Commit Graph

235 Commits

Author SHA1 Message Date
Neel Natu
12a6eb99a1 Support PCI extended config space in bhyve.
Add the ACPI MCFG table to advertise the extended config memory window.

Introduce a new flag MEM_F_IMMUTABLE for memory ranges that cannot be deleted
or moved in the guest's address space. The PCI extended config space is an
example of an immutable memory range.

Add emulation for the "movzw" instruction. This instruction is used by FreeBSD
to read a 16-bit extended config space register.

CR:		https://phabric.freebsd.org/D505
Reviewed by:	jhb, grehan
Requested by:	tychon
2014-08-08 03:49:01 +00:00
John Baldwin
06fc6db948 - Output a summary of optional VT-x features in dmesg similar to CPU
features.  If bootverbose is enabled, a detailed list is provided;
  otherwise, a single-line summary is displayed.
- Add read-only sysctls for optional VT-x capabilities used by bhyve
  under a new hw.vmm.vmx.cap node. Move a few exiting sysctls that
  indicate the presence of optional capabilities under this node.

CR:		https://phabric.freebsd.org/D498
Reviewed by:	grehan, neel
MFC after:	1 week
2014-07-30 00:00:12 +00:00
Neel Natu
f008d1571d If a vcpu has issued a HLT instruction with interrupts disabled then it sleeps
forever in vm_handle_hlt().

This is usually not an issue as long as one of the other vcpus properly resets
or powers off the virtual machine. However, if the bhyve(8) process is killed
with a signal the halted vcpu cannot be woken up because it's sleep cannot be
interrupted.

Fix this by waking up periodically and returning from vm_handle_hlt() if
TDF_ASTPENDING is set.

Reported by:	Leon Dang
Sponsored by:	Nahanni Systems
2014-07-26 02:53:51 +00:00
Neel Natu
1edccd0f30 Don't return -1 from the push emulation handler. Negative return values are
interpreted specially on return from sys_ioctl() and may cause undesirable
side-effects like restarting the system call.
2014-07-26 02:51:46 +00:00
Neel Natu
830be8acb4 Fix a couple of issues in the PUSH emulation:
It is not possible to PUSH a 32-bit operand on the stack in 64-bit mode. The
default operand size for PUSH is 64-bits and the operand size override prefix
changes that to 16-bits.

vm_copy_setup() can return '1' if it encounters a fault when walking the
guest page tables. This is a guest issue and is now handled properly by
resuming the guest to handle the fault.
2014-07-24 23:01:53 +00:00
Neel Natu
d37f2adb38 Fix fault injection in bhyve.
The faulting instruction needs to be restarted when the exception handler
is done handling the fault. bhyve now does this correctly by setting
'vmexit[vcpu].inst_length' to zero so the %rip is not advanced.

A minor complication is that the fault injection APIs are used by instruction
emulation code that is shared by vmm.ko and bhyve. Thus the argument that
refers to 'struct vm *' in kernel or 'struct vmctx *' in userspace needs to
be loosely typed as a 'void *'.
2014-07-24 01:38:11 +00:00
Neel Natu
d665d229ce Emulate instructions emitted by OpenBSD/i386 version 5.5:
- CMP REG, r/m
- MOV AX/EAX/RAX, moffset
- MOV moffset, AX/EAX/RAX
- PUSH r/m
2014-07-23 04:28:51 +00:00
Neel Natu
019008ebf5 Fix build without INVARIANTS defined by getting rid of unused variable 'exc'.
Reported by:	adrian, stefanf
2014-07-20 16:34:35 +00:00
Neel Natu
091d453222 Handle nested exceptions in bhyve.
A nested exception condition arises when a second exception is triggered while
delivering the first exception. Most nested exceptions can be handled serially
but some are converted into a double fault. If an exception is generated during
delivery of a double fault then the virtual machine shuts down as a result of
a triple fault.

vm_exit_intinfo() is used to record that a VM-exit happened while an event was
being delivered through the IDT. If an exception is triggered while handling
the VM-exit it will be treated like a nested exception.

vm_entry_intinfo() is used by processor-specific code to get the event to be
injected into the guest on the next VM-entry. This function is responsible for
deciding the disposition of nested exceptions.
2014-07-19 20:59:08 +00:00
Neel Natu
3d5444c864 Add emulation for legacy x86 task switching mechanism.
FreeBSD/i386 uses task switching to handle double fault exceptions and this
change enables that to work.

Reported by:	glebius
2014-07-16 21:26:26 +00:00
Neel Natu
f7a9f1784f Add support for operand size and address size override prefixes in bhyve's
instruction emulation [1].

Fix bug in emulation of opcode 0x8A where the destination is a legacy high
byte register and the guest vcpu is in 32-bit mode. Prior to this change
instead of modifying %ah, %bh, %ch or %dh the emulation would end up
modifying %spl, %bpl, %sil or %dil instead.

Add support for moffsets by treating it as a 2, 4 or 8 byte immediate value
during instruction decoding.

Fix bug in verify_gla() where the linear address computed after decoding
the instruction was not being truncated to the effective address size [2].

