New struct kvm_rmap_head makes the code type-safe to some extent.
Signed-off-by: NTakuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Commit 7a1638ce ("nEPT: Redefine EPT-specific link_shadow_page()",
2013-08-05) says:

    Since nEPT doesn't support A/D bit, we should not set those bit
    when building the shadow page table.

but this is not necessary.  Even though nEPT doesn't support A/D
bits, and hence the vmcs12 EPT pointer will never enable them,
we always use them for shadow page tables if available (see
construct_eptp in vmx.c).  So we can set the A/D bits freely
in the shadow page table.

This patch hence basically reverts commit 7a1638ce.

Cc: Yang Zhang <yang.z.zhang@Intel.com>
Cc: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Poor #AC was so unimportant until a few days ago that we were
not even tracing its name correctly.  But now it's all over
the place.

Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

RDTSCP was never supported for AMD CPUs, which nobody noticed because
Linux does not use it.  But exactly the fact that Linux does not
use it makes the implementation very simple; we can freely trash
MSR_TSC_AUX while running the guest.

Cc: Joerg Roedel <joro@8bytes.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

If we do not do this, it is not properly saved and restored across
migration.  Windows notices due to its self-protection mechanisms,
and is very upset about it (blue screen of death).

Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

A new vcpu exit is introduced to notify the userspace of the
changes in Hyper-V SynIC configuration triggered by guest writing to the
corresponding MSRs.

Changes v4:
* exit into userspace only if guest writes into SynIC MSR's

Changes v3:
* added KVM_EXIT_HYPERV types and structs notes into docs
Signed-off-by: NAndrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: NRoman Kagan <rkagan@virtuozzo.com>
Signed-off-by: NDenis V. Lunev <den@openvz.org>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

SynIC (synthetic interrupt controller) is a lapic extension,
which is controlled via MSRs and maintains for each vCPU
 - 16 synthetic interrupt "lines" (SINT's); each can be configured to
   trigger a specific interrupt vector optionally with auto-EOI
   semantics
 - a message page in the guest memory with 16 256-byte per-SINT message
   slots
 - an event flag page in the guest memory with 16 2048-bit per-SINT
   event flag areas

The host triggers a SINT whenever it delivers a new message to the
corresponding slot or flips an event flag bit in the corresponding area.
The guest informs the host that it can try delivering a message by
explicitly asserting EOI in lapic or writing to End-Of-Message (EOM)
MSR.

The userspace (qemu) triggers interrupts and receives EOM notifications
via irqfd with resampler; for that, a GSI is allocated for each
configured SINT, and irq_routing api is extended to support GSI-SINT
mapping.

Changes v4:
* added activation of SynIC by vcpu KVM_ENABLE_CAP
* added per SynIC active flag
* added deactivation of APICv upon SynIC activation

Changes v3:
* added KVM_CAP_HYPERV_SYNIC and KVM_IRQ_ROUTING_HV_SINT notes into
docs

Changes v2:
* do not use posted interrupts for Hyper-V SynIC AutoEOI vectors
* add Hyper-V SynIC vectors into EOI exit bitmap
* Hyper-V SyniIC SINT msr write logic simplified
Signed-off-by: NAndrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: NRoman Kagan <rkagan@virtuozzo.com>
Signed-off-by: NDenis V. Lunev <den@openvz.org>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The decision on whether to use hardware APIC virtualization used to be
taken globally, based on the availability of the feature in the CPU
and the value of a module parameter.

However, under certain circumstances we want to control it on per-vcpu
basis.  In particular, when the userspace activates HyperV synthetic
interrupt controller (SynIC), APICv has to be disabled as it's
incompatible with SynIC auto-EOI behavior.

