Commit Graph

20 Commits

Author SHA1 Message Date
Neel Natu
52e5c8a2ec Simplify APIC mode switching from MMIO to x2APIC. In part this is done to
simplify the implementation of the x2APIC virtualization assist in VT-x.

Prior to this change the vlapic allowed the guest to change its mode from
xAPIC to x2APIC. We don't allow that any more and the vlapic mode is locked
when the virtual machine is created. This is not very constraining because
operating systems already have to deal with BIOS setting up the APIC in
x2APIC mode at boot.

Fix a bug in the CPUID emulation where the x2APIC capability was leaking
from the host to the guest.

Ignore MMIO reads and writes to the vlapic in x2APIC mode. Similarly, ignore
MSR accesses to the vlapic when it is in xAPIC mode.

The default configuration of the vlapic is xAPIC. The "-x" option to bhyve(8)
can be used to change the mode to x2APIC instead.

Discussed with:	grehan@
2014-02-20 01:48:25 +00:00
Neel Natu
5b8a8cd1fe Add an API to rendezvous all active vcpus in a virtual machine. The rendezvous
can be initiated in the context of a vcpu thread or from the bhyve(8) control
process.

The first use of this functionality is to update the vlapic trigger-mode
register when the IOAPIC pin configuration is changed.

Prior to this change we would update the TMR in the virtual-APIC page at
the time of interrupt delivery. But this doesn't work with Posted Interrupts
because there is no way to program the EOI_exit_bitmap[] in the VMCS of
the target at the time of interrupt delivery.

Discussed with:	grehan@
2014-01-14 01:55:58 +00:00
Neel Natu
add611fd4c Don't expose 'vmm_ipinum' as a global. 2014-01-09 03:25:54 +00:00
Neel Natu
4d1e82a88e Allow vlapic_set_intr_ready() to return a value that indicates whether or not
the vcpu should be kicked to process a pending interrupt. This will be useful
in the implementation of the Posted Interrupt APICv feature.

Change the return value of 'vlapic_pending_intr()' to indicate whether or not
an interrupt is available to be delivered to the vcpu depending on the value
of the PPR.

Add KTR tracepoints to debug guest IPI delivery.
2014-01-07 00:38:22 +00:00
Neel Natu
7c05bc3124 Modify handling of writes to the vlapic LVT registers.
The handler is now called after the register value is updated in the virtual
APIC page. This will make it easier to handle APIC-write VM-exits with APIC
register virtualization turned on.

This also implies that we need to keep a snapshot of the last value written
to a LVT register. We can no longer rely on the LVT registers in the APIC
page to be "clean" because the guest can write anything to it before the
hypervisor has had a chance to sanitize it.
2013-12-28 00:20:55 +00:00
Neel Natu
fafe884473 Modify handling of writes to the vlapic ICR_TIMER, DCR_TIMER, ICRLO and ESR
registers.

The handler is now called after the register value is updated in the virtual
APIC page. This will make it easier to handle APIC-write VM-exits with APIC
register virtualization turned on.

We can no longer rely on the value of 'icr_timer' on the APIC page
in the callout handler. With APIC register virtualization the value of
'icr_timer' will be updated by the processor in guest-context before an
APIC-write VM-exit.

Clear the 'delivery status' bit in the ICRLO register in the write handler.
With APIC register virtualization the write happens in guest-context and
we cannot prevent a (buggy) guest from setting this bit.
2013-12-27 20:18:19 +00:00
Neel Natu
2c52dcd9a8 Modify handling of write to the vlapic SVR register.
The handler is now called after the register value is updated in the virtual
APIC page. This will make it easier to handle APIC-write VM-exits with APIC
register virtualization turned on.

Additionally, mask all the LVT entries when the vlapic is software-disabled.
2013-12-27 07:01:42 +00:00
Neel Natu
3f0ddc7c5c Modify handling of writes to the vlapic ID, LDR and DFR registers.
The handlers are now called after the register value is updated in the virtual
APIC page. This will make it easier to handle APIC-write VM-exits with APIC
register virtualization turned on.

Additionally, we need to ensure that the value of these registers is always
correctly reflected in the virtual APIC page, because there is no VM exit
when the guest reads these registers with APIC register virtualization.
2013-12-26 19:58:30 +00:00
Neel Natu
de5ea6b65e vlapic code restructuring to make it easy to support hardware-assist for APIC
emulation.

The vlapic initialization and cleanup is done via processor specific vmm_ops.
This will allow the VT-x/SVM modules to layer any hardware-assist for APIC
emulation or virtual interrupt delivery on top of the vlapic device model.

Add a parameter to 'vcpu_notify_event()' to distinguish between vlapic
interrupts versus other events (e.g. NMI). This provides an opportunity to
use hardware-assists like Posted Interrupts (VT-x) or doorbell MSR (SVM)
to deliver an interrupt to a guest without causing a VM-exit.

Get rid of lapic_pending_intr() and lapic_intr_accepted() and use the
vlapic_xxx() counterparts directly.

