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<title>user/sven/linux.git/include/uapi/linux/kvm.h, branch v4.14.263</title>
<subtitle>Linux Kernel
</subtitle>
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<updated>2020-09-23T08:46:34Z</updated>
<entry>
<title>KVM: MIPS: Change the definition of kvm type</title>
<updated>2020-09-23T08:46:34Z</updated>
<author>
<name>Huacai Chen</name>
<email>chenhc@lemote.com</email>
</author>
<published>2020-09-10T10:33:51Z</published>
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[ Upstream commit 15e9e35cd1dec2bc138464de6bf8ef828df19235 ]

MIPS defines two kvm types:

 #define KVM_VM_MIPS_TE          0
 #define KVM_VM_MIPS_VZ          1

In Documentation/virt/kvm/api.rst it is said that "You probably want to
use 0 as machine type", which implies that type 0 be the "automatic" or
"default" type. And, in user-space libvirt use the null-machine (with
type 0) to detect the kvm capability, which returns "KVM not supported"
on a VZ platform.

I try to fix it in QEMU but it is ugly:
https://lists.nongnu.org/archive/html/qemu-devel/2020-08/msg05629.html

And Thomas Huth suggests me to change the definition of kvm type:
https://lists.nongnu.org/archive/html/qemu-devel/2020-09/msg03281.html

So I define like this:

 #define KVM_VM_MIPS_AUTO        0
 #define KVM_VM_MIPS_VZ          1
 #define KVM_VM_MIPS_TE          2

Since VZ and TE cannot co-exists, using type 0 on a TE platform will
still return success (so old user-space tools have no problems on new
kernels); the advantage is that using type 0 on a VZ platform will not
return failure. So, the only problem is "new user-space tools use type
2 on old kernels", but if we treat this as a kernel bug, we can backport
this patch to old stable kernels.

Signed-off-by: Huacai Chen &lt;chenhc@lemote.com&gt;
Message-Id: &lt;1599734031-28746-1-git-send-email-chenhc@lemote.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit</title>
<updated>2020-06-20T08:25:09Z</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:sha1:86fde86b9307d33769a8a171ba5c9ae3c021a375</id>
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[ Upstream commit f7d31e65368aeef973fab788aa22c4f1d5a6af66 ]

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;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>KVM: x86: Add a framework for supporting MSR-based features</title>
<updated>2018-08-15T16:12:59Z</updated>
<author>
<name>Tom Lendacky</name>
<email>thomas.lendacky@amd.com</email>
</author>
<published>2018-02-21T19:39:51Z</published>
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<id>urn:sha1:f0660d587efed81cfe3d734d77e3fb03fce0b15b</id>
<content type='text'>
commit 801e459a6f3a63af9d447e6249088c76ae16efc4 upstream

Provide a new KVM capability that allows bits within MSRs to be recognized
as features.  Two new ioctls are added to the /dev/kvm ioctl routine to
retrieve the list of these MSRs and then retrieve their values. A kvm_x86_ops
callback is used to determine support for the listed MSR-based features.

Signed-off-by: Tom Lendacky &lt;thomas.lendacky@amd.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
[Tweaked documentation. - Radim]
Signed-off-by: Radim Krčmář &lt;rkrcmar@redhat.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>KVM: s390: wire up bpb feature</title>
<updated>2018-04-29T09:33:14Z</updated>
<author>
<name>Christian Borntraeger</name>
<email>borntraeger@de.ibm.com</email>
</author>
<published>2018-04-27T05:36:27Z</published>
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<content type='text'>
[ Upstream commit 35b3fde6203b932b2b1a5b53b3d8808abc9c4f60 ]

The new firmware interfaces for branch prediction behaviour changes
are transparently available for the guest. Nevertheless, there is
new state attached that should be migrated and properly resetted.
Provide a mechanism for handling reset, migration and VSIE.

Signed-off-by: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Reviewed-by: David Hildenbrand &lt;david@redhat.com&gt;
Reviewed-by: Cornelia Huck &lt;cohuck@redhat.com&gt;
[Changed capability number to 152. - Radim]
Signed-off-by: Radim Krčmář &lt;rkrcmar@redhat.com&gt;
Signed-off-by: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>License cleanup: add SPDX license identifier to uapi header files with no license</title>
<updated>2017-11-02T10:19:54Z</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2017-11-01T14:08:43Z</published>
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<id>urn:sha1:6f52b16c5b29b89d92c0e7236f4655dc8491ad70</id>
<content type='text'>
Many user space API headers are missing licensing information, which
makes it hard for compliance tools to determine the correct license.

By default are files without license information under the default
license of the kernel, which is GPLV2.  Marking them GPLV2 would exclude
them from being included in non GPLV2 code, which is obviously not
intended. The user space API headers fall under the syscall exception
which is in the kernels COPYING file:

   NOTE! This copyright does *not* cover user programs that use kernel
   services by normal system calls - this is merely considered normal use
   of the kernel, and does *not* fall under the heading of "derived work".

otherwise syscall usage would not be possible.

Update the files which contain no license information with an SPDX
license identifier.  The chosen identifier is 'GPL-2.0 WITH
Linux-syscall-note' which is the officially assigned identifier for the
Linux syscall exception.  SPDX license identifiers are a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.  See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>KVM: PPC: Book3S HV: Report storage key support to userspace</title>
<updated>2017-08-31T02:36:44Z</updated>
<author>
<name>Paul Mackerras</name>
<email>paulus@ozlabs.org</email>
</author>
<published>2017-08-25T09:53:39Z</published>
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<id>urn:sha1:e3bfed1df379c18f20feb06427d952b766e2c00f</id>
<content type='text'>
This adds information about storage keys to the struct returned by
the KVM_PPC_GET_SMMU_INFO ioctl.  The new fields replace a pad field,
which was zeroed by previous kernel versions.  Thus userspace that
knows about the new fields will see zeroes when running on an older
kernel, indicating that storage keys are not supported.  The size of
the structure has not changed.

