linux.git/Documentation/virt, branch v5.10-rc2

x86/kvm: Reserve KVM_FEATURE_MSI_EXT_DEST_ID

2020-10-28T17:52:05+00:00

No functional change; just reserve the feature bit for now so that VMMs
can start to implement it.

This will allow the host to indicate that MSI emulation supports 15-bit
destination IDs, allowing up to 32768 CPUs without interrupt remapping.

cf. https://patchwork.kernel.org/patch/11816693/ for qemu

Signed-off-by: David Woodhouse 
Acked-by: Paolo Bonzini 
Message-Id: <4cd59bed05f4b7410d3d1ffd1e997ab53683874d.camel@infradead.org>
Signed-off-by: Paolo Bonzini

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2020-10-23T18:17:56+00:00

Pull KVM updates from Paolo Bonzini:
 "For x86, there is a new alternative and (in the future) more scalable
  implementation of extended page tables that does not need a reverse
  map from guest physical addresses to host physical addresses.

  For now it is disabled by default because it is still lacking a few of
  the existing MMU's bells and whistles. However it is a very solid
  piece of work and it is already available for people to hammer on it.

  Other updates:

  ARM:
   - New page table code for both hypervisor and guest stage-2
   - Introduction of a new EL2-private host context
   - Allow EL2 to have its own private per-CPU variables
   - Support of PMU event filtering
   - Complete rework of the Spectre mitigation

  PPC:
   - Fix for running nested guests with in-kernel IRQ chip
   - Fix race condition causing occasional host hard lockup
   - Minor cleanups and bugfixes

  x86:
   - allow trapping unknown MSRs to userspace
   - allow userspace to force #GP on specific MSRs
   - INVPCID support on AMD
   - nested AMD cleanup, on demand allocation of nested SVM state
   - hide PV MSRs and hypercalls for features not enabled in CPUID
   - new test for MSR_IA32_TSC writes from host and guest
   - cleanups: MMU, CPUID, shared MSRs
   - LAPIC latency optimizations ad bugfixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (232 commits)
  kvm: x86/mmu: NX largepage recovery for TDP MMU
  kvm: x86/mmu: Don't clear write flooding count for direct roots
  kvm: x86/mmu: Support MMIO in the TDP MMU
  kvm: x86/mmu: Support write protection for nesting in tdp MMU
  kvm: x86/mmu: Support disabling dirty logging for the tdp MMU
  kvm: x86/mmu: Support dirty logging for the TDP MMU
  kvm: x86/mmu: Support changed pte notifier in tdp MMU
  kvm: x86/mmu: Add access tracking for tdp_mmu
  kvm: x86/mmu: Support invalidate range MMU notifier for TDP MMU
  kvm: x86/mmu: Allocate struct kvm_mmu_pages for all pages in TDP MMU
  kvm: x86/mmu: Add TDP MMU PF handler
  kvm: x86/mmu: Remove disallowed_hugepage_adjust shadow_walk_iterator arg
  kvm: x86/mmu: Support zapping SPTEs in the TDP MMU
  KVM: Cache as_id in kvm_memory_slot
  kvm: x86/mmu: Add functions to handle changed TDP SPTEs
  kvm: x86/mmu: Allocate and free TDP MMU roots
  kvm: x86/mmu: Init / Uninit the TDP MMU
  kvm: x86/mmu: Introduce tdp_iter
  KVM: mmu: extract spte.h and spte.c
  KVM: mmu: Separate updating a PTE from kvm_set_pte_rmapp
  ...

Documentation: kvm: fix some typos in cpuid.rst

2020-10-21T21:36:32+00:00

Reviewed-by: Jim Mattson 
Reviewed-by: Peter Shier 
Signed-off-by: Oliver Upton 
Change-Id: I0c6355b09fedf8f9cc4cc5f51be418e2c1c82b7b
Message-Id: <20200818152429.1923996-5-oupton@google.com>
Signed-off-by: Paolo Bonzini

kvm: x86: only provide PV features if enabled in guest's CPUID

2020-10-21T21:36:32+00:00

KVM unconditionally provides PV features to the guest, regardless of the
configured CPUID. An unwitting guest that doesn't check
KVM_CPUID_FEATURES before use could access paravirt features that
userspace did not intend to provide. Fix this by checking the guest's
CPUID before performing any paravirtual operations.

Introduce a capability, KVM_CAP_ENFORCE_PV_FEATURE_CPUID, to gate the
aforementioned enforcement. Migrating a VM from a host w/o this patch to
a host with this patch could silently change the ABI exposed to the
guest, warranting that we default to the old behavior and opt-in for
the new one.

