MIPS: introduce Kconfig for MIPS VZ

Since MIPS/KVM only supports hardware virtualization using MIPS VZ,
do not enable KVM blindly. Use a new Kconfig symbol CPU_SUPPORTS_VZ
and do not enable it for

MIPS: introduce Kconfig for MIPS VZ

Since MIPS/KVM only supports hardware virtualization using MIPS VZ,
do not enable KVM blindly. Use a new Kconfig symbol CPU_SUPPORTS_VZ
and do not enable it for R2 processors.

Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

kvm: replace __KVM_HAVE_READONLY_MEM with Kconfig symbol

KVM uses __KVM_HAVE_* symbols in the architecture-dependent uapi/asm/kvm.h to mask
unused definitions in include/uapi/linux/kvm.h. __KVM_HAV

kvm: replace __KVM_HAVE_READONLY_MEM with Kconfig symbol

KVM uses __KVM_HAVE_* symbols in the architecture-dependent uapi/asm/kvm.h to mask
unused definitions in include/uapi/linux/kvm.h. __KVM_HAVE_READONLY_MEM however
was nothing but a misguided attempt to define KVM_CAP_READONLY_MEM only on
architectures where KVM_CHECK_EXTENSION(KVM_CAP_READONLY_MEM) could possibly
return nonzero. This however does not make sense, and it prevented userspace
from supporting this architecture-independent feature without recompilation.

Therefore, these days __KVM_HAVE_READONLY_MEM does not mask anything and
is only used in virt/kvm/kvm_main.c. Userspace does not need to test it
and there should be no need for it to exist. Remove it and replace it
with a Kconfig symbol within Linux source code.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

KVM: introduce CONFIG_KVM_COMMON

CONFIG_HAVE_KVM is currently used by some architectures to either
enabled the KVM config proper, or to enable host-side code that is
not part of the KVM module. How

KVM: introduce CONFIG_KVM_COMMON

CONFIG_HAVE_KVM is currently used by some architectures to either
enabled the KVM config proper, or to enable host-side code that is
not part of the KVM module. However, CONFIG_KVM's "select" statement
in virt/kvm/Kconfig corresponds to a third meaning, namely to
enable common Kconfigs required by all architectures that support
KVM.

These three meanings can be replaced respectively by an
architecture-specific Kconfig, by IS_ENABLED(CONFIG_KVM), or by
a new Kconfig symbol that is in turn selected by the
architecture-specific "config KVM".

Start by introducing such a new Kconfig symbol, CONFIG_KVM_COMMON.
Unlike CONFIG_HAVE_KVM, it is selected by CONFIG_KVM, not by
architecture code, and it brings in all dependencies of common
KVM code. In particular, INTERVAL_TREE was missing in loongarch
and riscv, so that is another thing that is fixed.

Fixes: 8132d887a702 ("KVM: remove CONFIG_HAVE_KVM_EVENTFD", 2023-12-08)
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Closes: https://lore.kernel.org/all/44907c6b-c5bd-4e4a-a921-e4d3825539d8@infradead.org/
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

KVM: remove CONFIG_HAVE_KVM_EVENTFD

virt/kvm/eventfd.c is compiled unconditionally, meaning that the ioeventfds
member of struct kvm is accessed unconditionally. CONFIG_HAVE_KVM_EVENTFD
therefore m

KVM: remove CONFIG_HAVE_KVM_EVENTFD

virt/kvm/eventfd.c is compiled unconditionally, meaning that the ioeventfds
member of struct kvm is accessed unconditionally. CONFIG_HAVE_KVM_EVENTFD
therefore must be defined for KVM common code to compile successfully,
remove it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

KVM: Convert KVM_ARCH_WANT_MMU_NOTIFIER to CONFIG_KVM_GENERIC_MMU_NOTIFIER

Convert KVM_ARCH_WANT_MMU_NOTIFIER into a Kconfig and select it where
appropriate to effectively maintain existing behavior

KVM: Convert KVM_ARCH_WANT_MMU_NOTIFIER to CONFIG_KVM_GENERIC_MMU_NOTIFIER

Convert KVM_ARCH_WANT_MMU_NOTIFIER into a Kconfig and select it where
appropriate to effectively maintain existing behavior. Using a proper
Kconfig will simplify building more functionality on top of KVM's
mmu_notifier infrastructure.

