<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include/linux/kvm_host.h, branch v6.2.7</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v6.2.7</id>
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<updated>2022-12-15T19:12:21Z</updated>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm</title>
<updated>2022-12-15T19:12:21Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-12-15T19:12:21Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=8fa590bf344816c925810331eea8387627bbeb40'/>
<id>urn:sha1:8fa590bf344816c925810331eea8387627bbeb40</id>
<content type='text'>
Pull kvm updates from Paolo Bonzini:
 "ARM64:

   - Enable the per-vcpu dirty-ring tracking mechanism, together with an
     option to keep the good old dirty log around for pages that are
     dirtied by something other than a vcpu.

   - Switch to the relaxed parallel fault handling, using RCU to delay
     page table reclaim and giving better performance under load.

   - Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping
     option, which multi-process VMMs such as crosvm rely on (see merge
     commit 382b5b87a97d: "Fix a number of issues with MTE, such as
     races on the tags being initialised vs the PG_mte_tagged flag as
     well as the lack of support for VM_SHARED when KVM is involved.
     Patches from Catalin Marinas and Peter Collingbourne").

   - Merge the pKVM shadow vcpu state tracking that allows the
     hypervisor to have its own view of a vcpu, keeping that state
     private.

   - Add support for the PMUv3p5 architecture revision, bringing support
     for 64bit counters on systems that support it, and fix the
     no-quite-compliant CHAIN-ed counter support for the machines that
     actually exist out there.

   - Fix a handful of minor issues around 52bit VA/PA support (64kB
     pages only) as a prefix of the oncoming support for 4kB and 16kB
     pages.

   - Pick a small set of documentation and spelling fixes, because no
     good merge window would be complete without those.

  s390:

   - Second batch of the lazy destroy patches

   - First batch of KVM changes for kernel virtual != physical address
     support

   - Removal of a unused function

  x86:

   - Allow compiling out SMM support

   - Cleanup and documentation of SMM state save area format

   - Preserve interrupt shadow in SMM state save area

   - Respond to generic signals during slow page faults

   - Fixes and optimizations for the non-executable huge page errata
     fix.

   - Reprogram all performance counters on PMU filter change

   - Cleanups to Hyper-V emulation and tests

   - Process Hyper-V TLB flushes from a nested guest (i.e. from a L2
     guest running on top of a L1 Hyper-V hypervisor)

   - Advertise several new Intel features

   - x86 Xen-for-KVM:

      - Allow the Xen runstate information to cross a page boundary

      - Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured

      - Add support for 32-bit guests in SCHEDOP_poll

   - Notable x86 fixes and cleanups:

      - One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0).

      - Reinstate IBPB on emulated VM-Exit that was incorrectly dropped
        a few years back when eliminating unnecessary barriers when
        switching between vmcs01 and vmcs02.

      - Clean up vmread_error_trampoline() to make it more obvious that
        params must be passed on the stack, even for x86-64.

      - Let userspace set all supported bits in MSR_IA32_FEAT_CTL
        irrespective of the current guest CPUID.

      - Fudge around a race with TSC refinement that results in KVM
        incorrectly thinking a guest needs TSC scaling when running on a
        CPU with a constant TSC, but no hardware-enumerated TSC
        frequency.

      - Advertise (on AMD) that the SMM_CTL MSR is not supported

      - Remove unnecessary exports

  Generic:

   - Support for responding to signals during page faults; introduces
     new FOLL_INTERRUPTIBLE flag that was reviewed by mm folks

  Selftests:

   - Fix an inverted check in the access tracking perf test, and restore
     support for asserting that there aren't too many idle pages when
     running on bare metal.

   - Fix build errors that occur in certain setups (unsure exactly what
     is unique about the problematic setup) due to glibc overriding
     static_assert() to a variant that requires a custom message.

   - Introduce actual atomics for clear/set_bit() in selftests

   - Add support for pinning vCPUs in dirty_log_perf_test.

   - Rename the so called "perf_util" framework to "memstress".

   - Add a lightweight psuedo RNG for guest use, and use it to randomize
     the access pattern and write vs. read percentage in the memstress
     tests.

   - Add a common ucall implementation; code dedup and pre-work for
     running SEV (and beyond) guests in selftests.

