20 Jan, 2021
1 commit
-
commit ad0a6bad44758afa3b440c254a24999a0c7e35d5 upstream.
We've observed crashes due to an empty cpu mask in
hyperv_flush_tlb_others. Obviously the cpu mask in question is changed
between the cpumask_empty call at the beginning of the function and when
it is actually used later.One theory is that an interrupt comes in between and a code path ends up
changing the mask. Move the check after interrupt has been disabled to
see if it fixes the issue.Signed-off-by: Wei Liu
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20210105175043.28325-1-wei.liu@kernel.org
Reviewed-by: Michael Kelley
Signed-off-by: Greg Kroah-Hartman
06 Nov, 2020
1 commit
-
Pull hyperv fixes from Wei Liu:
- clarify a comment (Michael Kelley)
- change a pr_warn() to pr_info() (Olaf Hering)
* tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
x86/hyperv: Clarify comment on x2apic mode
hv_balloon: disable warning when floor reached
27 Oct, 2020
1 commit
-
The comment about Hyper-V accessors is unclear regarding their
potential use in x2apic mode, as is the associated commit message
in e211288b72f1. Clarify that while the architectural and
synthetic MSRs are equivalent in x2apic mode, the full set of xapic
accessors cannot be used because of register layout differences.Fixes: e211288b72f1 ("x86/hyperv: Make vapic support x2apic mode")
Signed-off-by: Michael Kelley
Link: https://lore.kernel.org/r/1603723972-81303-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu
27 Sep, 2020
1 commit
-
In the architecture independent version of hyperv-tlfs.h, commit c55a844f46f958b
removed the "X64" in the symbol names so they would make sense for both x86 and
ARM64. That commit added aliases with the "X64" in the x86 version of hyperv-tlfs.h
so that existing x86 code would continue to compile.As a cleanup, update the x86 code to use the symbols without the "X64", then remove
the aliases. There's no functional change.Signed-off-by: Joseph Salisbury
Signed-off-by: Thomas Gleixner
Reviewed-by: Michael Kelley
Acked-by: Paolo Bonzini
Link: https://lore.kernel.org/r/1601130386-11111-1-git-send-email-jsalisbury@linux.microsoft.com
04 Jul, 2020
1 commit
-
Fix the recently added new __vmalloc_node_range callers to pass the
correct values as the owner for display in /proc/vmallocinfo.Fixes: 800e26b81311 ("x86/hyperv: allocate the hypercall page with only read and execute bits")
Fixes: 10d5e97c1bf8 ("arm64: use PAGE_KERNEL_ROX directly in alloc_insn_page")
Fixes: 7a0e27b2a0ce ("mm: remove vmalloc_exec")
Reported-by: Ard Biesheuvel
Signed-off-by: Christoph Hellwig
Signed-off-by: Andrew Morton
Link: http://lkml.kernel.org/r/20200627075649.2455097-1-hch@lst.de
Signed-off-by: Linus Torvalds
26 Jun, 2020
1 commit
-
Patch series "fix a hyperv W^X violation and remove vmalloc_exec"
Dexuan reported a W^X violation due to the fact that the hyper hypercall
page due switching it to be allocated using vmalloc_exec.The problem is that PAGE_KERNEL_EXEC as used by vmalloc_exec actually
sets writable permissions in the pte. This series fixes the issue by
switching to the low-level __vmalloc_node_range interface that allows
specifing more detailed permissions instead. It then also open codes
the other two callers and removes the somewhat confusing vmalloc_exec
interface.Peter noted that the hyper hypercall page allocation also has another
long standing issue in that it shouldn't use the full vmalloc but just
the module space. This issue is so far theoretical as the allocation is
done early in the boot process. I plan to fix it with another bigger
series for 5.9.This patch (of 3):
Avoid a W^X violation cause by the fact that PAGE_KERNEL_EXEC includes
the writable bit.For this resurrect the removed PAGE_KERNEL_RX definition, but as
PAGE_KERNEL_ROX to match arm64 and powerpc.Link: http://lkml.kernel.org/r/20200618064307.32739-2-hch@lst.de
Fixes: 78bb17f76edc ("x86/hyperv: use vmalloc_exec for the hypercall page")
Signed-off-by: Christoph Hellwig
Reported-by: Dexuan Cui
Tested-by: Vitaly Kuznetsov
Acked-by: Wei Liu
Acked-by: Peter Zijlstra (Intel)
Cc: Catalin Marinas
Cc: Will Deacon
Cc: Jessica Yu
Cc: David Hildenbrand
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Jun, 2020
1 commit
-
Convert various hypervisor vectors to IDTENTRY_SYSVEC:
- Implement the C entry point with DEFINE_IDTENTRY_SYSVEC
- Emit the ASM stub with DECLARE_IDTENTRY_SYSVEC
- Remove the ASM idtentries in 64-bit
- Remove the BUILD_INTERRUPT entries in 32-bit
- Remove the old prototypesNo functional change.
Signed-off-by: Thomas Gleixner
Signed-off-by: Ingo Molnar
Acked-by: Andy Lutomirski
Reviewed-by: Wei Liu
Link: https://lore.kernel.org/r/20200521202119.647997594@linutronix.de
03 Jun, 2020
2 commits
-
The pgprot argument to __vmalloc is always PAGE_KERNEL now, so remove it.