Associate an 'Apic Page' with each vcpu and reference it from the 'vlapic'.
The 'Apic Page' is intended to be referenced from the Intel VMCS as the
'virtual APIC page' or from the AMD VMCB as the 'vAPIC backing page'.
2013-12-25 06:46:31 +00:00
John Baldwin
330baf58c6 Extend the support for local interrupts on the local APIC:
- Add a generic routine to trigger an LVT interrupt that supports both
  fixed and NMI delivery modes.
- Add an ioctl and bhyvectl command to trigger local interrupts inside a
  guest.  In particular, a global NMI similar to that raised by SERR# or
  PERR# can be simulated by asserting LINT1 on all vCPUs.
- Extend the LVT table in the vCPU local APIC to support CMCI.
- Flesh out the local APIC error reporting a bit to cache errors and
  report them via ESR when ESR is written to.  Add support for asserting
  the error LVT when an error occurs.  Raise illegal vector errors when
  attempting to signal an invalid vector for an interrupt or when sending
  an IPI.
- Ignore writes to reserved bits in LVT entries.
- Export table entries the MADT and MP Table advertising the stock x86
  config of LINT0 set to ExtInt and LINT1 wired to NMI.

Reviewed by:	neel (earlier version)
2013-12-23 19:29:07 +00:00
Neel Natu
4f8be175d5 Add an API to deliver message signalled interrupts to vcpus. This allows
callers treat the MSI 'addr' and 'data' fields as opaque and also lets
bhyve implement multiple destination modes: physical, flat and clustered.

Submitted by:	Tycho Nightingale (tycho.nightingale@pluribusnetworks.com)
Reviewed by:	grehan@
2013-12-16 19:59:31 +00:00
Neel Natu
becd984900 Fix x2apic support in bhyve.
When the guest is bringing up the APs in the x2APIC mode a write to the
ICR register will now trigger a return to userspace with an exitcode of
VM_EXITCODE_SPINUP_AP. This gets SMP guests working again with x2APIC.

Change the vlapic timer lock to be a spinlock because the vlapic can be
accessed from within a critical section (vm run loop) when guest is using
x2apic mode.

Reviewed by:	grehan@
2013-12-10 22:56:51 +00:00
Neel Natu
fb03ca4e42 Use callout(9) to drive the vlapic timer instead of clocking it on each VM exit.
This decouples the guest's 'hz' from the host's 'hz' setting. For e.g. it is
now possible to have a guest run at 'hz=1000' while the host is at 'hz=100'.

Discussed with:	grehan@
Tested by:	Tycho Nightingale (tycho.nightingale@pluribusnetworks.com)
2013-12-07 23:11:12 +00:00
Neel Natu
1c05219285 If a vcpu disables its local apic and then executes a 'HLT' then spin down the
vcpu and destroy its thread context. Also modify the 'HLT' processing to ignore
pending interrupts in the IRR if interrupts have been disabled by the guest.
The interrupt cannot be injected into the guest in any case so resuming it
is futile.

With this change "halt" from a Linux guest works correctly.

Reviewed by:	grehan@
Tested by:	Tycho Nightingale (tycho.nightingale@pluribusnetworks.com)
2013-12-07 22:18:36 +00:00
Neel Natu
b5b28fc9dc Add support for level triggered interrupt pins on the vioapic. Prior to this
commit level triggered interrupts would work as long as the pin was not shared
among multiple interrupt sources.

The vlapic now keeps track of level triggered interrupts in the trigger mode
register and will forward the EOI for a level triggered interrupt to the
vioapic. The vioapic in turn uses the EOI to sample the level on the pin and
re-inject the vector if the pin is still asserted.

The vhpet is the first consumer of level triggered interrupts and advertises
that it can generate interrupts on pins 20 through 23 of the vioapic.

Discussed with:	grehan@
2013-11-27 22:18:08 +00:00
Neel Natu
03cd05011f Remove the 'vdev' abstraction that was meant to sit on top of device models
in the kernel. This abstraction was redundant because the only device emulated
inside vmm.ko is the local apic and it is always at a fixed guest physical
address.

Discussed with:	grehan
2013-11-04 23:25:07 +00:00
Neel Natu
2e25737a49 Calculate the number of host ticks until the next guest timer interrupt.
This information will be used in conjunction with guest "HLT exiting" to
yield the thread hosting the virtual cpu.

Obtained from:	NetApp
2012-10-20 08:23:05 +00:00
Neel Natu
73820fb0a4 Add an option "-a" to present the local apic in the XAPIC mode instead of the
default X2APIC mode to the guest.
2012-09-26 00:06:17 +00:00
Neel Natu
2d3a73ed6d Restructure the x2apic access code in preparation for supporting memory mapped
access to the local apic.

The vlapic code is now aware of the mode that the guest is using to access the
local apic.

Reviewed by: grehan@
2012-09-21 03:09:23 +00:00
Peter Grehan
366f60834f Import of bhyve hypervisor and utilities, part 1.
vmm.ko - kernel module for VT-x, VT-d and hypervisor control
  bhyve  - user-space sequencer and i/o emulation
  vmmctl - dump of hypervisor register state
  libvmm - front-end to vmm.ko chardev interface

bhyve was designed and implemented by Neel Natu.

Thanks to the following folk from NetApp who helped to make this available:
	Joe CaraDonna
	Peter Snyder
	Jeff Heller
	Sandeep Mann
	Steve Miller
	Brian Pawlowski
2011-05-13 04:54:01 +00:00