Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"ARM:
- Page ownership tracking between host EL1 and EL2
- Rely on userspace page tables to create large stage-2 mappings
- Fix incompatibility between pKVM and kmemleak
- Fix the PMU reset state, and improve the performance of the virtual
PMU
- Move over to the generic KVM entry code
- Address PSCI reset issues w.r.t. save/restore
- Preliminary rework for the upcoming pKVM fixed feature
- A bunch of MM cleanups
- a vGIC fix for timer spurious interrupts
- Various cleanups
s390:
- enable interpretation of specification exceptions
- fix a vcpu_idx vs vcpu_id mixup
x86:
- fast (lockless) page fault support for the new MMU
- new MMU now the default
- increased maximum allowed VCPU count
- allow inhibit IRQs on KVM_RUN while debugging guests
- let Hyper-V-enabled guests run with virtualized LAPIC as long as
they do not enable the Hyper-V "AutoEOI" feature
- fixes and optimizations for the toggling of AMD AVIC (virtualized
LAPIC)
- tuning for the case when two-dimensional paging (EPT/NPT) is
disabled
- bugfixes and cleanups, especially with respect to vCPU reset and
choosing a paging mode based on CR0/CR4/EFER
- support for 5-level page table on AMD processors
Generic:
- MMU notifier invalidation callbacks do not take mmu_lock unless
necessary
- improved caching of LRU kvm_memory_slot
- support for histogram statistics
- add statistics for halt polling and remote TLB flush requests"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (210 commits)
KVM: Drop unused kvm_dirty_gfn_invalid()
KVM: x86: Update vCPU's hv_clock before back to guest when tsc_offset is adjusted
KVM: MMU: mark role_regs and role accessors as maybe unused
KVM: MIPS: Remove a "set but not used" variable
x86/kvm: Don't enable IRQ when IRQ enabled in kvm_wait
KVM: stats: Add VM stat for remote tlb flush requests
KVM: Remove unnecessary export of kvm_{inc,dec}_notifier_count()
KVM: x86/mmu: Move lpage_disallowed_link further "down" in kvm_mmu_page
KVM: x86/mmu: Relocate kvm_mmu_page.tdp_mmu_page for better cache locality
Revert "KVM: x86: mmu: Add guest physical address check in translate_gpa()"
KVM: x86/mmu: Remove unused field mmio_cached in struct kvm_mmu_page
kvm: x86: Increase KVM_SOFT_MAX_VCPUS to 710
kvm: x86: Increase MAX_VCPUS to 1024
kvm: x86: Set KVM_MAX_VCPU_ID to 4*KVM_MAX_VCPUS
KVM: VMX: avoid running vmx_handle_exit_irqoff in case of emulation
KVM: x86/mmu: Don't freak out if pml5_root is NULL on 4-level host
KVM: s390: index kvm->arch.idle_mask by vcpu_idx
KVM: s390: Enable specification exception interpretation
KVM: arm64: Trim guest debug exception handling
KVM: SVM: Add 5-level page table support for SVM
...
Al Viro [Tue, 7 Sep 2021 20:14:05 +0000 (16:14 -0400)]
putname(): IS_ERR_OR_NULL() is wrong here
Mixing NULL and ERR_PTR() just in case is a Bad Idea(tm). For
struct filename the former is wrong - failures are reported
as ERR_PTR(...), not as NULL.
Stephen Brennan [Wed, 1 Sep 2021 17:51:43 +0000 (10:51 -0700)]
namei: Standardize callers of filename_create()
filename_create() has two variants, one which drops the caller's
reference to filename (filename_create) and one which does
not (__filename_create). This can be confusing as it's unusual to drop a
caller's reference. Remove filename_create, rename __filename_create
to filename_create, and convert all callers.
Stephen Brennan [Wed, 1 Sep 2021 17:51:42 +0000 (10:51 -0700)]
namei: Standardize callers of filename_lookup()
filename_lookup() has two variants, one which drops the caller's
reference to filename (filename_lookup), and one which does
not (__filename_lookup). This can be confusing as it's unusual to drop a
caller's reference. Remove filename_lookup, rename __filename_lookup
to filename_lookup, and convert all callers. The cost is a few slightly
longer functions, but the clarity is greater.
[AV: consuming a reference is not at all unusual, actually; look at
e.g. do_mkdirat(), for example. It's more that we want non-consuming
variant for close relative of that function...]
Merge tag 'ntb-5.15' of git://github.com/jonmason/ntb
Pull NTB updates from Jon Mason:
"Bug fixes and clean-ups for Linux v5.15"
* tag 'ntb-5.15' of git://github.com/jonmason/ntb:
NTB: switch from 'pci_' to 'dma_' API
ntb: ntb_pingpong: remove redundant initialization of variables msg_data and spad_data
NTB: perf: Fix an error code in perf_setup_inbuf()
NTB: Fix an error code in ntb_msit_probe()
ntb: intel: remove invalid email address in header comment
Stephen Brennan [Wed, 1 Sep 2021 17:51:41 +0000 (10:51 -0700)]
namei: Fix use after free in kern_path_locked
In 0ee50b47532a ("namei: change filename_parentat() calling
conventions"), filename_parentat() was made to always call putname() on
the filename before returning, and kern_path_locked() was migrated to
this calling convention. However, kern_path_locked() uses the "last"
parameter to lookup and potentially create a new dentry. The last
parameter contains the last component of the path and points within the
filename, which was recently freed at the end of filename_parentat().
Thus, when kern_path_locked() calls __lookup_hash(), it is using the
filename after it has already been freed.
In other words, these calling conventions had been wrong for the
only remaining caller of filename_parentat(). Everything else
is using __filename_parentat(), which does not drop the reference;
so should kern_path_locked().
Switch kern_path_locked() to use of __filename_parentat() and move
getting/dropping struct filename into wrapper. Remove filename_parentat(),
now that we have no remaining callers.