Signed-off-by: Christoph Hellwig
Signed-off-by: Andrew Morton
Reviewed-by: Michael Kelley [hyperv]
Acked-by: Gao Xiang [erofs]
Acked-by: Peter Zijlstra (Intel)
Acked-by: Wei Liu
Cc: Christian Borntraeger
Cc: Christophe Leroy
Cc: Daniel Vetter
Cc: David Airlie
Cc: Greg Kroah-Hartman
Cc: Haiyang Zhang
Cc: Johannes Weiner
Cc: "K. Y. Srinivasan"
Cc: Laura Abbott
Cc: Mark Rutland
Cc: Minchan Kim
Cc: Nitin Gupta
Cc: Robin Murphy
Cc: Sakari Ailus
Cc: Stephen Hemminger
Cc: Sumit Semwal
Cc: Benjamin Herrenschmidt
Cc: Catalin Marinas
Cc: Heiko Carstens
Cc: Paul Mackerras
Cc: Vasily Gorbik
Cc: Will Deacon
Link: http://lkml.kernel.org/r/20200414131348.444715-22-hch@lst.de
Signed-off-by: Linus Torvalds -
Patch series "decruft the vmalloc API", v2.
Peter noticed that with some dumb luck you can toast the kernel address
space with exported vmalloc symbols.I used this as an opportunity to decruft the vmalloc.c API and make it
much more systematic. This also removes any chance to create vmalloc
mappings outside the designated areas or using executable permissions
from modules. Besides that it removes more than 300 lines of code.This patch (of 29):
Use the designated helper for allocating executable kernel memory, and
remove the now unused PAGE_KERNEL_RX define.Signed-off-by: Christoph Hellwig
Signed-off-by: Andrew Morton
Reviewed-by: Michael Kelley
Acked-by: Wei Liu
Acked-by: Peter Zijlstra (Intel)
Cc: Christian Borntraeger
Cc: Christophe Leroy
Cc: Daniel Vetter
Cc: David Airlie
Cc: Gao Xiang
Cc: Greg Kroah-Hartman
Cc: Haiyang Zhang
Cc: Johannes Weiner
Cc: "K. Y. Srinivasan"
Cc: Laura Abbott
Cc: Mark Rutland
Cc: Minchan Kim
Cc: Nitin Gupta
Cc: Robin Murphy
Cc: Sakari Ailus
Cc: Stephen Hemminger
Cc: Sumit Semwal
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: Catalin Marinas
Cc: Will Deacon
Cc: Heiko Carstens
Cc: Vasily Gorbik
Link: http://lkml.kernel.org/r/20200414131348.444715-1-hch@lst.de
Link: http://lkml.kernel.org/r/20200414131348.444715-2-hch@lst.de
Signed-off-by: Linus Torvalds
13 May, 2020
1 commit
-
Errors during hibernation with reenlightenment notifications enabled were
reported:[ 51.730435] PM: hibernation entry
[ 51.737435] PM: Syncing filesystems ...
...
[ 54.102216] Disabling non-boot CPUs ...
[ 54.106633] smpboot: CPU 1 is now offline
[ 54.110006] unchecked MSR access error: WRMSR to 0x40000106 (tried to
write 0x47c72780000100ee) at rIP: 0xffffffff90062f24
native_write_msr+0x4/0x20)
[ 54.110006] Call Trace:
[ 54.110006] hv_cpu_die+0xd9/0xf0
...Normally, hv_cpu_die() just reassigns reenlightenment notifications to some
other CPU when the CPU receiving them goes offline. Upon hibernation, there
is no other CPU which is still online so cpumask_any_but(cpu_online_mask)
returns >= nr_cpu_ids and using it as hv_vp_index index is incorrect.
Disable the feature when cpumask_any_but() fails.Also, as we now disable reenlightenment notifications upon hibernation we
need to restore them on resume. Check if hv_reenlightenment_cb was
previously set and restore from hv_resume().Signed-off-by: Vitaly Kuznetsov
Reviewed-by: Dexuan Cui
Reviewed-by: Tianyu Lan
Link: https://lore.kernel.org/r/20200512160153.134467-1-vkuznets@redhat.com
Signed-off-by: Wei Liu
21 Apr, 2020
1 commit
-
Unlike the other CPUs, CPU0 is never offlined during hibernation, so in the
resume path, the "new" kernel's VP assist page is not suspended (i.e. not
disabled), and later when we jump to the "old" kernel, the page is not
properly re-enabled for CPU0 with the allocated page from the old kernel.So far, the VP assist page is used by hv_apic_eoi_write(), and is also
used in the case of nested virtualization (running KVM atop Hyper-V).For hv_apic_eoi_write(), when the page is not properly re-enabled,
hvp->apic_assist is always 0, so the HV_X64_MSR_EOI MSR is always written.
This is not ideal with respect to performance, but Hyper-V can still
correctly handle this according to the Hyper-V spec; nevertheless, Linux
still must update the Hyper-V hypervisor with the correct VP assist page
to prevent Hyper-V from writing to the stale page, which causes guest
memory corruption and consequently may have caused the hangs and triple
faults seen during non-boot CPUs resume.Fix the issue by calling hv_cpu_die()/hv_cpu_init() in the syscore ops.
