Commit Graph

95 Commits

Author SHA1 Message Date
Neel Natu
f213ae0be6 Fix the RTC device model to operate correctly in 12-hour mode. The following
table documents the values in the RTC 'hour' field in the two modes:

Hour-of-the-day		12-hour mode	24-hour mode
12	AM		12		0
[1-11]	AM		[1-11]		[1-11]
12	PM		0x80 | 12	12
[1-11]	PM		0x80 | [1-11]	[13-23]

Reported by:	Julian Hsiao (madoka@nyanisore.net)
MFC after:	1 week
2015-03-28 02:55:16 +00:00
Neel Natu
18a2b08e65 Use lapic_ipi_alloc() to dynamically allocate IPI slots needed by bhyve when
vmm.ko is loaded.

Also relocate the 'justreturn' IPI handler to be alongside all other handlers.

Requested by:	kib
2015-03-14 02:32:08 +00:00
Tycho Nightingale
76b3c718be When ICW1 is issued the edge sense circuit is reset which means that
following an initialization a low-to-high transistion is necesary to
generate an interrupt.

Reviewed by:	neel
2015-03-06 02:05:45 +00:00
Ryan Stone
a15f820a27 Allow passthrough devices to be hinted.
Allow the ppt driver to attach to devices that were hinted to be
passthrough devices by the PCI code creating them with a driver
name of "ppt".

Add a tunable that allows the IOMMU to be forced to be used.  With
SR-IOV passthrough devices the VFs may be created after vmm.ko is
loaded.  The current code will not initialize the IOMMU in that
case, meaning that the passthrough devices can't actually be used.

Differential Revision:	https://reviews.freebsd.org/D73
Reviewed by:		neel
MFC after: 		1 month
Sponsored by:		Sandvine Inc.
2015-03-01 00:39:48 +00:00
Neel Natu
0dafa5cd4b Replace bhyve's minimal RTC emulation with a fully featured one in vmm.ko.
The new RTC emulation supports all interrupt modes: periodic, update ended
and alarm. It is also capable of maintaining the date/time and NVRAM contents
across virtual machine reset. Also, the date/time fields can now be modified
by the guest.

Since bhyve now emulates both the PIT and the RTC there is no need for
"Legacy Replacement Routing" in the HPET so get rid of it.

The RTC device state can be inspected via bhyvectl as follows:
bhyvectl --vm=vm --get-rtc-time
bhyvectl --vm=vm --set-rtc-time=<unix_time_secs>
bhyvectl --vm=vm --rtc-nvram-offset=<offset> --get-rtc-nvram
bhyvectl --vm=vm --rtc-nvram-offset=<offset> --set-rtc-nvram=<value>

Reviewed by:	tychon
Discussed with:	grehan
Differential Revision:	https://reviews.freebsd.org/D1385
MFC after:	2 weeks
2014-12-30 22:19:34 +00:00
Neel Natu
1a5934ef8e Implement "special mask mode" in vatpic.
OpenBSD guests always enable "special mask mode" during boot. As a result of
r275952 this is flagged as an error and the guest cannot boot.

Reviewed by:	grehan
Differential Revision:	https://reviews.freebsd.org/D1384
MFC after:	1 week
2014-12-28 00:53:52 +00:00
Neel Natu
ac721e53ec Various 8259 device model improvements:
- implement 8259 "polled" mode.
- set 'atpic->sfn' if bit 4 in ICW4 is set during master initialization.
- report error if guest tries to enable the "special mask" mode.

Differential Revision:	https://reviews.freebsd.org/D1328
Reviewed by:		tychon
Reported by:		grehan
Tested by:		grehan
MFC after:		1 week
2014-12-20 04:57:45 +00:00
Neel Natu
e64c5af3f8 Fix 8259 IRQ priority resolver.
Initialize the 8259 such that IRQ7 is the lowest priority.

Reviewed by:		tychon
Differential Revision:	https://reviews.freebsd.org/D1322
MFC after:		1 week
2014-12-17 03:04:43 +00:00
Neel Natu
09eced2549 For level triggered interrupts clear the PIC IRR bit when the interrupt pin
is deasserted. Prior to this change each assertion on a level triggered irq
pin resulted in two interrupts being delivered to the CPU.

Differential Revision:	https://reviews.freebsd.org/D1310
Reviewed by:	tychon
MFC after:	1 week
2014-12-16 06:33:57 +00:00
Neel Natu
f0c8263e55 Change the type of the first argument to the I/O emulation handlers to
'struct vm *'. Previously it used to be a 'void *' but there is no reason
to hide the actual type from the handler.

