207 Commits

Author SHA1 Message Date
neel
4b40e47cf8 Add segment protection and limits violation checks in vie_calculate_gla()
for 32-bit x86 guests.

Tested using ins/outs executed in a FreeBSD/i386 guest.
2014-05-27 04:26:22 +00:00
neel
07a8a1c99a Remove restriction on insb/insw/insl emulation. These instructions are
properly emulated.
2014-05-25 02:05:23 +00:00
neel
ffc6a38259 Do the linear address calculation for the ins/outs emulation using a new
API function 'vie_calculate_gla()'.

While the current implementation is simplistic it forms the basis of doing
segmentation checks if the guest is in 32-bit protected mode.
2014-05-25 00:57:24 +00:00
neel
51a05acc08 Add libvmmapi functions vm_copyin() and vm_copyout() to copy into and out
of the guest linear address space. These APIs in turn use a new ioctl
'VM_GLA2GPA' to convert the guest linear address to guest physical.

Use the new copyin/copyout APIs when emulating ins/outs instruction in
bhyve(8).
2014-05-24 23:12:30 +00:00
neel
6a6e13c407 Consolidate all the information needed by the guest page table walker into
'struct vm_guest_paging'.

Check for canonical addressing in vmm_gla2gpa() and inject a protection
fault into the guest if a violation is detected.

If the page table walk is restarted in vmm_gla2gpa() then reset 'ptpphys' to
point to the root of the page tables.
2014-05-24 20:26:57 +00:00
neel
52a4f11861 When injecting a page fault into the guest also update the guest's %cr2 to
indicate the faulting linear address.

If the guest PML4 entry has the PG_PS bit set then inject a page fault into
the guest with the PGEX_RSV bit set in the error_code.

Get rid of redundant checks for the PG_RW violations when walking the page
tables.
2014-05-24 19:13:25 +00:00
neel
2ccda87aca Check for alignment check violation when processing in/out string instructions. 2014-05-23 19:59:14 +00:00
neel
8f99933d82 Add emulation of the "outsb" instruction. NetBSD guests use this to write to
the UART FIFO.

The emulation is constrained in a number of ways: 64-bit only, doesn't check
for all exception conditions, limited to i/o ports emulated in userspace.

Some of these constraints will be relaxed in followup commits.

Requested by:	grehan
Reviewed by:	tychon (partially and a much earlier version)
2014-05-23 05:15:17 +00:00
neel
062bfb5ea3 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
neel
f33a3d02f0 Allow vmx_getdesc() and vmx_setdesc() to be called for a vcpu that is in the
VCPU_RUNNING state. This will let the VMX exit handler inspect the vcpu's
segment descriptors without having to exit the critical section.
2014-05-22 17:22:37 +00:00
neel
645d479a58 Inject page fault into the guest if the page table walker detects an invalid
translation for the guest linear address.
2014-05-22 03:14:54 +00:00
neel
6071e2741b Add PG_RW check when translating a guest linear to guest physical address.
Set the accessed and dirty bits in the page table entry. If it fails then
restart the page table walk from the beginning. This might happen if another
vcpu modifies the page tables simultaneously.

Reviewed by:	alc, kib
2014-05-20 20:30:28 +00:00
neel
b0752c3683 Add PG_U (user/supervisor) checks when translating a guest linear address
to a guest physical address.

PG_PS (page size) field is valid only in a PDE or a PDPTE so it is now
checked only in non-terminal paging entries.

Ignore the upper 32-bits of the CR3 for PAE paging.
2014-05-19 03:50:07 +00:00
grehan
9fa48763c0 Make the vmx asm code dtrace-fbt-friendly by
- inserting frame enter/leave sequences
 - restructuring the vmx_enter_guest routine so that it subsumes
   the vm_exit_guest block, which was the #vmexit RIP and not a
   callable routine.

Reviewed by:	neel
MFC after:	3 weeks
2014-05-18 03:50:17 +00:00
jhb
f558af85b7 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
5fd692c3b5 Virtual machine halt detection is turned on by default. Allow it to be
disabled via the tunable 'hw.vmm.halt_detection'.
2014-05-05 16:19:24 +00:00
neel
b735ae5b9a Add logic in the HLT exit handler to detect if the guest has put all vcpus
to sleep permanently by executing a HLT with interrupts disabled.

