The /etc/ttys entry for a serial console in FreeBSD/x86 is as follows:
ttyu0 "/usr/libexec/getty 3wire" vt100 onifconsole secure
The initial terminal type passed to getty(8) is "3wire" which sets the
CLOCAL flag. However reset(1) clears this flag and any programs that try
to open the terminal will hang waiting for DCD to be asserted.
Fix this by always asserting DCD and DSR in the emulated uart.
The following discussion on virtualization@ has more details:
https://lists.freebsd.org/pipermail/freebsd-virtualization/2015-June/003666.html
Reported by: jmg
Discussed with: grehan
devmem is used to represent MMIO devices like the boot ROM or a VESA framebuffer
where doing a trap-and-emulate for every access is impractical. devmem is a
hybrid of system memory (sysmem) and emulated device models.
devmem is mapped in the guest address space via nested page tables similar
to sysmem. However the address range where devmem is mapped may be changed
by the guest at runtime (e.g. by reprogramming a PCI BAR). Also devmem is
usually mapped RO or RW as compared to RWX mappings for sysmem.
Each devmem segment is named (e.g. "bootrom") and this name is used to
create a device node for the devmem segment (e.g. /dev/vmm/testvm.bootrom).
The device node supports mmap(2) and this decouples the host mapping of
devmem from its mapping in the guest address space (which can change).
Reviewed by: tychon
Discussed with: grehan
Differential Revision: https://reviews.freebsd.org/D2762
MFC after: 4 weeks
"sleeping" state. This is done by forcing the vcpu to transition to "idle"
by returning to userspace with an exit code of VM_EXITCODE_REQIDLE.
MFC after: 2 weeks
capablity by advertising pcie capability.
Since the 'hostbridge' device isn't a true pci-to-pci bridge, and
doesn't actaully use the bridge configuration space layout, change
the header-type from type 1 to type 0 to avoid confusion.
Reviewed by: neel
While there is no issued with the number of descriptors in
a virtio indirect descriptor, it's a guest's choice as to
whether indirect descriptors are used. For the case where
they aren't, the virtio block ring size is still 64 which
is less than the now reported max_segs of 67. This results
in an assertion in recent Linux guests even though it was
benign since they were using indirect descs.
The intertwined relationship between virtio ring size,
max seg size and blockif queue size will be addressed
in an upcoming commit, at which point the max descriptors
will again be bumped up to 67.
The Windows virtio driver ignores the advertized seg_max
field and assumes the host can accept up to 67 segments
in indirect descriptors, triggering an assert in the bhyve
process.
No objection from: mav
Reviewed by: neel
Reported and tested by: Leon Dang (ldang@nahannisys.com)
MFC after: 2 weeks
The default behavior is to infer the logical and physical sector sizes from
the block device backend. However older versions of Windows only work with
specific logical/physical combinations:
- Vista and Windows 7: 512/512
- Windows 7 SP1: 512/512 or 512/4096
For this reason allow the sector size to be specified using the following
block device option: sectorsize=logical[/physical]
Reported by: Leon Dang (ldang@nahannisys.com)
Reviewed by: grehan
MFC after: 2 weeks
not one that needs to be negotiated. Use the host capabilities
field and not the negotiated field when verifying that indirect
descriptors are supported.
Found with the Redhat Windows viostor driver, which clears
the indirect capability in the negotiated caps and then starts
using them.
Reported and tested by: Leon Dang (ldang@nahannisys.com)
MFC after: 2 weeks
This is needed to support Windows guests that use byte reads to access certain
AHCI registers (e.g. PxTFD.Status and PxTFD.Error).
Reviewed by: grehan, mav
Reported by: Leon Dang (ldang@nahannisys.com)
Differential Revision: https://reviews.freebsd.org/D2469
MFC after: 2 weeks
Prior to this change both functions returned 0 for success, -1 for failure
and +1 to indicate that an exception was injected into the guest.
The numerical value of ERESTART also happens to be -1 so when these functions
returned -1 it had to be translated to a positive errno value to prevent the
VM_RUN ioctl from being inadvertently restarted. This made it easy to introduce
bugs when writing emulation code.
Fix this by adding an 'int *guest_fault' parameter and setting it to '1' if
an exception was delivered to the guest. The return value is 0 or EFAULT so
no additional translation is needed.
Reviewed by: tychon
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D2428
It is not required to use CLO to recover from task file error, it should
be enough to do only stop/start, that does not clear the PxTFD.STS.ERR.
MFC after: 13 days
Using status updates in r282364, block queue on BSY, DRQ or ERR bits set.
This can be a performance penalization for non-NCQ commands, but it is
required for proper error recovery and standard compliance.
MFC after: 2 weeks
GEOM does not support scatter/gather lists in its I/Os. Such requests
are cut in pieces by physio(), that may be problematic, if those pieces
are not multiple of provider's sector size. If such case is detected,
move the data through temporary sequential buffer.
MFC after: 2 weeks
There are a number of assumptions about legacy interrupts always
being available in virtio so don't allow back-ends to make the
decision to support them.
This fixes the issue seen with virtio-rnd on OpenBSD. MSI-x vectors
were not being used, and the virtio-rnd backend wasn't allocating a
legacy interrupt resulting in a bhyve assert and guest exit.
Reported by: Julian Hsiao, madoka at nyanisore dot net
Reviewed by: neel
MFC after: 1 week
I've missed that network driver sometimes returns taken request back to
available queue without processing. Add new helper function for that case.
Reported by: flo
MFC after: 2 weeks
I/O interface.
Asynchronous operation, based on r280026 change, allows to not block virtual
CPU during I/O processing, that on slow/busy storage can take seconds.
Use of recently improved block I/O interface allows to process multiple
requests same time, that improves random I/O performance on wide storages.
Benchmarks of virtual disk, backed by ZVOL on RAID10 pool of 4 HDDs, show
~3.5 times random read performance improvements, while no degradation on
linear I/O. Guest CPU usage during test dropped from 100% to almost zero.
MFC after: 2 weeks
Original virtqueue design allows queued and out-of-order processing, but
helpers added in r253440 suppose only direct blocking in-order one.
It could be fine for network, etc., but it is a huge limitation for storage
devices.
On parallel random I/O this allows better utilize wide storage pools.
To not confuse prefetcher on linear I/O, consecutive requests are executed
sequentially, following the same logic as was earlier implemented in CTL.
Benchmarks of virtual AHCI disk, backed by ZVOL on RAID10 pool of 4 HDDs,
show ~3.5 times random read performance improvements, while no degradation
on linear I/O.
MFC after: 2 weeks