Discussed with:	tychon
MFC after:	1 week
2014-10-26 19:03:06 +00:00
Neel Natu
160ef77abf Move the ACPI PM timer emulation into vmm.ko.
This reduces variability during timer calibration by keeping the emulation
"close" to the guest. Additionally having all timer emulations in the kernel
will ease the transition to a per-VM clock source (as opposed to using the
host's uptime keep track of time).

Discussed with:	grehan
2014-10-26 04:44:28 +00:00
Neel Natu
107af8f2ed IFC @r272481 2014-10-05 01:28:21 +00:00
Neel Natu
970388bf8d IFC @r272185 2014-09-27 22:15:50 +00:00
Peter Grehan
a48c333805 Allow the PIC's IMR register to be read before ICW initialisation.
As of git submit e179f6914152eca9, the Linux kernel does a simple
probe of the PIC by writing a pattern to the IMR and then reading it
back, prior to the init sequence of ICW words.

The bhyve PIC emulation wasn't allowing the IMR to be read until
the ICW sequence was complete. This limitation isn't required so
relax the test.

With this change, Linux kernels 3.15-rc2 and later won't hang
on boot when calibrating the local APIC.

Reviewed by:	tychon
MFC after:	3 days
2014-09-27 01:15:24 +00:00
Neel Natu
9d8d8e3ee7 Add some more KTR events to help debugging. 2014-09-20 05:13:03 +00:00
Neel Natu
4e27d36d38 IFC @r271694 2014-09-17 18:46:51 +00:00
Neel Natu
79ad53fba3 Use V_IRQ, V_INTR_VECTOR and V_TPR to offload APIC interrupt delivery to the
processor. Briefly, the hypervisor sets V_INTR_VECTOR to the APIC vector
and sets V_IRQ to 1 to indicate a pending interrupt. The hardware then takes
care of injecting this vector when the guest is able to receive it.

Legacy PIC interrupts are still delivered via the event injection mechanism.
This is because the vector injected by the PIC must reflect the state of its
pins at the time the CPU is ready to accept the interrupt.

Accesses to the TPR via %CR8 are handled entirely in hardware. This requires
that the emulated TPR must be synced to V_TPR after a #VMEXIT.

The guest can also modify the TPR via the memory mapped APIC. This requires
that the V_TPR must be synced with the emulated TPR before a VMRUN.

Reviewed by:	Anish Gupta (akgupt3@gmail.com)
2014-09-16 03:31:40 +00:00
Neel Natu
7a244722d1 Return the spurious interrupt vector (IRQ7 or IRQ15) if the atpic cannot
find any unmasked pin with an interrupt asserted.

Reviewed by:	tychon
CR:		https://reviews.freebsd.org/D669
MFC after:	1 week
2014-08-23 21:16:26 +00:00
Neel Natu
4eec602102 Reword comment to match the interrupt mode names from the MPtable spec.
Reviewed by:	tychon
2014-08-14 18:03:38 +00:00
Neel Natu
051f2bd19d Add reserved bit checking when doing %CR8 emulation and inject #GP if required.
Pointed out by:	grehan
Reviewed by:	tychon
2014-06-09 20:51:08 +00:00
Tycho Nightingale
594db0024e Support guest accesses to %cr8.
Reviewed by:	neel
2014-06-06 18:23:49 +00:00
Neel Natu
95ebc360ef Activate vcpus from bhyve(8) using the ioctl VM_ACTIVATE_CPU instead of doing
it implicitly in vmm.ko.

Add ioctl VM_GET_CPUS to get the current set of 'active' and 'suspended' cpus
and display them via /usr/sbin/bhyvectl using the "--get-active-cpus" and
"--get-suspended-cpus" options.

This is in preparation for being able to reset virtual machine state without
having to destroy and recreate it.
2014-05-31 23:37:34 +00:00
Neel Natu
c5e423dd2e A Centos 6.4 guest will write 0xff to the 8259 mask register before beginning
the proper ICWx initialization sequence. It assumes, probably correctly, that
the boot firmware has done the 8259 initialization.

Since grub-bhyve does not initialize the 8259 this write to the mask register
takes a code path in which 'error' remains uninitialized (ready=0,icw_num=0).