When this condition is detected the guest with be suspended with a reason of
VM_SUSPEND_HALT and the bhyve(8) process will exit.

Tested by executing "halt" inside a RHEL7-beta guest.

Discussed with:	grehan@
Reviewed by:	jhb@, tychon@
2014-05-02 00:33:56 +00:00
neel
0601994645 Ignore writes to microcode update MSR. This MSR is accessed by RHEL7 guest.
Add KTR tracepoints to annotate wrmsr and rdmsr VM exits.
2014-04-30 02:08:27 +00:00
neel
9c85092013 Some Linux guests will implement a 'halt' by disabling the APIC and executing
the 'HLT' instruction. This condition was detected by 'vm_handle_hlt()' and
converted into the SPINDOWN_CPU exitcode . The bhyve(8) process would exit
the vcpu thread in response to a SPINDOWN_CPU and when the last vcpu was
spun down it would reset the virtual machine via vm_suspend(VM_SUSPEND_RESET).

This functionality was broken in r263780 in a way that made it impossible
to kill the bhyve(8) process because it would loop forever in
vm_handle_suspend().

Unbreak this by removing the code to spindown vcpus. Thus a 'halt' from
a Linux guest will appear to be hung but this is consistent with the
behavior on bare metal. The guest can be rebooted by using the bhyvectl
options '--force-reset' or '--force-poweroff'.

Reviewed by:	grehan@
2014-04-29 18:42:56 +00:00
neel
b616a9a2e4 Allow a virtual machine to be forcibly reset or powered off. This is done
by adding an argument to the VM_SUSPEND ioctl that specifies how the virtual
machine should be suspended, viz. VM_SUSPEND_RESET or VM_SUSPEND_POWEROFF.

The disposition of VM_SUSPEND is also made available to the exit handler
via the 'u.suspended' member of 'struct vm_exit'.

This capability is exposed via the '--force-reset' and '--force-poweroff'
arguments to /usr/sbin/bhyvectl.

Discussed with:	grehan@
2014-04-28 22:06:40 +00:00
neel
ebf51bf73a A VMCS is always inactive when it exits the vmx_run() loop.
Remove redundant code and the misleading comment that suggest otherwise.

Reviewed by:	grehan@
2014-04-26 22:37:56 +00:00
grehan
4f6dd265e1 Allow the guest to read the TSC via MSR 0x10.
NetBSD/amd64 does this, as does Linux on AMD CPUs.

Reviewed by:	neel
MFC after:	3 weeks
2014-04-24 00:27:34 +00:00
neel
360d54aa50 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
tychon
f44a06b5a1 Factor out common ioport handler code for better hygiene -- pointed
out by neel@.

Approved by:	neel (co-mentor)
2014-04-22 16:13:56 +00:00
tychon
d8c307b493 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
tychon
2c52df9a16 Respect the destination operand size of the 'Input from Port' instruction.
Approved by:	grehan (co-mentor)
2014-04-18 15:22:56 +00:00
tychon
4d0de44f39 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
jhb
03a8cfa7d9 Don't spindown the BSP if it executes hlt with the APIC disabled. A
guest that doesn't use the APIC at all can trigger this, plus the BSP
always needs to execute as it should trigger a reset, etc.

Reviewed by:	tychon
2014-04-15 20:53:53 +00:00
tychon
bbe78c2d72 Local APIC access via 32-bit naturally-aligned loads is merely
suggested in the SDM.  Since some OSes have implemented otherwise
don't be too rigorous in enforcing it.

Approved by:	grehan (co-mentor)
2014-04-15 17:06:26 +00:00
tychon
04f26f5235 Add support for emulating the byte move and sign extend instructions:
"movsx r/m8, r32" and "movsx r/m8, r64".