Without the fix, hibernation can fail at a rate of 1/300 ~ 1/500.
With the fix, hibernation can pass a long-haul test of 2000 runs.In the case of nested virtualization, disabling/reenabling the assist
page upon hibernation may be unsafe if there are active L2 guests.
It looks KVM should be enhanced to abort the hibernation request if
there is any active L2 guest.Fixes: 05bd330a7fd8 ("x86/hyperv: Suspend/resume the hypercall page for hibernation")
Cc: stable@vger.kernel.org
Signed-off-by: Dexuan Cui
Link: https://lore.kernel.org/r/1587437171-2472-1-git-send-email-decui@microsoft.com
Signed-off-by: Wei Liu
12 Apr, 2020
1 commit
-
When oops happens with panic_on_oops unset, the oops
thread is killed by die() and system continues to run.
In such case, guest should not report crash register
data to host since system still runs. Check panic_on_oops
and return directly in hyperv_report_panic() when the function
is called in the die() and panic_on_oops is unset. Fix it.Fixes: 7ed4325a44ea ("Drivers: hv: vmbus: Make panic reporting to be more useful")
Signed-off-by: Tianyu Lan
Reviewed-by: Michael Kelley
Link: https://lore.kernel.org/r/20200406155331.2105-7-Tianyu.Lan@microsoft.com
Signed-off-by: Wei Liu
01 Feb, 2020
1 commit
-
For hibernation the hypercall page must be disabled before the hibernation
image is created so that subsequent hypercall operations fail safely. On
resume the hypercall page has to be restored and reenabled to ensure proper
operation of the resumed kernel.Implement the necessary suspend/resume callbacks.
[ tglx: Decrypted changelog ]
Signed-off-by: Dexuan Cui
Signed-off-by: Thomas Gleixner
Reviewed-by: Michael Kelley
Link: https://lore.kernel.org/r/1578350559-130275-1-git-send-email-decui@microsoft.com
01 Dec, 2019
1 commit
-
Pull Hyper-V updates from Sasha Levin:
- support for new VMBus protocols (Andrea Parri)
- hibernation support (Dexuan Cui)
- latency testing framework (Branden Bonaby)
- decoupling Hyper-V page size from guest page size (Himadri Pandya)
* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (22 commits)
Drivers: hv: vmbus: Fix crash handler reset of Hyper-V synic
drivers/hv: Replace binary semaphore with mutex
drivers: iommu: hyperv: Make HYPERV_IOMMU only available on x86
HID: hyperv: Add the support of hibernation
hv_balloon: Add the support of hibernation
x86/hyperv: Implement hv_is_hibernation_supported()
Drivers: hv: balloon: Remove dependencies on guest page size
Drivers: hv: vmbus: Remove dependencies on guest page size
x86: hv: Add function to allocate zeroed page for Hyper-V
Drivers: hv: util: Specify ring buffer size using Hyper-V page size
Drivers: hv: Specify receive buffer size using Hyper-V page size
tools: hv: add vmbus testing tool
drivers: hv: vmbus: Introduce latency testing
video: hyperv: hyperv_fb: Support deferred IO for Hyper-V frame buffer driver
video: hyperv: hyperv_fb: Obtain screen resolution from Hyper-V host
hv_netvsc: Add the support of hibernation
hv_sock: Add the support of hibernation
video: hyperv_fb: Add the support of hibernation
scsi: storvsc: Add the support of hibernation
Drivers: hv: vmbus: Add module parameter to cap the VMBus version
...
22 Nov, 2019
2 commits
-
The API will be used by the hv_balloon and hv_vmbus drivers.
Balloon up/down and hot-add of memory must not be active if the user
wants the Linux VM to support hibernation, because they are incompatible
with hibernation according to Hyper-V team, e.g. upon suspend the
balloon VSP doesn't save any info about the ballooned-out pages (if any);
so, after Linux resumes, Linux balloon VSC expects that the VSP will
return the pages if Linux is under memory pressure, but the VSP will
never do that, since the VSP thinks it never stole the pages from the VM.So, if the user wants Linux VM to support hibernation, Linux must forbid
balloon up/down and hot-add, and the only functionality of the balloon VSC
driver is reporting the VM's memory pressure to the host.Ideally, when Linux detects that the user wants it to support hibernation,
the balloon VSC should tell the VSP that it does not support ballooning
and hot-add. However, the current version of the VSP requires the VSC
should support these capabilities, otherwise the capability negotiation
fails and the VSC can not load at all, so with the later changes to the
VSC driver, Linux VM still reports to the VSP that the VSC supports these
capabilities, but the VSC ignores the VSP's requests of balloon up/down
and hot add, and reports an error to the VSP, when applicable. BTW, in
the future the balloon VSP driver will allow the VSC to not support the
capabilities of balloon up/down and hot add.The ACPI S4 state is not a must for hibernation to work, because Linux is
able to hibernate as long as the system can shut down. However in practice
we decide to artificially use the presence of the virtual ACPI S4 state as
an indicator of the user's intent of using hibernation, because Linux VM
must find a way to know if the user wants to use the hibernation feature
or not.By default, Hyper-V does not enable the virtual ACPI S4 state; on recent
Hyper-V hosts (e.g. RS5, 19H1), the administrator is able to enable the
state for a VM by WMI commands.Once all the vmbus and VSC patches for the hibernation feature are
accepted, an extra patch will be submitted to forbid hibernation if the
virtual ACPI S4 state is absent, i.e. hv_is_hibernation_supported() is
false.Signed-off-by: Dexuan Cui
Reviewed-by: Michael Kelley
Acked-by: Thomas Gleixner
Signed-off-by: Sasha Levin -
