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git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Alexander Gordeev:
- Store AP Query Configuration Information in a static buffer
- Rework the AP initialization and add missing cleanups to the error
path
- Swap IRQ and AP bus/device registration to avoid race conditions
- Export prot_virt_guest symbol
- Introduce AP configuration changes notifier interface to facilitate
modularization of the AP bus
- Add CONFIG_AP kernel configuration option to allow modularization of
the AP bus
- Rework CONFIG_ZCRYPT_DEBUG kernel configuration option description
and dependency and rename it to CONFIG_AP_DEBUG
- Convert sprintf() and snprintf() to sysfs_emit() in CIO code
- Adjust indentation of RELOCS command build step
- Make crypto performance counters upward compatible
- Convert make_page_secure() and gmap_make_secure() to use folio
- Rework channel-utilization-block (CUB) handling in preparation of
introducing additional CUBs
- Use attribute groups to simplify registration, removal and extension
of measurement-related channel-path sysfs attributes
- Add a per-channel-path binary "ext_measurement" sysfs attribute that
provides access to extended channel-path measurement data
- Export measurement data for all channel-measurement-groups (CMG), not
only for a specific ones. This enables support of new CMG data
formats in userspace without the need for kernel changes
- Add a per-channel-path sysfs attribute "speed_bps" that provides the
operating speed in bits per second or 0 if the operating speed is not
available
- The CIO tracepoint subchannel-type field "st" is incorrectly set to
the value of subchannel-enabled SCHIB "ena" field. Fix that
- Do not forcefully limit vmemmap starting address to MAX_PHYSMEM_BITS
- Consider the maximum physical address available to a DCSS segment
(512GB) when memory layout is set up
- Simplify the virtual memory layout setup by reducing the size of
identity mapping vs vmemmap overlap
- Swap vmalloc and Lowcore/Real Memory Copy areas in virtual memory.
This will allow to place the kernel image next to kernel modules
- Move everyting KASLR related from <asm/setup.h> to <asm/page.h>
- Put virtual memory layout information into a structure to improve
code generation
- Currently __kaslr_offset is the kernel offset in both physical and
virtual memory spaces. Uncouple these offsets to allow uncoupling of
the addresses spaces
- Currently the identity mapping base address is implicit and is always
set to zero. Make it explicit by putting into __identity_base
persistent boot variable and use it in proper context
- Introduce .amode31 section start and end macros AMODE31_START and
AMODE31_END
- Introduce OS_INFO entries that do not reference any data in memory,
but rather provide only values
- Store virtual memory layout in OS_INFO. It is read out by
makedumpfile, crash and other tools
- Store virtual memory layout in VMCORE_INFO. It is read out by crash
and other tools when /proc/kcore device is used
- Create additional PT_LOAD ELF program header that covers kernel image
only, so that vmcore tools could locate kernel text and data when
virtual and physical memory spaces are uncoupled
- Uncouple physical and virtual address spaces
- Map kernel at fixed location when KASLR mode is disabled. The
location is defined by CONFIG_KERNEL_IMAGE_BASE kernel configuration
value.