Tested by:	Leon Dang [1]
Reported by:	Peter Grehan [2]
Sponsored by:	Nahanni Systems
2014-07-15 17:37:17 +00:00
Neel Natu
3ada6e07ac Use the correct offset when converting a logical address (segment:offset)
to a linear address.
2014-07-11 01:23:38 +00:00
Neel Natu
b301b9e28f Accurately identify the vcpu's operating mode as 64-bit, compatibility,
protected or real.
2014-07-08 21:48:57 +00:00
Neel Natu
3527963b26 Invalidate guest TLB mappings as a side-effect of its CR3 being updated.
This is a pre-requisite for task switch emulation since the CR3 is loaded
from the new TSS.
2014-07-08 20:51:03 +00:00
Hans Petter Selasky
af3b2549c4 Pull in r267961 and r267973 again. Fix for issues reported will follow. 2014-06-28 03:56:17 +00:00
Glen Barber
37a107a407 Revert r267961, r267973:
These changes prevent sysctl(8) from returning proper output,
such as:

 1) no output from sysctl(8)
 2) erroneously returning ENOMEM with tools like truss(1)
    or uname(1)
 truss: can not get etype: Cannot allocate memory
2014-06-27 22:05:21 +00:00
Hans Petter Selasky
3da1cf1e88 Extend the meaning of the CTLFLAG_TUN flag to automatically check if
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.

Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.

MFC after:	2 weeks
Sponsored by:	Mellanox Technologies
2014-06-27 16:33:43 +00:00
Tycho Nightingale
896d1f7723 Add support for emulating the move instruction: "mov r/m8, imm8".
Reviewed by:	neel
2014-06-26 17:15:41 +00:00
Peter Grehan
cf1d80d88c Expose the amount of resident and wired memory from the guest's vmspace.
This is different than the amount shown for the process e.g. by
/usr/bin/top - that is the mappings faulted in by the mmap'd region
of guest memory.

The values can be fetched with bhyvectl

 # bhyvectl --get-stats --vm=myvm
 ...
 Resident memory                         	413749248
 Wired memory                            	0
 ...

vmm_stat.[ch] -
 Modify the counter code in bhyve to allow direct setting of a counter
as opposed to incrementing, and providing a callback to fetch a
counter's value.

Reviewed by:	neel
2014-06-25 22:13:35 +00:00
Tycho Nightingale
a026dc3fcb Bring an overly enthusiastic KASSERT inline with the Intel SDM.
Reviewed by:	neel
2014-06-16 22:59:18 +00:00
Neel Natu
404874659f Add helper functions to populate VM exit information for rendezvous and
astpending exits. This is to reduce code duplication between VT-x and
SVM implementations.
2014-06-10 16:45:58 +00:00
Neel Natu
0494cb1bcb Turn on interrupt window exiting unconditionally when an ExtINT is being
injected into the guest. This allows the hypervisor to inject another
ExtINT or APIC vector as soon as the guest is able to process interrupts.

This change is not to address any correctness issue but to guarantee that
any pending APIC vector that was preempted by the ExtINT will be injected
as soon as possible. Prior to this change such pending interrupts could be
delayed until the next VM exit.
2014-06-10 01:38:02 +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
Neel Natu
5fcf252f41 Add ioctl(VM_REINIT) to reinitialize the virtual machine state maintained
by vmm.ko. This allows the virtual machine to be restarted without having
to destroy it first.

Reviewed by:	grehan
2014-06-07 21:36:52 +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
Tycho Nightingale
11669a681c If VMX isn't enabled so long as the lock bit isn't set yet in MSR
IA32_FEATURE_CONTROL it still can be.

Approved by:	grehan (co-mentor)
2014-05-30 23:37:31 +00:00
John Baldwin
44a68c4e40 - Rework the XSAVE/XRSTOR emulation to only expose XCR0 features to the
guest for which the rules regarding xsetbv emulation are known.  In
  particular future extensions like AVX-512 have interdependencies among
  feature bits that could allow a guest to trigger a GP# in the host with
  the current approach of allowing anything the host supports.
- Add proper checking of Intel MPX and AVX-512 XSAVE features in the
  xsetbv emulation and allow these features to be exposed to the guest if
  they are enabled in the host.
- Expose a subset of known-safe features from leaf 0 of the structured
  extended features to guests if they are supported on the host including
  RDFSBASE/RDGSBASE, BMI1/2, AVX2, AVX-512, HLE, ERMS, and RTM.  Aside
  from AVX-512, these features are all new instructions available for use
  in ring 3 with no additional hypervisor changes needed.

Reviewed by:	neel
2014-05-27 19:04:38 +00:00
Neel Natu
65ffa035a7 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 Natu
ae0780bbf1 Remove restriction on insb/insw/insl emulation. These instructions are
properly emulated.
2014-05-25 02:05:23 +00:00
Neel Natu
5382c19d81 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 Natu
da11f4aa1d 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 Natu
e813a87350 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 Natu
37a723a5b3 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 Natu
a7424861fb Check for alignment check violation when processing in/out string instructions. 2014-05-23 19:59:14 +00:00
Neel Natu
d17b5104a9 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 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
Neel Natu
ba6f5e23cc 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 Natu
fd949af642 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 Natu
f888763dd8 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 Natu
e4c8a13d61 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
Peter Grehan
897bb47e7b 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
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
055fc2cb5e 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 Natu
e50ce2aa06 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 Natu
2cb97c9dd6 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 Natu
c6a0cc2e21 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 Natu
f0fdcfe247 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 Natu
63c9389af6 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
Peter Grehan
8d1d7a9e5a 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