Merge tag 'backlight-next-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight
Pull backlight updates from Lee Jones:
"Fix-ups:
- Improve bootloader/kernel device handover
Bug Fixes:
- Stabilise backlight in ktd253 driver"
* tag 'backlight-next-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
backlight: pwm_bl: Improve bootloader/kernel device handover
backlight: ktd253: Stabilize backlight
Merge tag 'mfd-next-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd
Pull MFD updates from Lee Jones:
"Core Frameworks:
- Add support for registering devices via MFD cells to Simple MFD (I2C)
New Drivers:
- Add support for Renesas Synchronization Management Unit (SMU)
New Device Support:
- Add support for N5010 to Intel M10 BMC
- Add support for Cannon Lake to Intel LPSS ACPI
- Add support for Samsung SSG{1,2} to ST-Ericsson's U8500 family
- Add support for TQMx110EB and TQMxE40x to TQ-Systems PLD TQMx86
New Functionality:
- Add support for GPIO to Intel LPC ICH
- Add support for Reset to Texas Instruments TPS65086
Fix-ups:
- Trivial, sorting, whitespace, renaming, etc; mt6360-core, db8500-prcmu-regs, tqmx86
- Device Tree fiddling; syscon, axp20x, qcom,pm8008, ti,tps65086, brcm,cru
- Use proper APIs for IRQ map resolution; ab8500-core, stmpe, tc3589x, wm8994-irq
- Pass 'supplied-from' property through axp288_fuel_gauge via swnode
- Remove unused file entry; MAINTAINERS
- Make interrupt line optional; tps65086
- Rename db8500-cpuidle driver symbol; db8500-prcmu
- Remove support for unused hardware; tqmx86
- Provide a standard LPC clock frequency for unknown boards; tqmx86
- Remove unused code; ti_am335x_tscadc
- Use of_iomap() instead of ioremap(); syscon
Bug Fixes:
- Clear GPIO IRQ resource flags when no IRQ is set; tqmx86
- Fix incorrect/misleading frequencies; db8500-prcmu
- Mitigate namespace clash with other GPIOBASE users"
* tag 'mfd-next-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (31 commits)
mfd: lpc_sch: Rename GPIOBASE to prevent build error
mfd: syscon: Use of_iomap() instead of ioremap()
dt-bindings: mfd: Add Broadcom CRU
mfd: ti_am335x_tscadc: Delete superfluous error message
mfd: tqmx86: Assume 24MHz LPC clock for unknown boards
mfd: tqmx86: Add support for TQ-Systems DMI IDs
mfd: tqmx86: Add support for TQMx110EB and TQMxE40x
mfd: tqmx86: Fix typo in "platform"
mfd: tqmx86: Remove incorrect TQMx90UC board ID
mfd: tqmx86: Clear GPIO IRQ resource when no IRQ is set
mfd: simple-mfd-i2c: Add support for registering devices via MFD cells
mfd/cpuidle: ux500: Rename driver symbol
mfd: tps65086: Add cell entry for reset driver
mfd: tps65086: Make interrupt line optional
dt-bindings: mfd: Convert tps65086.txt to YAML
MAINTAINERS: Adjust ARM/NOMADIK/Ux500 ARCHITECTURES to file renaming
mfd: db8500-prcmu: Handle missing FW variant
mfd: db8500-prcmu: Rename register header
mfd: axp20x: Add supplied-from property to axp288_fuel_gauge cell
mfd: Don't use irq_create_mapping() to resolve a mapping
...
Merge tag 'gpio-updates-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio updates from Bartosz Golaszewski:
"We mostly have various improvements and refactoring all over the place
but also some interesting new features - like the virtio GPIO driver
that allows guest VMs to use host's GPIOs. We also have a new/old GPIO
driver for rockchip - this one has been split out of the pinctrl
driver.
Summary:
- new driver: gpio-virtio allowing a guest VM running linux to access
GPIO lines provided by the host
- split the GPIO driver out of the rockchip pin control driver
- add support for a new model to gpio-aspeed-sgpio, refactor the
driver and use generic device property interfaces, improve property
sanitization
- add ACPI support to gpio-tegra186
- improve the code setting the line names to support multiple GPIO
banks per device
- constify a bunch of OF functions in the core GPIO code and make the
declaration for one of the core OF functions we use consistent
within its header
- use software nodes in intel_quark_i2c_gpio
- add support for the gpio-line-names property in gpio-mt7621
- use the standard GPIO function for setting the GPIO names in
gpio-brcmstb
- fix a bunch of leaks and other bugs in gpio-mpc8xxx
- use generic pm callbacks in gpio-ml-ioh
- improve resource management and PM handling in gpio-mlxbf2
- modernize and improve the gpio-dwapb driver
- coding style improvements in gpio-rcar
- documentation fixes and improvements
- update the MAINTAINERS entry for gpio-zynq
- minor tweaks in several drivers"
* tag 'gpio-updates-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (35 commits)
gpio: mpc8xxx: Use 'devm_gpiochip_add_data()' to simplify the code and avoid a leak
gpio: mpc8xxx: Fix a potential double iounmap call in 'mpc8xxx_probe()'
gpio: mpc8xxx: Fix a resources leak in the error handling path of 'mpc8xxx_probe()'
gpio: viperboard: remove platform_set_drvdata() call in probe
gpio: virtio: Add missing mailings lists in MAINTAINERS entry
gpio: virtio: Fix sparse warnings
gpio: remove the obsolete MX35 3DS BOARD MC9S08DZ60 GPIO functions
gpio: max730x: Use the right include
gpio: Add virtio-gpio driver
gpio: mlxbf2: Use DEFINE_RES_MEM_NAMED() helper macro
gpio: mlxbf2: Use devm_platform_ioremap_resource()
gpio: mlxbf2: Drop wrong use of ACPI_PTR()
gpio: mlxbf2: Convert to device PM ops
gpio: dwapb: Get rid of legacy platform data
mfd: intel_quark_i2c_gpio: Convert GPIO to use software nodes
gpio: dwapb: Read GPIO base from gpio-base property
gpio: dwapb: Unify ACPI enumeration checks in get_irq() and configure_irqs()
gpiolib: Deduplicate forward declaration in the consumer.h header
MAINTAINERS: update gpio-zynq.yaml reference
gpio: tegra186: Add ACPI support
...
