<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include/uapi/linux/kvm.h, branch v5.8.1</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v5.8.1</id>
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<updated>2020-06-03T22:13:47Z</updated>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm</title>
<updated>2020-06-03T22:13:47Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-06-03T22:13:47Z</published>
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<id>urn:sha1:039aeb9deb9291f3b19c375a8bc6fa7f768996cc</id>
<content type='text'>
Pull kvm updates from Paolo Bonzini:
 "ARM:
   - Move the arch-specific code into arch/arm64/kvm

   - Start the post-32bit cleanup

   - Cherry-pick a few non-invasive pre-NV patches

  x86:
   - Rework of TLB flushing

   - Rework of event injection, especially with respect to nested
     virtualization

   - Nested AMD event injection facelift, building on the rework of
     generic code and fixing a lot of corner cases

   - Nested AMD live migration support

   - Optimization for TSC deadline MSR writes and IPIs

   - Various cleanups

   - Asynchronous page fault cleanups (from tglx, common topic branch
     with tip tree)

   - Interrupt-based delivery of asynchronous "page ready" events (host
     side)

   - Hyper-V MSRs and hypercalls for guest debugging

   - VMX preemption timer fixes

  s390:
   - Cleanups

  Generic:
   - switch vCPU thread wakeup from swait to rcuwait

  The other architectures, and the guest side of the asynchronous page
  fault work, will come next week"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (256 commits)
  KVM: selftests: fix rdtsc() for vmx_tsc_adjust_test
  KVM: check userspace_addr for all memslots
  KVM: selftests: update hyperv_cpuid with SynDBG tests
  x86/kvm/hyper-v: Add support for synthetic debugger via hypercalls
  x86/kvm/hyper-v: enable hypercalls regardless of hypercall page
  x86/kvm/hyper-v: Add support for synthetic debugger interface
  x86/hyper-v: Add synthetic debugger definitions
  KVM: selftests: VMX preemption timer migration test
  KVM: nVMX: Fix VMX preemption timer migration
  x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit
  KVM: x86/pmu: Support full width counting
  KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in
  KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT
  KVM: x86: acknowledgment mechanism for async pf page ready notifications
  KVM: x86: interrupt based APF 'page ready' event delivery
  KVM: introduce kvm_read_guest_offset_cached()
  KVM: rename kvm_arch_can_inject_async_page_present() to kvm_arch_can_dequeue_async_page_present()
  KVM: x86: extend struct kvm_vcpu_pv_apf_data with token info
  Revert "KVM: async_pf: Fix #DF due to inject "Page not Present" and "Page Ready" exceptions simultaneously"
  KVM: VMX: Replace zero-length array with flexible-array
  ...
</content>
</entry>
<entry>
<title>x86/kvm/hyper-v: Add support for synthetic debugger interface</title>
<updated>2020-06-01T08:26:11Z</updated>
<author>
<name>Jon Doron</name>
<email>arilou@gmail.com</email>
</author>
<published>2020-05-29T13:45:40Z</published>
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<id>urn:sha1:f97f5a56f5977311f3833056a73cdbb0ee56cb1e</id>
<content type='text'>
Add support for Hyper-V synthetic debugger (syndbg) interface.
The syndbg interface is using MSRs to emulate a way to send/recv packets
data.

The debug transport dll (kdvm/kdnet) will identify if Hyper-V is enabled
and if it supports the synthetic debugger interface it will attempt to
use it, instead of trying to initialize a network adapter.

Reviewed-by: Vitaly Kuznetsov &lt;vkuznets@redhat.com&gt;
Signed-off-by: Jon Doron &lt;arilou@gmail.com&gt;
Message-Id: &lt;20200529134543.1127440-4-arilou@gmail.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit</title>
<updated>2020-06-01T08:26:09Z</updated>
<author>
<name>Jon Doron</name>
<email>arilou@gmail.com</email>
</author>
<published>2020-04-24T11:37:40Z</published>
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<id>urn:sha1:f7d31e65368aeef973fab788aa22c4f1d5a6af66</id>
<content type='text'>
The problem the patch is trying to address is the fact that 'struct
kvm_hyperv_exit' has different layout on when compiling in 32 and 64 bit
modes.