To achieve that, introduce 'apicv_active' flag on struct
kvm_vcpu_arch, and kvm_vcpu_deactivate_apicv() function to turn APICv
off.  The flag is initialized based on the module parameter and CPU
capability, and consulted whenever an APICv-specific action is
performed.
Signed-off-by: NAndrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: NRoman Kagan <rkagan@virtuozzo.com>
Signed-off-by: NDenis V. Lunev <den@openvz.org>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The function to determine if the vector is handled by ioapic used to
rely on the fact that only ioapic-handled vectors were set up to
cause vmexits when virtual apic was in use.

We're going to break this assumption when introducing Hyper-V
synthetic interrupts: they may need to cause vmexits too.

To achieve that, introduce a new bitmap dedicated specifically for
ioapic-handled vectors, and populate EOI exit bitmap from it for now.
Signed-off-by: NAndrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: NRoman Kagan <rkagan@virtuozzo.com>
Signed-off-by: NDenis V. Lunev <den@openvz.org>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Actually kvm_arch_irq_routing_update() should be
kvm_arch_post_irq_routing_update() as it's called at the end
of irq routing update.

This renaming frees kvm_arch_irq_routing_update function name.
kvm_arch_irq_routing_update() weak function which will be used
to update mappings for arch-specific irq routing entries
(in particular, the upcoming Hyper-V synthetic interrupts).
Signed-off-by: NAndrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: NRoman Kagan <rkagan@virtuozzo.com>
Signed-off-by: NDenis V. Lunev <den@openvz.org>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This patch removes the vpid check when emulating nested invvpid
instruction of type all-contexts invalidation. The existing code is
incorrect because:
 (1) According to Intel SDM Vol 3, Section "INVVPID - Invalidate
     Translations Based on VPID", invvpid instruction does not check
     vpid in the invvpid descriptor when its type is all-contexts
     invalidation.
 (2) According to the same document, invvpid of type all-contexts
     invalidation does not require there is an active VMCS, so/and
     get_vmcs12() in the existing code may result in a NULL-pointer
     dereference. In practice, it can crash both KVM itself and L1
     hypervisors that use invvpid (e.g. Xen).
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Before this patch, we incorrectly enter the guest without requesting an
interrupt window if the IRQ chip is split between user space and the
kernel.

Because lapic_in_kernel no longer implies the PIC is in the kernel, this
patch tests pic_in_kernel to determining whether an interrupt window
should be requested when entering the guest.

If the APIC is in the kernel and we request an interrupt window the
guest will return immediately. If the APIC is masked the guest will not
not make forward progress and unmask it, leading to a loop when KVM
reenters and requests again. This patch adds a check to ensure the APIC
is ready to accept an interrupt before requesting a window.
Reviewed-by: NSteve Rutherford <srutherford@google.com>
Signed-off-by: NMatt Gingell <gingell@google.com>
[Use the other newly introduced functions. - Paolo]
Fixes: 1c1a9ce9
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Set KVM_REQ_EVENT when a PIC in user space injects a local interrupt.

Currently a request is only made when neither the PIC nor the APIC is in
the kernel, which is not sufficient in the split IRQ chip case.

This addresses a problem in QEMU where interrupts are delayed until
another path invokes the event loop.
Reviewed-by: NSteve Rutherford <srutherford@google.com>
Signed-off-by: NMatt Gingell <gingell@google.com>
Fixes: 1c1a9ce9
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This patch breaks out a new function kvm_vcpu_ready_for_interrupt_injection.
This routine encapsulates the logic required to determine whether a vcpu
is ready to accept an interrupt injection, which is now required on
multiple paths.
Reviewed-by: NSteve Rutherford <srutherford@google.com>
Signed-off-by: NMatt Gingell <gingell@google.com>
Fixes: 1c1a9ce9
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This patch ensures that dm_request_for_irq_injection and
post_kvm_run_save are in sync, avoiding that an endless ping-pong
between userspace (who correctly notices that IF=0) and
the kernel (who insists that userspace handles its request
for the interrupt window).

