linux.git/arch/x86/kernel/cpu/mshyperv.c, branch v4.16

x86/hyperv: Reenlightenment notifications support

2018-01-30T22:55:32+00:00

Hyper-V supports Live Migration notification. This is supposed to be used
in conjunction with TSC emulation: when a VM is migrated to a host with
different TSC frequency for some short period the host emulates the
accesses to TSC and sends an interrupt to notify about the event. When the
guest is done updating everything it can disable TSC emulation and
everything will start working fast again.

These notifications weren't required until now as Hyper-V guests are not
supposed to use TSC as a clocksource: in Linux the TSC is even marked as
unstable on boot. Guests normally use 'tsc page' clocksource and host
updates its values on migrations automatically.

Things change when with nested virtualization: even when the PV
clocksources (kvm-clock or tsc page) are passed through to the nested
guests the TSC frequency and frequency changes need to be know..

Hyper-V Top Level Functional Specification (as of v5.0b) wrongly specifies
EAX:BIT(12) of CPUID:0x40000009 as the feature identification bit. The
right one to check is EAX:BIT(13) of CPUID:0x40000003. I was assured that
the fix in on the way.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Thomas Gleixner 
Cc: Stephen Hemminger 
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář 
Cc: Haiyang Zhang 
Cc: "Michael Kelley (EOSG)" 
Cc: Roman Kagan 
Cc: Andy Lutomirski 
Cc: devel@linuxdriverproject.org
Cc: Paolo Bonzini 
Cc: "K. Y. Srinivasan" 
Cc: Cathy Avery 
Cc: Mohammed Gamal 
Link: https://lkml.kernel.org/r/20180124132337.30138-4-vkuznets@redhat.com

x86/virt: Add enum for hypervisors to replace x86_hyper

2017-11-10T09:03:12+00:00

The x86_hyper pointer is only used for checking whether a virtual
device is supporting the hypervisor the system is running on.

Use an enum for that purpose instead and drop the x86_hyper pointer.

Signed-off-by: Juergen Gross 
Acked-by: Thomas Gleixner 
Acked-by: Xavier Deguillard 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: akataria@vmware.com
Cc: arnd@arndb.de
Cc: boris.ostrovsky@oracle.com
Cc: devel@linuxdriverproject.org
Cc: dmitry.torokhov@gmail.com
Cc: gregkh@linuxfoundation.org
Cc: haiyangz@microsoft.com
Cc: kvm@vger.kernel.org
Cc: kys@microsoft.com
Cc: linux-graphics-maintainer@vmware.com
Cc: linux-input@vger.kernel.org
Cc: moltmann@vmware.com
Cc: pbonzini@redhat.com
Cc: pv-drivers@vmware.com
Cc: rkrcmar@redhat.com
Cc: sthemmin@microsoft.com
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20171109132739.23465-3-jgross@suse.com
Signed-off-by: Ingo Molnar

x86/virt, x86/platform: Merge 'struct x86_hyper' into 'struct x86_platform' and 'struct x86_init'

2017-11-10T09:03:12+00:00

Instead of x86_hyper being either NULL on bare metal or a pointer to a
struct hypervisor_x86 in case of the kernel running as a guest merge
the struct into x86_platform and x86_init.

This will remove the need for wrappers making it hard to find out what
is being called. With dummy functions added for all callbacks testing
for a NULL function pointer can be removed, too.

Suggested-by: Ingo Molnar 
Signed-off-by: Juergen Gross 
Acked-by: Thomas Gleixner 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: akataria@vmware.com
Cc: boris.ostrovsky@oracle.com
Cc: devel@linuxdriverproject.org
Cc: haiyangz@microsoft.com
Cc: kvm@vger.kernel.org
Cc: kys@microsoft.com
Cc: pbonzini@redhat.com
Cc: rkrcmar@redhat.com
Cc: rusty@rustcorp.com.au
Cc: sthemmin@microsoft.com
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20171109132739.23465-2-jgross@suse.com
Signed-off-by: Ingo Molnar

x86/hyper-V: Allocate the IDT entry early in boot

2017-09-13T09:02:26+00:00

Allocate the hypervisor callback IDT entry early in the boot sequence.

The previous code would allocate the entry as part of registering the handler
when the vmbus driver loaded, and this caused a problem for the IDT cleanup
that Thomas is working on for v4.15.

Signed-off-by: K. Y. Srinivasan 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: apw@canonical.com
Cc: devel@linuxdriverproject.org
Cc: gregkh@linuxfoundation.org
Cc: jasowang@redhat.com
Cc: olaf@aepfle.de
Link: http://lkml.kernel.org/r/20170908231557.2419-1-kys@exchange.microsoft.com
Signed-off-by: Ingo Molnar

Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-09-07T16:25:15+00:00

Pull x86 platform updates from Ingo Molnar:
 "The main changes include various Hyper-V optimizations such as faster
  hypercalls and faster/better TLB flushes - and there's also some
  Intel-MID cleanups"

* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tracing/hyper-v: Trace hyperv_mmu_flush_tlb_others()
  x86/hyper-v: Support extended CPU ranges for TLB flush hypercalls
  x86/platform/intel-mid: Make several arrays static, to make code smaller
  MAINTAINERS: Add missed file for Hyper-V
  x86/hyper-v: Use hypercall for remote TLB flush
  hyper-v: Globalize vp_index
  x86/hyper-v: Implement rep hypercalls
  hyper-v: Use fast hypercall for HVCALL_SIGNAL_EVENT
  x86/hyper-v: Introduce fast hypercall implementation
  x86/hyper-v: Make hv_do_hypercall() inline
  x86/hyper-v: Include hyperv/ only when CONFIG_HYPERV is set
  x86/platform/intel-mid: Make 'bt_sfi_data' const
  x86/platform/intel-mid: Make IRQ allocation a bit more flexible
  x86/platform/intel-mid: Group timers callbacks together

Merge tag 'char-misc-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2017-09-05T18:08:17+00:00

Pull char/misc driver updates from Greg KH:
 "Here is the big char/misc driver update for 4.14-rc1.