The number of keys is hard-coded for the CPUs supported by HV KVM,
which is just POWER7, POWER8 and POWER9.

Signed-off-by: Paul Mackerras &lt;paulus@ozlabs.org&gt;
Reviewed-by: David Gibson &lt;david@gibson.dropbear.id.au&gt;
Signed-off-by: Paul Mackerras &lt;paulus@ozlabs.org&gt;
</content>
</entry>
<entry>
<title>kvm: x86: hyperv: make VP_INDEX managed by userspace</title>
<updated>2017-07-14T14:28:18Z</updated>
<author>
<name>Roman Kagan</name>
<email>rkagan@virtuozzo.com</email>
</author>
<published>2017-07-14T14:13:20Z</published>
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<id>urn:sha1:d3457c877b14aaee8c52923eedf05a3b78af0476</id>
<content type='text'>
Hyper-V identifies vCPUs by Virtual Processor Index, which can be
queried via HV_X64_MSR_VP_INDEX msr.  It is defined by the spec as a
sequential number which can't exceed the maximum number of vCPUs per VM.
APIC ids can be sparse and thus aren't a valid replacement for VP
indices.

Current KVM uses its internal vcpu index as VP_INDEX.  However, to make
it predictable and persistent across VM migrations, the userspace has to
control the value of VP_INDEX.

This patch achieves that, by storing vp_index explicitly on vcpu, and
allowing HV_X64_MSR_VP_INDEX to be set from the host side.  For
compatibility it's initialized to KVM vcpu index.  Also a few variables
are renamed to make clear distinction betweed this Hyper-V vp_index and
KVM vcpu_id (== APIC id).  Besides, a new capability,
KVM_CAP_HYPERV_VP_INDEX, is added to allow the userspace to skip
attempting msr writes where unsupported, to avoid spamming error logs.

Signed-off-by: Roman Kagan &lt;rkagan@virtuozzo.com&gt;
Signed-off-by: Radim Krčmář &lt;rkrcmar@redhat.com&gt;
</content>
</entry>
<entry>
<title>kvm: x86: hyperv: add KVM_CAP_HYPERV_SYNIC2</title>
<updated>2017-07-13T15:41:04Z</updated>
<author>
<name>Roman Kagan</name>
<email>rkagan@virtuozzo.com</email>
</author>
<published>2017-06-22T13:51:01Z</published>
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<id>urn:sha1:efc479e6900c22bad9a2b649d13405ed9cde2d53</id>
<content type='text'>
There is a flaw in the Hyper-V SynIC implementation in KVM: when message
page or event flags page is enabled by setting the corresponding msr,
KVM zeroes it out.  This is problematic because on migration the
corresponding MSRs are loaded on the destination, so the content of
those pages is lost.

This went unnoticed so far because the only user of those pages was
in-KVM hyperv synic timers, which could continue working despite that
zeroing.

Newer QEMU uses those pages for Hyper-V VMBus implementation, and
zeroing them breaks the migration.

Besides, in newer QEMU the content of those pages is fully managed by
QEMU, so zeroing them is undesirable even when writing the MSRs from the
guest side.

To support this new scheme, introduce a new capability,
KVM_CAP_HYPERV_SYNIC2, which, when enabled, makes sure that the synic
pages aren't zeroed out in KVM.

Signed-off-by: Roman Kagan &lt;rkagan@virtuozzo.com&gt;
Signed-off-by: Radim Krčmář &lt;rkrcmar@redhat.com&gt;
</content>
</entry>
<entry>
<title>KVM: s390: Fix KVM_S390_GET_CMMA_BITS ioctl definition</title>
<updated>2017-07-12T20:38:26Z</updated>
<author>
<name>Gleb Fotengauer-Malinovskiy</name>
<email>glebfm@altlinux.org</email>
</author>
<published>2017-07-10T21:22:33Z</published>
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<id>urn:sha1:949c033694864082db9b3f5304723a6d7407f8e2</id>
<content type='text'>
In case of KVM_S390_GET_CMMA_BITS, the kernel does not only read struct
kvm_s390_cmma_log passed from userspace (which constitutes _IOC_WRITE),
it also writes back a return value (which constitutes _IOC_READ) making
this an _IOWR ioctl instead of _IOW.

Fixes: 4036e387 ("KVM: s390: ioctls to get and set guest storage attributes")
Signed-off-by: Gleb Fotengauer-Malinovskiy &lt;glebfm@altlinux.org&gt;
Acked-by: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Signed-off-by: Radim Krčmář &lt;rkrcmar@redhat.com&gt;
</content>
</entry>
<entry>
<title>Merge branch 'kvm-ppc-next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD</title>
<updated>2017-07-03T08:41:59Z</updated>
<author>
<name>Paolo Bonzini</name>
<email>pbonzini@redhat.com</email>
</author>
<published>2017-07-03T08:41:59Z</published>
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<id>urn:sha1:8a53e7e572252e551fd4b172dc207f8beca1ae20</id>
<content type='text'>
- Better machine check handling for HV KVM
- Ability to support guests with threads=2, 4 or 8 on POWER9
- Fix for a race that could cause delayed recognition of signals
- Fix for a bug where POWER9 guests could sleep with interrupts
  pending.
</content>
</entry>
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