- Rework deployment of kernel image for both compressed and
uncompressed variants as defined by CONFIG_KERNEL_UNCOMPRESSED kernel
configuration value
- Move .vmlinux.relocs section in front of the compressed kernel. The
interim section rescue step is avoided as result
- Correct modules thunk offset calculation when branch target is more
than 2GB away
- Kernel modules contain their own set of expoline thunks. Now that the
kernel modules area is less than 4GB away from kernel expoline
thunks, make modules use kernel expolines. Also make EXPOLINE_EXTERN
the default if the compiler supports it
- userfaultfd can insert shared zeropages into processes running VMs,
but that is not allowed for s390. Fallback to allocating a fresh
zeroed anonymous folio and insert that instead
- Re-enable shared zeropages for non-PV and non-skeys KVM guests
- Rename hex2bitmap() to ap_hex2bitmap() and export it for external use
- Add ap_config sysfs attribute to provide the means for setting or
displaying adapters, domains and control domains assigned to a
vfio-ap mediated device in a single operation
- Make vfio_ap_mdev_link_queue() ignore duplicate link requests
- Add write support to ap_config sysfs attribute to allow atomic update
a vfio-ap mediated device state
- Document ap_config sysfs attribute
- Function os_info_old_init() is expected to be called only from a
regular kdump kernel. Enable it to be called from a stand-alone dump
kernel
- Address gcc -Warray-bounds warning and fix array size in struct
os_info
- s390 does not support SMBIOS, so drop unneeded CONFIG_DMI checks
- Use unwinder instead of __builtin_return_address() with ftrace to
prevent returning of undefined values
- Sections .hash and .gnu.hash are only created when CONFIG_PIE_BUILD
kernel is enabled. Drop these for the case CONFIG_PIE_BUILD is
disabled
- Compile kernel with -fPIC and link with -no-pie to allow kpatch
feature always succeed and drop the whole CONFIG_PIE_BUILD
option-enabled code
- Add missing virt_to_phys() converter for VSIE facility and crypto
control blocks
* tag 's390-6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (54 commits)
Revert "s390: Relocate vmlinux ELF data to virtual address space"
KVM: s390: vsie: Use virt_to_phys for crypto control block
s390: Relocate vmlinux ELF data to virtual address space
s390: Compile kernel with -fPIC and link with -no-pie
s390: vmlinux.lds.S: Drop .hash and .gnu.hash for !CONFIG_PIE_BUILD
s390/ftrace: Use unwinder instead of __builtin_return_address()
s390/pci: Drop unneeded reference to CONFIG_DMI
s390/os_info: Fix array size in struct os_info
s390/os_info: Initialize old os_info in standalone dump kernel
docs: Update s390 vfio-ap doc for ap_config sysfs attribute
s390/vfio-ap: Add write support to sysfs attr ap_config
s390/vfio-ap: Ignore duplicate link requests in vfio_ap_mdev_link_queue
s390/vfio-ap: Add sysfs attr, ap_config, to export mdev state
s390/ap: Externalize AP bus specific bitmap reading function
s390/mm: Re-enable the shared zeropage for !PV and !skeys KVM guests
mm/userfaultfd: Do not place zeropages when zeropages are disallowed
s390/expoline: Make modules use kernel expolines
s390/nospec: Correct modules thunk offset calculation
s390/boot: Do not rescue .vmlinux.relocs section
s390/boot: Rework deployment of the kernel image
...
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__split_huge_pmd_locked() can be called for a present THP, devmap or
(non-present) migration entry. It calls pmdp_invalidate() unconditionally
on the pmdp and only determines if it is present or not based on the
returned old pmd. This is a problem for the migration entry case because
pmd_mkinvalid(), called by pmdp_invalidate() must only be called for a
present pmd.
On arm64 at least, pmd_mkinvalid() will mark the pmd such that any future
call to pmd_present() will return true. And therefore any lockless
pgtable walker could see the migration entry pmd in this state and start
interpretting the fields as if it were present, leading to BadThings (TM).
GUP-fast appears to be one such lockless pgtable walker.
x86 does not suffer the above problem, but instead pmd_mkinvalid() will
corrupt the offset field of the swap entry within the swap pte. See link
below for discussion of that problem.
Fix all of this by only calling pmdp_invalidate() for a present pmd. And
for good measure let's add a warning to all implementations of
pmdp_invalidate[_ad](). I've manually reviewed all other
pmdp_invalidate[_ad]() call sites and believe all others to be conformant.
This is a theoretical bug found during code review. I don't have any test
case to trigger it in practice.
Link: https://lkml.kernel.org/r/20240501143310.1381675-1-ryan.roberts@arm.com
Link: https://lore.kernel.org/all/0dd7827a-6334-439a-8fd0-43c98e6af22b@arm.com/
Fixes: 84c3fc4e9c56 ("mm: thp: check pmd migration entry in common path")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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This reverts commit 9ecaa2e94e602a3cbcbfe182535f6297f7630b98.
