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@
to inject edge triggered legacy interrupts into the guest.
Start using the new API in device models that use edge triggered interrupts:
viz. the 8254 timer and the LPC/uart device emulation.
Submitted by: Tycho Nightingale (tycho.nightingale@pluribusnetworks.com)
upcoming in-kernel device emulations like the HPET.
The ioctls VM_IOAPIC_ASSERT_IRQ and VM_IOAPIC_DEASSERT_IRQ are used to
manipulate the ioapic pin state.
Discussed with: grehan@
Submitted by: Tycho Nightingale (tycho.nightingale@pluribusnetworks.com)
to a virtual machine then we implicitly create COM1 and COM2 ISA devices.
Prior to this change the only way of attaching a COM port to the virtual
machine was by presenting it as a PCI device that is mapped at the legacy
I/O address 0x3F8 or 0x2F8.
There were some issues with the original approach:
- It did not work at all with UEFI because UEFI will reprogram the PCI device
BARs and remap the COM1/COM2 ports at non-legacy addresses.
- OpenBSD GENERIC kernel does not create a /dev/console because it expects
the uart device at the legacy 0x3F8/0x2F8 address to be an ISA device.
- It was functional with a FreeBSD guest but caused the console to appear
on /dev/ttyu2 which was not intuitive.
The uart emulation is now independent of the bus on which it resides. Thus it
is possible to have uart devices on the PCI bus in addition to the legacy
COM1/COM2 devices behind the LPC bus.
The command line option to attach ISA COM1/COM2 ports to a virtual machine is
"-s <bus>,lpc -l com1,stdio".
The command line option to create a PCI-attached uart device is:
"-s <bus>,uart[,stdio]"
The command line option to create PCI-attached COM1/COM2 device is:
"-S <bus>,uart[,stdio]". This style of creating COM ports is deprecated.
Discussed with: grehan
Reviewed by: grehan
Submitted by: Tycho Nightingale (tycho.nightingale@pluribusnetworks.com)
M share/examples/bhyve/vmrun.sh
AM usr.sbin/bhyve/legacy_irq.c
AM usr.sbin/bhyve/legacy_irq.h
M usr.sbin/bhyve/Makefile
AM usr.sbin/bhyve/uart_emul.c
M usr.sbin/bhyve/bhyverun.c
AM usr.sbin/bhyve/uart_emul.h
M usr.sbin/bhyve/pci_uart.c
M usr.sbin/bhyve/pci_emul.c
M usr.sbin/bhyve/inout.c
M usr.sbin/bhyve/pci_emul.h
M usr.sbin/bhyve/inout.h
AM usr.sbin/bhyve/pci_lpc.c
AM usr.sbin/bhyve/pci_lpc.h
the 2 read-only bytes at the start of a PCI capability.
This is the sequence that OpenBSD uses when enabling
MSI interrupts, and works fine on real h/w.
In bhyve, convert the 4 byte write to a 2-byte write to
the r/w area past the first 2 r/o bytes of a capability.
Reviewed by: neel
Approved by: re@ (blanket)
Make the amd64/pmap code aware of nested page table mappings used by bhyve
guests. This allows bhyve to associate each guest with its own vmspace and
deal with nested page faults in the context of that vmspace. This also
enables features like accessed/dirty bit tracking, swapping to disk and
transparent superpage promotions of guest memory.
Guest vmspace:
Each bhyve guest has a unique vmspace to represent the physical memory
allocated to the guest. Each memory segment allocated by the guest is
mapped into the guest's address space via the 'vmspace->vm_map' and is
backed by an object of type OBJT_DEFAULT.
pmap types:
The amd64/pmap now understands two types of pmaps: PT_X86 and PT_EPT.
The PT_X86 pmap type is used by the vmspace associated with the host kernel
as well as user processes executing on the host. The PT_EPT pmap is used by
the vmspace associated with a bhyve guest.