PM: sleep: core: Avoid setting power.must_resume to false
There are variables(power.may_skip_resume and dev->power.must_resume)
and DPM_FLAG_MAY_SKIP_RESUME flags to control the resume of devices after
a system wide suspend transition.
Setting the DPM_FLAG_MAY_SKIP_RESUME flag means that the driver allows
its "noirq" and "early" resume callbacks to be skipped if the device
can be left in suspend after a system-wide transition into the working
state. PM core determines that the driver's "noirq" and "early" resume
callbacks should be skipped or not with dev_pm_skip_resume() function by
checking power.may_skip_resume variable.
power.must_resume variable is getting set to false in __device_suspend()
function without checking device's DPM_FLAG_MAY_SKIP_RESUME settings.
In problematic scenario, where all the devices in the suspend_late
stage are successful and some device can fail to suspend in
suspend_noirq phase. So some devices successfully suspended in suspend_late
stage are not getting chance to execute __device_suspend_noirq()
to set dev->power.must_resume variable to true and not getting
resumed in early_resume phase.
Add a check for device's DPM_FLAG_MAY_SKIP_RESUME flag before
setting power.must_resume variable in __device_suspend function.
Fixes: 6e176bf8d461 ("PM: sleep: core: Do not skip callbacks in the resume phase") Signed-off-by: Prasad Sodagudi <[email protected]> Signed-off-by: Rafael J. Wysocki <[email protected]>
Merge tag 'fuse-update-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi:
- Allow mounting an active fuse device. Previously the fuse device
would always be mounted during initialization, and sharing a fuse
superblock was only possible through mount or namespace cloning
- Fix data flushing in syncfs (virtiofs only)
- Fix data flushing in copy_file_range()
- Fix a possible deadlock in atomic O_TRUNC
- Misc fixes and cleanups
* tag 'fuse-update-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
fuse: remove unused arg in fuse_write_file_get()
fuse: wait for writepages in syncfs
fuse: flush extending writes
fuse: truncate pagecache on atomic_o_trunc
fuse: allow sharing existing sb
fuse: move fget() to fuse_get_tree()
fuse: move option checking into fuse_fill_super()
fuse: name fs_context consistently
fuse: fix use after free in fuse_read_interrupt()
Lukasz Luba [Mon, 6 Sep 2021 08:44:53 +0000 (09:44 +0100)]
Documentation: power: include kernel-doc in Energy Model doc
Improve the existing documentation of the Energy Model and add kernel-doc
comments. This extends an API description and helps better understanding
the usage.
The current HWP calibration for hybrid processors in intel_pstate is
fragile, because it depends too much on the information provided by
the platform firmware via CPPC which may not be reliable enough. It
also need not be so complicated.
In order to improve that mechanism and make it more resistant to
platform firmware issues, make it only use the CPPC nominal_perf
values to compute the HWP-to-frequency scaling factors for all
CPUs and possibly use the HWP_CAP highest_perf values to recompute
them if the ones derived from the CPPC nominal_perf values alone
appear to be too high.
Namely, fetch CPC.nominal_perf for all CPUs present in the system,
find the minimum one and use it as a reference for computing all of
the CPUs' scaling factors (using the observation that for the CPUs
having the minimum CPC.nominal_perf the HWP range of available
performance levels should be the same as the range of available
"legacy" P-states and so the HWP-to-frequency scaling factor for
them should be the same as the corresponding scaling factor used
for representing the P-state values in kHz).
On some systems the nominal_perf value retrieved via CPPC is just
a constant and fetching it doesn't require accessing any registers,
so if it is the only CPPC capability that's needed, it is wasteful
to run cppc_get_perf_caps() in order to get just that value alone,
especially when this is done for CPUs other than the one running
the code.
For this reason, introduce cppc_get_nominal_perf() allowing
nominal_perf to be obtained individually, by generalizing the
existing cppc_get_desired_perf() (and renaming it) so it can be
used to retrieve any specific CPPC capability value.
While at it, clean up the cppc_get_desired_perf() kerneldoc comment
a bit.
Merge tag 'kgdb-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux
Pull kgdb updates from Daniel Thompson:
"Changes for kgdb/kdb this cycle are dominated by a change from Sumit
that removes as small (256K) private heap from kdb. This is change
I've hoped for ever since I discovered how few users of this heap
remained in the kernel, so many thanks to Sumit for hunting these
down.
The other change is an incremental step towards SPDX headers"
* tag 'kgdb-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
kernel: debug: Convert to SPDX identifier
kdb: Rename members of struct kdbtab_t
kdb: Simplify kdb_defcmd macro logic
kdb: Get rid of redundant kdb_register_flags()
kdb: Rename struct defcmd_set to struct kdb_macro
kdb: Get rid of custom debug heap allocator
Dan Williams [Sat, 4 Sep 2021 02:20:45 +0000 (19:20 -0700)]
cxl/pci: Fix lockdown level
A proposed rework of security_locked_down() users identified that the
cxl_pci driver was passing the wrong lockdown_reason. Update
cxl_mem_raw_command_allowed() to fail raw command access when raw pci
access is also disabled.
cxl/acpi: Do not add DSDT disabled ACPI0016 host bridge ports
During CXL ACPI probe, host bridge ports are discovered by scanning
the ACPI0017 root port for ACPI0016 host bridge devices. The scan
matches on the hardware id of "ACPI0016". An issue occurs when an
ACPI0016 device is defined in the DSDT yet disabled on the platform.
Attempts by the cxl_acpi driver to add host bridge ports using a
disabled device fails, and the entire cxl_acpi probe fails.
The DSDT table includes an _STA method that sets the status and the
ACPI subsystem has checks available to examine it. One such check is
in the acpi_pci_find_root() path. Move the call to acpi_pci_find_root()
to the matching function to prevent this issue when adding either
upstream or downstream ports.
Just like with the memcg lock accounting, the kernel test robot reports
a sizeable performance regression for this commit, and while it clearly
does the rigth thing in theory, we'll need to look at just how to avoid
or minimize the performance overhead of the memcg accounting.
People already have suggestions on how to do that, but it's "future
work".
So revert it for now.