In case CONFIG_MODULES kernel option is not defined the build fails
with the following linker error:
block/partitions/ibm.o: in function `ibm_partition':
ibm.c:(.text+0x8bc): relocation truncated to fit: R_390_PLT32DBL against undefined symbol `dasd_biodasdinfo'
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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David Hildenbrand says:
===================
This series fixes one issue with uffd + shared zeropages on s390x and
fixes that "ordinary" KVM guests can make use of shared zeropages again.
userfaultfd could currently end up mapping shared zeropages into processes
that forbid shared zeropages. This only apples to s390x, relevant for
handling PV guests and guests that use storage kets correctly. Fix it
by placing a zeroed folio instead of the shared zeropage during
UFFDIO_ZEROPAGE instead.
I stumbled over this issue while looking into a customer scenario that
is using:
(1) Memory ballooning for dynamic resizing. Start a VM with, say, 100 GiB
and inflate the balloon during boot to 60 GiB. The VM has ~40 GiB
available and additional memory can be "fake hotplugged" to the VM
later on demand by deflating the balloon. Actual memory overcommit is
not desired, so physical memory would only be moved between VMs.
(2) Live migration of VMs between sites to evacuate servers in case of
emergency.
Without the shared zeropage, during (2), the VM would suddenly consume
100 GiB on the migration source and destination. On the migration source,
where we don't excpect memory overcommit, we could easilt end up crashing
the VM during migration.
Independent of that, memory handed back to the hypervisor using "free page
reporting" would end up consuming actual memory after the migration on the
destination, not getting freed up until reused+freed again.
While there might be ways to optimize parts of this in QEMU, we really
should just support the shared zeropage again for ordinary VMs.
We only expect legcy guests to make use of storage keys, so let's handle
zeropages again when enabling storage keys or when enabling PV. To not
break userfaultfd like we did in the past, don't zap the shared zeropages,
but instead trigger unsharing faults, just like we do for unsharing
KSM pages in break_ksm().
Unsharing faults will simply replace the shared zeropage by a zeroed
anonymous folio. We can already trigger the same fault path using GUP,
when trying to long-term pin a shared zeropage, but also when unmerging
a KSM-placed zeropages, so this is nothing new.
Patch #1 tested on 86-64 by forcing mm_forbids_zeropage() to be 1, and
running the uffd selftests.
Patch #2 tested on s390x: the live migration scenario now works as
expected, and kvm-unit-tests that trigger usage of skeys work well, whereby
I can see detection and unsharing of shared zeropages.
Further (as broken in v2), I tested that the shared zeropage is no
longer populated after skeys are used -- that mm_forbids_zeropage() works
as expected:
./s390x-run s390x/skey.elf \
-no-shutdown \
-chardev socket,id=monitor,path=/var/tmp/mon,server,nowait \
-mon chardev=monitor,mode=readline
Then, in another shell:
# cat /proc/`pgrep qemu`/smaps_rollup | grep Rss
Rss: 31484 kB
# echo "dump-guest-memory tmp" | sudo nc -U /var/tmp/mon
...
# cat /proc/`pgrep qemu`/smaps_rollup | grep Rss
Rss: 160452 kB
-> Reading guest memory does not populate the shared zeropage
Doing the same with selftest.elf (no skeys)
# cat /proc/`pgrep qemu`/smaps_rollup | grep Rss
Rss: 30900 kB
# echo "dump-guest-memory tmp" | sudo nc -U /var/tmp/mon
...
# cat /proc/`pgrep qemu`/smaps_rollup | grep Rsstmp/mon
Rss: 30924 kB
-> Reading guest memory does populate the shared zeropage
===================
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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Currently kernel image relocation tables and other ELF
data are set to base zero. Since kernel virtual and
physical address spaces are uncoupled the kernel is
mapped at the top of the virtual address space, hence
making the information contained in vmlinux ELF tables
inconsistent.
That does not pose any issue with regard to the kernel
booting and operation, but makes it difficult to use a
generated vmlinux with some debugging tools (e.g. gdb).
