYPERVISOR) case) forget to clear interrupt
  shadow.

Note that we intentionally don't handle the case when the skipped
instruction is supposed to prolong the interrupt shadow ("MOV/POP SS") as
skip-emulation of those instructions should not happen under normal
circumstances.
Suggested-by: NSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

On AMD, kvm_x86_ops->skip_emulated_instruction(vcpu) can, in theory,
fail: in !nrips case we call kvm_emulate_instruction(EMULTYPE_SKIP).
Currently, we only do printk(KERN_DEBUG) when this happens and this
is not ideal. Propagate the error up the stack.

On VMX, skip_emulated_instruction() doesn't fail, we have two call
sites calling it explicitly: handle_exception_nmi() and
handle_task_switch(), we can just ignore the result.

On SVM, we also have two explicit call sites:
svm_queue_exception() and it seems we don't need to do anything there as
we check if RIP was advanced or not. In task_switch_interception(),
however, we are better off not proceeding to kvm_task_switch() in case
skip_emulated_instruction() failed.
Suggested-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Similar to AMD bits, set the Intel bits from the vendor-independent
feature and bug flags, because KVM_GET_SUPPORTED_CPUID does not care
about the vendor and they should be set on AMD processors as well.
Suggested-by: NJim Mattson <jmattson@google.com>
Reviewed-by: NJim Mattson <jmattson@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

After commit d73eb57b (KVM: Boost vCPUs that are delivering interrupts), a
five years old bug is exposed. Running ebizzy benchmark in three 80 vCPUs VMs
on one 80 pCPUs Skylake server, a lot of rcu_sched stall warning splatting
in the VMs after stress testing:

 INFO: rcu_sched detected stalls on CPUs/tasks: { 4 41 57 62 77} (detected by 15, t=60004 jiffies, g=899, c=898, q=15073)
 Call Trace:
   flush_tlb_mm_range+0x68/0x140
   tlb_flush_mmu.part.75+0x37/0xe0
   tlb_finish_mmu+0x55/0x60
   zap_page_range+0x142/0x190
   SyS_madvise+0x3cd/0x9c0
   system_call_fastpath+0x1c/0x21

swait_active() sustains to be true before finish_swait() is called in
kvm_vcpu_block(), voluntarily preempted vCPUs are taken into account
by kvm_vcpu_on_spin() loop greatly increases the probability condition
kvm_arch_vcpu_runnable(vcpu) is checked and can be true, when APICv
is enabled the yield-candidate vCPU's VMCS RVI field leaks(by
vmx_sync_pir_to_irr()) into spinning-on-a-taken-lock vCPU's current
VMCS.

This patch fixes it by checking conservatively a subset of events.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>
Cc: stable@vger.kernel.org
Fixes: 98f4a146 (KVM: add kvm_arch_vcpu_runnable() test to kvm_vcpu_on_spin() loop)
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Commit 11752adb (locking/pvqspinlock: Implement hybrid PV queued/unfair locks)
introduces hybrid PV queued/unfair locks
 - queued mode (no starvation)
 - unfair mode (good performance on not heavily contended lock)
The lock waiter goes into the unfair mode especially in VMs with over-commit
vCPUs since increaing over-commitment increase the likehood that the queue
head vCPU may have been preempted and not actively spinning.

However, reschedule queue head vCPU timely to acquire the lock still can get
better performance than just depending on lock stealing in over-subscribe
scenario.

Testing on 80 HT 2 socket Xeon Skylake server, with 80 vCPUs VM 80GB RAM:
ebizzy -M
             vanilla     boosting    improved
 1VM          23520        25040         6%
 2VM           8000        13600        70%
 3VM           3100         5400        74%

The lock holder vCPU yields to the queue head vCPU when unlock, to boost queue
head vCPU which is involuntary preemption or the one which is voluntary halt
due to fail to acquire the lock after a short spin in the guest.

Cc: Waiman Long <longman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

After reverting commit 240c35a3 (kvm: x86: Use task structs fpu field
for user), struct kvm_vcpu is 19456 bytes on my server, PAGE_ALLOC_COSTLY_ORDER(3)
is the order at which allocations are deemed costly to service. In serveless
scenario, one host can service hundreds/thoudands firecracker/kata-container
instances, howerver, new instance will fail to launch after memory is too
fragmented to allocate kvm_vcpu struct on host, this was observed in some
cloud provider product environments.