Approved by:	grehan (co-mentor)
2014-04-15 15:11:10 +00:00
tychon
5906c6773b Add support for emulating the slave PIC.
Reviewed by:	grehan, jhb
Approved by:	grehan (co-mentor)
2014-04-14 19:00:20 +00:00
neel
335d93f16d There is no need to save and restore the host's return address in the
'struct vmxctx'. It is preserved on the host stack across a guest entry
and exit and just restoring the host's '%rsp' is sufficient.

Pointed out by:	grehan@
2014-04-11 20:15:53 +00:00
tychon
45ec65c336 Account for the "plus 1" encoding of the CPUID Function 4 reported
core per package and cache sharing values.

Approved by:	grehan (co-mentor)
2014-04-11 18:19:21 +00:00
grehan
2ac5c08506 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
imp
e8da9ba992 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
rstone
35a855d80f 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
rstone
120bf54d08 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
rstone
4df7085933 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
neel
3e49998fdf Add an ioctl to suspend a virtual machine (VM_SUSPEND). The ioctl can be called
from any context i.e., it is not required to be called from a vcpu thread. The
ioctl simply sets a state variable 'vm->suspend' to '1' and returns.

The vcpus inspect 'vm->suspend' in the run loop and if it is set to '1' the
vcpu breaks out of the loop with a reason of 'VM_EXITCODE_SUSPENDED'. The
suspend handler waits until all 'vm->active_cpus' have transitioned to
'vm->suspended_cpus' before returning to userspace.

Discussed with:	grehan
2014-03-26 23:34:27 +00:00
tychon
58699bc5fc 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
neel
3818d66305 When a vcpu is deactivated it must also unblock any rendezvous that may be
blocked on it.

This is done by issuing a wakeup after clearing the 'vcpuid' from 'active_cpus'.
Also, use CPU_CLR_ATOMIC() to guarantee visibility of the updated 'active_cpus'
across all host cpus.
2014-03-18 02:49:28 +00:00
neel
9e498dc116 Notify vcpus participating in the rendezvous of the pending event to ensure
that they execute the rendezvous function as soon as possible.
2014-03-17 23:30:38 +00:00
tychon
5460439295 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
tychon
9affb68b8d 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
tychon
25c8b61cfd 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
4e6374765e Fix a race between VMRUN() and vcpu_notify_event() due to 'vcpu->hostcpu'
being updated outside of the vcpu_lock(). The race is benign and could
potentially result in a missed notification about a pending interrupt to
a vcpu. The interrupt would not be lost but rather delayed until the next
VM exit.

The vcpu's hostcpu is now updated concurrently with the vcpu state change.
When the vcpu transitions to the RUNNING state the hostcpu is set to 'curcpu'.
It is set to 'NOCPU' in all other cases.

Reviewed by:	grehan
2014-03-01 03:17:58 +00:00
jhb
4905c0f870 Correct VMware capitalization.
Submitted by:	joeld
2014-02-28 21:33:40 +00:00
jhb
4ce54b93eb Workaround an apparent bug in VMWare Fusion's nested VT support where it
triggers a VM exit with the exit reason of an external interrupt but
without a valid interrupt set in the exit interrupt information.

Tested by:	Michael Dexter
Reviewed by:	neel
MFC after:	1 week
2014-02-28 19:07:55 +00:00
neel
e01c440dae Queue pending exceptions in the 'struct vcpu' instead of directly updating the
processor-specific VMCS or VMCB. The pending exception will be delivered right
before entering the guest.

The order of event injection into the guest is:
- hardware exception
- NMI
- maskable interrupt

In the Intel VT-x case, a pending NMI or interrupt will enable the interrupt
window-exiting and inject it as soon as possible after the hardware exception
is injected. Also since interrupts are inherently asynchronous, injecting
them after the hardware exception should not affect correctness from the
guest perspective.

Rename the unused ioctl VM_INJECT_EVENT to VM_INJECT_EXCEPTION and restrict
it to only deliver x86 hardware exceptions. This new ioctl is now used to
inject a protection fault when the guest accesses an unimplemented MSR.

Discussed with:	grehan, jhb
Reviewed by:	jhb
2014-02-26 00:52:05 +00:00
neel
3e0732cf3e 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