The try lock loop in HN_LOCK put the thread spinning on cpu if the lock
is not available. It is possible to cause deadlock if the thread holding
the lock is sleeping. Relinquish the cpu to work around this problem even
it doesn't completely solve the issue. The priority inversion could cause
the livelock no matter how less likely it could happen. A more complete
solution may be needed in the future.
Reported by: Microsoft, Netapp
MFC after: 2 weeks
Sponsored by: Microsoft
It is possible that the vmbus pcib channel is revoked during attach path.
The attach path could be waiting for response from host and this response will never
arrive since the channel has already been revoked from host point of view. Check
this situation during wait complete and return failed if this happens.
Reported by: Netapp
MFC after: 2 weeks
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D26486
In hv_storvsc_io_request() when coring, prevent changing of the send channel
from the base channel to another one. storvsc_poll always probes on the base
channel.
Based upon conversations with Microsoft, changed the handling of srb_status
codes. Most we should never get, others yes. All are treated as retry-able
except for two. We should not get these statuses, but if we ever do, the I/O
state is not known.
Submitted by: Alexander Sideropoulos <Alexander.Sideropoulos@netapp.com>
Reviewed by: trasz, allanjude, whu
MFC after: 1 week
Sponsored by: Netapp Inc
Differential Revision: https://reviews.freebsd.org/D25756
On Gen2 VMs, Hyper-V provides mmio space for framebuffer.
This mmio address range is not useable for other PCI devices.
Currently only efifb driver is using this range without reserving
it from system.
Therefore, vmbus driver reserves it before any other PCI device
drivers start to request mmio addresses.
PR: 222996
Submitted by: weh@microsoft.com
Reported by: dmitry_kuleshov@ukr.net
Reviewed by: decui@microsoft.com
Sponsored by: Microsoft
This change adds Hyper-V socket feature in FreeBSD. New socket address
family AF_HYPERV and its kernel support are added.
Submitted by: Wei Hu <weh@microsoft.com>
Reviewed by: Dexuan Cui <decui@microsoft.com>
Relnotes: yes
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D24061
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.
This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.
Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT
Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718
switch over to opt-in instead of opt-out for epoch.
Instead of IFF_NEEDSEPOCH, provide IFF_KNOWSEPOCH. If driver marks
itself with IFF_KNOWSEPOCH, then ether_input() would not enter epoch
when processing its packets.
Now this will create recursive entrance in epoch in >90% network
drivers, but will guarantee safeness of the transition.
Mark several tested drivers as IFF_KNOWSEPOCH.
Reviewed by: hselasky, jeff, bz, gallatin
Differential Revision: https://reviews.freebsd.org/D23674
supposedly may call into ether_input() without network epoch.
They all need to be reviewed before 13.0-RELEASE. Some may need
be fixed. The flag is not planned to be used in the kernel for
a long time.
This change is based on Linux commit 40630f462824ee. csio.resid should
account for transfer_len only for success and SRB_STATUS_DATA_OVERRUN
condition.
I am not sure how exactly this change works, but I have a report from a
user that they see lots of checksum errors when running a pool scrub
concurrently with iozone -l 1 -s 100G. After applying this patch the
problem cannot be reproduced.
Reviewed by: nobody
Sponsored by: CyberSecure
Differential Revision: https://reviews.freebsd.org/D22312
r356087 made it rather innocuous to double-register built-in keyboard
drivers; we now set a flag to indicate that it's been registered and only
act once on a registration anyways. There is no misleading here, as the
follow-up kbd_delete_driver will actually remove the driver as needed now
that the linker set isn't also consulted after kbdinit.
Keyboard drivers are generally registered via linker set. In these cases,
they're also available as kmods which use KPI for registering/unregistering
keyboard drivers outside of the linker set.
For built-in modules, we still fire off MOD_LOAD and maybe even MOD_UNLOAD
if an error occurs, leading to registration via linker set and at MOD_LOAD
time.
This is a minor optimization at best, but it keeps the internal kbd driver
tidy as a future change will merge the linker set driver list into its
internal keyboard_drivers list via SYSINIT and simplify driver lookup by
removing the need to consult the linker set.
