linux.git/arch/x86/hyperv, branch v4.17

x86/hyper-v: allocate and use Virtual Processor Assist Pages

2018-03-28T20:47:06+00:00

Virtual Processor Assist Pages usage allows us to do optimized EOI
processing for APIC, enable Enlightened VMCS support in KVM and more.
struct hv_vp_assist_page is defined according to the Hyper-V TLFS v5.0b.

Signed-off-by: Vitaly Kuznetsov 
Reviewed-by: Thomas Gleixner 
Acked-by: Thomas Gleixner 
Signed-off-by: Radim Krčmář

x86/hyper-v: move hyperv.h out of uapi

2018-03-28T20:47:06+00:00

hyperv.h is not part of uapi, there are no (known) users outside of kernel.
We are making changes to this file to match current Hyper-V Hypervisor
Top-Level Functional Specification (TLFS, see:
https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs)
and we don't want to maintain backwards compatibility.

Move the file renaming to hyperv-tlfs.h to avoid confusing it with
mshyperv.h. In future, all definitions from TLFS should go to it and
all kernel objects should go to mshyperv.h or include/linux/hyperv.h.

Signed-off-by: Vitaly Kuznetsov 
Acked-by: Thomas Gleixner 
Signed-off-by: Radim Krčmář

Merge tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2018-02-10T21:16:35+00:00

Pull KVM updates from Radim Krčmář:
 "ARM:

   - icache invalidation optimizations, improving VM startup time

   - support for forwarded level-triggered interrupts, improving
     performance for timers and passthrough platform devices

   - a small fix for power-management notifiers, and some cosmetic
     changes

  PPC:

   - add MMIO emulation for vector loads and stores

   - allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
     requiring the complex thread synchronization of older CPU versions

   - improve the handling of escalation interrupts with the XIVE
     interrupt controller

   - support decrement register migration

   - various cleanups and bugfixes.

  s390:

   - Cornelia Huck passed maintainership to Janosch Frank

   - exitless interrupts for emulated devices

   - cleanup of cpuflag handling

   - kvm_stat counter improvements

   - VSIE improvements

   - mm cleanup

  x86:

   - hypervisor part of SEV

   - UMIP, RDPID, and MSR_SMI_COUNT emulation

   - paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit

   - allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more
     AVX512 features

   - show vcpu id in its anonymous inode name

   - many fixes and cleanups

   - per-VCPU MSR bitmaps (already merged through x86/pti branch)

   - stable KVM clock when nesting on Hyper-V (merged through
     x86/hyperv)"

* tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (197 commits)
  KVM: PPC: Book3S: Add MMIO emulation for VMX instructions
  KVM: PPC: Book3S HV: Branch inside feature section
  KVM: PPC: Book3S HV: Make HPT resizing work on POWER9
  KVM: PPC: Book3S HV: Fix handling of secondary HPTEG in HPT resizing code
  KVM: PPC: Book3S PR: Fix broken select due to misspelling
  KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs()
  KVM: PPC: Book3S PR: Fix svcpu copying with preemption enabled
  KVM: PPC: Book3S HV: Drop locks before reading guest memory
  kvm: x86: remove efer_reload entry in kvm_vcpu_stat
  KVM: x86: AMD Processor Topology Information
  x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested
  kvm: embed vcpu id to dentry of vcpu anon inode
  kvm: Map PFN-type memory regions as writable (if possible)
  x86/kvm: Make it compile on 32bit and with HYPYERVISOR_GUEST=n
  KVM: arm/arm64: Fixup userspace irqchip static key optimization
  KVM: arm/arm64: Fix userspace_irqchip_in_use counting
  KVM: arm/arm64: Fix incorrect timer_is_pending logic
  MAINTAINERS: update KVM/s390 maintainers
  MAINTAINERS: add Halil as additional vfio-ccw maintainer
  MAINTAINERS: add David as a reviewer for KVM/s390
  ...

Merge tag 'char-misc-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2018-02-01T18:31:17+00:00

Pull char/misc driver updates from Greg KH:
 "Here is the big pull request for char/misc drivers for 4.16-rc1.

  There's a lot of stuff in here. Three new driver subsystems were added
  for various types of hardware busses:

   - siox
   - slimbus
   - soundwire

  as well as a new vboxguest subsystem for the VirtualBox hypervisor
  drivers.