This patch dynamically allocates user_fpu, kvm_vcpu is 15168 bytes now on my
Skylake server.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The idea before commit 240c35a3 (which has just been reverted)
was that we have the following FPU states:

               userspace (QEMU)             guest
---------------------------------------------------------------------------
               processor                    vcpu->arch.guest_fpu
>>> KVM_RUN: kvm_load_guest_fpu
               vcpu->arch.user_fpu          processor
>>> preempt out
               vcpu->arch.user_fpu          current->thread.fpu
>>> preempt in
               vcpu->arch.user_fpu          processor
>>> back to userspace
>>> kvm_put_guest_fpu
               processor                    vcpu->arch.guest_fpu
---------------------------------------------------------------------------

With the new lazy model we want to get the state back to the processor
when schedule in from current->thread.fpu.
Reported-by: NThomas Lambertz <mail@thomaslambertz.de>
Reported-by: Nanthony <antdev66@gmail.com>
Tested-by: Nanthony <antdev66@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Thomas Lambertz <mail@thomaslambertz.de>
Cc: anthony <antdev66@gmail.com>
Cc: stable@vger.kernel.org
Fixes: 5f409e20 (x86/fpu: Defer FPU state load until return to userspace)
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
[Add a comment in front of the warning. - Paolo]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This reverts commit 240c35a3
("kvm: x86: Use task structs fpu field for user", 2018-11-06).
The commit is broken and causes QEMU's FPU state to be destroyed
when KVM_RUN is preempted.

Fixes: 240c35a3 ("kvm: x86: Use task structs fpu field for user")
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Dedicated instances are currently disturbed by unnecessary jitter due
to the emulated lapic timers firing on the same pCPUs where the
vCPUs reside.  There is no hardware virtual timer on Intel for guest
like ARM, so both programming timer in guest and the emulated timer fires
incur vmexits.  This patch tries to avoid vmexit when the emulated timer
fires, at least in dedicated instance scenario when nohz_full is enabled.

In that case, the emulated timers can be offload to the nearest busy
housekeeping cpus since APICv has been found for several years in server
processors. The guest timer interrupt can then be injected via posted interrupts,
which are delivered by the housekeeping cpu once the emulated timer fires.

The host should tuned so that vCPUs are placed on isolated physical
processors, and with several pCPUs surplus for busy housekeeping.
If disabled mwait/hlt/pause vmexits keep the vCPUs in non-root mode,
~3% redis performance benefit can be observed on Skylake server, and the
number of external interrupt vmexits drops substantially.  Without patch

            VM-EXIT  Samples  Samples%  Time%   Min Time  Max Time   Avg time
EXTERNAL_INTERRUPT    42916    49.43%   39.30%   0.47us   106.09us   0.71us ( +-   1.09% )

While with patch:

            VM-EXIT  Samples  Samples%  Time%   Min Time  Max Time         Avg time
EXTERNAL_INTERRUPT    6871     9.29%     2.96%   0.44us    57.88us   0.72us ( +-   4.02% )

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Commit 61abdbe0 ("kvm: x86: make lapic hrtimer pinned") pinned the
lapic timer to avoid to wait until the next kvm exit for the guest to
see KVM_REQ_PENDING_TIMER set. There is another solution to give a kick
after setting the KVM_REQ_PENDING_TIMER bit, make lapic timer unpinned
will be used in follow up patches.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

There are some pr_debug in TSC code, which may have
been no use, so remove them as Paolo suggested.
Signed-off-by: NYi Wang <wang.yi59@zte.com.cn>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

On VMX, KVM currently does not re-enable irqs until after it has exited
the guest context.  As a result, a tick that fires in the window between
VM-Exit and guest_exit_irqoff() will be accounted as system time.  While
said window is relatively small, it's large enough to be problematic in
some configurations, e.g. if VM-Exits are consistently occurring a hair
earlier than the tick irq.

Intentionally toggle irqs back off so that guest_exit_irqoff() can be
used in lieu of guest_exit() in order to avoid the save/restore of flags
in guest_exit().  On my Haswell system, "nop; cli; sti" is ~6 cycles,
versus ~28 cycles for "pushf; pop <reg>; cli; push <reg>; popf".