Page Table Entries:
The EPT page table entries as mostly similar in functionality to regular
page table entries although there are some differences in terms of what
bits are used to express that functionality. For e.g. the dirty bit is
represented by bit 9 in the nested PTE as opposed to bit 6 in the regular
x86 PTE. Therefore the bitmask representing the dirty bit is now computed
at runtime based on the type of the pmap. Thus PG_M that was previously a
macro now becomes a local variable that is initialized at runtime using
'pmap_modified_bit(pmap)'.
An additional wrinkle associated with EPT mappings is that older Intel
processors don't have hardware support for tracking accessed/dirty bits in
the PTE. This means that the amd64/pmap code needs to emulate these bits to
provide proper accounting to the VM subsystem. This is achieved by using
the following mapping for EPT entries that need emulation of A/D bits:
Bit Position Interpreted By
PG_V 52 software (accessed bit emulation handler)
PG_RW 53 software (dirty bit emulation handler)
PG_A 0 hardware (aka EPT_PG_RD)
PG_M 1 hardware (aka EPT_PG_WR)
The idea to use the mapping listed above for A/D bit emulation came from
Alan Cox (alc@).
The final difference with respect to x86 PTEs is that some EPT implementations
do not support superpage mappings. This is recorded in the 'pm_flags' field
of the pmap.
TLB invalidation:
The amd64/pmap code has a number of ways to do invalidation of mappings
that may be cached in the TLB: single page, multiple pages in a range or the
entire TLB. All of these funnel into a single EPT invalidation routine called
'pmap_invalidate_ept()'. This routine bumps up the EPT generation number and
sends an IPI to the host cpus that are executing the guest's vcpus. On a
subsequent entry into the guest it will detect that the EPT has changed and
invalidate the mappings from the TLB.
Guest memory access:
Since the guest memory is no longer wired we need to hold the host physical
page that backs the guest physical page before we can access it. The helper
functions 'vm_gpa_hold()/vm_gpa_release()' are available for this purpose.
PCI passthru:
Guest's with PCI passthru devices will wire the entire guest physical address
space. The MMIO BAR associated with the passthru device is backed by a
vm_object of type OBJT_SG. An IOMMU domain is created only for guest's that
have one or more PCI passthru devices attached to them.
Limitations:
There isn't a way to map a guest physical page without execute permissions.
This is because the amd64/pmap code interprets the guest physical mappings as
user mappings since they are numerically below VM_MAXUSER_ADDRESS. Since PG_U
shares the same bit position as EPT_PG_EXECUTE all guest mappings become
automatically executable.
Thanks to Alan Cox and Konstantin Belousov for their rigorous code reviews
as well as their support and encouragement.
Thanks for John Baldwin for reviewing the use of OBJT_SG as the backing
object for pci passthru mmio regions.
Special thanks to Peter Holm for testing the patch on short notice.
Approved by: re
Discussed with: grehan
Reviewed by: alc, kib
Tested by: pho
users to set the MAC address for a device.
Clean up some obsolete code in pci_virtio_net.c
Allow an error return from a PCI device emulation's init routine
to be propagated all the way back to the top-level and result in
the process exiting.
Submitted by: Dinakar Medavaram dinnu sun at gmail (original version)
silently overwriting the previous assignment.
Gripe if the emulation is not recognized instead of silently ignoring the
emulated device.
If an error is detected by pci_parse_slot() then exit from the command line
parsing loop in main().
Submitted by (initial version): Chris Torek (chris.torek@gmail.com)
- Respect the MEMEN and PORTEN bits in the command register
- Allow the guest to reprogram the address decoded by the BAR
Submitted by: Gopakumar T
Obtained from: NetApp
command line option "-m <memsize in MB>" to specify the memory size.
Prior to this change the user needed to explicitly specify the amount of
memory allocated below 4G (-m <lowmem>) and the amount above 4G (-M <highmem>).
The "-M" option is no longer supported by 'bhyveload' and 'bhyve'.
The start of the PCI hole is fixed at 3GB and cannot be directly changed
using command line options. However it is still possible to change this in
special circumstances via the 'vm_set_lowmem_limit()' API provided by
libvmmapi.