Add a forward declaration of kvm_gfn_range to kvm_types.h so that
including arch/powerpc/include/asm/kvm_ppc.h's with CONFIG_KVM=n doesn't
generate warnings due to kvm_gfn_range being undeclared. PPC defines
hooks for PR vs. HV without guarding them via #ifdeffery, e.g.

bool (*unmap_gfn_range)(struct kvm *kvm, struct kvm_gfn_range *range);
bool (*age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);
bool (*test_age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);
bool (*set_spte_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);

Alternatively, PPC could forward declare kvm_gfn_range, but there's no
good reason not to define it in common KVM.

Acked-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Message-Id: <20231027182217.3615211-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

kvm: Remove "select SRCU"

Now that the SRCU Kconfig option is unconditionally selected, there is
no longer any point in selecting it. Therefore, remove the "select SRCU"
Kconfig statements from the

kvm: Remove "select SRCU"

Now that the SRCU Kconfig option is unconditionally selected, there is
no longer any point in selecting it. Therefore, remove the "select SRCU"
Kconfig statements from the various KVM Kconfig files.

Acked-by: Sean Christopherson <seanjc@google.com> (x86)
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <kvm@vger.kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org> (arm64)
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Anup Patel <anup@brainfault.org> (riscv)
Acked-by: Heiko Carstens <hca@linux.ibm.com> (s390)
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>

show more ...

KVM: Opt out of generic hardware enabling on s390 and PPC

Allow architectures to opt out of the generic hardware enabling logic,
and opt out on both s390 and PPC, which don't need to manually enable

KVM: Opt out of generic hardware enabling on s390 and PPC

Allow architectures to opt out of the generic hardware enabling logic,
and opt out on both s390 and PPC, which don't need to manually enable
virtualization as it's always on (when available).

In addition to letting s390 and PPC drop a bit of dead code, this will
hopefully also allow ARM to clean up its related code, e.g. ARM has its
own per-CPU flag to track which CPUs have enable hardware due to the
need to keep hardware enabled indefinitely when pKVM is enabled.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Acked-by: Anup Patel <anup@brainfault.org>
Message-Id: <20221130230934.1014142-50-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

KVM: Use interval tree to do fast hva lookup in memslots

The current memslots implementation only allows quick binary search by gfn,
quick lookup by hva is not possible - the implementation has to d

KVM: Use interval tree to do fast hva lookup in memslots

The current memslots implementation only allows quick binary search by gfn,
quick lookup by hva is not possible - the implementation has to do a linear
scan of the whole memslots array, even though the operation being performed
might apply just to a single memslot.

This significantly hurts performance of per-hva operations with higher
memslot counts.

Since hva ranges can overlap between memslots an interval tree is needed
for tracking them.

[sean: handle interval tree updates in kvm_replace_memslot()]
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <d66b9974becaa9839be9c4e1a5de97b177b4ac20.1638817640.git.maciej.szmigiero@oracle.com>

show more ...

MIPS: Remove KVM_TE support

After removal of the guest part of KVM TE (trap and emulate), also remove
the host part.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: KVM: Limit Trap-and-Emulate to MIPS32R2 only

After tons of fixes to get Trap-and-Emulate build on Loongson64,
I've got panic on host machine when trying to run a VM.

I found that it can never

MIPS: KVM: Limit Trap-and-Emulate to MIPS32R2 only

After tons of fixes to get Trap-and-Emulate build on Loongson64,
I've got panic on host machine when trying to run a VM.