Fixes: f2485b3e ("KVM: x86: use guest_exit_irqoff")
Reported-by: NWei Yang <w90p710@gmail.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Some events can provide a guest with information about other guests or the
host (e.g. L3 cache stats); providing the capability to restrict access
to a "safe" set of events would limit the potential for the PMU to be used
in any side channel attacks. This change introduces a new VM ioctl that
sets an event filter. If the guest attempts to program a counter for
any blacklisted or non-whitelisted event, the kernel counter won't be
created, so any RDPMC/RDMSR will show 0 instances of that event.
Signed-off-by: NEric Hankland <ehankland@google.com>
[Lots of changes. All remaining bugs are probably mine. - Paolo]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Continue consolidating Hyper-V clock and timer code into an ISA
independent Hyper-V clocksource driver.

Move the existing clocksource code under drivers/hv and arch/x86 to the new
clocksource driver while separating out the ISA dependencies. Update
Hyper-V initialization to call initialization and cleanup routines since
the Hyper-V synthetic clock is not independently enumerated in ACPI.

Update Hyper-V clocksource users in KVM and VDSO to get definitions from
the new include file.

No behavior is changed and no new functionality is added.
Suggested-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NMichael Kelley <mikelley@microsoft.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Cc: "bp@alien8.de" <bp@alien8.de>
Cc: "will.deacon@arm.com" <will.deacon@arm.com>
Cc: "catalin.marinas@arm.com" <catalin.marinas@arm.com>
Cc: "mark.rutland@arm.com" <mark.rutland@arm.com>
Cc: "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>
Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Cc: "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>
Cc: "olaf@aepfle.de" <olaf@aepfle.de>
Cc: "apw@canonical.com" <apw@canonical.com>
Cc: "jasowang@redhat.com" <jasowang@redhat.com>
Cc: "marcelo.cerri@canonical.com" <marcelo.cerri@canonical.com>
Cc: Sunil Muthuswamy <sunilmut@microsoft.com>
Cc: KY Srinivasan <kys@microsoft.com>
Cc: "sashal@kernel.org" <sashal@kernel.org>
Cc: "vincenzo.frascino@arm.com" <vincenzo.frascino@arm.com>
Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>
Cc: "linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org>
Cc: "linux-kselftest@vger.kernel.org" <linux-kselftest@vger.kernel.org>
Cc: "arnd@arndb.de" <arnd@arndb.de>
Cc: "linux@armlinux.org.uk" <linux@armlinux.org.uk>
Cc: "ralf@linux-mips.org" <ralf@linux-mips.org>
Cc: "paul.burton@mips.com" <paul.burton@mips.com>
Cc: "daniel.lezcano@linaro.org" <daniel.lezcano@linaro.org>
Cc: "salyzyn@android.com" <salyzyn@android.com>
Cc: "pcc@google.com" <pcc@google.com>
Cc: "shuah@kernel.org" <shuah@kernel.org>
Cc: "0x7f454c46@gmail.com" <0x7f454c46@gmail.com>
Cc: "linux@rasmusvillemoes.dk" <linux@rasmusvillemoes.dk>
Cc: "huw@codeweavers.com" <huw@codeweavers.com>
Cc: "sfr@canb.auug.org.au" <sfr@canb.auug.org.au>
Cc: "pbonzini@redhat.com" <pbonzini@redhat.com>
Cc: "rkrcmar@redhat.com" <rkrcmar@redhat.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>
Link: https://lkml.kernel.org/r/1561955054-1838-3-git-send-email-mikelley@microsoft.com

This warning can be triggered easily by userspace, so it should certainly not
cause a panic if panic_on_warn is set.

Reported-by: syzbot+c03f30b4f4c46bdf8575@syzkaller.appspotmail.com
Suggested-by: NAlexander Potapenko <glider@google.com>
Acked-by: NAlexander Potapenko <glider@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The target vCPUs are in runnable state after vcpu_kick and suitable
as a yield target. This patch implements the sched yield hypercall.

17% performance increasement of ebizzy benchmark can be observed in an
over-subscribe environment. (w/ kvm-pv-tlb disabled, testing TLB flush
call-function IPI-many since call-function is not easy to be trigged
by userspace workload).

