<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/powerpc/kvm, branch v6.7</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'powerpc-6.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux</title>
<updated>2023-11-03T20:07:39+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-11-03T20:07:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=707df298cbde200b939c70be2577b20775fe3345'/>
<id>707df298cbde200b939c70be2577b20775fe3345</id>
<content type='text'>
Pull powerpc updates from Michael Ellerman:

 - Add support for KVM running as a nested hypervisor under development
   versions of PowerVM, using the new PAPR nested virtualisation API

 - Add support for the BPF prog pack allocator

 - A rework of the non-server MMU handling to support execute-only on
   all platforms

 - Some optimisations &amp; cleanups for the powerpc qspinlock code

 - Various other small features and fixes

Thanks to Aboorva Devarajan, Aditya Gupta, Amit Machhiwal, Benjamin
Gray, Christophe Leroy, Dr. David Alan Gilbert, Gaurav Batra, Gautam
Menghani, Geert Uytterhoeven, Haren Myneni, Hari Bathini, Joel Stanley,
Jordan Niethe, Julia Lawall, Kautuk Consul, Kuan-Wei Chiu, Michael
Neuling, Minjie Du, Muhammad Muzammil, Naveen N Rao, Nicholas Piggin,
Nick Child, Nysal Jan K.A, Peter Lafreniere, Rob Herring, Sachin Sant,
Sebastian Andrzej Siewior, Shrikanth Hegde, Srikar Dronamraju, Stanislav
Kinsburskii, Vaibhav Jain, Wang Yufen, Yang Yingliang, and Yuan Tan.

* tag 'powerpc-6.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (100 commits)
  powerpc/vmcore: Add MMU information to vmcoreinfo
  Revert "powerpc: add `cur_cpu_spec` symbol to vmcoreinfo"
  powerpc/bpf: use bpf_jit_binary_pack_[alloc|finalize|free]
  powerpc/bpf: rename powerpc64_jit_data to powerpc_jit_data
  powerpc/bpf: implement bpf_arch_text_invalidate for bpf_prog_pack
  powerpc/bpf: implement bpf_arch_text_copy
  powerpc/code-patching: introduce patch_instructions()
  powerpc/32s: Implement local_flush_tlb_page_psize()
  powerpc/pseries: use kfree_sensitive() in plpks_gen_password()
  powerpc/code-patching: Perform hwsync in __patch_instruction() in case of failure
  powerpc/fsl_msi: Use device_get_match_data()
  powerpc: Remove cpm_dp...() macros
  powerpc/qspinlock: Rename yield_propagate_owner tunable
  powerpc/qspinlock: Propagate sleepy if previous waiter is preempted
  powerpc/qspinlock: don't propagate the not-sleepy state
  powerpc/qspinlock: propagate owner preemptedness rather than CPU number
  powerpc/qspinlock: stop queued waiters trying to set lock sleepy
  powerpc/perf: Fix disabling BHRB and instruction sampling
  powerpc/trace: Add support for HAVE_FUNCTION_ARG_ACCESS_API
  powerpc/tools: Pass -mabi=elfv2 to gcc-check-mprofile-kernel.sh
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull powerpc updates from Michael Ellerman:

 - Add support for KVM running as a nested hypervisor under development
   versions of PowerVM, using the new PAPR nested virtualisation API

 - Add support for the BPF prog pack allocator

 - A rework of the non-server MMU handling to support execute-only on
   all platforms

 - Some optimisations &amp; cleanups for the powerpc qspinlock code

 - Various other small features and fixes

Thanks to Aboorva Devarajan, Aditya Gupta, Amit Machhiwal, Benjamin
Gray, Christophe Leroy, Dr. David Alan Gilbert, Gaurav Batra, Gautam
Menghani, Geert Uytterhoeven, Haren Myneni, Hari Bathini, Joel Stanley,
Jordan Niethe, Julia Lawall, Kautuk Consul, Kuan-Wei Chiu, Michael
Neuling, Minjie Du, Muhammad Muzammil, Naveen N Rao, Nicholas Piggin,
Nick Child, Nysal Jan K.A, Peter Lafreniere, Rob Herring, Sachin Sant,
Sebastian Andrzej Siewior, Shrikanth Hegde, Srikar Dronamraju, Stanislav
Kinsburskii, Vaibhav Jain, Wang Yufen, Yang Yingliang, and Yuan Tan.