  There's also big updates from the FPGA subsystem, lots of Android
  binder fixes, the usual handful of hyper-v updates, and lots of other
  smaller driver updates.

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

* tag 'char-misc-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (155 commits)
  char: lp: use true or false for boolean values
  android: binder: use VM_ALLOC to get vm area
  android: binder: Use true and false for boolean values
  lkdtm: fix handle_irq_event symbol for INT_HW_IRQ_EN
  EISA: Delete error message for a failed memory allocation in eisa_probe()
  EISA: Whitespace cleanup
  misc: remove AVR32 dependencies
  virt: vbox: Add error mapping for VERR_INVALID_NAME and VERR_NO_MORE_FILES
  soundwire: Fix a signedness bug
  uio_hv_generic: fix new type mismatch warnings
  uio_hv_generic: fix type mismatch warnings
  auxdisplay: img-ascii-lcd: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE
  uio_hv_generic: add rescind support
  uio_hv_generic: check that host supports monitor page
  uio_hv_generic: create send and receive buffers
  uio: document uio_hv_generic regions
  doc: fix documentation about uio_hv_generic
  vmbus: add monitor_id and subchannel_id to sysfs per channel
  vmbus: fix ABI documentation
  uio_hv_generic: use ISR callback method
  ...

x86/irq: Count Hyper-V reenlightenment interrupts

2018-01-30T22:55:33+00:00

Hyper-V reenlightenment interrupts arrive when the VM is migrated, While
they are not interesting in general it's important when L2 nested guests
are running.

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/20180124132337.30138-6-vkuznets@redhat.com

x86/hyperv: Redirect reenlightment notifications on CPU offlining

2018-01-30T22:55:33+00:00

It is very unlikely for CPUs to get offlined when running on Hyper-V as
there is a protection in the vmbus module which prevents it when the guest
has any VMBus devices assigned. This, however, may change in future if an
option to reassign an already active channel will be added. It is also
possible to run without any Hyper-V devices or to have a CPU with no
assigned channels.

Reassign reenlightenment notifications to some other active CPU when the
CPU which is assigned to them goes offline.

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/20180124132337.30138-5-vkuznets@redhat.com

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/hyperv: Add a function to read both TSC and TSC page value simulateneously

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

This is going to be used from KVM code where both TSC and TSC page value
are needed.

Nothing is supposed to use the function when Hyper-V code is compiled out,
just BUG().

Signed-off-by: Vitaly Kuznetsov 
Signed-off-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/20180124132337.30138-3-vkuznets@redhat.com

x86/hyperv: Check for required priviliges in hyperv_init()

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

In hyperv_init() its presumed that it always has access to VP index and
hypercall MSRs while according to the specification it should be checked if
it's allowed to access the corresponding MSRs before accessing them.

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/20180124132337.30138-2-vkuznets@redhat.com

x86/hyperv: Stop suppressing X86_FEATURE_PCID

2018-01-25T08:40:59+00:00

When hypercall-based TLB flush was enabled for Hyper-V guests PCID feature
was deliberately suppressed as a precaution: back then PCID was never
exposed to Hyper-V guests and it wasn't clear what will happen if some day
it becomes available. The day came and PCID/INVPCID features are already
exposed on certain Hyper-V hosts.

From TLFS (as of 5.0b) it is unclear how TLB flush hypercalls combine with
PCID. In particular the usage of PCID is per-cpu based: the same mm gets
different CR3 values on different CPUs. If the hypercall does exact
matching this will fail. However, this is not the case. David Zhang
explains:

 "In practice, the AddressSpace argument is ignored on any VM that supports
  PCIDs.

  Architecturally, the AddressSpace argument must match the CR3 with PCID
  bits stripped out (i.e., the low 12 bits of AddressSpace should be 0 in
  long mode). The flush hypercalls flush all PCIDs for the specified
  AddressSpace."

With this, PCID can be enabled.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: Thomas Gleixner 
Cc: David Zhang 
Cc: Stephen Hemminger 
Cc: Haiyang Zhang 
Cc: "Michael Kelley (EOSG)" 
Cc: Andy Lutomirski 
Cc: devel@linuxdriverproject.org
Cc: "K. Y. Srinivasan" 
Cc: Aditya Bhandari 
Link: https://lkml.kernel.org/r/20180124103629.29980-1-vkuznets@redhat.com