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Liran Alon <liran.alon@oracle.com>
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This allows userspace to know which MSRs are supported by the hypervisor.
Unfortunately userspace must resort to tricks for everything except
MSR_IA32_VMX_VMFUNC (which was just added in the previous patch).
One possibility is to use the feature control MSR, which is tied to nested
VMX as well and is present on all KVM versions that support feature MSRs.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This makes boot uniformly boottime and tai uniformly clocktai, to
address the remaining oversights.
Signed-off-by: NJason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Link: https://lkml.kernel.org/r/20190621203249.3909-2-Jason@zx2c4.com

Based on 1 normalized pattern(s):

  this work is licensed under the terms of the gnu gpl version 2 see
  the copying file in the top level directory

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 35 file(s).
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: NEnrico Weigelt <info@metux.net>
Reviewed-by: NAllison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.797835076@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Checking for 32-bit PAE is quite common around code that fiddles with
the PDPTRs.  Add a function to compress all checks into a single
invocation.
Reviewed-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Per commit 1b6269db ("KVM: VMX: Handle NMIs before enabling
interrupts and preemption"), NMIs are handled directly in vmx_vcpu_run()
to "make sure we handle NMI on the current cpu, and that we don't
service maskable interrupts before non-maskable ones".  The other
exceptions handled by complete_atomic_exit(), e.g. async #PF and #MC,
have similar requirements, and are located there to avoid extra VMREADs
since VMX bins hardware exceptions and NMIs into a single exit reason.

Clean up the code and eliminate the vaguely named complete_atomic_exit()
by moving the interrupts-disabled exception and NMI handling into the
existing handle_external_intrs() callback, and rename the callback to
a more appropriate name.  Rename VMexit handlers throughout so that the
atomic and non-atomic counterparts have similar names.

In addition to improving code readability, this also ensures the NMI
handler is run with the host's debug registers loaded in the unlikely
event that the user is debugging NMIs.  Accuracy of the last_guest_tsc
field is also improved when handling NMIs (and #MCs) as the handler
will run after updating said field.
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
[Naming cleanups. - Paolo]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

VMX can conditionally call kvm_{before,after}_interrupt() since KVM
always uses "ack interrupt on exit" and therefore explicitly handles
interrupts as opposed to blindly enabling irqs.
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Make it available to AMD hosts as well, just in case someone is trying
to use an Intel processor's CPUID setup.
Suggested-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Add an MSRs which allows the guest to disable
host polling (specifically the cpuidle-haltpoll,
when performing polling in the guest, disables
host side polling).
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Make all code consistent with kvm_deliver_exception_payload() by using
appropriate symbolic constant instead of hard-coded number.
Reviewed-by: NNikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: NKrish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: NLiran Alon <liran.alon@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Even when asynchronous page fault is disabled, KVM does not want to pause
the host if a guest triggers a page fault; instead it will put it into
an artificial HLT state that allows running other host processes while
allowing interrupt delivery into the guest.

However, the way this feature is triggered is a bit confusing.
First, it is not used for page faults while a nested guest is
running: but this is not an issue since the artificial halt
is completely invisible to the guest, either L1 or L2.  Second,
it is used even if kvm_halt_in_guest() returns true; in this case,
the guest probably should not pay the additional latency cost of the
artificial halt, and thus we should handle the page fault in a
completely synchronous way.

By introducing a new function kvm_can_deliver_async_pf, this patch
commonizes the code that chooses whether to deliver an async page fault
(kvm_arch_async_page_not_present) and the code that chooses whether a
page fault should be handled synchronously (kvm_can_do_async_pf).
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

It doesn't seem as if there is any particular need for kvm_lock to be a
spinlock, so convert the lock to a mutex so that sleepable functions (in
particular cond_resched()) can be called while holding it.
Signed-off-by: NJunaid Shahid <junaids@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

MSR IA32_MISC_ENABLE bit 18, according to SDM:

| When this bit is set to 0, the MONITOR feature flag is not set (CPUID.01H:ECX[bit 3] = 0).
| This indicates that MONITOR/MWAIT are not supported.
|
| Software attempts to execute MONITOR/MWAIT will cause #UD when this bit is 0.
|
| When this bit is set to 1 (default), MONITOR/MWAIT are supported (CPUID.01H:ECX[bit 3] = 1).

The CPUID.01H:ECX[bit 3] ought to mirror the value of the MSR bit,
CPUID.01H:ECX[bit 3] is a better guard than kvm_mwait_in_guest().
kvm_mwait_in_guest() affects the behavior of MONITOR/MWAIT, not its
guest visibility.

This patch implements toggling of the CPUID bit based on guest writes
to the MSR.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
[Fixes for backwards compatibility - Paolo]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Allow guest reads CORE cstate when exposing host CPU power management capabilities
to the guest. PKG cstate is restricted to avoid a guest to get the whole package
information in multi-tenant scenario.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Liran Alon <liran.alon@oracle.com>
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

1. Using X86_FEATURE_ARCH_CAPABILITIES to enumerate the existence of
MSR_IA32_ARCH_CAPABILITIES to avoid using rdmsrl_safe().