* tag 'powerpc-6.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (100 commits)
  powerpc/vmcore: Add MMU information to vmcoreinfo
  Revert "powerpc: add `cur_cpu_spec` symbol to vmcoreinfo"
  powerpc/bpf: use bpf_jit_binary_pack_[alloc|finalize|free]
  powerpc/bpf: rename powerpc64_jit_data to powerpc_jit_data
  powerpc/bpf: implement bpf_arch_text_invalidate for bpf_prog_pack
  powerpc/bpf: implement bpf_arch_text_copy
  powerpc/code-patching: introduce patch_instructions()
  powerpc/32s: Implement local_flush_tlb_page_psize()
  powerpc/pseries: use kfree_sensitive() in plpks_gen_password()
  powerpc/code-patching: Perform hwsync in __patch_instruction() in case of failure
  powerpc/fsl_msi: Use device_get_match_data()
  powerpc: Remove cpm_dp...() macros
  powerpc/qspinlock: Rename yield_propagate_owner tunable
  powerpc/qspinlock: Propagate sleepy if previous waiter is preempted
  powerpc/qspinlock: don't propagate the not-sleepy state
  powerpc/qspinlock: propagate owner preemptedness rather than CPU number
  powerpc/qspinlock: stop queued waiters trying to set lock sleepy
  powerpc/perf: Fix disabling BHRB and instruction sampling
  powerpc/trace: Add support for HAVE_FUNCTION_ARG_ACCESS_API
  powerpc/tools: Pass -mabi=elfv2 to gcc-check-mprofile-kernel.sh
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'topic/ppc-kvm' into next</title>
<updated>2023-10-27T09:58:03+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2023-10-27T09:58:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=303d77a6e1707498f09c9d8ee91b1dc07ca315a5'/>
<id>303d77a6e1707498f09c9d8ee91b1dc07ca315a5</id>
<content type='text'>
Merge our KVM topic branch, this has been independently included in linux-next
for most of the development cycle.
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge our KVM topic branch, this has been independently included in linux-next
for most of the development cycle.
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Remove extern from function implementations</title>
<updated>2023-10-19T06:12:47+00:00</updated>
<author>
<name>Benjamin Gray</name>
<email>bgray@linux.ibm.com</email>
</author>
<published>2023-10-11T05:37:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=419d5d112c2e1e78beda9c3299f71c35141d8dba'/>
<id>419d5d112c2e1e78beda9c3299f71c35141d8dba</id>
<content type='text'>
Sparse reports several function implementations annotated with extern.
This is clearly incorrect, likely just copied from an actual extern
declaration in another file.

Fix the sparse warnings by removing extern.

Signed-off-by: Benjamin Gray &lt;bgray@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20231011053711.93427-6-bgray@linux.ibm.com

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Sparse reports several function implementations annotated with extern.
This is clearly incorrect, likely just copied from an actual extern
declaration in another file.

Fix the sparse warnings by removing extern.

Signed-off-by: Benjamin Gray &lt;bgray@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20231011053711.93427-6-bgray@linux.ibm.com

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Use NULL instead of 0 for null pointers</title>
<updated>2023-10-19T06:12:47+00:00</updated>
<author>
<name>Benjamin Gray</name>
<email>bgray@linux.ibm.com</email>
</author>
<published>2023-10-11T05:37:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ddfb7d9db843fd4fbdff81fb8a8743f865c3dd96'/>
<id>ddfb7d9db843fd4fbdff81fb8a8743f865c3dd96</id>
<content type='text'>
Sparse reports several uses of 0 for pointer arguments and comparisons.
Replace with NULL to better convey the intent. Remove entirely if a
comparison to follow the kernel style of implicit boolean conversions.

Signed-off-by: Benjamin Gray &lt;bgray@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20231011053711.93427-5-bgray@linux.ibm.com

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Sparse reports several uses of 0 for pointer arguments and comparisons.
Replace with NULL to better convey the intent. Remove entirely if a
comparison to follow the kernel style of implicit boolean conversions.