Hyper-V assumes page size to be 4K. While this assumption holds true on
x86 architecture, it might not be true for ARM64 architecture. Hence
define hyper-v specific function to allocate a zeroed page which can
have a different implementation on ARM64 architecture to handle the
conflict between hyper-v's assumed page size and actual guest page size.Signed-off-by: Himadri Pandya
Reviewed-by: Michael Kelley
Signed-off-by: Sasha Levin
15 Nov, 2019
2 commits
-
Hyper-V has historically initialized stimer-based clockevents late in the
process of onlining a CPU because clockevents depend on stimer
interrupts. In the original Hyper-V design, stimer interrupts generate a
VMbus message, so the VMbus machinery must be running first, and VMbus
can't be initialized until relatively late. On x86/64, LAPIC timer based
clockevents are used during early initialization before VMbus and
stimer-based clockevents are ready, and again during CPU offlining after
the stimer clockevents have been shut down.Unfortunately, this design creates problems when offlining CPUs for
hibernation or other purposes. stimer-based clockevents are shut down
relatively early in the offlining process, so clockevents_unbind_device()
must be used to fallback to the LAPIC-based clockevents for the remainder
of the offlining process. Furthermore, the late initialization and early
shutdown of stimer-based clockevents doesn't work well on ARM64 since there
is no other timer like the LAPIC to fallback to. So CPU onlining and
offlining doesn't work properly.Fix this by recognizing that stimer Direct Mode is the normal path for
newer versions of Hyper-V on x86/64, and the only path on other
architectures. With stimer Direct Mode, stimer interrupts don't require any
VMbus machinery. stimer clockevents can be initialized and shut down
consistent with how it is done for other clockevent devices. While the old
VMbus-based stimer interrupts must still be supported for backward
compatibility on x86, that mode of operation can be treated as legacy.So add a new Hyper-V stimer entry in the CPU hotplug state list, and use
that new state when in Direct Mode. Update the Hyper-V clocksource driver
to allocate and initialize stimer clockevents earlier during boot. Update
Hyper-V initialization and the VMbus driver to use this new design. As a
result, the LAPIC timer is no longer used during boot or CPU
onlining/offlining and clockevents_unbind_device() is not called. But
retain the old design as a legacy implementation for older versions of
Hyper-V that don't support Direct Mode.Signed-off-by: Michael Kelley
Signed-off-by: Thomas Gleixner
Tested-by: Dexuan Cui
Reviewed-by: Dexuan Cui
Link: https://lkml.kernel.org/r/1573607467-9456-1-git-send-email-mikelley@microsoft.com -
Pick up upstream fixes to avoid conflicts.
12 Nov, 2019
1 commit
-
When sending an IPI to a single CPU there is no need to deal with cpumasks.
With 2 CPU guest on WS2019 a minor (like 3%, 8043 -> 7761 CPU cycles)
improvement with smp_call_function_single() loop benchmark can be seeb. The
optimization, however, is tiny and straitforward. Also, send_ipi_one() is
important for PV spinlock kick.Switching to the regular APIC IPI send for CPU > 64 case does not make
sense as it is twice as expesive (12650 CPU cycles for __send_ipi_mask_ex()
call, 26000 for orig_apic.send_IPI(cpu, vector)).Signed-off-by: Vitaly Kuznetsov
Signed-off-by: Thomas Gleixner
Reviewed-by: Michael Kelley
Reviewed-by: Roman Kagan
Link: https://lkml.kernel.org/r/20191027151938.7296-1-vkuznets@redhat.com
15 Oct, 2019
1 commit
-
Now that there's Hyper-V IOMMU driver, Linux can switch to x2apic mode
when supported by the vcpus.However, the apic access functions for Hyper-V enlightened apic assume
xapic mode only.As a result, Linux fails to bring up secondary cpus when run as a guest
in QEMU/KVM with both hv_apic and x2apic enabled.According to Michael Kelley, when in x2apic mode, the Hyper-V synthetic
apic MSRs behave exactly the same as the corresponding architectural
x2apic MSRs, so there's no need to override the apic accessors. The
only exception is hv_apic_eoi_write, which benefits from lazy EOI when
available; however, its implementation works for both xapic and x2apic
modes.Fixes: 29217a474683 ("iommu/hyper-v: Add Hyper-V stub IOMMU driver")
Fixes: 6b48cb5f8347 ("X86/Hyper-V: Enlighten APIC access")
Suggested-by: Michael Kelley
Signed-off-by: Roman Kagan
Signed-off-by: Thomas Gleixner
Reviewed-by: Vitaly Kuznetsov
Reviewed-by: Michael Kelley
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20191010123258.16919-1-rkagan@virtuozzo.com
18 Sep, 2019
1 commit
-
Pull core timer updates from Thomas Gleixner:
"Timers and timekeeping updates:- A large overhaul of the posix CPU timer code which is a preparation
for moving the CPU timer expiry out into task work so it can be
properly accounted on the task/process.An update to the bogus permission checks will come later during the
merge window as feedback was not complete before heading of for
travel.- Switch the timerqueue code to use cached rbtrees and get rid of the
homebrewn caching of the leftmost node.- Consolidate hrtimer_init() + hrtimer_init_sleeper() calls into a
single function- Implement the separation of hrtimers to be forced to expire in hard
interrupt context even when PREEMPT_RT is enabled and mark the
affected timers accordingly.- Implement a mechanism for hrtimers and the timer wheel to protect
RT against priority inversion and live lock issues when a (hr)timer
which should be canceled is currently executing the callback.