I found that it can never work on 64bit systems. Revewing the
code, it looks like R6 can't supportrd by TE as well.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Message-Id: <20200710063047.154611-3-jiaxun.yang@flygoat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

treewide: replace '---help---' in Kconfig files with 'help'

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasi

treewide: replace '---help---' in Kconfig files with 'help'

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

show more ...

KVM: MIPS: Add EVENTFD support which is needed by VHOST

Add EVENTFD support for KVM/MIPS, which is needed by VHOST. Tested on
Loongson-3 platform.

Reviewed-by: Aleksandar Markovic <aleksandar.qemu.

KVM: MIPS: Add EVENTFD support which is needed by VHOST

Add EVENTFD support for KVM/MIPS, which is needed by VHOST. Tested on
Loongson-3 platform.

Reviewed-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Co-developed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Message-Id: <1590220602-3547-5-git-send-email-chenhc@lemote.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

vhost: refine vhost and vringh kconfig

Currently, CONFIG_VHOST depends on CONFIG_VIRTUALIZATION. But vhost is
not necessarily for VM since it's a generic userspace and kernel
communication protocol.

vhost: refine vhost and vringh kconfig

Currently, CONFIG_VHOST depends on CONFIG_VIRTUALIZATION. But vhost is
not necessarily for VM since it's a generic userspace and kernel
communication protocol. Such dependency may prevent archs without
virtualization support from using vhost.

To solve this, a dedicated vhost menu is created under drivers so
CONIFG_VHOST can be decoupled out of CONFIG_VIRTUALIZATION.

While at it, also squash Kconfig.vringh into vhost Kconfig file. This
avoids the trick of conditional inclusion from VOP or CAIF. Then it
will be easier to introduce new vringh users and common dependency for
both vringh and vhost.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200326140125.19794-2-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

show more ...

Make anon_inodes unconditional

Make the anon_inodes facility unconditional so that it can be used by core
VFS code and pidfd code.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by:

Make anon_inodes unconditional

Make the anon_inodes facility unconditional so that it can be used by core
VFS code and pidfd code.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[christian@brauner.io: adapt commit message to mention pidfds]
Signed-off-by: Christian Brauner <christian@brauner.io>

show more ...

treewide: surround Kconfig file paths with double quotes

The Kconfig lexer supports special characters such as '.' and '/' in
the parameter context. In my understanding, the reason is just to
suppor

treewide: surround Kconfig file paths with double quotes

The Kconfig lexer supports special characters such as '.' and '/' in
the parameter context. In my understanding, the reason is just to
support bare file paths in the source statement.

I do not see a good reason to complicate Kconfig for the room of
ambiguity.

The majority of code already surrounds file paths with double quotes,
and it makes sense since file paths are constant string literals.

Make it treewide consistent now.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Ingo Molnar <mingo@kernel.org>

show more ...

MIPS: Introduce CONFIG_MIPS_FP_SUPPORT

Introduce a Kconfig variable that will indicate whether to include
support for floating point in the kernel. For now this is always
enabled, and will be made c

MIPS: Introduce CONFIG_MIPS_FP_SUPPORT

Introduce a Kconfig variable that will indicate whether to include
support for floating point in the kernel. For now this is always
enabled, and will be made configurable in a later patch.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21016/
Cc: linux-mips@linux-mips.org

show more ...

KVM: introduce kvm_arch_vcpu_async_ioctl

After the vcpu_load/vcpu_put pushdown, the handling of asynchronous VCPU
ioctl is already much clearer in that it is obvious that they bypass
vcpu_load and v

KVM: introduce kvm_arch_vcpu_async_ioctl

After the vcpu_load/vcpu_put pushdown, the handling of asynchronous VCPU
ioctl is already much clearer in that it is obvious that they bypass
vcpu_load and vcpu_put.