Fix this by initializing 'error' at the start of the function.
2014-05-23 05:04:50 +00:00
John Baldwin
b3e9732a76 Implement a PCI interrupt router to route PCI legacy INTx interrupts to
the legacy 8259A PICs.
- Implement an ICH-comptabile PCI interrupt router on the lpc device with
  8 steerable pins configured via config space access to byte-wide
  registers at 0x60-63 and 0x68-6b.
- For each configured PCI INTx interrupt, route it to both an I/O APIC
  pin and a PCI interrupt router pin.  When a PCI INTx interrupt is
  asserted, ensure that both pins are asserted.
- Provide an initial routing of PCI interrupt router (PIRQ) pins to
  8259A pins (ISA IRQs) and initialize the interrupt line config register
  for the corresponding PCI function with the ISA IRQ as this matches
  existing hardware.
- Add a global _PIC method for OSPM to select the desired interrupt routing
  configuration.
- Update the _PRT methods for PCI bridges to provide both APIC and legacy
  PRT tables and return the appropriate table based on the configured
  routing configuration.  Note that if the lpc device is not configured, no
  routing information is provided.
- When the lpc device is enabled, provide ACPI PCI link devices corresponding
  to each PIRQ pin.
- Add a VMM ioctl to adjust the trigger mode (edge vs level) for 8259A
  pins via the ELCR.
- Mark the power management SCI as level triggered.
- Don't hardcode the number of elements in Packages in the source for
  the DSDT.  iasl(8) will fill in the actual number of elements, and
  this makes it simpler to generate a Package with a variable number of
  elements.

Reviewed by:	tycho
2014-05-15 14:16:55 +00:00
Neel Natu
c5d216b786 Change the vlapic timer frequency to be in the ballpark of contemporary
hardware. This also decouples the vlapic emulation from the host's TSC
frequency.

Requested by:	grehan@
2014-04-23 16:50:40 +00:00
Tycho Nightingale
c46ff7fa0b Add support for the PIT 'readback' command -- based on a patch by grehan@.
Approved by:	grehan (co-mentor)
2014-04-18 16:05:12 +00:00
Tycho Nightingale
d6aa08c3ef Respect the destination operand size of the 'Input from Port' instruction.
Approved by:	grehan (co-mentor)
2014-04-18 15:22:56 +00:00
Tycho Nightingale
79d6ca331e Add support for reading the PIT Counter 2 output signal via the NMI
Status and Control register at port 0x61.

Be more conservative about "catching up" callouts that were supposed
to fire in the past by skipping an interrupt if it was
scheduled too far in the past.

Restore the PIT ACPI DSDT entries and add an entry for NMISC too.

Approved by:	neel (co-mentor)
2014-04-18 00:02:06 +00:00
Tycho Nightingale
b96be57a2d Add support for emulating the slave PIC.
Reviewed by:	grehan, jhb
Approved by:	grehan (co-mentor)
2014-04-14 19:00:20 +00:00
Peter Grehan
201b1ccc22 Rework r264179.
- remove redundant code
- remove erroneous setting of the error return
  in vmmdev_ioctl()
- use style(9) initialization
- in vmx_inject_pir(), document the race condition
  that the final conditional statement was detecting,

Tested with both gcc and clang builds.

Reviewed by:	neel
2014-04-10 19:15:58 +00:00
Warner Losh
0e30c5c0b4 Make the vmm code compile with gcc too. Not entirely sure things are
correct for the pirbase test (since I'd have thought we'd need to do
something even when the offset is 0 and that test looks like a
misguided attempt to not use an uninitialized variable), but it is at
least the same as today.
2014-04-05 22:43:23 +00:00
Ryan Stone
a86672509c Re-write bhyve's I/O MMU handling in terms of PCI RID.
Reviewed by:	neel
MFC after:	2 months
Sponsored by:	Sandvine Inc.
2014-04-01 15:54:03 +00:00
Ryan Stone
7036ae46bf Revert PCI RID changes.
My PCI RID changes somehow got intermixed with my PCI ARI patch when I
committed it.  I may have accidentally applied a patch to a non-clean
working tree.  Revert everything while I figure out what went wrong.

Pointy hat to: rstone
2014-04-01 15:06:03 +00:00
Ryan Stone
956ed3830c Re-write bhyve's I/O MMU handling in terms of PCI RIDs
Reviewed by:	neel
Sponsored by:	Sandvine Inc
2014-04-01 14:54:43 +00:00
Tycho Nightingale
e883c9bb40 Move the atpit device model from userspace into vmm.ko for better
precision and lower latency.

Approved by:	grehan (co-mentor)
2014-03-25 19:20:34 +00:00
Tycho Nightingale
0775fbb475 Fix a race wherein the source of an interrupt vector is wrongly
attributed if an ExtINT arrives during interrupt injection.

Also, fix a spurious interrupt if the PIC tries to raise an interrupt
before the outstanding one is accepted.

Finally, improve the PIC interrupt latency when another interrupt is
raised immediately after the outstanding one is accepted by creating a
vmexit rather than waiting for one to occur by happenstance.

Approved by:	neel (co-mentor)
2014-03-15 23:09:34 +00:00
Tycho Nightingale
1ed19b835a Don't try to return a vector to a caller that only cares if a vector
is pending or not.