   - Provide a common constructor and arch hook, which will eventually
     be used by x86 to automatically select the right hypercall (AMD vs.
     Intel).

   - A bunch of added/enabled/fixed selftests for ARM64, covering
     memslots, breakpoints, stage-2 faults and access tracking.

   - x86-specific selftest changes:

      - Clean up x86's page table management.

      - Clean up and enhance the "smaller maxphyaddr" test, and add a
        related test to cover generic emulation failure.

      - Clean up the nEPT support checks.

      - Add X86_PROPERTY_* framework to retrieve multi-bit CPUID values.

      - Fix an ordering issue in the AMX test introduced by recent
        conversions to use kvm_cpu_has(), and harden the code to guard
        against similar bugs in the future. Anything that tiggers
        caching of KVM's supported CPUID, kvm_cpu_has() in this case,
        effectively hides opt-in XSAVE features if the caching occurs
        before the test opts in via prctl().

  Documentation:

   - Remove deleted ioctls from documentation

   - Clean up the docs for the x86 MSR filter.

   - Various fixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (361 commits)
  KVM: x86: Add proper ReST tables for userspace MSR exits/flags
  KVM: selftests: Allocate ucall pool from MEM_REGION_DATA
  KVM: arm64: selftests: Align VA space allocator with TTBR0
  KVM: arm64: Fix benign bug with incorrect use of VA_BITS
  KVM: arm64: PMU: Fix period computation for 64bit counters with 32bit overflow
  KVM: x86: Advertise that the SMM_CTL MSR is not supported
  KVM: x86: remove unnecessary exports
  KVM: selftests: Fix spelling mistake "probabalistic" -&gt; "probabilistic"
  tools: KVM: selftests: Convert clear/set_bit() to actual atomics
  tools: Drop "atomic_" prefix from atomic test_and_set_bit()
  tools: Drop conflicting non-atomic test_and_{clear,set}_bit() helpers
  KVM: selftests: Use non-atomic clear/set bit helpers in KVM tests
  perf tools: Use dedicated non-atomic clear/set bit helpers
  tools: Take @bit as an "unsigned long" in {clear,set}_bit() helpers
  KVM: arm64: selftests: Enable single-step without a "full" ucall()
  KVM: x86: fix APICv/x2AVIC disabled when vm reboot by itself
  KVM: Remove stale comment about KVM_REQ_UNHALT
  KVM: Add missing arch for KVM_CREATE_DEVICE and KVM_{SET,GET}_DEVICE_ATTR
  KVM: Reference to kvm_userspace_memory_region in doc and comments
  KVM: Delete all references to removed KVM_SET_MEMORY_ALIAS ioctl
  ...
</content>
</entry>
<entry>
<title>Merge remote-tracking branch 'kvm/queue' into HEAD</title>
<updated>2022-12-12T20:54:07Z</updated>
<author>
<name>Paolo Bonzini</name>
<email>pbonzini@redhat.com</email>
</author>
<published>2022-12-06T17:29:06Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=9352e7470a1b4edd2fa9d235420ecc7bc3971bdc'/>
<id>urn:sha1:9352e7470a1b4edd2fa9d235420ecc7bc3971bdc</id>
<content type='text'>
x86 Xen-for-KVM:

* Allow the Xen runstate information to cross a page boundary

* Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured

* add support for 32-bit guests in SCHEDOP_poll

x86 fixes:

* One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0).

* Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few
   years back when eliminating unnecessary barriers when switching between
   vmcs01 and vmcs02.

* Clean up the MSR filter docs.

* Clean up vmread_error_trampoline() to make it more obvious that params
  must be passed on the stack, even for x86-64.

* Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective
  of the current guest CPUID.

* Fudge around a race with TSC refinement that results in KVM incorrectly
  thinking a guest needs TSC scaling when running on a CPU with a
  constant TSC, but no hardware-enumerated TSC frequency.

* Advertise (on AMD) that the SMM_CTL MSR is not supported

* Remove unnecessary exports

Selftests:

* Fix an inverted check in the access tracking perf test, and restore
  support for asserting that there aren't too many idle pages when
  running on bare metal.