However, it is still not perfect in that the different state of the VCPU
mutex is still hidden in the caller. Separate those ioctls into a new
function kvm_arch_vcpu_async_ioctl that returns -ENOIOCTLCMD for more
"traditional" synchronous ioctls.

Cc: James Hogan <jhogan@kernel.org>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Suggested-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is 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.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

KVM: MIPS: Add VZ support to build system

Add support for the MIPS Virtualization (VZ) ASE to the MIPS KVM build
system. For now KVM can only be configured for T&E or VZ and not both,
but the design

KVM: MIPS: Add VZ support to build system

Add support for the MIPS Virtualization (VZ) ASE to the MIPS KVM build
system. For now KVM can only be configured for T&E or VZ and not both,
but the design of the user facing APIs support the possibility of having
both available, so this could change in future.

Note that support for various optional guest features (some of which
can't be turned off) are implemented in immediately following commits,
so although it should now be possible to build VZ support, it may not
work yet on your hardware.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org

show more ...

KVM: MIPS/MMU: Implement KVM_CAP_SYNC_MMU

Implement the SYNC_MMU capability for KVM MIPS, allowing changes in the
underlying user host virtual address (HVA) mappings to be promptly
reflected in the

KVM: MIPS/MMU: Implement KVM_CAP_SYNC_MMU

Implement the SYNC_MMU capability for KVM MIPS, allowing changes in the
underlying user host virtual address (HVA) mappings to be promptly
reflected in the corresponding guest physical address (GPA) mappings.

This allows for several features to work with guest RAM which require
mappings to be altered or protected, such as copy-on-write, KSM (Kernel
Samepage Merging), idle page tracking, memory swapping, and guest memory
ballooning.

There are two main aspects of this change, described below.

The KVM MMU notifier architecture callbacks are implemented so we can be
notified of changes in the HVA mappings. These arrange for the guest
physical address (GPA) page tables to be modified and possibly for
derived mappings (GVA page tables and TLBs) to be flushed.

- kvm_unmap_hva[_range]() - These deal with HVA mappings being removed,
for example before a copy-on-write takes place, which requires the
corresponding GPA page table mappings to be removed too.

- kvm_set_spte_hva() - These update a GPA page table entry to match the
new HVA entry, but must be careful to respect KVM specific
configuration such as not dirtying a clean guest page which is dirty
to the host, and write protecting writable pages in read only
memslots (which will soon be supported).

- kvm[_test]_age_hva() - These update GPA page table entries to be old
(invalid) so that access can be tracked, making them young again.

The GPA page fault handling (kvm_mips_map_page) is updated to use
gfn_to_pfn_prot() (which may provide read-only pages), to handle
asynchronous page table invalidation from MMU notifier callbacks, and to
handle more cases in the fast path.

- mmu_notifier_seq is used to detect asynchronous page table
invalidations while we're holding a pfn from gfn_to_pfn_prot()
outside of kvm->mmu_lock, retrying if invalidations have taken place,
e.g. a COW or a KSM page merge.

- The fast path (_kvm_mips_map_page_fast) now handles marking old pages
as young / accessed, and disallowing dirtying of clean pages that
aren't actually writable (e.g. shared pages that should COW, and
read-only memory regions when they are enabled in a future patch).

- Due to the use of MMU notifications we no longer need to keep the
page references after we've updated the GPA page tables.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org

show more ...

KVM: MIPS/MMU: Use generic dirty log & protect helper

MIPS hasn't up to this point properly supported dirty page logging, as
pages in slots with dirty logging enabled aren't made clean, and tlbmod
e

KVM: MIPS/MMU: Use generic dirty log & protect helper

MIPS hasn't up to this point properly supported dirty page logging, as
pages in slots with dirty logging enabled aren't made clean, and tlbmod
exceptions from writes to clean pages have been assumed to be due to
guest TLB protection and unconditionally passed to the guest.