To synchronize them, it also adds checks for kvm_arch_interrupt_allowed
and !kvm_event_needs_reinjection.  These are always needed, not
just for in-kernel LAPIC.
Signed-off-by: NMatt Gingell <gingell@google.com>
[A collage of two patches from Matt. - Paolo]
Fixes: 1c1a9ce9
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Because #DB is now intercepted unconditionally, this callback
only operates on #BP for both VMX and SVM.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This is needed to avoid the possibility that the guest triggers
an infinite stream of #DB exceptions (CVE-2015-8104).

VMX is not affected: because it does not save DR6 in the VMCS,
it already intercepts #DB unconditionally.
Reported-by: NJan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

It was found that a guest can DoS a host by triggering an infinite
stream of "alignment check" (#AC) exceptions.  This causes the
microcode to enter an infinite loop where the core never receives
another interrupt.  The host kernel panics pretty quickly due to the
effects (CVE-2015-5307).
Signed-off-by: NEric Northup <digitaleric@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This patch enhances dump_vmcs() to dump the value of TSC multiplier
field in VMCS.
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This patch makes kvm-intel to return a scaled host TSC plus the TSC
offset when handling guest readings to MSR_IA32_TSC.
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This patch makes kvm-intel module to load TSC scaling ratio into TSC
multiplier field of VMCS when a vcpu is loaded, so that TSC scaling
ratio can take effect if VMX TSC scaling is enabled.
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This patch exhances kvm-intel module to enable VMX TSC scaling and
collects information of TSC scaling ratio during initialization.
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This patch makes KVM use virtual_tsc_khz rather than the host TSC rate
as vcpu's TSC rate to compute the time scale if TSC scaling is enabled.
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Both VMX and SVM scales the host TSC in the same way in call-back
read_l1_tsc(), so this patch moves the scaling logic from call-back
read_l1_tsc() to a common function kvm_read_l1_tsc().
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

For both VMX and SVM, if the 2nd argument of call-back
adjust_tsc_offset() is the host TSC, then adjust_tsc_offset() will scale
it first. This patch moves this common TSC scaling logic to its caller
adjust_tsc_offset_host() and rename the call-back adjust_tsc_offset() to
adjust_tsc_offset_guest().
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Both VMX and SVM calculate the tsc-offset in the same way, so this
patch removes the call-back compute_tsc_offset() and replaces it with a
common function kvm_compute_tsc_offset().
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Both VMX and SVM propagate virtual_tsc_khz in the same way, so this
patch removes the call-back set_tsc_khz() and replaces it with a common
function.
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

VMX and SVM calculate the TSC scaling ratio in a similar logic, so this
patch generalizes it to a common TSC scaling function.
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
[Inline the multiplication and shift steps into mul_u64_u64_shr.  Remove
 BUG_ON.  - Paolo]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This patch moves the field of TSC scaling ratio from the architecture
struct vcpu_svm to the common struct kvm_vcpu_arch.
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The number of bits of the fractional part of the 64-bit TSC scaling
ratio in VMX and SVM is different. This patch makes the architecture
code to collect the number of fractional bits and other related
information into variables that can be accessed in the common code.
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

These include module parameters and variables that are set by
kvm_x86_ops->hardware_setup.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

They are exactly the same, except that handle_mmio_page_fault
has an unused argument and a call to WARN_ON.  Remove the unused
argument from the callers, and move the warning to (the former)
handle_mmio_page_fault_common.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

I found PML was broken since below commit:

	commit feda805f
	Author: Xiao Guangrong <guangrong.xiao@linux.intel.com>
	Date:   Wed Sep 9 14:05:55 2015 +0800

	KVM: VMX: unify SECONDARY_VM_EXEC_CONTROL update

	Unify the update in vmx_cpuid_update()
Signed-off-by: NXiao Guangrong <guangrong.xiao@linux.intel.com>
	[Rewrite to use vmcs_set_secondary_exec_control. - Paolo]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The reason is in above commit vmx_cpuid_update calls vmx_secondary_exec_control,
in which currently SECONDARY_EXEC_ENABLE_PML bit is cleared unconditionally (as
PML is enabled in creating vcpu). Therefore if vcpu_cpuid_update is called after
vcpu is created, PML will be disabled unexpectedly while log-dirty code still
thinks PML is used.