Most keyboard drivers are using the genkbd implementations as it is;
formally use them for any that aren't set and make
genkbd_get_fkeystr/genkbd_diag private.
A future change will provide default implementations for some of these where
it makes sense and most of them are already using the genkbd
implementation (e.g. get_fkeystr, diag).
These invocations were directly calling enkbd_diag(), rather than
indirection back through kbdd_diag/kbdsw. While they're functionally
equivent, invoking kbdd_diag where feasible (i.e. not in a diag
implementation) makes it easier to visually identify locking needs in these
other drivers.
A SIM-private field is used for that.
The pointer can be useful when examining a state of a queued ccb.
E.g., a ccb on a da_softc.pending_ccbs.
MFC after: 2 weeks
Add VMBus protocol version 4.0. and 5.0 to support Windows 10 and newer HyperV hosts.
For VMBus 4.0 and newer HyperV, the netvsc gpadl teardown must be done after vmbus close.
Submitted by: whu
MFC after: 2 weeks
Sponsored by: Microsoft
error in the function hypercall_memfree(), where the wrong arena was being
passed to kmem_free().
Introduce a per-page flag, VPO_KMEM_EXEC, to mark physical pages that are
mapped in kmem with execute permissions. Use this flag to determine which
arena the kmem virtual addresses are returned to.
Eliminate UMA_SLAB_KRWX. The introduction of VPO_KMEM_EXEC makes it
redundant.
Update the nearby comment for UMA_SLAB_KERNEL.
Reviewed by: kib, markj
Discussed with: jeff
Approved by: re (marius)
Differential Revision: https://reviews.freebsd.org/D16845
became unused in FreeBSD 12.x as a side-effect of the NUMA-related
changes.)
Reviewed by: kib, markj
Discussed with: jeff, re@
Differential Revision: https://reviews.freebsd.org/D16825
Summary:
Base gcc fails to compile `sys/dev/hyperv/pcib/vmbus_pcib.c` for i386,
with the following -Werror warnings:
cc1: warnings being treated as errors
/usr/src/sys/dev/hyperv/pcib/vmbus_pcib.c: In function 'new_pcichild_device':
/usr/src/sys/dev/hyperv/pcib/vmbus_pcib.c:567: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
/usr/src/sys/dev/hyperv/pcib/vmbus_pcib.c: In function 'vmbus_pcib_on_channel_callback':
/usr/src/sys/dev/hyperv/pcib/vmbus_pcib.c:940: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
/usr/src/sys/dev/hyperv/pcib/vmbus_pcib.c: In function 'hv_pci_protocol_negotiation':
/usr/src/sys/dev/hyperv/pcib/vmbus_pcib.c:1012: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
/usr/src/sys/dev/hyperv/pcib/vmbus_pcib.c: In function 'hv_pci_enter_d0':
/usr/src/sys/dev/hyperv/pcib/vmbus_pcib.c:1073: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
/usr/src/sys/dev/hyperv/pcib/vmbus_pcib.c: In function 'hv_send_resources_allocated':
/usr/src/sys/dev/hyperv/pcib/vmbus_pcib.c:1125: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
/usr/src/sys/dev/hyperv/pcib/vmbus_pcib.c: In function 'vmbus_pcib_map_msi':
/usr/src/sys/dev/hyperv/pcib/vmbus_pcib.c:1730: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
This is because on i386, several casts from `uint64_t` to a pointer
reduce the value from 64 bit to 32 bit.
For gcc, this can be fixed by an intermediate cast to uintptr_t. Note
that I am assuming the incoming values will always fit into 32 bit!
Differential Revision: https://reviews.freebsd.org/D15753
MFC after: 3 days
Ifuncs selectors dispatch copyin(9) family to the suitable variant, to
set rflags.AC around userspace access. Rflags.AC bit is cleared in
all kernel entry points unconditionally even on machines not
supporting SMAP.
Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D13838
FreeBSD VM can't boot up on Hyper-V after the recent malloc change in
r335068: Make UMA and malloc(9) return non-executable memory in most cases.
The hypercall page here must be executable.
Fix the boot-up issue by adding M_EXEC.