Submitted by: Dinakar Medavaram (initial version)
Reviewed by: grehan
Obtained from: NetApp
These set of ranges will be looked at if a standard memory
range isn't found, and won't be installed in the cache.
Use this to implement the memory behaviour of the PCI hole on
x86 systems, where writes are ignored and reads always return -1.
This allows breakpoints to be set when issuing a 'boot -d', which
has the side effect of accessing the PCI hole when changing the
PTE protection on kernel code, since the pmap layer hasn't been
initialized (a bug, but present in existing FreeBSD releases so
has to be handled).
Reviewed by: neel
Obtained from: NetApp
devices are MSI-X capable. This in turn would lead it to treat bar 0 as
the MSI-X table bar even if the underlying device did not support MSI-X.
Fix this by providing an API to query the MSI-X table index of the emulated
device. If the underlying device does not support MSI-X then this API will
return -1.
Obtained from: NetApp
the default.
The current behavior of advertising a single MSI vector can be requested by
setting the environment variable "BHYVE_USE_MSI" to "true". The use of MSI
is not compliant with the virtio specification and will be eventually phased
out.
Submitted by: Gopakumar T
Obtained from: NetApp
bhyve is intended to be a generic hypervisor, and not FreeBSD-specific.
(renaming internal routines will come later)
Reviewed by: neel
Obtained from: NetApp
Firmware tables require too much knowledge of system configuration,
and it's difficult to pass that information in general terms to a library.
The upcoming ACPI work exposed this - it will also livein bhyve.
Also, remove code specific to NetApp from the mptable name, and remove
the -n option from bhyve.
Reviewed by: neel
Obtained from: NetApp
- New memory region interface. An RB tree holds the regions,
with a last-found per-vCPU cache to deal with the common case
of repeated guest accesses to MMIO registers in the same page.
- Support memory-mapped BARs in PCI emulation.
mem.c/h - memory region interface
instruction_emul.c/h - remove old region interface.
Use gpa from EPT exit to avoid a tablewalk to
determine operand address. Determine operand size
and use when calling through to region handler.
fbsdrun.c - call into region interface on paging
exit. Distinguish between instruction emul error
and region not found
pci_emul.c/h - implement new BAR callback api.
Split BAR alloc routine into routines that
require/don't require the BAR phys address.
ioapic.c
pci_passthru.c
pci_virtio_block.c
pci_virtio_net.c
pci_uart.c - update to new BAR callback i/f
Reviewed by: neel
Obtained from: NetApp
the guest. Prior to the fix it was possible for such a bar to appear as a
32-bit bar as long as it was allocated from the region below 4GB.
This had the potential to confuse some drivers that were particular about
the size of the bars.
Obtained from: NetApp
These function number is specified by an optional [:<func>] after the slot
number: -s 1:0,virtio-net,tap0
Ditto for the mptable naming: -n 1:0,e0a
Obtained from: NetApp
be activated as part of the slot config options.
The syntax is:
-s <slotnum>,uart[,stdio]
The stdio parameter instructs the code to perform i/o using
stdin/stdout. It can only be used for one instance.
To allow legacy i/o ports/irqs to be used, a new variant of
the slot command, -S, is introduced. When used to specify a
slot, the device will use legacy resources if it supports
them; otherwise it will be treated the same as the '-s' option.
Specifying the -S option with the uart will first use the 0x3f8/irq 4
config, and the second -S will use 0x2F8/irq 3.
Interrupt delivery is awaiting the arrival of the i/o apic code,
but this works fine in uart(4)'s polled mode.
This code was written by Cynthia Lu @ MIT while an intern at NetApp,
with further work from neel@ and grehan@.
Obtained from: NetApp
Includes instruction emulation for memory r/w access. This
opens the door for io-apic, local apic, hpet timer, and
legacy device emulation.
Submitted by: ryan dot berryhill at sandvine dot com
Reviewed by: grehan
Obtained from: Sandvine
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