Instead of infinitely spinning, the task which tries to cancel the
timer blocks on a per cpu base expiry lock which is held and
released by the (hr)timer expiry code.- Enable the Hyper-V TSC page based sched_clock for Hyper-V guests
resulting in faster access to timekeeping functions.- Updates to various clocksource/clockevent drivers and their device
tree bindings.- The usual small improvements all over the place"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits)
posix-cpu-timers: Fix permission check regression
posix-cpu-timers: Always clear head pointer on dequeue
hrtimer: Add a missing bracket and hide `migration_base' on !SMP
posix-cpu-timers: Make expiry_active check actually work correctly
posix-timers: Unbreak CONFIG_POSIX_TIMERS=n build
tick: Mark sched_timer to expire in hard interrupt context
hrtimer: Add kernel doc annotation for HRTIMER_MODE_HARD
x86/hyperv: Hide pv_ops access for CONFIG_PARAVIRT=n
posix-cpu-timers: Utilize timerqueue for storage
posix-cpu-timers: Move state tracking to struct posix_cputimers
posix-cpu-timers: Deduplicate rlimit handling
posix-cpu-timers: Remove pointless comparisons
posix-cpu-timers: Get rid of 64bit divisions
posix-cpu-timers: Consolidate timer expiry further
posix-cpu-timers: Get rid of zero checks
rlimit: Rewrite non-sensical RLIMIT_CPU comment
posix-cpu-timers: Respect INFINITY for hard RTTIME limit
posix-cpu-timers: Switch thread group sampling to array
posix-cpu-timers: Restructure expiry array
posix-cpu-timers: Remove cputime_expires
...
17 Sep, 2019
1 commit
-
Pull x86 hyperv updates from Ingo Molnar:
"Misc updates related to page size abstractions within the HyperV code,
in preparation for future features"* 'x86-hyperv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
drivers: hv: vmbus: Replace page definition with Hyper-V specific one
x86/hyperv: Add functions to allocate/deallocate page for Hyper-V
x86/hyperv: Create and use Hyper-V page definitions
03 Sep, 2019
1 commit
-
When the 'start' parameter is >= 0xFF000000 on 32-bit
systems, or >= 0xFFFFFFFF'FF000000 on 64-bit systems,
fill_gva_list() gets into an infinite loop.With such inputs, 'cur' overflows after adding HV_TLB_FLUSH_UNIT
and always compares as less than end. Memory is filled with
guest virtual addresses until the system crashes.Fix this by never incrementing 'cur' to be larger than 'end'.
Reported-by: Jong Hyun Park
Signed-off-by: Tianyu Lan
Reviewed-by: Michael Kelley
Cc: Borislav Petkov
Cc: Linus Torvalds
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Fixes: 2ffd9e33ce4a ("x86/hyper-v: Use hypercall for remote TLB flush")
Signed-off-by: Ingo Molnar
23 Aug, 2019
1 commit
-
Hyper-V guests use the default native_sched_clock() in
pv_ops.time.sched_clock on x86. But native_sched_clock() directly uses the
raw TSC value, which can be discontinuous in a Hyper-V VM.Add the generic hv_setup_sched_clock() to set the sched clock function
appropriately. On x86, this sets pv_ops.time.sched_clock to read the
Hyper-V reference TSC value that is scaled and adjusted to be continuous.Also move the Hyper-V reference TSC initialization much earlier in the boot
process so no discontinuity is observed when pv_ops.time.sched_clock
calculates its offset.[ tglx: Folded build fix ]
Signed-off-by: Tianyu Lan
Signed-off-by: Thomas Gleixner
Reviewed-by: Michael Kelley
Link: https://lkml.kernel.org/r/20190814123216.32245-3-Tianyu.Lan@microsoft.com
22 Jul, 2019
1 commit
-
Introduce two new functions, hv_alloc_hyperv_page() and
hv_free_hyperv_page(), to allocate/deallocate memory with the size and
alignment that Hyper-V expects as a page. Although currently they are not
used, they are ready to be used to allocate/deallocate memory on x86 when
their ARM64 counterparts are implemented, keeping symmetry between
architectures with potentially different guest page sizes.Signed-off-by: Maya Nakamura
Signed-off-by: Thomas Gleixner
Reviewed-by: Michael Kelley
Reviewed-by: Vitaly Kuznetsov
Link: https://lore.kernel.org/lkml/alpine.DEB.2.21.1906272334560.32342@nanos.tec.linutronix.de/
Link: https://lore.kernel.org/lkml/87muindr9c.fsf@vitty.brq.redhat.com/
Link: https://lkml.kernel.org/r/706b2e71eb3e587b5f8801e50f090fae2a00e35d.1562916939.git.m.maya.nakamura@gmail.com
19 Jul, 2019
1 commit
-
The VP ASSIST PAGE is an "overlay" page (see Hyper-V TLFS's Section
5.2.1 "GPA Overlay Pages" for the details) and here is an excerpt:"The hypervisor defines several special pages that "overlay" the guest's
Guest Physical Addresses (GPA) space. Overlays are addressed GPA but are
not included in the normal GPA map maintained internally by the hypervisor.