[ Note: the first link below is for this same commit but a different
commit ID, because it's the kernel test robot ended up noticing it in
Andrew Morton's patch queue ]
The kernel test robot reports a sizeable performance regression for this
commit, and while it clearly does the rigth thing in theory, we'll need
to look at just how to avoid or minimize the performance overhead of the
memcg accounting.
People already have suggestions on how to do that, but it's "future
work".
That commit was completely broken, and I should have caught on to it
earlier. But happily, the kernel test robot noticed the breakage fairly
quickly.
The breakage is because "try_get_page()" is about avoiding the page
reference count overflow case, but is otherwise the exact same as a
plain "get_page()".
In contrast, "try_get_compound_head()" is an entirely different beast,
and uses __page_cache_add_speculative() because it's not just about the
page reference count, but also about possibly racing with the underlying
page going away.
So all the commentary about how
"try_get_page() has fallen a little behind in terms of maintenance,
try_get_compound_head() handles speculative page references more
thoroughly"
was just completely wrong: yes, try_get_compound_head() handles
speculative page references, but the point is that try_get_page() does
not, and must not.
So there's no lack of maintainance - there are fundamentally different
semantics.
A speculative page reference would be entirely wrong in "get_page()",
and it's entirely wrong in "try_get_page()". It's not about
speculation, it's purely about "uhhuh, you can't get this page because
you've tried to increment the reference count too much already".
The reason the kernel test robot noticed this bug was that it hit the
VM_BUG_ON() in __page_cache_add_speculative(), which is all about
verifying that the context of any speculative page access is correct.
But since that isn't what try_get_page() is all about, the VM_BUG_ON()
tests things that are not correct to test for try_get_page().
Merge tag 'nvme-5.15-2021-09-07' of git://git.infradead.org/nvme into block-5.15
Pull NVMe fixes from Christoph:
"nvme fixes for Linux 5.15
- fix nvmet command set reporting for passthrough controllers
(Adam Manzanares)
- updated
- update a MAINTAINERS email address (Chaitanya Kulkarni)
- set QUEUE_FLAG_NOWAIT for nvme-multipth (me)
- handle errors from add_disk() (Luis Chamberlain)
- update the keep alive interval when kato is modified (Tatsuya Sasaki)
- fix a buffer overrun in nvmet_subsys_attr_serial (Hannes Reinecke)
- do not reset transport on data digest errors in nvme-tcp (Daniel Wagner)
- only call synchronize_srcu when clearing current path (Daniel Wagner)
- revalidate paths during rescan (Hannes Reinecke)"
* tag 'nvme-5.15-2021-09-07' of git://git.infradead.org/nvme:
nvme: update MAINTAINERS email address
nvme: add error handling support for add_disk()
nvme: only call synchronize_srcu when clearing current path
nvme: update keep alive interval when kato is modified
nvme-tcp: Do not reset transport on data digest errors
nvmet: fixup buffer overrun in nvmet_subsys_attr_serial()
nvmet: return bool from nvmet_passthru_ctrl and nvmet_is_passthru_req
nvmet: looks at the passthrough controller when initializing CAP
nvme: move nvme_multi_css into nvme.h
nvme-multipath: revalidate paths during rescan
nvme-multipath: set QUEUE_FLAG_NOWAIT
Li Jinlin [Tue, 7 Sep 2021 12:12:42 +0000 (20:12 +0800)]
blk-throttle: fix UAF by deleteing timer in blk_throtl_exit()
The pending timer has been set up in blk_throtl_init(). However, the
timer is not deleted in blk_throtl_exit(). This means that the timer
handler may still be running after freeing the timer, which would
result in a use-after-free.
Fix by calling del_timer_sync() to delete the timer in blk_throtl_exit().
block: genhd: don't call blkdev_show() with major_names_lock held
If CONFIG_BLK_DEV_LOOP && CONFIG_MTD (at least; there might be other
combinations), lockdep complains circular locking dependency at
__loop_clr_fd(), for major_names_lock serves as a locking dependency
aggregating hub across multiple block modules.
======================================================
WARNING: possible circular locking dependency detected
5.14.0+ #757 Tainted: G E
------------------------------------------------------
systemd-udevd/7568 is trying to acquire lock: ffff88800f334d48 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x70/0x560
but task is already holding lock: ffff888014a7d4a0 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x4d/0x400 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
Commit 1c500ad706383f1a ("loop: reduce the loop_ctl_mutex scope") is for
breaking "loop_ctl_mutex => &lo->lo_mutex" dependency chain. But enabling
a different block module results in forming circular locking dependency
due to shared major_names_lock mutex.
The simplest fix is to call probe function without holding
major_names_lock [1], but Christoph Hellwig does not like such idea.
Therefore, instead of holding major_names_lock in blkdev_show(),
introduce a different lock for blkdev_show() in order to break
"sb_writers#$N => &p->lock => major_names_lock" dependency chain.
Revert "cpufreq: intel_pstate: Process HWP Guaranteed change notification"
Revert commit d0e936adbd22 ("cpufreq: intel_pstate: Process HWP
Guaranteed change notification"), because it causes a NULL pointer
dereference to occur on Lenovo X1 gen9 laptops due to an HWP
guaranteed performance change interrupt arriving prematurely.
David S. Miller [Tue, 7 Sep 2021 13:04:59 +0000 (14:04 +0100)]
Merge branch 'stmmac-wol-fix'
Joakim Zhang says:
====================
net: stmmac: fix WoL issue
This patch set fixes stmmac not working after system resume back with WoL
active. Thanks a lot for Russell King keeps looking into this issue.
====================
net: stmmac: fix MAC not working when system resume back with WoL active
We can reproduce this issue with below steps:
1) enable WoL on the host
2) host system suspended
3) remote client send out wakeup packets
We can see that host system resume back, but can't work, such as ping failed.
After a bit digging, this issue is introduced by the commit 46f69ded988d
("net: stmmac: Use resolved link config in mac_link_up()"), which use
the finalised link parameters in mac_link_up() rather than the
parameters in mac_config().