* Fix an ordering issue in the AMX test introduced by recent conversions
  to use kvm_cpu_has(), and harden the code to guard against similar bugs
  in the future.  Anything that tiggers caching of KVM's supported CPUID,
  kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if
  the caching occurs before the test opts in via prctl().

* Fix build errors that occur in certain setups (unsure exactly what is
  unique about the problematic setup) due to glibc overriding
  static_assert() to a variant that requires a custom message.

* Introduce actual atomics for clear/set_bit() in selftests

Documentation:

* Remove deleted ioctls from documentation

* Various fixes
</content>
</entry>
<entry>
<title>Merge tag 'rcu.2022.12.02a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu</title>
<updated>2022-12-12T15:47:15Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-12-12T15:47:15Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=1fab45ab6e823f9d7e5bc9520b2aa6564d6d58a7'/>
<id>urn:sha1:1fab45ab6e823f9d7e5bc9520b2aa6564d6d58a7</id>
<content type='text'>
Pull RCU updates from Paul McKenney:

 - Documentation updates. This is the second in a series from an ongoing
   review of the RCU documentation.

 - Miscellaneous fixes.

 - Introduce a default-off Kconfig option that depends on RCU_NOCB_CPU
   that, on CPUs mentioned in the nohz_full or rcu_nocbs boot-argument
   CPU lists, causes call_rcu() to introduce delays.

   These delays result in significant power savings on nearly idle
   Android and ChromeOS systems. These savings range from a few percent
   to more than ten percent.

   This series also includes several commits that change call_rcu() to a
   new call_rcu_hurry() function that avoids these delays in a few
   cases, for example, where timely wakeups are required. Several of
   these are outside of RCU and thus have acks and reviews from the
   relevant maintainers.

 - Create an srcu_read_lock_nmisafe() and an srcu_read_unlock_nmisafe()
   for architectures that support NMIs, but which do not provide
   NMI-safe this_cpu_inc(). These NMI-safe SRCU functions are required
   by the upcoming lockless printk() work by John Ogness et al.

 - Changes providing minor but important increases in torture test
   coverage for the new RCU polled-grace-period APIs.

 - Changes to torturescript that avoid redundant kernel builds, thus
   providing about a 30% speedup for the torture.sh acceptance test.

* tag 'rcu.2022.12.02a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (49 commits)
  net: devinet: Reduce refcount before grace period
  net: Use call_rcu_hurry() for dst_release()
  workqueue: Make queue_rcu_work() use call_rcu_hurry()
  percpu-refcount: Use call_rcu_hurry() for atomic switch
  scsi/scsi_error: Use call_rcu_hurry() instead of call_rcu()
  rcu/rcutorture: Use call_rcu_hurry() where needed
  rcu/rcuscale: Use call_rcu_hurry() for async reader test
  rcu/sync: Use call_rcu_hurry() instead of call_rcu
  rcuscale: Add laziness and kfree tests
  rcu: Shrinker for lazy rcu
  rcu: Refactor code a bit in rcu_nocb_do_flush_bypass()
  rcu: Make call_rcu() lazy to save power
  rcu: Implement lockdep_rcu_enabled for !CONFIG_DEBUG_LOCK_ALLOC
  srcu: Debug NMI safety even on archs that don't require it
  srcu: Explain the reason behind the read side critical section on GP start
  srcu: Warn when NMI-unsafe API is used in NMI
  arch/s390: Add ARCH_HAS_NMI_SAFE_THIS_CPU_OPS Kconfig option
  arch/loongarch: Add ARCH_HAS_NMI_SAFE_THIS_CPU_OPS Kconfig option
  rcu: Fix __this_cpu_read() lockdep warning in rcu_force_quiescent_state()
  rcu-tasks: Make grace-period-age message human-readable
  ...
</content>
</entry>
<entry>
<title>Merge tag 'kvmarm-6.2' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD</title>
<updated>2022-12-09T08:12:12Z</updated>
<author>
<name>Paolo Bonzini</name>
<email>pbonzini@redhat.com</email>
</author>
<published>2022-12-06T17:27:39Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=eb5618911af0ac069d2313b289d4c19ca3379401'/>
<id>urn:sha1:eb5618911af0ac069d2313b289d4c19ca3379401</id>
<content type='text'>
KVM/arm64 updates for 6.2

- Enable the per-vcpu dirty-ring tracking mechanism, together with an
  option to keep the good old dirty log around for pages that are
  dirtied by something other than a vcpu.