Signed-off-by: Benjamin Gray &lt;bgray@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20231011053711.93427-5-bgray@linux.ibm.com

</pre>
</div>
</content>
</entry>
<entry>
<title>docs: move powerpc under arch</title>
<updated>2023-10-10T19:35:55+00:00</updated>
<author>
<name>Costa Shulyupin</name>
<email>costa.shul@redhat.com</email>
</author>
<published>2023-08-26T16:56:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=17e02586ed18501c11115b8dea9055a5973f45a4'/>
<id>17e02586ed18501c11115b8dea9055a5973f45a4</id>
<content type='text'>
and fix all in-tree references.

Architecture-specific documentation is being moved into Documentation/arch/
as a way of cleaning up the top-level documentation directory and making
the docs hierarchy more closely match the source hierarchy.

Signed-off-by: Costa Shulyupin &lt;costa.shul@redhat.com&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Jonathan Corbet &lt;corbet@lwn.net&gt;
Link: https://lore.kernel.org/r/20230826165737.2101199-1-costa.shul@redhat.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
and fix all in-tree references.

Architecture-specific documentation is being moved into Documentation/arch/
as a way of cleaning up the top-level documentation directory and making
the docs hierarchy more closely match the source hierarchy.

Signed-off-by: Costa Shulyupin &lt;costa.shul@redhat.com&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Jonathan Corbet &lt;corbet@lwn.net&gt;
Link: https://lore.kernel.org/r/20230826165737.2101199-1-costa.shul@redhat.com
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: PPC: Add support for nestedv2 guests</title>
<updated>2023-09-14T12:04:24+00:00</updated>
<author>
<name>Jordan Niethe</name>
<email>jniethe5@gmail.com</email>
</author>
<published>2023-09-14T03:05:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=19d31c5f115754c369c0995df47479c384757f82'/>
<id>19d31c5f115754c369c0995df47479c384757f82</id>
<content type='text'>
A series of hcalls have been added to the PAPR which allow a regular
guest partition to create and manage guest partitions of its own. KVM
already had an interface that allowed this on powernv platforms. This
existing interface will now be called "nestedv1". The newly added PAPR
interface will be called "nestedv2".  PHYP will support the nestedv2
interface. At this time the host side of the nestedv2 interface has not
been implemented on powernv but there is no technical reason why it
could not be added.

The nestedv1 interface is still supported.

Add support to KVM to utilize these hcalls to enable running nested
guests as a pseries guest on PHYP.

Overview of the new hcall usage:

- L1 and L0 negotiate capabilities with
  H_GUEST_{G,S}ET_CAPABILITIES()

- L1 requests the L0 create a L2 with
  H_GUEST_CREATE() and receives a handle to use in future hcalls

- L1 requests the L0 create a L2 vCPU with
  H_GUEST_CREATE_VCPU()

- L1 sets up the L2 using H_GUEST_SET and the
  H_GUEST_VCPU_RUN input buffer

- L1 requests the L0 runs the L2 vCPU using H_GUEST_VCPU_RUN()

- L2 returns to L1 with an exit reason and L1 reads the
  H_GUEST_VCPU_RUN output buffer populated by the L0

- L1 handles the exit using H_GET_STATE if necessary

- L1 reruns L2 vCPU with H_GUEST_VCPU_RUN

- L1 frees the L2 in the L0 with H_GUEST_DELETE()

Support for the new API is determined by trying
H_GUEST_GET_CAPABILITIES. On a successful return, use the nestedv2
interface.

Use the vcpu register state setters for tracking modified guest state
elements and copy the thread wide values into the H_GUEST_VCPU_RUN input
buffer immediately before running a L2. The guest wide
elements can not be added to the input buffer so send them with a
separate H_GUEST_SET call if necessary.

Make the vcpu register getter load the corresponding value from the real
host with H_GUEST_GET. To avoid unnecessarily calling H_GUEST_GET, track
which values have already been loaded between H_GUEST_VCPU_RUN calls. If
an element is present in the H_GUEST_VCPU_RUN output buffer it also does
not need to be loaded again.