Use the generic dirty logging helper kvm_get_dirty_log_protect() to
properly implement kvm_vm_ioctl_get_dirty_log(), similar to how ARM
does. This uses xchg to clear the dirty bits when reading them, rather
than wiping them out afterwards with a memset, which would potentially
wipe recently set bits that weren't caught by kvm_get_dirty_log(). It
also makes the pages clean again using the
kvm_arch_mmu_enable_log_dirty_pt_masked() architecture callback so that
further writes after the shadow memslot is flushed will trigger tlbmod
exceptions and dirty handling.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org

show more ...

MIPS; KVM: Convert exception entry to uasm

Convert the whole of locore.S (assembly to enter guest and handle
exception entry) to be generated dynamically with uasm. This is done
with minimal changes

MIPS; KVM: Convert exception entry to uasm

Convert the whole of locore.S (assembly to enter guest and handle
exception entry) to be generated dynamically with uasm. This is done
with minimal changes to the resulting code.

The main changes are:
- Some constants are generated by uasm using LUI+ADDIU instead of
LUI+ORI.
- Loading of lo and hi are swapped around in vcpu_run but not when
resuming the guest after an exit. Both bits of logic are now generated
by the same code.
- Register MOVEs in uasm use different ADDU operand ordering to GNU as,
putting zero register into rs instead of rt.
- The JALR.HB to call the C exit handler is switched to JALR, since the
hazard barrier would appear to be unnecessary.

This will allow further optimisation in the future to dynamically handle
the capabilities of the CPU.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim KrÄmář <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rcu: Make SRCU optional by using CONFIG_SRCU

SRCU is not necessary to be compiled by default in all cases. For tinification
efforts not compiling SRCU unless necessary is desirable.

The current pat

rcu: Make SRCU optional by using CONFIG_SRCU

SRCU is not necessary to be compiled by default in all cases. For tinification
efforts not compiling SRCU unless necessary is desirable.

The current patch tries to make compiling SRCU optional by introducing a new
Kconfig option CONFIG_SRCU which is selected when any of the components making
use of SRCU are selected.

If we do not select CONFIG_SRCU, srcu.o will not be compiled at all.

text data bss dec hex filename
2007 0 0 2007 7d7 kernel/rcu/srcu.o

Size of arch/powerpc/boot/zImage changes from

text data bss dec hex filename
831552 64180 23944 919676 e087c arch/powerpc/boot/zImage : before
829504 64180 23952 917636 e0084 arch/powerpc/boot/zImage : after

so the savings are about ~2000 bytes.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: resolve conflict due to removal of arch/ia64/kvm/Kconfig. ]

show more ...

MIPS: kvm: Kconfig: Drop HAVE_KVM dependency from VIRTUALIZATION

Virtualization does not always need KVM capabilities so drop the
dependency. The KVM symbol already depends on HAVE_KVM.

Fixes the f

MIPS: kvm: Kconfig: Drop HAVE_KVM dependency from VIRTUALIZATION

Virtualization does not always need KVM capabilities so drop the
dependency. The KVM symbol already depends on HAVE_KVM.

Fixes the following problem on a randconfig:
warning: (REMOTEPROC && RPMSG) selects VIRTUALIZATION which has unmet direct
dependencies (HAVE_KVM)
warning: (REMOTEPROC && RPMSG) selects VIRTUALIZATION which has unmet
direct dependencies (HAVE_KVM)

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Acked-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5443/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

show more ...

KVM/MIPS32: Infrastructure/build files.

- Add the KVM option to MIPS build files.
- Add default config files for KVM host/guest kernels.
- Change the link address for the Malta KVM Guest kernel to U

KVM/MIPS32: Infrastructure/build files.

- Add the KVM option to MIPS build files.
- Add default config files for KVM host/guest kernels.
- Change the link address for the Malta KVM Guest kernel to UM (0x40100000).
- Add KVM Kconfig file with KVM/MIPS specific options

Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

show more ...