Approved by:	neel (co-mentor)
2014-03-11 22:12:12 +00:00
Tycho Nightingale
762fd20804 Replace the userspace atpic stub with a more functional vmm.ko model.
New ioctls VM_ISA_ASSERT_IRQ, VM_ISA_DEASSERT_IRQ and VM_ISA_PULSE_IRQ
can be used to manipulate the pic, and optionally the ioapic, pin state.

Reviewed by:	jhb, neel
Approved by:	neel (co-mentor)
2014-03-11 16:56:00 +00:00
Neel Natu
159dd56f94 Add support for x2APIC virtualization assist in Intel VT-x.
The vlapic.ops handler 'enable_x2apic_mode' is called when the vlapic mode
is switched to x2APIC. The VT-x implementation of this handler turns off the
APIC-access virtualization and enables the x2APIC virtualization in the VMCS.

The x2APIC virtualization is done by allowing guest read access to a subset
of MSRs in the x2APIC range. In non-root operation the processor will satisfy
an 'rdmsr' access to these MSRs by reading from the virtual APIC page instead.

The guest is also given write access to TPR, EOI and SELF_IPI MSRs which
get special treatment in non-root operation. This is documented in the
Intel SDM section titled "Virtualizing MSR-Based APIC Accesses".

Enforce that APIC-write and APIC-access VM-exits are handled only if
APIC-access virtualization is enabled. The one exception to this is
SELF_IPI virtualization which may result in an APIC-write VM-exit.
2014-02-21 06:03:54 +00:00
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
294d0d88fc Handle writes to the SELF_IPI MSR by the guest when the vlapic is configured
in x2apic mode. Reads to this MSR are currently ignored but should cause a
general proctection exception to be injected into the vcpu.

All accesses to the corresponding offset in xAPIC mode are ignored.

Also, do not panic the host if there is mismatch between the trigger mode
programmed in the TMR and the actual interrupt being delivered. Instead the
anomaly is logged to aid debugging and to prevent a misbehaving guest from
panicking the host.
2014-02-17 23:07:16 +00:00
Neel Natu
9c43cd07ec Use spinlocks to lock accesses to the vioapic.
This is necessary because if the vlapic is configured in x2apic mode the
vioapic_process_eoi() function is called inside the critical section
established by vm_run().
2014-02-17 22:57:51 +00:00
Neel Natu
30b94db8c0 Support level triggered interrupts with VT-x virtual interrupt delivery.
The VMCS field EOI_bitmap[] is an array of 256 bits - one for each vector.
If a bit is set to '1' in the EOI_bitmap[] then the processor will trigger
an EOI-induced VM-exit when it is doing EOI virtualization.

The EOI-induced VM-exit results in the EOI being forwarded to the vioapic
so that level triggered interrupts can be properly handled.

Tested by:	Anish Gupta (akgupt3@gmail.com)
2014-01-25 20:58:05 +00:00
Neel Natu
51f45d0146 There is no need to initialize the IOMMU if no passthru devices have been
configured for bhyve to use.

Suggested by:	grehan@
2014-01-21 03:01:34 +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
88c4b8d145 Use the 'Virtual Interrupt Delivery' feature of Intel VT-x if supported by
hardware. It is possible to turn this feature off and fall back to software
emulation of the APIC by setting the tunable hw.vmm.vmx.use_apic_vid to 0.

We now start handling two new types of VM-exits:

APIC-access: This is a fault-like VM-exit and is triggered when the APIC
register access is not accelerated (e.g. apic timer CCR). In response to
this we do emulate the instruction that triggered the APIC-access exit.

APIC-write: This is a trap-like VM-exit which does not require any instruction
emulation but it does require the hypervisor to emulate the access to the
specified register (e.g. icrlo register).

Introduce 'vlapic_ops' which are function pointers to vector the various
vlapic operations into processor-dependent code. The 'Virtual Interrupt
Delivery' feature installs 'ops' for setting the IRR bits in the virtual
APIC page and to return whether any interrupts are pending for this vcpu.

Tested on an "Intel Xeon E5-2620 v2" courtesy of Allan Jude at ScaleEngine.
2014-01-07 21:04:49 +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
0a9ae358fd Fix a bug in the HPET emulation where a timer interrupt could be lost when the
guest disables the HPET.

The HPET timer interrupt is triggered from the callout handler associated with
the timer. It is possible for the callout handler to be delayed before it gets
a chance to execute. If the guest disables the HPET during this window then the
handler never gets a chance to execute and the timer interrupt is lost.

This is now fixed by injecting a timer interrupt into the guest if the callout
time is detected to be in the past when the HPET is disabled.
2014-01-03 19:25:52 +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