Tested-by: Sachin Sant &lt;sachinp@linux.ibm.com&gt;
Signed-off-by: Vaibhav Jain &lt;vaibhav@linux.ibm.com&gt;
Signed-off-by: Gautam Menghani &lt;gautam@linux.ibm.com&gt;
Signed-off-by: Kautuk Consul &lt;kconsul@linux.vnet.ibm.com&gt;
Signed-off-by: Amit Machhiwal &lt;amachhiw@linux.vnet.ibm.com&gt;
Signed-off-by: Jordan Niethe &lt;jniethe5@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230914030600.16993-11-jniethe5@gmail.com

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
A series of hcalls have been added to the PAPR which allow a regular
guest partition to create and manage guest partitions of its own. KVM
already had an interface that allowed this on powernv platforms. This
existing interface will now be called "nestedv1". The newly added PAPR
interface will be called "nestedv2".  PHYP will support the nestedv2
interface. At this time the host side of the nestedv2 interface has not
been implemented on powernv but there is no technical reason why it
could not be added.

The nestedv1 interface is still supported.

Add support to KVM to utilize these hcalls to enable running nested
guests as a pseries guest on PHYP.

Overview of the new hcall usage:

- L1 and L0 negotiate capabilities with
  H_GUEST_{G,S}ET_CAPABILITIES()

- L1 requests the L0 create a L2 with
  H_GUEST_CREATE() and receives a handle to use in future hcalls

- L1 requests the L0 create a L2 vCPU with
  H_GUEST_CREATE_VCPU()

- L1 sets up the L2 using H_GUEST_SET and the
  H_GUEST_VCPU_RUN input buffer

- L1 requests the L0 runs the L2 vCPU using H_GUEST_VCPU_RUN()

- L2 returns to L1 with an exit reason and L1 reads the
  H_GUEST_VCPU_RUN output buffer populated by the L0

- L1 handles the exit using H_GET_STATE if necessary

- L1 reruns L2 vCPU with H_GUEST_VCPU_RUN

- L1 frees the L2 in the L0 with H_GUEST_DELETE()

Support for the new API is determined by trying
H_GUEST_GET_CAPABILITIES. On a successful return, use the nestedv2
interface.

Use the vcpu register state setters for tracking modified guest state
elements and copy the thread wide values into the H_GUEST_VCPU_RUN input
buffer immediately before running a L2. The guest wide
elements can not be added to the input buffer so send them with a
separate H_GUEST_SET call if necessary.

Make the vcpu register getter load the corresponding value from the real
host with H_GUEST_GET. To avoid unnecessarily calling H_GUEST_GET, track
which values have already been loaded between H_GUEST_VCPU_RUN calls. If
an element is present in the H_GUEST_VCPU_RUN output buffer it also does
not need to be loaded again.

Tested-by: Sachin Sant &lt;sachinp@linux.ibm.com&gt;
Signed-off-by: Vaibhav Jain &lt;vaibhav@linux.ibm.com&gt;
Signed-off-by: Gautam Menghani &lt;gautam@linux.ibm.com&gt;
Signed-off-by: Kautuk Consul &lt;kconsul@linux.vnet.ibm.com&gt;
Signed-off-by: Amit Machhiwal &lt;amachhiw@linux.vnet.ibm.com&gt;
Signed-off-by: Jordan Niethe &lt;jniethe5@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230914030600.16993-11-jniethe5@gmail.com

</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: PPC: Book3s HV: Hold LPIDs in an unsigned long</title>
<updated>2023-09-14T12:04:24+00:00</updated>
<author>
<name>Jordan Niethe</name>
<email>jniethe5@gmail.com</email>
</author>
<published>2023-09-14T03:05:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=dfcaacc8f970c6b4ea4e32d2186f2bea4a1d5255'/>
<id>dfcaacc8f970c6b4ea4e32d2186f2bea4a1d5255</id>
<content type='text'>
The LPID register is 32 bits long. The host keeps the lpids for each
guest in an unsigned word struct kvm_arch. Currently, LPIDs are already
limited by mmu_lpid_bits and KVM_MAX_NESTED_GUESTS_SHIFT.

The nestedv2 API returns a 64 bit "Guest ID" to be used be the L1 host
for each L2 guest. This value is used as an lpid, e.g. it is the
parameter used by H_RPT_INVALIDATE. To minimize needless special casing
it makes sense to keep this "Guest ID" in struct kvm_arch::lpid.

This means that struct kvm_arch::lpid is too small so prepare for this
and make it an unsigned long. This is not a problem for the KVM-HV and
nestedv1 cases as their lpid values are already limited to valid ranges
so in those contexts the lpid can be used as an unsigned word safely as
needed.