There are two scenarios for MAC suspend/resume in STMMAC driver:
1) MAC suspend with WoL inactive, stmmac_suspend() call
phylink_mac_change() to notify phylink machine that a change in MAC
state, then .mac_link_down callback would be invoked. Further, it will
call phylink_stop() to stop the phylink instance. When MAC resume back,
firstly phylink_start() is called to start the phylink instance, then
call phylink_mac_change() which will finally trigger phylink machine to
invoke .mac_config and .mac_link_up callback. All is fine since
configuration in these two callbacks will be initialized, that means MAC
can restore the state.
2) MAC suspend with WoL active, phylink_mac_change() will put link
down, but there is no phylink_stop() to stop the phylink instance, so it
will link up again, that means .mac_config and .mac_link_up would be
invoked before system suspended. After system resume back, it will do
DMA initialization and SW reset which let MAC lost the hardware setting
(i.e MAC_Configuration register(offset 0x0) is reset). Since link is up
before system suspended, so .mac_link_up would not be invoked after
system resume back, lead to there is no chance to initialize the
configuration in .mac_link_up callback, as a result, MAC can't work any
longer.
After discussed with Russell King [1], we confirm that phylink framework
have not take WoL into consideration yet. This patch calls
phylink_suspend()/phylink_resume() functions which is newly introduced
by Russell King to fix this issue.
Fixes: 46f69ded988d ("net: stmmac: Use resolved link config in mac_link_up()") Signed-off-by: Joakim Zhang <[email protected]> Signed-off-by: David S. Miller <[email protected]>
Joakim Zhang reports that Wake-on-Lan with the stmmac ethernet driver broke
when moving the incorrect handling of mac link state out of mac_config().
This reason this breaks is because the stmmac's WoL is handled by the MAC
rather than the PHY, and phylink doesn't cater for that scenario.
This patch adds the necessary phylink code to handle suspend/resume events
according to whether the MAC still needs a valid link or not. This is the
barest minimum for this support.
The cur_tx counter must be incremented after TACT bit of
txdesc->status was set. However, a CPU is possible to reorder
instructions and/or memory accesses between cur_tx and
txdesc->status. And then, if TX interrupt happened at such a
timing, the sh_eth_tx_free() may free the descriptor wrongly.
So, add wmb() before cur_tx++.
Otherwise NETDEV WATCHDOG timeout is possible to happen.
Fixes: 86a74ff21a7a ("net: sh_eth: add support for Renesas SuperH Ethernet") Signed-off-by: Yoshihiro Shimoda <[email protected]> Signed-off-by: David S. Miller <[email protected]>
btrfs: zoned: fix double counting of split ordered extent
btrfs_add_ordered_extent_*() add num_bytes to fs_info->ordered_bytes.
Then, splitting an ordered extent will call btrfs_add_ordered_extent_*()
again for split extents, leading to double counting of the region of
a split extent. These leaked bytes are finally reported at unmount time
as follow:
BTRFS info (device dm-1): at unmount dio bytes count 364544
Fix the double counting by subtracting split extent's size from
fs_info->ordered_bytes.
Both of these threads hold uuid_mutex which is sufficient to protect
getting the seed device(s) freed while we are trying to clone it for
sprouting [2] or mounting a sprout [1] (as above). A mounted seed device
can not free/write/replace because it is read-only. An unmounted seed
device can be freed by btrfs_free_stale_devices(), but it needs
uuid_mutex. So this patch removes the unnecessary device_list_mutex in
clone_fs_devices(). And adds a lockdep_assert_held(&uuid_mutex) in
clone_fs_devices().
Josef Bacik [Tue, 27 Jul 2021 21:01:17 +0000 (17:01 -0400)]
btrfs: delay blkdev_put until after the device remove
When removing the device we call blkdev_put() on the device once we've
removed it, and because we have an EXCL open we need to take the
->open_mutex on the block device to clean it up. Unfortunately during
device remove we are holding the sb writers lock, which results in the
following lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #407 Not tainted
------------------------------------------------------
losetup/11595 is trying to acquire lock: ffff973ac35dd138 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0
but task is already holding lock: ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
Josef Bacik [Tue, 27 Jul 2021 21:01:16 +0000 (17:01 -0400)]
btrfs: update the bdev time directly when closing
We update the ctime/mtime of a block device when we remove it so that
blkid knows the device changed. However we do this by re-opening the
block device and calling filp_update_time. This is more correct because
it'll call the inode->i_op->update_time if it exists, but the block dev
inodes do not do this. Instead call generic_update_time() on the
bd_inode in order to avoid the blkdev_open path and get rid of the
following lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #406 Not tainted
------------------------------------------------------
losetup/11596 is trying to acquire lock: ffff939640d2f538 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0
but task is already holding lock: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
Kari Argillander [Mon, 30 Aug 2021 21:51:52 +0000 (00:51 +0300)]
btrfs: use correct header for div_u64 in misc.h
asm/do_div.h is for div_u64, but it is found in math64.h. This change
will make compiler job easier and prevent compiler errors in situation
where compiler will not find math64.h from another paths.
Anand Jain [Tue, 10 Aug 2021 15:23:44 +0000 (23:23 +0800)]
btrfs: fix upper limit for max_inline for page size 64K
The mount option max_inline ranges from 0 to the sectorsize (which is
now equal to page size). But we parse the mount options too early and
before the actual sectorsize is read from the superblock. So the upper
limit of max_inline is unaware of the actual sectorsize and is limited
by the temporary sectorsize 4096, even on a system where the default
sectorsize is 64K.
Fix this by reading the superblock sectorsize before the mount option
parse.
Support for expanded storage was only available until z13 and z/VM 6.3
respectively. However there haven't been any use cases a long time
before for this device driver.
Therefore remove it.
With commit cc049eecfb7a ("s390/pci: simplify CLP List PCI handling")
clp_get_state() was changed to make use of the new clp_find_pci() helper
function to query a specific function. This however returns -ENODEV when
the device is not found at all and this error was passed to the caller.
It was missed however that the callers actually expect a success return
from clp_get_state() if the device is gone.
Fix this by handling the -ENODEV return of clp_find_pci() explicitly in
clp_get_state() returning success and setting the state parameter to
ZPCI_FN_STATE_RESERVED matching the design concept that a PCI function
that disappeared must have been resverved elsewhere. For all other error
returns continue to just pass them on to the caller.