2. Since kvm_get_arch_capabilities() is only used in this file, making
it static.
Signed-off-by: NXiaoyao Li <xiaoyao.li@linux.intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Add a wrapper to invoke kvm_arch_check_processor_compat() so that the
boilerplate ugliness of checking virtualization support on all CPUs is
hidden from the arch specific code.  x86's implementation in particular
is quite heinous, as it unnecessarily propagates the out-param pattern
into kvm_x86_ops.

While the x86 specific issue could be resolved solely by changing
kvm_x86_ops, make the change for all architectures as returning a value
directly is prettier and technically more robust, e.g. s390 doesn't set
the out param, which could lead to subtle breakage in the (highly
unlikely) scenario where the out-param was not pre-initialized by the
caller.

Opportunistically annotate svm_check_processor_compat() with __init.
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Advance lapic timer tries to hidden the hypervisor overhead between the
host emulated timer fires and the guest awares the timer is fired. However,
it just hidden the time between apic_timer_fn/handle_preemption_timer ->
wait_lapic_expire, instead of the real position of vmentry which is
mentioned in the orignial commit d0659d94 ("KVM: x86: add option to
advance tscdeadline hrtimer expiration"). There is 700+ cpu cycles between
the end of wait_lapic_expire and before world switch on my haswell desktop.

This patch tries to narrow the last gap(wait_lapic_expire -> world switch),
it takes the real overhead time between apic_timer_fn/handle_preemption_timer
and before world switch into consideration when adaptively tuning timer
advancement. The patch can reduce 40% latency (~1600+ cycles to ~1000+ cycles
on a haswell desktop) for kvm-unit-tests/tscdeadline_latency when testing
busy waits.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Liran Alon <liran.alon@oracle.com>
Reviewed-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

wait_lapic_expire() call was moved above guest_enter_irqoff() because of
its tracepoint, which violated the RCU extended quiescent state invoked
by guest_enter_irqoff()[1][2]. This patch simply moves the tracepoint
below guest_exit_irqoff() in vcpu_enter_guest(). Snapshot the delta before
VM-Enter, but trace it after VM-Exit. This can help us to move
wait_lapic_expire() just before vmentry in the later patch.

[1] Commit 8b89fe1f ("kvm: x86: move tracepoints outside extended quiescent state")
[2] https://patchwork.kernel.org/patch/7821111/

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Liran Alon <liran.alon@oracle.com>
Suggested-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
[Track whether wait_lapic_expire was called, and do not invoke the tracepoint
 if not. - Paolo]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

As a prerequisite to fix several SPTE reserved bits related calculation
errors caused by MKTME, which requires kvm_set_mmio_spte_mask() to use
local static variable defined in mmu.c.

Also move call site of kvm_set_mmio_spte_mask() from kvm_arch_init() to
kvm_mmu_module_init() so that kvm_set_mmio_spte_mask() can be static.
Reviewed-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NKai Huang <kai.huang@linux.intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

KVM_CAP_MAX_VCPU_ID is currently always reporting KVM_MAX_VCPU_ID on all
architectures. However, on s390x, the amount of usable CPUs is determined
during runtime - it is depending on the features of the machine the code
is running on. Since we are using the vcpu_id as an index into the SCA
structures that are defined by the hardware (see e.g. the sca_add_vcpu()
function), it is not only the amount of CPUs that is limited by the hard-
ware, but also the range of IDs that we can use.
Thus KVM_CAP_MAX_VCPU_ID must be determined during runtime on s390x, too.
So the handling of KVM_CAP_MAX_VCPU_ID has to be moved from the common
code into the architecture specific code, and on s390x we have to return
the same value here as for KVM_CAP_MAX_VCPUS.
This problem has been discovered with the kvm_create_max_vcpus selftest.
With this change applied, the selftest now passes on s390x, too.
Reviewed-by: NAndrew Jones <drjones@redhat.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NThomas Huth <thuth@redhat.com>
Message-Id: <20190523164309.13345-9-thuth@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Commit 11988499 ("KVM: x86: Skip EFER vs. guest CPUID checks for
host-initiated writes", 2019-04-02) introduced a "return false" in a
function returning int, and anyway set_efer has a "nonzero on error"
conventon so it should be returning 1.
Reported-by: NPavel Machek <pavel@denx.de>
Fixes: 11988499 ("KVM: x86: Skip EFER vs. guest CPUID checks for host-initiated writes")
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>