In the PAPR, the H_RPT_INVALIDATE pid/lpid parameter is already
specified as an unsigned long so change pseries_rpt_invalidate() to
match that.  Update the callers of pseries_rpt_invalidate() to also take
an unsigned long if they take an lpid value.

Signed-off-by: Jordan Niethe &lt;jniethe5@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230914030600.16993-10-jniethe5@gmail.com

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The LPID register is 32 bits long. The host keeps the lpids for each
guest in an unsigned word struct kvm_arch. Currently, LPIDs are already
limited by mmu_lpid_bits and KVM_MAX_NESTED_GUESTS_SHIFT.

The nestedv2 API returns a 64 bit "Guest ID" to be used be the L1 host
for each L2 guest. This value is used as an lpid, e.g. it is the
parameter used by H_RPT_INVALIDATE. To minimize needless special casing
it makes sense to keep this "Guest ID" in struct kvm_arch::lpid.

This means that struct kvm_arch::lpid is too small so prepare for this
and make it an unsigned long. This is not a problem for the KVM-HV and
nestedv1 cases as their lpid values are already limited to valid ranges
so in those contexts the lpid can be used as an unsigned word safely as
needed.

In the PAPR, the H_RPT_INVALIDATE pid/lpid parameter is already
specified as an unsigned long so change pseries_rpt_invalidate() to
match that.  Update the callers of pseries_rpt_invalidate() to also take
an unsigned long if they take an lpid value.

Signed-off-by: Jordan Niethe &lt;jniethe5@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230914030600.16993-10-jniethe5@gmail.com

</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: PPC: Add helper library for Guest State Buffers</title>
<updated>2023-09-14T12:04:24+00:00</updated>
<author>
<name>Jordan Niethe</name>
<email>jniethe5@gmail.com</email>
</author>
<published>2023-09-14T03:05:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6ccbbc33f06adaf79acde18571c6543ad1cb4be6'/>
<id>6ccbbc33f06adaf79acde18571c6543ad1cb4be6</id>
<content type='text'>
The PAPR "Nestedv2" guest API introduces the concept of a Guest State
Buffer for communication about L2 guests between L1 and L0 hosts.

In the new API, the L0 manages the L2 on behalf of the L1. This means
that if the L1 needs to change L2 state (e.g. GPRs, SPRs, partition
table...), it must request the L0 perform the modification. If the
nested host needs to read L2 state likewise this request must
go through the L0.

The Guest State Buffer is a Type-Length-Value style data format defined
in the PAPR which assigns all relevant partition state a unique
identity. Unlike a typical TLV format the length is redundant as the
length of each identity is fixed but is included for checking
correctness.

A guest state buffer consists of an element count followed by a stream
of elements, where elements are composed of an ID number, data length,
then the data:

  Header:

   &lt;---4 bytes---&gt;
  +----------------+-----
  | Element Count  | Elements...
  +----------------+-----

  Element:

   &lt;----2 bytes---&gt; &lt;-2 bytes-&gt; &lt;-Length bytes-&gt;
  +----------------+-----------+----------------+
  | Guest State ID |  Length   |      Data      |
  +----------------+-----------+----------------+

Guest State IDs have other attributes defined in the PAPR such as
whether they are per thread or per guest, or read-only.

Introduce a library for using guest state buffers. This includes support
for actions such as creating buffers, adding elements to buffers,
reading the value of elements and parsing buffers. This will be used
later by the nestedv2 guest support.

Signed-off-by: Jordan Niethe &lt;jniethe5@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230914030600.16993-9-jniethe5@gmail.com

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The PAPR "Nestedv2" guest API introduces the concept of a Guest State
Buffer for communication about L2 guests between L1 and L0 hosts.

In the new API, the L0 manages the L2 on behalf of the L1. This means
that if the L1 needs to change L2 state (e.g. GPRs, SPRs, partition
table...), it must request the L0 perform the modification. If the
nested host needs to read L2 state likewise this request must
go through the L0.

The Guest State Buffer is a Type-Length-Value style data format defined
in the PAPR which assigns all relevant partition state a unique
identity. Unlike a typical TLV format the length is redundant as the
length of each identity is fixed but is included for checking
correctness.

