registered simultaneously. Due to topology unlock between the ID allocation
and the bus registration there is a chance that two buses may get the
same IDs. That is supposed reason of lock assertion panic in CAM during
initial bus scanning after new iscsid initiates two sessions same time.
Reported by: trasz
Approved by: re (glebus, marius)
MFC after: 2 weeks
sbdrop_locked() to cut acked mbufs from the socket buffer. Free this
chain a batch manner after the socket buffer lock is dropped.
This measurably reduces contention on socket buffer.
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
Approved by: re (marius)
mbufs, but return chain of free mbufs to a caller. Caller can either reuse
them or return to allocator in a batch manner.
- Implement sbdrop()/sbdrop_locked() as a wrapper around sbcut_internal().
- Expose sbcut_locked() for outside usage.
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
Approved by: re (marius)
* the mips74k cores only need EHB (which is 'sll $0, $0, 3')
here; NOPs don't actually work.
* add EHB as the last NOP for the default barriers/hazards;
that is "better" behaviour and should work on a wider
variety of processors.
This allows the existing (icky) TLB code to work, allowing
the AR9344 SoC (mips74k) to actually get through kernel startup.
Tested:
* AR9344 SoC - (mips74k)
* AR9331 SoC - (mips24k)
TODO:
* test on mips4k CPUs, just to be sure.
* document that sll $0, $0, 3 is actually "EHB" and that it
falls back to being a NOP for pre-mips32r1.
* mips24k has an errata that we currently don't correctly explicitly
state - ie, that after DERET/ERET, the only valid instruction is
a NOP.
Reviewed by: imp@
Approved by: re@ (gjb)
They're both different cores:
* mips24k is an 8-stage pipeline, mips32r1 ABI, non-superscalar core.
* mips74k is a dual-issue 15-stage superscalar design, mips32r2 ABI.
They have different sets of quirks and bugs; these #define entries
will be used to work around these.
Now, strictly speaking, we should have CPU ABI families (mips32r1, mips32r2,
etc) and CPU core types (mips4k, mips24k, mips74k, etc.) But this is the
starting point of that particular tidy-up.
Reviewed by: imp@
Approved by: re@ (gjb)
extensions, we can change the .byte directives in sys/dev/random/ivy.c
to plain 'rdrand' mnemonics. This already worked for clang users, but
now it will also work for gcc users.
Approved by: re (kib)
Approved by: so (des)
MFC after: 1 week
they occur.
This prevents repeated notifications of the same event.
Status of these events may be viewed at any time by viewing the
SMART/Health Info Page using nvmecontrol, whether or not asynchronous
events notifications for those events are enabled. This log page can
be viewed using:
nvmecontrol logpage -p 2 <ctrlr id>
Future enhancements may re-enable these notifications on a periodic basis
so that if the notified condition persists, it will continue to be logged.
Sponsored by: Intel
Reviewed by: carl
Approved by: re (hrs)
MFC after: 1 week
when calculating stats in nvmecontrol perftest.
Sponsored by: Intel
Reported by: Joe Golio <joseph.golio@emc.com>
Reviewed by: carl
Approved by: re (hrs)
MFC after: 1 week
handlers rather than in the dtrace device open/close methods. The current
approach can cause a panic if the device is closed which the taskqueue
thread is active, or if a kernel module containing a provider is unloaded
while retained enablings are present and the dtrace device isn't opened.
Submitted by: gibbs (original version)
Reviewed by: gibbs
Approved by: re (glebius)
MFC after: 2 weeks
The AR5212 series of MACs implement the same channel counters as the
later 11n chips - except, of course, the 11n specific counter (extension
channel busy.)
This allows users of these NICs to use 'athsurvey' to see how busy their
current channel is.
Tested:
* AR5212, AR2413 NICs, STA mode
Approved by: re@ (gleb)
field. Perform vcpu enumeration for Xen PV and HVM environments
and convert all Xen drivers to use vcpu_id instead of a hard coded
assumption of the mapping algorithm (acpi or apic ID) in use.
Submitted by: Roger Pau Monné
Sponsored by: Citrix Systems R&D
Reviewed by: gibbs
Approved by: re (blanket Xen)
amd64/include/pcpu.h:
i386/include/pcpu.h:
Add vcpu_id to the amd64 and i386 pcpu structures.
dev/xen/timer/timer.c
x86/xen/xen_intr.c
Use new vcpu_id instead of assuming acpi_id == vcpu_id.
i386/xen/mp_machdep.c:
i386/xen/mptable.c
x86/xen/hvm.c:
Perform Xen HVM and Xen full PV vcpu_id mapping.
x86/xen/hvm.c:
x86/acpica/madt.c
Change SYSINIT ordering of acpi CPU enumeration so that it
is guaranteed to be available at the time of Xen HVM vcpu
id mapping.
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
aware drivers on Xen hypervisors that advertise support for some
HyperV features.
x86/xen/hvm.c:
When running in HVM mode on a Xen hypervisor, set vm_guest
to VM_GUEST_XEN so other virtualization aware components in
the FreeBSD kernel can detect this mode is active.
dev/hyperv/vmbus/hv_hv.c:
Use vm_guest to ignore Xen's HyperV emulation when Xen is
detected and Xen PV drivers are active.
Reported by: Shanker Balan
Submitted by: Roger Pau Monné
Sponsored by: Citrix Systems R&D
Reviewed by: gibbs
Approved by: re (Xen blanket)
Device level sysctls are already exposed as dev.ix.<device>
Fixing the case where number of queues for igb is auto-tuned and
hw.igb.num_queues does not return current/updated value.
Reviewed by: jfv
Approved by: re (delphij)
MFC after: 2 weeks
kmeminit() runs, so it contributes nothing to 'vm_kmem_size'; update a
comment to reflect that r254025 replaced the kmem submap with the kmem
arena.
Reviewed by: kib
Approved by: re (gjb)
Sponsored by: EMC / Isilon Storage Division