Conceptually, they exist in a separate map that overlays the GPA map.If a page within the GPA space is overlaid, any SPA page mapped to the
GPA page is effectively "obscured" and generally unreachable by the
virtual processor through processor memory accesses.If an overlay page is disabled, the underlying GPA page is "uncovered",
and an existing mapping becomes accessible to the guest."SPA = System Physical Address = the final real physical address.
When a CPU (e.g. CPU1) is onlined, hv_cpu_init() allocates the VP ASSIST
PAGE and enables the EOI optimization for this CPU by writing the MSR
HV_X64_MSR_VP_ASSIST_PAGE. From now on, hvp->apic_assist belongs to the
special SPA page, and this CPU *always* uses hvp->apic_assist (which is
shared with the hypervisor) to decide if it needs to write the EOI MSR.When a CPU is offlined then on the outgoing CPU:
1. hv_cpu_die() disables the EOI optimizaton for this CPU, and from
now on hvp->apic_assist belongs to the original "normal" SPA page;
2. the remaining work of stopping this CPU is done
3. this CPU is completely stopped.Between 1 and 3, this CPU can still receive interrupts (e.g. reschedule
IPIs from CPU0, and Local APIC timer interrupts), and this CPU *must* write
the EOI MSR for every interrupt received, otherwise the hypervisor may not
deliver further interrupts, which may be needed to completely stop the CPU.So, after the EOI optimization is disabled in hv_cpu_die(), it's required
that the hvp->apic_assist's bit0 is zero, which is not guaranteed by the
current allocation mode because it lacks __GFP_ZERO. As a consequence the
bit might be set and interrupt handling would not write the EOI MSR causing
interrupt delivery to become stuck.Add the missing __GFP_ZERO to the allocation.
Note 1: after the "normal" SPA page is allocted and zeroed out, neither the
hypervisor nor the guest writes into the page, so the page remains with
zeros.Note 2: see Section 10.3.5 "EOI Assist" for the details of the EOI
optimization. When the optimization is enabled, the guest can still write
the EOI MSR register irrespective of the "No EOI required" value, but
that's slower than the optimized assist based variant.Fixes: ba696429d290 ("x86/hyper-v: Implement EOI assist")
Signed-off-by: Dexuan Cui
Signed-off-by: Thomas Gleixner
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/ <PU1P153MB0169B716A637FABF07433C04BFCB0@PU1P153MB0169.APCP153.PROD.OUTLOOK.COM
03 Jul, 2019
1 commit
-
Continue consolidating Hyper-V clock and timer code into an ISA
independent Hyper-V clocksource driver.Move the existing clocksource code under drivers/hv and arch/x86 to the new
clocksource driver while separating out the ISA dependencies. Update
Hyper-V initialization to call initialization and cleanup routines since
the Hyper-V synthetic clock is not independently enumerated in ACPI.Update Hyper-V clocksource users in KVM and VDSO to get definitions from
the new include file.No behavior is changed and no new functionality is added.
Suggested-by: Marc Zyngier
Signed-off-by: Michael Kelley
Signed-off-by: Thomas Gleixner
Reviewed-by: Vitaly Kuznetsov
Cc: "bp@alien8.de"
Cc: "will.deacon@arm.com"
Cc: "catalin.marinas@arm.com"
Cc: "mark.rutland@arm.com"
Cc: "linux-arm-kernel@lists.infradead.org"
Cc: "gregkh@linuxfoundation.org"
Cc: "linux-hyperv@vger.kernel.org"
Cc: "olaf@aepfle.de"
Cc: "apw@canonical.com"
Cc: "jasowang@redhat.com"
Cc: "marcelo.cerri@canonical.com"
Cc: Sunil Muthuswamy
Cc: KY Srinivasan
Cc: "sashal@kernel.org"
Cc: "vincenzo.frascino@arm.com"
Cc: "linux-arch@vger.kernel.org"
Cc: "linux-mips@vger.kernel.org"
Cc: "linux-kselftest@vger.kernel.org"
Cc: "arnd@arndb.de"
Cc: "linux@armlinux.org.uk"
Cc: "ralf@linux-mips.org"
Cc: "paul.burton@mips.com"
Cc: "daniel.lezcano@linaro.org"
Cc: "salyzyn@android.com"
Cc: "pcc@google.com"
Cc: "shuah@kernel.org"
Cc: "0x7f454c46@gmail.com"
Cc: "linux@rasmusvillemoes.dk"
Cc: "huw@codeweavers.com"
Cc: "sfr@canb.auug.org.au"
Cc: "pbonzini@redhat.com"
Cc: "rkrcmar@redhat.com"
Cc: "kvm@vger.kernel.org"
Link: https://lkml.kernel.org/r/1561955054-1838-3-git-send-email-mikelley@microsoft.com
05 Jun, 2019
1 commit
-
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose good title or non infringement see
the gnu general public license for more detailsextracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 9 file(s).