Move array from header to C file to avoid that it gets defined in
every C file where the header is included:
In file included from arch/s390/kernel/perf_cpum_cf_common.c:19:
./arch/s390/include/asm/cpu_mcf.h:27:18: warning: ‘cpumf_ctr_ctl’ defined but not used [-Wunused-const-variable=]
27 | static const u64 cpumf_ctr_ctl[CPUMF_CTR_SET_MAX] = {
| ^~~~~~~~~~~~~
Sven Schnelle [Fri, 27 Aug 2021 18:21:05 +0000 (20:21 +0200)]
s390/topology: fix topology information when calling cpu hotplug notifiers
The cpu hotplug notifiers are called without updating the core/thread
masks when a new CPU is added. This causes problems with code setting
up data structures in a cpu hotplug notifier, and relying on that later
in normal code.
This caused a crash in the new core scheduling code (SCHED_CORE),
where rq->core was set up in a notifier depending on cpu masks.
To fix this, add a cpu_setup_mask which is used in update_cpu_masks()
instead of the cpu_online_mask to determine whether the cpu masks should
be set for a certain cpu. Also move update_cpu_masks() to update the
masks before calling notify_cpu_starting() so that the notifiers are
seeing the updated masks.
s390/unwind: use current_frame_address() to unwind current task
current_stack_pointer() simply returns current value of %r15. If
current_stack_pointer() caller allocates stack (which is the case in
unwind code) %r15 points to a stack frame allocated for callees, meaning
current_stack_pointer() caller (e.g. stack_trace_save) will end up in
the stacktrace. This is not expected by stack_trace_save*() callers and
causes problems.
current_frame_address() on the other hand returns function stack frame
address, which matches %r15 upon function invocation. Using it in
get_stack_pointer() makes it more aligned with x86 implementation
(according to BACKTRACE_SELF_TEST output) and meets stack_trace_save*()
caller's expectations, notably KCSAN.
ALSA: gus: Fix repeated probe for ISA interwave card
The legacy ISA probe tries to probe the card repeatedly, and this
would conflict with the refactoring using devres. Put the card
creation out of the loop and only probe GUS object repeatedly.
Colin Ian King [Tue, 7 Sep 2021 08:45:34 +0000 (09:45 +0100)]
bonding: 3ad: pass parameter bond_params by reference
The parameter bond_params is a relatively large 192 byte sized
struct so pass it by reference rather than by value to reduce
copying.
Addresses-Coverity: ("Big parameter passed by value") Signed-off-by: Colin Ian King <[email protected]> Signed-off-by: David S. Miller <[email protected]>
David S. Miller [Tue, 7 Sep 2021 09:04:47 +0000 (10:04 +0100)]
Merge tag 'wireless-drivers-2021-09-07' of git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers
Kalle Valo says:
====================
wireless-drivers fixes for v5.15
First set of fixes for v5.15 and only iwlwifi patches this time. Most
important being support for new hardware and new firmware API.
I had already earlier applied a fix which also Linus applied to this
tree as commit 1476ff21abb4 ("iwl: fix debug printf format strings"),
but this doesn't seem to cause any conflicts so I left it there.
iwlwifi
* add support for firmware API 66
* add support for Samsung Galaxy Book Flex2 Alpha
* fix a leak happening every time module is loaded
* fix a printk compiler warning
====================
When removing the driver module w/o bringing an interface up before
the error below occurs. Reason seems to be that cancel_work_sync() is
called in t3_sge_stop() for a queue that hasn't been initialized yet.
Fixes: 5e0b8928927f ("net:cxgb3: replace tasklets with works") Signed-off-by: Heiner Kallweit <[email protected]> Signed-off-by: David S. Miller <[email protected]>
Randy Dunlap [Tue, 7 Sep 2021 00:19:49 +0000 (17:19 -0700)]
mfd: lpc_sch: Rename GPIOBASE to prevent build error
One MIPS platform (mach-rc32434) defines GPIOBASE. This macro
conflicts with one of the same name in lpc_sch.c. Rename the latter one
to prevent the build error.
../drivers/mfd/lpc_sch.c:25: error: "GPIOBASE" redefined [-Werror]
25 | #define GPIOBASE 0x44
../arch/mips/include/asm/mach-rc32434/rb.h:32: note: this is the location of the previous definition
32 | #define GPIOBASE 0x050000
Cc: Denis Turischev <[email protected]> Fixes: e82c60ae7d3a ("mfd: Introduce lpc_sch for Intel SCH LPC bridge") Signed-off-by: Randy Dunlap <[email protected]> Signed-off-by: Lee Jones <[email protected]>
dma-buf: DMABUF_SYSFS_STATS should depend on DMA_SHARED_BUFFER
DMA-BUF sysfs statistics are an option of DMA-BUF. It does not make
much sense to bother the user with a question about DMA-BUF sysfs
statistics if DMA-BUF itself is not enabled. Worse, enabling the
statistics enables the feature.
dma-buf: DMABUF_DEBUG should depend on DMA_SHARED_BUFFER
DMA-BUF debug checks are an option of DMA-BUF. Enabling DMABUF_DEBUG
without DMA_SHARED_BUFFER does not have any impact, as drivers/dma-buf/
is not entered during the build when DMA_SHARED_BUFFER is disabled.
The pdev maybe not a platform device, e.g. c_can_pci device, in this
case, calling to_platform_device() would not make sense. Also, per the
comment in drivers/net/can/c_can/c_can_ethtool.c, @bus_info should
match dev_name() string, so I am replacing this with dev_name() to fix
this issue.
can: rcar_canfd: add __maybe_unused annotation to silence warning
Since commit
| dd3bd23eb438 ("can: rcar_canfd: Add Renesas R-Car CAN FD driver")
the rcar_canfd driver can be compile tested on all architectures. On
non OF enabled archs, or archs where OF is optional (and disabled in
the .config) the compilation throws the following warning:
Input: elan_i2c - reduce the resume time for controller in Whitebox
Similar to controllers found Voxel, Delbin, Magpie and Bobba, the one found
in Whitebox does not need to be reset after issuing power-on command, and
skipping reset saves resume time.
a recent refactor created a null pointer vx in snd_vx222_probe().
