linux-stable.git/Documentation/virt, branch v5.16

Merge branch 'kvm-sev-move-context' into kvm-master

2021-11-11T16:02:58+00:00

Add support for AMD SEV and SEV-ES intra-host migration support.  Intra
host migration provides a low-cost mechanism for userspace VMM upgrades.

In the common case for intra host migration, we can rely on the normal
ioctls for passing data from one VMM to the next. SEV, SEV-ES, and other
confidential compute environments make most of this information opaque, and
render KVM ioctls such as "KVM_GET_REGS" irrelevant.  As a result, we need
the ability to pass this opaque metadata from one VMM to the next. The
easiest way to do this is to leave this data in the kernel, and transfer
ownership of the metadata from one KVM VM (or vCPU) to the next.  In-kernel
hand off makes it possible to move any data that would be
unsafe/impossible for the kernel to hand directly to userspace, and
cannot be reproduced using data that can be handed to userspace.

Signed-off-by: Paolo Bonzini

KVM: SEV: Add support for SEV intra host migration

2021-11-11T15:35:27+00:00

For SEV to work with intra host migration, contents of the SEV info struct
such as the ASID (used to index the encryption key in the AMD SP) and
the list of memory regions need to be transferred to the target VM.
This change adds a commands for a target VMM to get a source SEV VM's sev
info.

Signed-off-by: Peter Gonda 
Suggested-by: Sean Christopherson 
Reviewed-by: Marc Orr 
Cc: Marc Orr 
Cc: Paolo Bonzini 
Cc: Sean Christopherson 
Cc: David Rientjes 
Cc: Dr. David Alan Gilbert 
Cc: Brijesh Singh 
Cc: Tom Lendacky 
Cc: Vitaly Kuznetsov 
Cc: Wanpeng Li 
Cc: Jim Mattson 
Cc: Joerg Roedel 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: "H. Peter Anvin" 
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Message-Id: <20211021174303.385706-3-pgonda@google.com>
Signed-off-by: Paolo Bonzini

Merge tag 'char-misc-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2021-11-04T15:21:47+00:00

Pull char/misc driver updates from Greg KH:
 "Here is the big set of char and misc and other tiny driver subsystem
  updates for 5.16-rc1.

  Loads of things in here, all of which have been in linux-next for a
  while with no reported problems (except for one called out below.)

  Included are:

   - habanana labs driver updates, including dma_buf usage, reviewed and
     acked by the dma_buf maintainers

   - iio driver update (going through this tree not staging as they
     really do not belong going through that tree anymore)

   - counter driver updates

   - hwmon driver updates that the counter drivers needed, acked by the
     hwmon maintainer

   - xillybus driver updates

   - binder driver updates

   - extcon driver updates

   - dma_buf module namespaces added (will cause a build error in arm64
     for allmodconfig, but that change is on its way through the drm
     tree)

   - lkdtm driver updates

   - pvpanic driver updates

   - phy driver updates

   - virt acrn and nitr_enclaves driver updates

   - smaller char and misc driver updates"

* tag 'char-misc-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (386 commits)
  comedi: dt9812: fix DMA buffers on stack
  comedi: ni_usb6501: fix NULL-deref in command paths
  arm64: errata: Enable TRBE workaround for write to out-of-range address
  arm64: errata: Enable workaround for TRBE overwrite in FILL mode
  coresight: trbe: Work around write to out of range
  coresight: trbe: Make sure we have enough space
  coresight: trbe: Add a helper to determine the minimum buffer size
  coresight: trbe: Workaround TRBE errata overwrite in FILL mode
  coresight: trbe: Add infrastructure for Errata handling
  coresight: trbe: Allow driver to choose a different alignment
  coresight: trbe: Decouple buffer base from the hardware base
  coresight: trbe: Add a helper to pad a given buffer area
  coresight: trbe: Add a helper to calculate the trace generated
  coresight: trbe: Defer the probe on offline CPUs
  coresight: trbe: Fix incorrect access of the sink specific data
  coresight: etm4x: Add ETM PID for Kryo-5XX
  coresight: trbe: Prohibit trace before disabling TRBE
  coresight: trbe: End the AUX handle on truncation
  coresight: trbe: Do not truncate buffer on IRQ
  coresight: trbe: Fix handling of spurious interrupts
  ...

Merge tag 'docs-5.16' of git://git.lwn.net/linux

2021-11-03T05:11:39+00:00

Pull documentation updates from Jonathan Corbet:
 "This is a relatively unexciting cycle for documentation.

   - Some small scripts/kerneldoc fixes

   - More Chinese translation work, but at a much reduced rate.