In 64-bit mode the default alignment boundary is 64 bits thus
forcing extra gaps after 'type' and 'msr' but in 32-bit mode the
boundary is at 32 bits thus no extra gaps.

This is an issue as even when the kernel is 64 bit, the userspace using
the interface can be both 32 and 64 bit but the same 32 bit userspace has
to work with 32 bit kernel.

The issue is fixed by forcing the 64 bit layout, this leads to ABI
change for 32 bit builds and while we are obviously breaking '32 bit
userspace with 32 bit kernel' case, we're fixing the '32 bit userspace
with 64 bit kernel' one.

As the interface has no (known) users and 32 bit KVM is rather baroque
nowadays, this seems like a reasonable decision.

Reviewed-by: Vitaly Kuznetsov &lt;vkuznets@redhat.com&gt;
Signed-off-by: Jon Doron &lt;arilou@gmail.com&gt;
Message-Id: &lt;20200424113746.3473563-2-arilou@gmail.com&gt;
Reviewed-by: Roman Kagan &lt;rvkagan@yandex-team.ru&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT</title>
<updated>2020-06-01T08:26:08Z</updated>
<author>
<name>Vitaly Kuznetsov</name>
<email>vkuznets@redhat.com</email>
</author>
<published>2020-05-25T14:41:22Z</published>
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<id>urn:sha1:72de5fa4c16195827252b961ba44028a39dfeaff</id>
<content type='text'>
Introduce new capability to indicate that KVM supports interrupt based
delivery of 'page ready' APF events. This includes support for both
MSR_KVM_ASYNC_PF_INT and MSR_KVM_ASYNC_PF_ACK.

Signed-off-by: Vitaly Kuznetsov &lt;vkuznets@redhat.com&gt;
Message-Id: &lt;20200525144125.143875-8-vkuznets@redhat.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>kvm: add capability for halt polling</title>
<updated>2020-04-24T16:53:17Z</updated>
<author>
<name>David Matlack</name>
<email>dmatlack@google.com</email>
</author>
<published>2020-04-17T22:14:46Z</published>
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<id>urn:sha1:acd05785e48c01edb2c4f4d014d28478b5f19fb5</id>
<content type='text'>
KVM_CAP_HALT_POLL is a per-VM capability that lets userspace
control the halt-polling time, allowing halt-polling to be tuned or
disabled on particular VMs.

With dynamic halt-polling, a VM's VCPUs can poll from anywhere from
[0, halt_poll_ns] on each halt. KVM_CAP_HALT_POLL sets the
upper limit on the poll time.

Signed-off-by: David Matlack &lt;dmatlack@google.com&gt;
Signed-off-by: Jon Cargille &lt;jcargill@google.com&gt;
Reviewed-by: Jim Mattson &lt;jmattson@google.com&gt;
Message-Id: &lt;20200417221446.108733-1-jcargill@google.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>docs: fix broken references for ReST files that moved around</title>
<updated>2020-04-20T21:45:03Z</updated>
<author>
<name>Mauro Carvalho Chehab</name>
<email>mchehab+huawei@kernel.org</email>
</author>
<published>2020-04-14T16:48:36Z</published>
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<id>urn:sha1:3ecad8c2c1ff333e204c26e2f0dddfa623153f87</id>
<content type='text'>
Some broken references happened due to shifting files around
and ReST renames. Those can't be auto-fixed by the script,
so let's fix them manually.

Signed-off-by: Mauro Carvalho Chehab &lt;mchehab+huawei@kernel.org&gt;
Acked-by: Corentin Labbe &lt;clabbe.montjoie@gmail.com&gt;
Link: https://lore.kernel.org/r/64773a12b4410aaf3e3be89e3ec7e34de2484eea.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet &lt;corbet@lwn.net&gt;
</content>
</entry>
<entry>
<title>KVM: PPC: Book3S HV: Add a capability for enabling secure guests</title>
<updated>2020-03-26T00:09:04Z</updated>
<author>
<name>Paul Mackerras</name>
<email>paulus@ozlabs.org</email>
</author>
<published>2020-03-19T04:29:55Z</published>
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<id>urn:sha1:9a5788c615f52f6d7bf0b61986a632d4ec86791d</id>
<content type='text'>
At present, on Power systems with Protected Execution Facility
hardware and an ultravisor, a KVM guest can transition to being a
secure guest at will.  Userspace (QEMU) has no way of knowing
whether a host system is capable of running secure guests.  This
will present a problem in future when the ultravisor is capable of
migrating secure guests from one host to another, because
virtualization management software will have no way to ensure that
secure guests only run in domains where all of the hosts can
support secure guests.