Reviewed-by: Jim Mattson 
Reviewed-by: Peter Shier 
Signed-off-by: Oliver Upton 
Change-Id: I202a0926f65035b872bfe8ad15307c026de59a98
Message-Id: <20200818152429.1923996-4-oupton@google.com>
Reviewed-by: Wanpeng Li 
Signed-off-by: Paolo Bonzini

Documentation: kvm: fix a typo

2020-10-21T21:36:30+00:00

Fixes: e287d6de62f74 ("Documentation: kvm: Convert cpuid.txt to .rst")
Signed-off-by: Li Qiang 
Message-Id: <20201001095333.7611-1-liq3ea@163.com>
Signed-off-by: Paolo Bonzini

KVM: VMX: Forbid userspace MSR filters for x2APIC

2020-10-21T21:36:24+00:00

Allowing userspace to intercept reads to x2APIC MSRs when APICV is
fully enabled for the guest simply can't work.   But more in general,
the LAPIC could be set to in-kernel after the MSR filter is setup
and allowing accesses by userspace would be very confusing.

We could in principle allow userspace to intercept reads and writes to TPR,
and writes to EOI and SELF_IPI, but while that could be made it work, it
would still be silly.

Cc: Alexander Graf 
Cc: Aaron Lewis 
Cc: Peter Xu 
Cc: Sean Christopherson 
Signed-off-by: Paolo Bonzini

KVM: VMX: Ignore userspace MSR filters for x2APIC

2020-10-21T21:36:19+00:00

Rework the resetting of the MSR bitmap for x2APIC MSRs to ignore userspace
filtering.  Allowing userspace to intercept reads to x2APIC MSRs when
APICV is fully enabled for the guest simply can't work; the LAPIC and thus
virtual APIC is in-kernel and cannot be directly accessed by userspace.
To keep things simple we will in fact forbid intercepting x2APIC MSRs
altogether, independent of the default_allow setting.

Cc: Alexander Graf 
Cc: Aaron Lewis 
Cc: Peter Xu 
Signed-off-by: Sean Christopherson 
Message-Id: <20201005195532.8674-3-sean.j.christopherson@intel.com>
[Modified to operate even if APICv is disabled, adjust documentation. - Paolo]
Signed-off-by: Paolo Bonzini

Merge tag 'kvmarm-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

2020-10-20T12:14:25+00:00

KVM/arm64 updates for Linux 5.10

- New page table code for both hypervisor and guest stage-2
- Introduction of a new EL2-private host context
- Allow EL2 to have its own private per-CPU variables
- Support of PMU event filtering
- Complete rework of the Spectre mitigation

Merge tag 'docs/v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media

2020-10-16T22:02:21+00:00

Pull documentation updates from Mauro Carvalho Chehab:
 "A series of patches addressing warnings produced by make htmldocs.
  This includes:

   - kernel-doc markup fixes

   - ReST fixes

   - Updates at the build system in order to support newer versions of
     the docs build toolchain (Sphinx)

  After this series, the number of html build warnings should reduce
  significantly, and building with Sphinx 3.1 or later should now be
  supported (although it is still recommended to use Sphinx 2.4.4).

  As agreed with Jon, I should be sending you a late pull request by the
  end of the merge window addressing remaining issues with docs build,
  as there are a number of warning fixes that depends on pull requests
  that should be happening along the merge window.

  The end goal is to have a clean htmldocs build on Kernel 5.10.

  PS. It should be noticed that Sphinx 3.0 is not currently supported,
  as it lacks support for C domain namespaces. Such feature, needed in
  order to document uAPI system calls with Sphinx 3.x, was added only on
  Sphinx 3.1"

* tag 'docs/v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (75 commits)
  PM / devfreq: remove a duplicated kernel-doc markup
  mm/doc: fix a literal block markup
  workqueue: fix a kernel-doc warning
  docs: virt: user_mode_linux_howto_v2.rst: fix a literal block markup
  Input: sparse-keymap: add a description for @sw
  rcu/tree: docs: document bkvcache new members at struct kfree_rcu_cpu
  nl80211: docs: add a description for s1g_cap parameter
  usb: docs: document altmode register/unregister functions
  kunit: test.h: fix a bad kernel-doc markup
  drivers: core: fix kernel-doc markup for dev_err_probe()
  docs: bio: fix a kerneldoc markup
  kunit: test.h: solve kernel-doc warnings
  block: bio: fix a warning at the kernel-doc markups
  docs: powerpc: syscall64-abi.rst: fix a malformed table
  drivers: net: hamradio: fix document location
  net: appletalk: Kconfig: Fix docs location
  dt-bindings: fix references to files converted to yaml
  memblock: get rid of a :c:type leftover
  math64.h: kernel-docs: Convert some markups into normal comments
  media: uAPI: buffer.rst: remove a left-over documentation
  ...

docs: virt: user_mode_linux_howto_v2.rst: fix a literal block markup

2020-10-16T05:28:20+00:00

There's a missing new line for a literal block:

	.../Documentation/virt/uml/user_mode_linux_howto_v2.rst:682: WARNING: Unexpected indentation.

Fixes: 04301bf5b072 ("docs: replace the old User Mode Linux HowTo with a new one")
Signed-off-by: Mauro Carvalho Chehab