  Lots of different stuff in here, it's been an active development cycle
  for some reason. Highlights are:

   - updated binder driver, this brings binder up to date with what
     shipped in the Android O release, plus some more changes that
     happened since then that are in the Android development trees.

   - coresight updates and fixes

   - mux driver file renames to be a bit "nicer"

   - intel_th driver updates

   - normal set of hyper-v updates and changes

   - small fpga subsystem and driver updates

   - lots of const code changes all over the driver trees

   - extcon driver updates

   - fmc driver subsystem upadates

   - w1 subsystem minor reworks and new features and drivers added

   - spmi driver updates

  Plus a smattering of other minor driver updates and fixes.

  All of these have been in linux-next with no reported issues for a
  while"

* tag 'char-misc-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (244 commits)
  ANDROID: binder: don't queue async transactions to thread.
  ANDROID: binder: don't enqueue death notifications to thread todo.
  ANDROID: binder: Don't BUG_ON(!spin_is_locked()).
  ANDROID: binder: Add BINDER_GET_NODE_DEBUG_INFO ioctl
  ANDROID: binder: push new transactions to waiting threads.
  ANDROID: binder: remove proc waitqueue
  android: binder: Add page usage in binder stats
  android: binder: fixup crash introduced by moving buffer hdr
  drivers: w1: add hwmon temp support for w1_therm
  drivers: w1: refactor w1_slave_show to make the temp reading functionality separate
  drivers: w1: add hwmon support structures
  eeprom: idt_89hpesx: Support both ACPI and OF probing
  mcb: Fix an error handling path in 'chameleon_parse_cells()'
  MCB: add support for SC31 to mcb-lpc
  mux: make device_type const
  char: virtio: constify attribute_group structures.
  Documentation/ABI: document the nvmem sysfs files
  lkdtm: fix spelling mistake: "incremeted" -> "incremented"
  perf: cs-etm: Fix ETMv4 CONFIGR entry in perf.data file
  nvmem: include linux/err.h from header
  ...

x86/idt: Simplify alloc_intr_gate()

2017-08-29T10:07:28+00:00

The only users of alloc_intr_gate() are hypervisors, which both check the
used_vectors bitmap whether they have allocated the gate already. Move that
check into alloc_intr_gate() and simplify the users.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Juergen Gross 
Reviewed-by: K. Y. Srinivasan 
Cc: Andy Lutomirski 
Cc: Boris Ostrovsky 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Stephen Hemminger 
Cc: Steven Rostedt 
Link: http://lkml.kernel.org/r/20170828064959.580830286@linutronix.de
Signed-off-by: Ingo Molnar

x86/hyper-v: Use hypercall for remote TLB flush

2017-08-10T18:16:44+00:00

Hyper-V host can suggest us to use hypercall for doing remote TLB flush,
this is supposed to work faster than IPIs.

Implementation details: to do HvFlushVirtualAddress{Space,List} hypercalls
we need to put the input somewhere in memory and we don't really want to
have memory allocation on each call so we pre-allocate per cpu memory areas
on boot.

pv_ops patching is happening very early so we need to separate
hyperv_setup_mmu_ops() and hyper_alloc_mmu().

It is possible and easy to implement local TLB flushing too and there is
even a hint for that. However, I don't see a room for optimization on the
host side as both hypercall and native tlb flush will result in vmexit. The
hint is also not set on modern Hyper-V versions.

Signed-off-by: Vitaly Kuznetsov 
Reviewed-by: Andy Shevchenko 
Reviewed-by: Stephen Hemminger 
Cc: Andy Lutomirski 
Cc: Haiyang Zhang 
Cc: Jork Loeser 
Cc: K. Y. Srinivasan 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Simon Xiao 
Cc: Steven Rostedt 
Cc: Thomas Gleixner 
Cc: devel@linuxdriverproject.org
Link: http://lkml.kernel.org/r/20170802160921.21791-8-vkuznets@redhat.com
Signed-off-by: Ingo Molnar

x86/hyper-v: stash the max number of virtual/logical processor

2017-07-17T15:20:28+00:00

Max virtual processor will be needed for 'extended' hypercalls supporting
more than 64 vCPUs. While on it, unify on 'Hyper-V' in mshyperv.c as we
currently have a mix, report acquired misc features as well.

Signed-off-by: Vitaly Kuznetsov 
Reviewed-by: Andy Shevchenko 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

x86/hyperv: Read TSC frequency from a synthetic MSR

2017-06-22T13:35:12+00:00

It was found that SMI_TRESHOLD of 50000 is not enough for Hyper-V
guests in nested environment and falling back to counting jiffies
is not an option for Gen2 guests as they don't have PIT. As Hyper-V
provides TSC frequency in a synthetic MSR we can just use this information
instead of doing a error prone calibration.

Reported-and-tested-by: Ladi Prosek 
Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: Thomas Gleixner 
Cc: Stephen Hemminger 
Cc: Haiyang Zhang 
Cc: Jork Loeser 
Cc: devel@linuxdriverproject.org
Cc: "K. Y. Srinivasan" 
Link: http://lkml.kernel.org/r/20170622100730.18112-3-vkuznets@redhat.com