The vx pointer should have been populated in snd_vx222_create() as
suggested in earlier version, otherwise vx->core.ibl.size will throw an
error.
Akira Yokosawa [Sun, 29 Aug 2021 02:06:16 +0000 (11:06 +0900)]
docs: pdfdocs: Fix typo in CJK-language specific font settings
There were typos in the fallback definitions of dummy LaTeX macros
for systems without CJK fonts.
They cause build errors in "make pdfdocs" on such systems.
Fix them.
thunderbolt: test: split up test cases in tb_test_credit_alloc_all
The tb_test_credit_alloc_all() function had a huge number of
KUNIT_ASSERT() statements, all of which (though the magic of many many
layers of inscrutable macros) ended up allocating and initializing
various test assertion structures on the stack.
Don't do that. The kernel stack isn't infinite, and we have compiler
warnings (now errors) for the case where a stack frame grows too large.
Like it did here, by not an inconsiderable margin:
drivers/thunderbolt/test.c: In function ‘tb_test_credit_alloc_all’:
drivers/thunderbolt/test.c:2367:1: error: the frame size of 4500 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
2367 | }
| ^
Solve this similarly to the lib/test_scanf case: split out the tests
into several smaller functions, each just testing one particular tunnel
credit allocation.
This makes the i386 allyesconfig build work for me again.
lib/test_scanf: split up number parsing test routines
It turns out that gcc has real trouble merging all the temporary
on-stack buffer allocation. So despite the fact that their lifetimes do
not overlap, gcc will allocate stack for all of them when they have
different types. Which they do in the number scanning test routines.
This is unfortunate in general, but with lots of test-cases in one
function, it becomes a real problem. gcc will allocate a huge stack
frame for no actual good reason.
We have tried to counteract this tendency of gcc not merging stack slots
(see "-fconserve-stack"), but that has limited effect (and should be on
by default these days, iirc).
So with all the debug options enabled on an i386 allmodconfig build, we
end up with overly big stack frames, and the resulting stack frame size
warnings (now errors):
lib/test_scanf.c: In function ‘numbers_list_field_width_val_width’:
lib/test_scanf.c:530:1: error: the frame size of 2088 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
530 | }
| ^
lib/test_scanf.c: In function ‘numbers_list_field_width_typemax’:
lib/test_scanf.c:488:1: error: the frame size of 2568 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
488 | }
| ^
lib/test_scanf.c: In function ‘numbers_list’:
lib/test_scanf.c:437:1: error: the frame size of 2088 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
437 | }
| ^
In this particular case, the reasonably straightforward solution is to
just split out the test routines into multiple more targeted versions.
That way we don't have one huge stack, but several smaller ones, and
they aren't active all at the same time.
The variable 'package_size' is an unsigned long, and should be printed
out using '%lu', not '%zd' (that would be for a size_t).
Yes, on many architectures (including x86-64), 'size_t' is in fact the
same type as 'long', but that's a fairly random architecture definition,
and on some platforms 'size_t' is in fact 'int' rather than 'long'.
That is the case on traditional 32-bit x86. Yes, both types are the
exact same 32-bit size, and it would all print out perfectly correctly,
but '%zd' ends up still being wrong.
And we can't make 'package_size' be a 'size_t', because we get the
actual value using efivar_entry_get() that takes a pointer to an
'unsigned long'. So '%lu' it is.
This fixes two of the i386 allmodconfig build warnings (that is now an
error due to -Werror).
Merge tag 'block-5.15-2021-09-05' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"Was going to send this one in later this week, but given that -Werror
is now enabled (or at least available), the mq-deadline fix really
should go in for the folks hitting that.
- Ensure dd_queued() is only there if needed (Geert)
- Fix a kerneldoc warning for bio_alloc_kiocb()
- BFQ fix for queue merging
- loop locking fix (Tetsuo)"
* tag 'block-5.15-2021-09-05' of git://git.kernel.dk/linux-block:
loop: reduce the loop_ctl_mutex scope
bio: fix kerneldoc documentation for bio_alloc_kiocb()
block, bfq: honor already-setup queue merges
block/mq-deadline: Move dd_queued() to fix defined but not used warning
Merge tag 'misc-5.15-2021-09-05' of git://git.kernel.dk/linux-block
Pull CDROM maintainer update from Jens Axboe:
"It's been about 22 years since I originally started maintaining the
CDROM code, and I just haven't been able to even get reviews done in a
timely fashion the last handful of years.
Time to pass it on, and Phillip has volunteered take over these
duties. I'll be helping as needed for the foreseeable future"
* tag 'misc-5.15-2021-09-05' of git://git.kernel.dk/linux-block:
cdrom: update uniform CD-ROM maintainership in MAINTAINERS file
Merge tag 'libata-5.15-2021-09-05' of git://git.kernel.dk/linux-block
Pull libata fixes from Jens Axboe:
"Fixes for queued trim on certain Samsung SSDs, in conjunction with
certain ATI controllers"
* tag 'libata-5.15-2021-09-05' of git://git.kernel.dk/linux-block:
libata: Add ATA_HORKAGE_NO_NCQ_ON_ATI for Samsung 860 and 870 SSD.
libata: add ATA_HORKAGE_NO_NCQ_TRIM for Samsung 860 and 870 SSDs
Merge tag 'for-5.15/io_uring-2021-09-04' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe:
"As sometimes happens, two reports came in around the merge window open
that led to some fixes. Hence this one is a bit bigger than usual
followup fixes, but most of it will be going towards stable, outside
of the fixes that are addressing regressions from this merge window.
In detail:
- postgres is a heavy user of signals between tasks, and if we're
unlucky this can interfere with io-wq worker creation. Make sure
we're resilient against unrelated signal handling. This set of
changes also includes hardening against allocation failures, which
could previously had led to stalls.
- Some use cases that end up having a mix of bounded and unbounded
work would have starvation issues related to that. Split the
pending work lists to handle that better.