Fix this by clearing SECONDARY_EXEC_ENABLE_PML in vmx_secondary_exec_control
only when PML is not supported or not enabled (!enable_pml). This is more
reasonable as PML is currently either always enabled or disabled. With this
explicit updating SECONDARY_EXEC_ENABLE_PML in vmx_enable{disable}_pml is not
needed so also rename vmx_enable{disable}_pml to vmx_create{destroy}_pml_buffer.

Fixes: feda805fSigned-off-by: NKai Huang <kai.huang@linux.intel.com>
[While at it, change a wrong ASSERT to an "if".  The condition can happen
 if creating the VCPU fails with ENOMEM. - Paolo]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Commit b18d5431 ("KVM: x86: fix CR0.CD virtualization") was
technically correct, but it broke OVMF guests by slowing down various
parts of the firmware.

Commit fb279950 ("KVM: vmx: obey KVM_QUIRK_CD_NW_CLEARED") quirked the
first function modified by b18d5431, vmx_get_mt_mask(), for OVMF's
sake. This restored the speed of the OVMF code that runs before
PlatformPei (including the memory intensive LZMA decompression in SEC).

This patch extends the quirk to the second function modified by
b18d5431, kvm_set_cr0(). It eliminates the intrusive slowdown that
hits the EFI_MP_SERVICES_PROTOCOL implementation of edk2's
UefiCpuPkg/CpuDxe -- which is built into OVMF --, when CpuDxe starts up
all APs at once for initialization, in order to count them.

We also carry over the kvm_arch_has_noncoherent_dma() sub-condition from
the other half of the original commit b18d5431.

Fixes: b18d5431
Cc: stable@vger.kernel.org
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: NXiao Guangrong <guangrong.xiao@linux.intel.com>
Tested-by: NJanusz Mocek <januszmk6@gmail.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>#
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The SDM says that exiting system management mode from 64-bit mode
is invalid, but that would be too good to be true.  But actually,
most of the code is already there to support exiting from compat
mode (EFER.LME=1, EFER.LMA=0).  Getting all the way from 64-bit
mode to real mode only requires clearing CS.L and CR4.PCIDE.

Cc: stable@vger.kernel.org
Fixes: 660a5d51Tested-by: NLaszlo Ersek <lersek@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The comment in code had it mostly right, but we enable paging for
emulated real mode regardless of EPT.

Without EPT (which implies emulated real mode), secondary VCPUs won't
start unless we disable SM[AE]P when the guest doesn't use paging.
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The function is not used outside device assignment, and
kvm_arch_set_irq_inatomic has a different prototype.  Move it here and
make it static to avoid confusion.
Reviewed-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The symbols are always defined.
Reviewed-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

We do not want to do too much work in atomic context, in particular
not walking all the VCPUs of the virtual machine.  So we want
to distinguish the architecture-specific injection function for irqfd
from kvm_set_msi.  Since it's still empty, reuse the newly added
kvm_arch_set_irq and rename it to kvm_arch_set_irq_inatomic.
Reviewed-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

BSP doesn't get INIT so its apic_arb_prio isn't zeroed after reboot.
BSP won't get lowest priority interrupts until other VCPUs get enough
interrupts to match their pre-reboot apic_arb_prio.

That behavior doesn't fit into KVM's round-robin-like interpretation of
lowest priority delivery ... userspace should KVM_SET_LAPIC on reset, so
just zero apic_arb_prio there.
Reported-by: NYuki Shibuya <shibuya.yk@ncos.nec.co.jp>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>