[hypervisor][time] Add support for KVM CLOCK_PAIRING hypercall

The hypercall allows to provide the guest with mapping of tsc to
wall time at some moment in time, so in the way it's the same as
boot time provided by pvclock.

Hypercall itself is not particularly interesting, but linux calls
it when kvmclock based PTP clock is enabled in the guest, which
happens for default debian_guest kernel for example. However, since
hypervisor doesn't handle VMCALL exits it fails. In general we
should not stop hypervisor on VMCALL VM exits, instead we should
return error to the guest indicating that hypercall is not supported.

Test: buildall, manually run debian_guest on Intel NUC
MAC-158 #comment In Progress

Change-Id: I79c28df80a23df6bcda8737305e6a6b169b67d78

[hypervisor][x86] Remove sysenter MSRs from guest and host msr pages

These MSRs are stored in the guest and host state so they're not needed
here.

Also, ignore upper 32 bits of rcx for msr handling.

Change-Id: Ia70980dbed920e71dffb75badfc80fecb7f9b58d

[hypervisor][x86]Handle LVT Thermal Sensor and CMCI MSR

These MSRs appear to be accessed by Linux Kernel 4.9, and lack of support
causes kernel panic during early boot process.

Change-Id: I29907dde592463e864aff0de012c8d22ff777961

[hypervisor][ktrace] Add VCPU blocking events

Add ktrace events for when the VCPU is blocked while either waiting for
an interrupt or waiting for a port packet to become available.

This also restructures the way we record metadata for VCPU ktraces in
order to be more efficient.

PD-100 #comment

Change-Id: I43551a0068bb3d6393a9a58c21b3ea813edfb726

[hypervisor] Add ktrace to VCPU

Add tracing of VCPU enter and exit, as well as VM exit reasons.

Change-Id: Iad8c544219f8e2a5da8fd33a0868717a2634879d

[x86][hypervisor] Mask CR0.NE and handle writes to CR0

Linux writes values to CR0 that are incompatible with VMX on secondary
processor start-up. Here we mask CR0.NE, which is the only bit that we
need to keep set on secondary processors, to cause a VM exit on writes
to CR0 that don't set NE. The downside of this is that we need to
manually handle the CR0 write including entering long mode when the
guest sets CR0.PG and EFER.LME.

Change-Id: I3acc0c01b938de6f52e57f2fd4bc476c7b7ce185

[hypervisor] Expand VCPU packet to include all IPIs.

Also handle FIXED IPIs from the guest on x86 by constructing a packet.

The changes to the packet should be compatible with SGIs on ARM.

This change breaks Garnet, a patch at that layer will follow.

Change-Id: I661dbf650624df8449ebabe0fe9e34b65275712a

[lib][hypervisor] Move everything into a namespace

Move everything, but vmm_guest_page_fault_handler, into the hypervisor
namespace.

Change-Id: Ied96a7945b26c4a1ed24c03b293d42c7d89e7812

[kernel][hypervisor] KVM clock support in hypervisor

KVM/Xen paravirtualized clock API consists of monotonic clock
source (we refer to it as system time) and fixed point in time
(we refer to it as boot time), and boot time + system time should
give current wall time. Since system time is supposed to be
monotonic it means that boot time may be adjusted (for example,
by NTP) and therefore we use sys_get_clock to get boot time.

System time is exported per VCPU and periodically updated by host.
TSC is used to adjust system time value in the guest between
those updates. We update system time on VCPU resume.

Getting system time in the guest is expected to be fast, but boot
time on the other hand is not expected to be fast and only
guaranteed to be updated by host after MSR write from guest and
therefore incurs vmexit. Despite the name boot time doesn't need
to be guest boot time. In KVM it's actually host boot time and we
use the same boot time for this implementation.

And one comment regarding naming. KVM and Xen use the same
structures layout for paravirtualized clock, but KVM uses MSRs
to communicate with guests and Xen uses PV ops for that. So data
strcutures are common and use prefix pv or Pv, while constants
describing MSRs and KVM specific flags use Kvm prefix.

Change-Id: I81cdbd893985ad17bcf5f163e652ec1bb63feacb

[x86][hypervisor] Add additional vmexit logging.

Change-Id: I0fbc3a579fd9610521aeaa180be09f4b45492c6a

[hypervisor][x86] Add VCPU packet type

Capture START_UP IPIs and forward the instruction pointer and APIC ID to
userland so it can bring up another VCPU.