A guest state buffer consists of an element count followed by a stream
of elements, where elements are composed of an ID number, data length,
then the data:

  Header:

   &lt;---4 bytes---&gt;
  +----------------+-----
  | Element Count  | Elements...
  +----------------+-----

  Element:

   &lt;----2 bytes---&gt; &lt;-2 bytes-&gt; &lt;-Length bytes-&gt;
  +----------------+-----------+----------------+
  | Guest State ID |  Length   |      Data      |
  +----------------+-----------+----------------+

Guest State IDs have other attributes defined in the PAPR such as
whether they are per thread or per guest, or read-only.

Introduce a library for using guest state buffers. This includes support
for actions such as creating buffers, adding elements to buffers,
reading the value of elements and parsing buffers. This will be used
later by the nestedv2 guest support.

Signed-off-by: Jordan Niethe &lt;jniethe5@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230914030600.16993-9-jniethe5@gmail.com

</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: PPC: Book3S HV: Introduce low level MSR accessor</title>
<updated>2023-09-14T12:04:24+00:00</updated>
<author>
<name>Jordan Niethe</name>
<email>jniethe5@gmail.com</email>
</author>
<published>2023-09-14T03:05:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6de2e837babb411cfb3cdb570581c3a65576ddaf'/>
<id>6de2e837babb411cfb3cdb570581c3a65576ddaf</id>
<content type='text'>
kvmppc_get_msr() and kvmppc_set_msr_fast() serve as accessors for the
MSR. However because the MSR is kept in the shared regs they include a
conditional check for kvmppc_shared_big_endian() and endian conversion.

Within the Book3S HV specific code there are direct reads and writes of
shregs::msr. In preparation for Nested APIv2 these accesses need to be
replaced with accessor functions so it is possible to extend their
behavior. However, using the kvmppc_get_msr() and kvmppc_set_msr_fast()
functions is undesirable because it would introduce a conditional branch
and endian conversion that is not currently present.

kvmppc_set_msr_hv() already exists, it is used for the
kvmppc_ops::set_msr callback.

Introduce a low level accessor __kvmppc_{s,g}et_msr_hv() that simply
gets and sets shregs::msr. This will be extend for Nested APIv2 support.

Signed-off-by: Jordan Niethe &lt;jniethe5@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230914030600.16993-8-jniethe5@gmail.com

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
kvmppc_get_msr() and kvmppc_set_msr_fast() serve as accessors for the
MSR. However because the MSR is kept in the shared regs they include a
conditional check for kvmppc_shared_big_endian() and endian conversion.

Within the Book3S HV specific code there are direct reads and writes of
shregs::msr. In preparation for Nested APIv2 these accesses need to be
replaced with accessor functions so it is possible to extend their
behavior. However, using the kvmppc_get_msr() and kvmppc_set_msr_fast()
functions is undesirable because it would introduce a conditional branch
and endian conversion that is not currently present.

kvmppc_set_msr_hv() already exists, it is used for the
kvmppc_ops::set_msr callback.

Introduce a low level accessor __kvmppc_{s,g}et_msr_hv() that simply
gets and sets shregs::msr. This will be extend for Nested APIv2 support.

Signed-off-by: Jordan Niethe &lt;jniethe5@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230914030600.16993-8-jniethe5@gmail.com

</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: PPC: Book3S HV: Use accessors for VCPU registers</title>
<updated>2023-09-14T12:04:24+00:00</updated>
<author>
<name>Jordan Niethe</name>
<email>jniethe5@gmail.com</email>
</author>
<published>2023-09-14T03:05:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ebc88ea7a6ad0ea349df9c765357d3aa4e662aa9'/>
<id>ebc88ea7a6ad0ea349df9c765357d3aa4e662aa9</id>
<content type='text'>
Introduce accessor generator macros for Book3S HV VCPU registers. Use
the accessor functions to replace direct accesses to this registers.

This will be important later for Nested APIv2 support which requires
additional functionality for accessing and modifying VCPU state.

Signed-off-by: Jordan Niethe &lt;jniethe5@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230914030600.16993-7-jniethe5@gmail.com

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Introduce accessor generator macros for Book3S HV VCPU registers. Use
the accessor functions to replace direct accesses to this registers.

This will be important later for Nested APIv2 support which requires
additional functionality for accessing and modifying VCPU state.

Signed-off-by: Jordan Niethe &lt;jniethe5@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230914030600.16993-7-jniethe5@gmail.com

</pre>
</div>
</content>
</entry>
</feed>