PR: 229167
Sponsored by: Microsoft
omcast was used without being initialized in the non-multicast case.
The only effect was that the interface's multicast output counter could be
incorrect.
Reported by: Coverity
CID: 1379662
MFC after: 3 days
Sponsored by: Dell EMC
The change makes the user and kernel address spaces on i386
independent, giving each almost the full 4G of usable virtual addresses
except for one PDE at top used for trampoline and per-CPU trampoline
stacks, and system structures that must be always mapped, namely IDT,
GDT, common TSS and LDT, and process-private TSS and LDT if allocated.
By using 1:1 mapping for the kernel text and data, it appeared
possible to eliminate assembler part of the locore.S which bootstraps
initial page table and KPTmap. The code is rewritten in C and moved
into the pmap_cold(). The comment in vmparam.h explains the KVA
layout.
There is no PCID mechanism available in protected mode, so each
kernel/user switch forth and back completely flushes the TLB, except
for the trampoline PTD region. The TLB invalidations for userspace
becomes trivial, because IPI handlers switch page tables. On the other
hand, context switches no longer need to reload %cr3.
copyout(9) was rewritten to use vm_fault_quick_hold(). An issue for
new copyout(9) is compatibility with wiring user buffers around sysctl
handlers. This explains two kind of locks for copyout ptes and
accounting of the vslock() calls. The vm_fault_quick_hold() AKA slow
path, is only tried after the 'fast path' failed, which temporary
changes mapping to the userspace and copies the data to/from small
per-cpu buffer in the trampoline. If a page fault occurs during the
copy, it is short-circuit by exception.s to not even reach C code.
The change was motivated by the need to implement the Meltdown
mitigation, but instead of KPTI the full split is done. The i386
architecture already shows the sizing problems, in particular, it is
impossible to link clang and lld with debugging. I expect that the
issues due to the virtual address space limits would only exaggerate
and the split gives more liveness to the platform.
Tested by: pho
Discussed with: bde
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D14633
CAM_SEL_TIMEOUT was introduced in
https://reviews.freebsd.org/D7521 (r304251), which claimed:
"VM shall response to CAM layer with CAM_SEL_TIMEOUT to filter those
invalid LUNs. Never use CAM_DEV_NOT_THERE which will block LUN scan
for LUN number higher than 7."
But it turns out this is not correct:
I think what really filters the invalid LUNs in r304251 is that:
before r304251, we could set the CAM_REQ_CMP without checking
vm_srb->srb_status at all:
ccb->ccb_h.status |= CAM_REQ_CMP.
r304251 checks vm_srb->srb_status and sets ccb->ccb_h.status properly,
so the invalid LUNs are filtered.
I changed my code version to r304251 but replaced the CAM_SEL_TIMEOUT
with CAM_DEV_NOT_THERE, and I confirmed the invalid LUNs can also be
filtered, and I successfully hot-added and hot-removed 8 disks to/from
the VM without any issue.
CAM_SEL_TIMEOUT has an unwanted side effect -- see cam_periph_error():
For a selection timeout, we consider all of the LUNs on
the target to be gone. If the status is CAM_DEV_NOT_THERE,
then we only get rid of the device(s) specified by the
path in the original CCB.
This means: for a VM with a valid LUN on 3:0:0:0, when the VM inquires
3:0:0:1 and the host reports 3:0:0:1 doesn't exist and storvsc returns
CAM_SEL_TIMEOUT to the CAM layer, CAM will detech 3:0:0:0 as well: this
is the bug I reported recently:
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=226583
PR: 226583
Reviewed by: mav
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D14690
assym is only to be included by other .s files, and should never
actually be assembled by itself.
Reviewed by: imp, bdrewery (earlier)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D14180
The implementation of the Kernel Page Table Isolation (KPTI) for
amd64, first version. It provides a workaround for the 'meltdown'
vulnerability. PTI is turned off by default for now, enable with the
loader tunable vm.pmap.pti=1.
The pmap page table is split into kernel-mode table and user-mode
table. Kernel-mode table is identical to the non-PTI table, while
usermode table is obtained from kernel table by leaving userspace
mappings intact, but only leaving the following parts of the kernel
mapped:
kernel text (but not modules text)
PCPU
GDT/IDT/user LDT/task structures
IST stacks for NMI and doublefault handlers.