- Completion trace int -> unsigned -> long fix
- Fix issue with REGISTER_IOWQ_MAX_WORKERS and SQPOLL
- Fix regression with hash wait lock in this merge window
- Fix retry issued on block devices (Ming)
- Fix regression with links in this merge window (Pavel)
- Fix race with multi-shot poll and completions (Xiaoguang)
- Ensure submissions are flushed after running task_work (Pavel)"
* tag 'for-5.15/io_uring-2021-09-04' of git://git.kernel.dk/linux-block:
io_uring: io_uring_complete() trace should take an integer
io_uring: fix possible poll event lost in multi shot mode
io_uring: prolong tctx_task_work() with flushing
io_uring: don't disable kiocb_done() CQE batching
io_uring: ensure IORING_REGISTER_IOWQ_MAX_WORKERS works with SQPOLL
io-wq: make worker creation resilient against signals
io-wq: get rid of FIXED worker flag
io-wq: only exit on fatal signals
io-wq: split bounded and unbounded work into separate lists
io-wq: fix queue stalling race
io_uring: don't submit half-prepared drain request
io_uring: fix queueing half-created requests
io-wq: ensure that hash wait lock is IRQ disabling
io_uring: retry in case of short read on block device
io_uring: IORING_OP_WRITE needs hash_reg_file set
io-wq: fix race between adding work and activating a free worker
Andy Shevchenko [Mon, 6 Sep 2021 12:44:48 +0000 (15:44 +0300)]
net: wwan: iosm: Replace io.*64_lo_hi() with regular accessors
The io.*_lo_hi() variants are not strictly needed on the x86 hardware
and especially the PCI bus. Replace them with regular accessors, but
leave headers in place in case of 32-bit build.
Jason Wang [Mon, 6 Sep 2021 13:56:53 +0000 (21:56 +0800)]
net: qcom/emac: Replace strlcpy with strscpy
The strlcpy should not be used because it doesn't limit the source
length. As linus says, it's a completely useless function if you
can't implicitly trust the source string - but that is almost always
why people think they should use it! All in all the BSD function
will lead some potential bugs.
But the strscpy doesn't require reading memory from the src string
beyond the specified "count" bytes, and since the return value is
easier to error-check than strlcpy()'s. In addition, the implementation
is robust to the string changing out from underneath it, unlike the
current strlcpy() implementation.
This commit was added for equivalence with a similar fix to ip_gre.
That fix proved to have a bug. Upon closer inspection, ip6_gre is not
susceptible to the original bug.
So revert the unnecessary extra check.
In short, ipgre_xmit calls skb_pull to remove ipv4 headers previously
inserted by dev_hard_header. ip6gre_tunnel_xmit does not.
Jussi Maki [Mon, 6 Sep 2021 08:56:38 +0000 (10:56 +0200)]
selftests/bpf: Test XDP bonding nest and unwind
Modify the test to check that enslaving a bond slave with a XDP program
is now allowed.
Extend attach test to exercise the program unwinding in bond_xdp_set and
add a new test for loading XDP program on doubly nested bond device to
verify that static key incr/decr is correct.
Jussi Maki [Mon, 6 Sep 2021 08:56:37 +0000 (10:56 +0200)]
bonding: Fix negative jump label count on nested bonding
With nested bonding devices the nested bond device's ndo_bpf was
called without a program causing it to decrement the static key
without a prior increment leading to negative count.
Fix the issue by 1) only calling slave's ndo_bpf when there's a
program to be loaded and 2) only decrement the count when a program
is unloaded.
Add a new entry for VM Sockets (AF_VSOCK) that covers vsock core,
tests, and headers. Move some general vsock stuff from virtio-vsock
entry into this new more general vsock entry.
I've been reviewing and contributing for the last few years,
so I'm available to help maintain this code.
In case of fuse the MM subsystem doesn't guarantee that page writeback
completes by the time ->sync_fs() is called. This is because fuse
completes page writeback immediately to prevent DoS of memory reclaim by
the userspace file server.
This means that fuse itself must ensure that writes are synced before
sending the SYNCFS request to the server.
Introduce sync buckets, that hold a counter for the number of outstanding
write requests. On syncfs replace the current bucket with a new one and
wait until the old bucket's counter goes down to zero.
It is possible to have multiple syncfs calls in parallel, in which case
there could be more than one waited-on buckets. Descendant buckets must
not complete until the parent completes. Add a count to the child (new)
bucket until the (parent) old bucket completes.
Use RCU protection to dereference the current bucket and to wake up an
emptied bucket. Use fc->lock to protect against parallel assignments to
the current bucket.
This leaves just the counter to be a possible scalability issue. The
fc->num_waiting counter has a similar issue, so both should be addressed at
the same time.
Xie Yongji [Tue, 31 Aug 2021 10:36:34 +0000 (18:36 +0800)]
Documentation: Add documentation for VDUSE
VDUSE (vDPA Device in Userspace) is a framework to support
implementing software-emulated vDPA devices in userspace. This
document is intended to clarify the VDUSE design and usage.
Xie Yongji [Tue, 31 Aug 2021 10:36:33 +0000 (18:36 +0800)]
vduse: Introduce VDUSE - vDPA Device in Userspace
This VDUSE driver enables implementing software-emulated vDPA
devices in userspace. The vDPA device is created by
ioctl(VDUSE_CREATE_DEV) on /dev/vduse/control. Then a char device
interface (/dev/vduse/$NAME) is exported to userspace for device
emulation.
In order to make the device emulation more secure, the device's
control path is handled in kernel. A message mechnism is introduced
to forward some dataplane related control messages to userspace.
And in the data path, the DMA buffer will be mapped into userspace
address space through different ways depending on the vDPA bus to
which the vDPA device is attached. In virtio-vdpa case, the MMU-based
software IOTLB is used to achieve that. And in vhost-vdpa case, the
DMA buffer is reside in a userspace memory region which can be shared
to the VDUSE userspace processs via transferring the shmfd.
For more details on VDUSE design and usage, please see the follow-on
Documentation commit.
NB(mst): when merging this with b542e383d8c0 ("eventfd: Make signal recursion protection a task bit")
replace eventfd_signal_count with eventfd_signal_allowed,
and drop the previous
("eventfd: Export eventfd_wake_count to modules").
projects / linux.git / log