- Switch to the relaxed parallel fault handling, using RCU to delay
  page table reclaim and giving better performance under load.

- Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping
  option, which multi-process VMMs such as crosvm rely on.

- Merge the pKVM shadow vcpu state tracking that allows the hypervisor
  to have its own view of a vcpu, keeping that state private.

- Add support for the PMUv3p5 architecture revision, bringing support
  for 64bit counters on systems that support it, and fix the
  no-quite-compliant CHAIN-ed counter support for the machines that
  actually exist out there.

- Fix a handful of minor issues around 52bit VA/PA support (64kB pages
  only) as a prefix of the oncoming support for 4kB and 16kB pages.

- Add/Enable/Fix a bunch of selftests covering memslots, breakpoints,
  stage-2 faults and access tracking. You name it, we got it, we
  probably broke it.

- Pick a small set of documentation and spelling fixes, because no
  good merge window would be complete without those.

As a side effect, this tag also drags:

- The 'kvmarm-fixes-6.1-3' tag as a dependency to the dirty-ring
  series

- A shared branch with the arm64 tree that repaints all the system
  registers to match the ARM ARM's naming, and resulting in
  interesting conflicts
</content>
</entry>
<entry>
<title>Merge branch kvm-arm64/dirty-ring into kvmarm-master/next</title>
<updated>2022-12-05T14:19:50Z</updated>
<author>
<name>Marc Zyngier</name>
<email>maz@kernel.org</email>
</author>
<published>2022-12-05T14:19:50Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=a937f37d85f3347a1b6de69990fcd214ce882886'/>
<id>urn:sha1:a937f37d85f3347a1b6de69990fcd214ce882886</id>
<content type='text'>
* kvm-arm64/dirty-ring:
  : .
  : Add support for the "per-vcpu dirty-ring tracking with a bitmap
  : and sprinkles on top", courtesy of Gavin Shan.
  :
  : This branch drags the kvmarm-fixes-6.1-3 tag which was already
  : merged in 6.1-rc4 so that the branch is in a working state.
  : .
  KVM: Push dirty information unconditionally to backup bitmap
  KVM: selftests: Automate choosing dirty ring size in dirty_log_test
  KVM: selftests: Clear dirty ring states between two modes in dirty_log_test
  KVM: selftests: Use host page size to map ring buffer in dirty_log_test
  KVM: arm64: Enable ring-based dirty memory tracking
  KVM: Support dirty ring in conjunction with bitmap
  KVM: Move declaration of kvm_cpu_dirty_log_size() to kvm_dirty_ring.h
  KVM: x86: Introduce KVM_REQ_DIRTY_RING_SOFT_FULL

Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
</content>
</entry>
<entry>
<title>Merge branch 'gpc-fixes' of git://git.infradead.org/users/dwmw2/linux into HEAD</title>
<updated>2022-12-02T19:01:43Z</updated>
<author>
<name>Paolo Bonzini</name>
<email>pbonzini@redhat.com</email>
</author>
<published>2022-12-02T19:00:53Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=5656374b168c98377b6feee8d7500993eebda230'/>
<id>urn:sha1:5656374b168c98377b6feee8d7500993eebda230</id>
<content type='text'>
Pull Xen-for-KVM changes from David Woodhouse:

* add support for 32-bit guests in SCHEDOP_poll

* the rest of the gfn-to-pfn cache API cleanup

"I still haven't reinstated the last of those patches to make gpc-&gt;len
immutable."

Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>KVM: Reference to kvm_userspace_memory_region in doc and comments</title>
<updated>2022-12-02T17:54:40Z</updated>
<author>
<name>Javier Martinez Canillas</name>
<email>javierm@redhat.com</email>
</author>
<published>2022-12-02T10:50:10Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=30ee198ce42d60101620d33f8bc70c3234798365'/>
<id>urn:sha1:30ee198ce42d60101620d33f8bc70c3234798365</id>
<content type='text'>
There are still references to the removed kvm_memory_region data structure
but the doc and comments should mention struct kvm_userspace_memory_region
instead, since that is what's used by the ioctl that replaced the old one
and this data structure support the same set of flags.