   - The tip-tree maintainer's handbook

  ...plus the usual array of build fixes, typo fixes, etc"

* tag 'docs-5.16' of git://git.lwn.net/linux: (53 commits)
  kernel-doc: support DECLARE_PHY_INTERFACE_MASK()
  docs/zh_CN: add core-api xarray translation
  docs/zh_CN: add core-api assoc_array translation
  speakup: Fix typo in documentation "boo" -> "boot"
  docs: submitting-patches: make section about the Link: tag more explicit
  docs: deprecated.rst: Clarify open-coded arithmetic with literals
  scripts: documentation-file-ref-check: fix bpf selftests path
  scripts: documentation-file-ref-check: ignore hidden files
  coding-style.rst: trivial: fix location of driver model macros
  docs: f2fs: fix text alignment
  docs/zh_CN add PCI pci.rst translation
  docs/zh_CN add PCI index.rst translation
  docs: translations: zh_CN: memory-hotplug.rst: fix a typo
  docs: translations: zn_CN: irq-affinity.rst: add a missing extension
  block: add documentation for inflight
  scripts: kernel-doc: Ignore __alloc_size() attribute
  docs: pdfdocs: Adjust \headheight for fancyhdr
  docs: UML: user_mode_linux_howto_v2 edits
  docs: use the lore redirector everywhere
  docs: proc.rst: mountinfo: align columns
  ...

selftests: KVM: Introduce system counter offset test

2021-10-18T18:43:46+00:00

Introduce a KVM selftest to verify that userspace manipulation of the
TSC (via the new vCPU attribute) results in the correct behavior within
the guest.

Reviewed-by: Andrew Jones 
Signed-off-by: Oliver Upton 
Message-Id: <20210916181555.973085-6-oupton@google.com>
Signed-off-by: Paolo Bonzini

KVM: x86: Expose TSC offset controls to userspace

2021-10-18T18:43:45+00:00

To date, VMM-directed TSC synchronization and migration has been a bit
messy. KVM has some baked-in heuristics around TSC writes to infer if
the VMM is attempting to synchronize. This is problematic, as it depends
on host userspace writing to the guest's TSC within 1 second of the last
write.

A much cleaner approach to configuring the guest's views of the TSC is to
simply migrate the TSC offset for every vCPU. Offsets are idempotent,
and thus not subject to change depending on when the VMM actually
reads/writes values from/to KVM. The VMM can then read the TSC once with
KVM_GET_CLOCK to capture a (realtime, host_tsc) pair at the instant when
the guest is paused.

Cc: David Matlack 
Cc: Sean Christopherson 
Signed-off-by: Oliver Upton 
Signed-off-by: Paolo Bonzini 
Message-Id: <20210916181538.968978-8-oupton@google.com>
Signed-off-by: Paolo Bonzini

KVM: x86: Report host tsc and realtime values in KVM_GET_CLOCK

2021-10-18T18:43:44+00:00

Handling the migration of TSCs correctly is difficult, in part because
Linux does not provide userspace with the ability to retrieve a (TSC,
realtime) clock pair for a single instant in time. In lieu of a more
convenient facility, KVM can report similar information in the kvm_clock
structure.

Provide userspace with a host TSC & realtime pair iff the realtime clock
is based on the TSC. If userspace provides KVM_SET_CLOCK with a valid
realtime value, advance the KVM clock by the amount of elapsed time. Do
not step the KVM clock backwards, though, as it is a monotonic
oscillator.

Suggested-by: Paolo Bonzini 
Signed-off-by: Oliver Upton 
Signed-off-by: Paolo Bonzini 
Message-Id: <20210916181538.968978-5-oupton@google.com>
Signed-off-by: Paolo Bonzini

docs: UML: user_mode_linux_howto_v2 edits

2021-10-12T20:07:35+00:00

Fix various typos, command syntax, punctuation, capitalization,
and whitespace.

Fixes: 04301bf5b072 ("docs: replace the old User Mode Linux HowTo with a new one")
Signed-off-by: Randy Dunlap 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Anton Ivanov 
Cc: linux-um@lists.infradead.org
Cc: Jonathan Corbet 
Cc: linux-doc@vger.kernel.org
Acked-By: anton ivanov 
Link: https://lore.kernel.org/r/20211010064827.3405-1-rdunlap@infradead.org
Signed-off-by: Jonathan Corbet

Merge tag 'kvm-riscv-5.16-1' of git://github.com/kvm-riscv/linux into HEAD

2021-10-05T08:19:24+00:00

Initial KVM RISC-V support

Following features are supported by the initial KVM RISC-V support:
1. No RISC-V specific KVM IOCTL
2. Loadable KVM RISC-V module
3. Minimal possible KVM world-switch which touches only GPRs and few CSRs
4. Works on both RV64 and RV32 host
5. Full Guest/VM switch via vcpu_get/vcpu_put infrastructure
6. KVM ONE_REG interface for VCPU register access from KVM user-space
7. Interrupt controller emulation in KVM user-space
8. Timer and IPI emuation in kernel
9. Both Sv39x4 and Sv48x4 supported for RV64 host
10. MMU notifiers supported
11. Generic dirty log supported
12. FP lazy save/restore supported
13. SBI v0.1 emulation for Guest/VM
14. Forward unhandled SBI calls to KVM user-space
15. Hugepage support for Guest/VM
16. IOEVENTFD support for Vhost

RISC-V: KVM: Document RISC-V specific parts of KVM API

2021-10-04T10:42:34+00:00

Document RISC-V specific parts of the KVM API, such as:
 - The interrupt numbers passed to the KVM_INTERRUPT ioctl.
 - The states supported by the KVM_{GET,SET}_MP_STATE ioctls.
 - The registers supported by the KVM_{GET,SET}_ONE_REG interface
   and the encoding of those register ids.
 - The exit reason KVM_EXIT_RISCV_SBI for SBI calls forwarded to
   userspace tool.

CC: Jonathan Corbet 
CC: linux-doc@vger.kernel.org
Signed-off-by: Anup Patel 
Acked-by: Palmer Dabbelt