ZX-1246 #comment

Change-Id: I624d87eb6031492dc7125750e28de7c4a1c1662c

[hypervisor][x86] Add X2APIC support and pretend to be KVM.

Linux doesn't support X2APIC without IRQ remapping unless it recognises
that it's running as a guest. For now we can pretend to be KVM to
trigger hypervisor detection.

ZX-1257 #done

Change-Id: I66094b65f4299c5a6a51eab8ce24f419e05d23f7

[hypervisor] Refactor common interrupt logic

Introduce interrupt_tracker, so that we can share common interrupt
tracking logic between arm64 and x86.

Furthermore, this improves interrupt handling on arm64, bringing it up
to the same level as x86.

We also now inject the timer interrupt correctly on arm64.

Change-Id: I09c4d37667b9e7c14831400875bc972df64f97de

[x86][hypervisor] Cleanup ExitInfo debug output.

Minor cleanup for consistency.

Change-Id: Id92c90914201a997385826c758298cb6fcd8152c

[x86][hypervisor] Inject interrupts on VCPU resume.

If there are interrupts pending, inject them at VCPU resume instead of
waiting for an EOI. This also corrects the situation where we are
executing on the same CPU as the VCPU when we issue an interrupt.
Without this, the interrupt processing would be delayed until an EOI was
seen.

ZX-1340 #done

Change-Id: I4dabbc616a8750190a424948982b0e1b0b911b5e

[x86][hypervisor] Cleanup some tiny nits.

We should settle on using single-line comments.

Change-Id: I971eef3ec51570496a88e92aed73d7413120a8c0

[x86][hypervisor] Fix present-bit in page fault.

According to the Intel SDM, bits 3 to 5 of the EPT violation exit
qualification indicate whether the PTE marked the page as read, write,
or execute, respectively. There is no bit to indicate whether the PTE
was present.

Since we now require that all traps be set explicitly, we can
additionally early-exit if there was no trap associated with the access
and it is outside guest physical address space.

Change-Id: If2c2ec93b6972f7b03b9667518cf76878c89a1fe

[hypervisor][x86] Fix exit reason decode on vmentry failure.

Bit 31 indicates there was a VM entry failure and should not be
included in part of the basic exit reason.

This fixes the handling of vmentry errors.

Change-Id: I779e6e05454300beede7e7b9c71cd2516bdcffcf

[hypervisor][x86] Enabled "ack-interrupts-on-vmexit"

With this feature enabled if vmexit happens due to external interrupt CPU
acknowledges the interrupt and provides us with vector number. We can
examine this information and call the handler directly.

ZX-1254 #done

Change-Id: I4472fa037c731c1943b7c035e471523a2b70e46f

[x86][hypervisor] Minor cleanups to x86 code.

Change-Id: I076c1bfc3df3dfcd623d68dc6ed2a7a4a3522fe5

[lib][hypervisor] Rename PacketMux to TrapMap.

This more accurately describes what it does, and makes more sense in
the code.

Change-Id: Iae0223645dbf4b399ce29e15e10a8d3eeb8d3cf5

[zx] Magenta -> Zircon

The Great Renaming is here!

Change-Id: I3229bdeb2a3d0e40fb4db6fec8ca7d971fbffb94

[hypervisor] Replace all status_t with mx_status_t.

As requested from a previous CL. (Also ran clang-format.)

Change-Id: Ib4106f3c03f2084755c596062d34c8f72e42dcdb

[hypervisor] Make guest traps use ports.

Ports are a much better fit for the hypervisor than FIFOs. To take
advantage of ports, we use our arena for PortPackets, rather than
relying on the system-wide arena. This also allows us to easily wait
and signal in response to packet availability in our own per-trap
arenas.

Change-Id: I8664f8438710e38abf96aefedc6ba446aaf04683

[x86][hypervisor] Run clang-format over code.

Run clang-format over x86 hypervisor code.

Change-Id: I8616a2e5c4b3865bf9fdcac5627c833bc21bb39c

[hypervisor] Restructure around VCPUs.

This changes the structure of the hypervisor to be modelled around
virtual CPUs. Each VCPU is associated with a thread and a CPU, in
order to increase performance and simplify communication with user
space.

While the kernel-side of the hypervisor has been restructured, the
user space-side has not been modified to take advantage of the
optimisations that are possible. This will come in a follow up CL.

Change-Id: Ic0c9be724f12c9de601fc4b892d74ba224b0d85e