Signed-off-by: Javier Martinez Canillas &lt;javierm@redhat.com&gt;
Message-Id: &lt;20221202105011.185147-4-javierm@redhat.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>KVM: Drop @gpa from exported gfn=&gt;pfn cache check() and refresh() helpers</title>
<updated>2022-11-30T19:25:24Z</updated>
<author>
<name>Sean Christopherson</name>
<email>seanjc@google.com</email>
</author>
<published>2022-10-13T21:12:31Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=58f5ee5fedd981e05cb086cba4e8f923c3727a04'/>
<id>urn:sha1:58f5ee5fedd981e05cb086cba4e8f923c3727a04</id>
<content type='text'>
Drop the @gpa param from the exported check()+refresh() helpers and limit
changing the cache's GPA to the activate path.  All external users just
feed in gpc-&gt;gpa, i.e. this is a fancy nop.

Allowing users to change the GPA at check()+refresh() is dangerous as
those helpers explicitly allow concurrent calls, e.g. KVM could get into
a livelock scenario.  It's also unclear as to what the expected behavior
should be if multiple tasks attempt to refresh with different GPAs.

Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
Signed-off-by: David Woodhouse &lt;dwmw@amazon.co.uk&gt;
</content>
</entry>
<entry>
<title>KVM: Drop KVM's API to allow temporarily unmapping gfn=&gt;pfn cache</title>
<updated>2022-11-30T19:25:24Z</updated>
<author>
<name>Sean Christopherson</name>
<email>seanjc@google.com</email>
</author>
<published>2022-10-13T21:12:29Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=9f87791d686d85614584438d4f249eb32ef7964c'/>
<id>urn:sha1:9f87791d686d85614584438d4f249eb32ef7964c</id>
<content type='text'>
Drop kvm_gpc_unmap() as it has no users and unclear requirements.  The
API was added as part of the original gfn_to_pfn_cache support, but its
sole usage[*] was never merged.  Fold the guts of kvm_gpc_unmap() into
the deactivate path and drop the API.  Omit acquiring refresh_lock as
as concurrent calls to kvm_gpc_deactivate() are not allowed (this is
not enforced, e.g. via lockdep. due to it being called during vCPU
destruction).

If/when temporary unmapping makes a comeback, the desirable behavior is
likely to restrict temporary unmapping to vCPU-exclusive mappings and
require the vcpu-&gt;mutex be held to serialize unmap.  Use of the
refresh_lock to protect unmapping was somewhat specuatively added by
commit 93984f19e7bc ("KVM: Fully serialize gfn=&gt;pfn cache refresh via
mutex") to guard against concurrent unmaps, but the primary use case of
the temporary unmap, nested virtualization[*], doesn't actually need or
want concurrent unmaps.

[*] https://lore.kernel.org/all/20211210163625.2886-7-dwmw2@infradead.org

Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
Signed-off-by: David Woodhouse &lt;dwmw@amazon.co.uk&gt;
</content>
</entry>
<entry>
<title>KVM: Use gfn_to_pfn_cache's immutable "kvm" in kvm_gpc_refresh()</title>
<updated>2022-11-30T19:25:24Z</updated>
<author>
<name>Michal Luczaj</name>
<email>mhal@rbox.co</email>
</author>
<published>2022-10-13T21:12:28Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=0318f207d1c2e297d1ec1c6e145bb8bd053236f9'/>
<id>urn:sha1:0318f207d1c2e297d1ec1c6e145bb8bd053236f9</id>
<content type='text'>
Make kvm_gpc_refresh() use kvm instance cached in gfn_to_pfn_cache.

No functional change intended.

Suggested-by: Sean Christopherson &lt;seanjc@google.com&gt;
Signed-off-by: Michal Luczaj &lt;mhal@rbox.co&gt;
[sean: leave kvm_gpc_unmap() as-is]
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
Signed-off-by: David Woodhouse &lt;dwmw@amazon.co.uk&gt;
</content>
</entry>
</feed>