Signed-off-by: Thomas Gleixner
Reviewed-by: Alexios Zavras
Reviewed-by: Allison Randal
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.459653302@linutronix.de
Signed-off-by: Greg Kroah-Hartman
21 May, 2019
1 commit
-
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:GPL-2.0-only
Signed-off-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
19 Apr, 2019
1 commit
-
This function is referrenced from assembler, so it needs to be marked
visible for LTO.Fixes: 3a025de64bf8 ("x86/hyperv: Enable PV qspinlock for Hyper-V")
Signed-off-by: Andi Kleen
Signed-off-by: Thomas Gleixner
Reviewed-by: Yi Sun
Cc: kys@microsoft.com
Cc: haiyangz@microsoft.com
Link: https://lkml.kernel.org/r/20190330004743.29541-6-andi@firstfloor.org
16 Apr, 2019
1 commit
-
Hyper-V TLFS suggests an optimization to avoid imminent VMExit on EOI:
"The OS performs an EOI by atomically writing zero to the EOI Assist field
of the virtual VP assist page and checking whether the "No EOI required"
field was previously zero. If it was, the OS must write to the
HV_X64_APIC_EOI MSR thereby triggering an intercept into the hypervisor."Implement the optimization in Linux.
Tested-by: Long Li
Signed-off-by: Vitaly Kuznetsov
Cc: Borislav Petkov
Cc: Haiyang Zhang
Cc: K. Y. Srinivasan
Cc: Linus Torvalds
Cc: Michael Kelley (EOSG)
Cc: Peter Zijlstra
Cc: Sasha Levin
Cc: Simon Xiao
Cc: Stephen Hemminger
Cc: Thomas Gleixner
Cc: linux-hyperv@vger.kernel.org
Link: http://lkml.kernel.org/r/20190403170309.4107-1-vkuznets@redhat.com
Signed-off-by: Ingo Molnar
21 Mar, 2019
1 commit
-
The page allocation in hv_cpu_init() can fail, but the code does not
have a check for that.Add a check and return -ENOMEM when the allocation fails.
[ tglx: Massaged changelog ]
Signed-off-by: Kangjie Lu
Signed-off-by: Thomas Gleixner
Reviewed-by: Mukesh Ojha
Acked-by: "K. Y. Srinivasan"
Cc: pakki001@umn.edu
Cc: Haiyang Zhang
Cc: Stephen Hemminger
Cc: Sasha Levin
Cc: Borislav Petkov
Cc: "H. Peter Anvin"
Cc: linux-hyperv@vger.kernel.org
Link: https://lkml.kernel.org/r/20190314054651.1315-1-kjlu@umn.edu
11 Mar, 2019
1 commit
-
Pull x86 fixes from Thomas Gleixner:
"A set of fixes for x86:- Make the unwinder more robust when it encounters a NULL pointer
call, so the backtrace becomes more useful- Fix the bogus ORC unwind table alignment
- Prevent kernel panic during kexec on HyperV caused by a cleared but
not disabled hypercall page.- Remove the now pointless stacksize increase for KASAN_EXTRA, as
KASAN_EXTRA is gone.- Remove unused variables from the x86 memory management code"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/hyperv: Fix kernel panic when kexec on HyperV
x86/mm: Remove unused variable 'old_pte'
x86/mm: Remove unused variable 'cpu'
Revert "x86_64: Increase stack size for KASAN_EXTRA"
x86/unwind: Add hardcoded ORC entry for NULL
x86/unwind: Handle NULL pointer calls better in frame unwinder
x86/unwind/orc: Fix ORC unwind table alignment
07 Mar, 2019
1 commit
-
After commit 68bb7bfb7985 ("X86/Hyper-V: Enable IPI enlightenments"),
kexec fails with a kernel panic:kexec_core: Starting new kernel
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v3.0 03/02/2018
RIP: 0010:0xffffc9000001d000Call Trace:
? __send_ipi_mask+0x1c6/0x2d0
? hv_send_ipi_mask_allbutself+0x6d/0xb0
? mp_save_irq+0x70/0x70
? __ioapic_read_entry+0x32/0x50
? ioapic_read_entry+0x39/0x50
? clear_IO_APIC_pin+0xb8/0x110
? native_stop_other_cpus+0x6e/0x170
? native_machine_shutdown+0x22/0x40
? kernel_kexec+0x136/0x156That happens if hypercall based IPIs are used because the hypercall page is
reset very early upon kexec reboot, but kexec sends IPIs to stop CPUs,
which invokes the hypercall and dereferences the unusable page.To fix his, reset hv_hypercall_pg to NULL before the page is reset to avoid
any misuse, IPI sending will fall back to the non hypercall based
method. This only happens on kexec / kdump so just setting the pointer to
NULL is good enough.Fixes: 68bb7bfb7985 ("X86/Hyper-V: Enable IPI enlightenments")