This adds a VM capability which has two functions: (a) userspace
can query it to find out whether the host can support secure guests,
and (b) userspace can enable it for a guest, which allows that
guest to become a secure guest.  If userspace does not enable it,
KVM will return an error when the ultravisor does the hypercall
that indicates that the guest is starting to transition to a
secure guest.  The ultravisor will then abort the transition and
the guest will terminate.

Signed-off-by: Paul Mackerras &lt;paulus@ozlabs.org&gt;
Reviewed-by: David Gibson &lt;david@gibson.dropbear.id.au&gt;
Reviewed-by: Ram Pai &lt;linuxram@us.ibm.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'kvm-s390-next-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD</title>
<updated>2020-03-16T17:19:34Z</updated>
<author>
<name>Paolo Bonzini</name>
<email>pbonzini@redhat.com</email>
</author>
<published>2020-03-16T17:19:34Z</published>
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<id>urn:sha1:1c482452d5db0f52e4e8eed95bd7314eec537d78</id>
<content type='text'>
KVM: s390: Features and Enhancements for 5.7 part1

1. Allow to disable gisa
2. protected virtual machines
  Protected VMs (PVM) are KVM VMs, where KVM can't access the VM's
  state like guest memory and guest registers anymore. Instead the
  PVMs are mostly managed by a new entity called Ultravisor (UV),
  which provides an API, so KVM and the PV can request management
  actions.

  PVMs are encrypted at rest and protected from hypervisor access
  while running.  They switch from a normal operation into protected
  mode, so we can still use the standard boot process to load a
  encrypted blob and then move it into protected mode.

  Rebooting is only possible by passing through the unprotected/normal
  mode and switching to protected again.

  One mm related patch will go via Andrews mm tree ( mm/gup/writeback:
  add callbacks for inaccessible pages)
</content>
</entry>
<entry>
<title>KVM: x86: enable dirty log gradually in small chunks</title>
<updated>2020-03-16T16:57:37Z</updated>
<author>
<name>Jay Zhou</name>
<email>jianjay.zhou@huawei.com</email>
</author>
<published>2020-02-27T01:32:27Z</published>
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<id>urn:sha1:3c9bd4006bfc2dccda1823db61b3f470ef91cfaa</id>
<content type='text'>
It could take kvm-&gt;mmu_lock for an extended period of time when
enabling dirty log for the first time. The main cost is to clear
all the D-bits of last level SPTEs. This situation can benefit from
manual dirty log protect as well, which can reduce the mmu_lock
time taken. The sequence is like this:

1. Initialize all the bits of the dirty bitmap to 1 when enabling
   dirty log for the first time
2. Only write protect the huge pages
3. KVM_GET_DIRTY_LOG returns the dirty bitmap info
4. KVM_CLEAR_DIRTY_LOG will clear D-bit for each of the leaf level
   SPTEs gradually in small chunks

Under the Intel(R) Xeon(R) Gold 6152 CPU @ 2.10GHz environment,
I did some tests with a 128G windows VM and counted the time taken
of memory_global_dirty_log_start, here is the numbers:

VM Size        Before    After optimization
128G           460ms     10ms

Signed-off-by: Jay Zhou &lt;jianjay.zhou@huawei.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>KVM: s390: protvirt: introduce and enable KVM_CAP_S390_PROTECTED</title>
<updated>2020-02-27T18:47:13Z</updated>
<author>
<name>Christian Borntraeger</name>
<email>borntraeger@de.ibm.com</email>
</author>
<published>2020-02-18T20:08:07Z</published>
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<id>urn:sha1:13da9ae1cdbf1ec4ea36b7612e606681c27cca13</id>
<content type='text'>
Now that everything is in place, we can announce the feature.

Signed-off-by: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Reviewed-by: Cornelia Huck &lt;cohuck@redhat.com&gt;
Reviewed-by: David Hildenbrand &lt;david@redhat.com&gt;
</content>
</entry>
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