Kernel switches to user page table before returning to usermode, and
restores full kernel page table on the entry. Initial kernel-mode
stack for PTI trampoline is allocated in PCPU, it is only 16
qwords. Kernel entry trampoline switches page tables. then the
hardware trap frame is copied to the normal kstack, and execution
continues.
IST stacks are kept mapped and no trampoline is needed for
NMI/doublefault, but of course page table switch is performed.
On return to usermode, the trampoline is used again, iret frame is
copied to the trampoline stack, page tables are switched and iretq is
executed. The case of iretq faulting due to the invalid usermode
context is tricky, since the frame for fault is appended to the
trampoline frame. Besides copying the fault frame and original
(corrupted) frame to kstack, the fault frame must be patched to make
it look as if the fault occured on the kstack, see the comment in
doret_iret detection code in trap().
Currently kernel pages which are mapped during trampoline operation
are identical for all pmaps. They are registered using
pmap_pti_add_kva(). Besides initial registrations done during boot,
LDT and non-common TSS segments are registered if user requested their
use. In principle, they can be installed into kernel page table per
pmap with some work. Similarly, PCPU can be hidden from userspace
mapping using trampoline PCPU page, but again I do not see much
benefits besides complexity.
PDPE pages for the kernel half of the user page tables are
pre-allocated during boot because we need to know pml4 entries which
are copied to the top-level paging structure page, in advance on a new
pmap creation. I enforce this to avoid iterating over the all
existing pmaps if a new PDPE page is needed for PTI kernel mappings.
The iteration is a known problematic operation on i386.
The need to flush hidden kernel translations on the switch to user
mode make global tables (PG_G) meaningless and even harming, so PG_G
use is disabled for PTI case. Our existing use of PCID is
incompatible with PTI and is automatically disabled if PTI is
enabled. PCID can be forced on only for developer's benefit.
MCE is known to be broken, it requires IST stack to operate completely
correctly even for non-PTI case, and absolutely needs dedicated IST
stack because MCE delivery while trampoline did not switched from PTI
stack is fatal. The fix is pending.
Reviewed by: markj (partially)
Tested by: pho (previous version)
Discussed with: jeff, jhb
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
This provides a nice wrarpper around the XPT_PATH_INQ ccb creation and
calling.
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D13387
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Background:
- UDP 4-tuple hash type is unconditionally enabled in Hyper-V on WS2016,
which is _not_ affected by NDIS_OBJTYPE_RSS_PARAMS.
- Non-fragment UDP/IPv4 datagrams' hash type is delivered to VM as
TCP_IPV4.
Currently this erroneous behavior only applies to WS2016/Windows10.
Force l3/l4 protocol check, if the RXed packet's hash type is TCP_IPV4,
and the Hyper-V is running on WS2016/Windows10. If the RXed packet is
UDP datagram, adjust mbuf hash type to UDP_IPV4.
MFC after: 3 days
Sponsored by: Microsoft
Event tasks are pinned to their respective CPU by default, in the same
fashion as they were.
Unpin the event tasks by setting hw.vmbus.pin_evttask to 0, if certain
CPUs serve special purpose.
MFC after: 3 days
Sponsored by: Microsoft
UDP checksum offload does not work in Azure if following conditions are
met:
- sizeof(IP hdr + UDP hdr + payload) > 1420.
- IP_DF is not set in IP hdr
Use software checksum for UDP datagrams falling into this category.
Add two tunables to disable UDP/IPv4 and UDP/IPv6 checksum offload, in
case something unexpected happened.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D12429
- Add size of an ethernet header to the value configured to NVS. This
does not seem to have any effects if MTU is 1500, but fix hypervisor
side's setting if MTU > 1500.
- Override the MTU setting according to the view from the hypervisor
side.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D12352
Since in Azure SYN and SYN|ACK go through the synthetic parts while the
rest of the same TCP flow goes through the VF, apply VF's RSS settings
to synthetic parts to have a consistent hash value/type for the same TCP
flow.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D12333