Signed-off-by: Kairui Song
Signed-off-by: Thomas Gleixner
Cc: "K. Y. Srinivasan"
Cc: Haiyang Zhang
Cc: Stephen Hemminger
Cc: Sasha Levin
Cc: Borislav Petkov
Cc: "H. Peter Anvin"
Cc: Vitaly Kuznetsov
Cc: Dave Young
Cc: devel@linuxdriverproject.org
Link: https://lkml.kernel.org/r/20190306111827.14131-1-kasong@redhat.com
01 Mar, 2019
1 commit
-
Remove the duplicate implementation of cpumask_to_vpset() and use the
shared implementation. Export hv_max_vp_index, which is required by
cpumask_to_vpset().Signed-off-by: Maya Nakamura
Signed-off-by: Lorenzo Pieralisi
Reviewed-by: Michael Kelley
Reviewed-by: Vitaly Kuznetsov
Tested-by: Vitaly Kuznetsov
21 Dec, 2018
1 commit
-
Hyper-V provides HvFlushGuestAddressList() hypercall to flush EPT tlb
with specified ranges. This patch is to add the hypercall support.Reviewed-by: Michael Kelley
Signed-off-by: Lan Tianyu
Signed-off-by: Paolo Bonzini
24 Oct, 2018
1 commit
-
Pull x86 paravirt updates from Ingo Molnar:
"Two main changes:- Remove no longer used parts of the paravirt infrastructure and put
large quantities of paravirt ops under a new config option
PARAVIRT_XXL=y, which is selected by XEN_PV only. (Joergen Gross)- Enable PV spinlocks on Hyperv (Yi Sun)"
* 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/hyperv: Enable PV qspinlock for Hyper-V
x86/hyperv: Add GUEST_IDLE_MSR support
x86/paravirt: Clean up native_patch()
x86/paravirt: Prevent redefinition of SAVE_FLAGS macro
x86/xen: Make xen_reservation_lock static
x86/paravirt: Remove unneeded mmu related paravirt ops bits
x86/paravirt: Move the Xen-only pv_mmu_ops under the PARAVIRT_XXL umbrella
x86/paravirt: Move the pv_irq_ops under the PARAVIRT_XXL umbrella
x86/paravirt: Move the Xen-only pv_cpu_ops under the PARAVIRT_XXL umbrella
x86/paravirt: Move items in pv_info under PARAVIRT_XXL umbrella
x86/paravirt: Introduce new config option PARAVIRT_XXL
x86/paravirt: Remove unused paravirt bits
x86/paravirt: Use a single ops structure
x86/paravirt: Remove clobbers from struct paravirt_patch_site
x86/paravirt: Remove clobbers parameter from paravirt patch functions
x86/paravirt: Make paravirt_patch_call() and paravirt_patch_jmp() static
x86/xen: Add SPDX identifier in arch/x86/xen files
x86/xen: Link platform-pci-unplug.o only if CONFIG_XEN_PVHVM
x86/xen: Move pv specific parts of arch/x86/xen/mmu.c to mmu_pv.c
x86/xen: Move pv irq related functions under CONFIG_XEN_PV umbrella
09 Oct, 2018
1 commit
-
Implement the required wait and kick callbacks to support PV spinlocks in
Hyper-V guests.[ tglx: Document the requirement for disabling interrupts in the wait()
callback. Remove goto and unnecessary includes. Add prototype
for hv_vcpu_is_preempted(). Adapted to pending paravirt changes. ]Signed-off-by: Yi Sun
Signed-off-by: Thomas Gleixner
Reviewed-by: Juergen Gross
Cc: "K. Y. Srinivasan"
Cc: Haiyang Zhang
Cc: Stephen Hemminger
Cc: Michael Kelley (EOSG)
Cc: chao.p.peng@intel.com
Cc: chao.gao@intel.com
Cc: isaku.yamahata@intel.com
Cc: tianyu.lan@microsoft.com
Link: https://lkml.kernel.org/r/1538987374-51217-3-git-send-email-yi.y.sun@linux.intel.com
28 Sep, 2018
2 commits
-
Remove including . It's not needed.
Signed-off-by: YueHaibing
Signed-off-by: Thomas Gleixner
Reviewed-by: Michael Kelley
Cc: "K. Y. Srinivasan"
Cc: Haiyang Zhang
Cc: Stephen Hemminger
Cc: "H. Peter Anvin"
Cc:
Cc:
Link: https://lkml.kernel.org/r/1537690822-97455-1-git-send-email-yuehaibing@huawei.com -
A Generation-2 Linux VM on Hyper-V doesn't have the legacy PCI bus, and
users always see the scary warning, which is actually harmless.Suppress it.
Signed-off-by: Dexuan Cui
Signed-off-by: Thomas Gleixner
Reviewed-by: Michael Kelley
Cc: "H. Peter Anvin"
Cc: KY Srinivasan
Cc: Haiyang Zhang
Cc: Stephen Hemminger
Cc: "devel@linuxdriverproject.org"
Cc: Olaf Aepfle
Cc: Andy Whitcroft
Cc: Jason Wang
Cc: Vitaly Kuznetsov
Cc: Marcelo Cerri
Cc: Josh Poulson
Link: https://lkml.kernel.org/r/ <KU1P153MB0166D977DC930996C4BF538ABF1D0@KU1P153MB0166.APCP153.PROD.OUTLOOK.COM