Relocate vmlinux image base address from zero to a base
address in the virtual address space. It is the address
that kernel is mapped to in cases KASLR is disabled.
The vmlinux ELF header before and after this change looks
like this:
Elf file type is EXEC (Executable file)
Entry point 0x100000
There are 3 program headers, starting at offset 64
Program Headers:
Type Offset VirtAddr PhysAddr
FileSiz MemSiz Flags Align
LOAD 0x0000000000001000 0x0000000000100000 0x0000000000100000
0x0000000001323378 0x0000000001323378 R E 0x1000
LOAD 0x0000000001325000 0x0000000001424000 0x0000000001424000
0x00000000003a4200 0x000000000048fdb8 RWE 0x1000
NOTE 0x00000000012a33b0 0x00000000013a23b0 0x00000000013a23b0
0x0000000000000054 0x0000000000000054 0x4
Elf file type is EXEC (Executable file)
Entry point 0x3ffe0000000
There are 3 program headers, starting at offset 64
Program Headers:
Type Offset VirtAddr PhysAddr
FileSiz MemSiz Flags Align
LOAD 0x0000000000001000 0x000003ffe0000000 0x000003ffe0000000
0x0000000001323378 0x0000000001323378 R E 0x1000
LOAD 0x0000000001325000 0x000003ffe1324000 0x000003ffe1324000
0x00000000003a4200 0x000000000048fdb8 RWE 0x1000
NOTE 0x00000000012a33b0 0x000003ffe12a23b0 0x000003ffe12a23b0
0x0000000000000054 0x0000000000000054 0x4
Suggested-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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Using __builtin_return_address(n) might return undefined values
when used with values of n outside of the stack. This was noticed
when __builtin_return_address() was called in ftrace on top level
functions like the interrupt handlers.
As this behaviour cannot be fixed, use the s390 stack unwinder and
remove the ftrace compilation flags for unwind_bc.c and stacktrace.c
to prevent the unwinding function polluting function traces.
Another advantage is that this also works with clang.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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gcc's -Warray-bounds warned about an out-of-bounds access to
the entry array contained in struct os_info. This doesn't trigger
a bug right now because there's a large reserved space after the
array. Nevertheless fix this, and also add a BUILD_BUG_ON to make
sure struct os_info is always exactly on page in size.
Fixes: f4cac27dc0d6 ("s390/crash: Use old os_info to create PT_LOAD headers")
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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The return-address (RA) register r14 is specified as volatile in the
s390x ELF ABI [1]. Nevertheless proper CFI directives must be provided
for an unwinder to restore the return address, if the RA register
value is changed from its value at function entry, as it is the case.
[1]: s390x ELF ABI, https://github.com/IBM/s390x-abi/releases
Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO")
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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The comment in the code explains the reasons. We took a different
approach comparing to pmd_pfn() by providing a fallback function.
Another option is to provide some lower level config options (compare to
HUGETLB_PAGE or THP) to identify which layer an arch can support for such
huge mappings. However that can be an overkill.
[peterx@redhat.com: fix loongson defconfig]
Link: https://lkml.kernel.org/r/20240403013249.1418299-4-peterx@redhat.com
Link: https://lkml.kernel.org/r/20240327152332.950956-6-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Jones <andrew.jones@linux.dev>
Cc: Aneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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All implementations that aren't no-ops just set a bit in the flags, and we
want to use the folio flags rather than the page flags for that. Rename
it to arch_clear_hugetlb_flags() while we're touching it so nobody thinks
it's used for THP.
[willy@infradead.org: fix arm64 build]
Link: https://lkml.kernel.org/r/ZgQvNKGdlDkwhQEX@casper.infradead.org
Link: https://lkml.kernel.org/r/20240326171045.410737-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Complete switching the __iowriteXX_copy() routines over to use #define and
arch provided inline/macro functions instead of weak symbols.
S390 has an implementation that simply calls another memcpy
function. Inline this so the callers don't have to do two jumps.
Link: https://lore.kernel.org/r/3-v3-1893cd8b9369+1925-mlx5_arm_wc_jgg@nvidia.com
Acked-by: Niklas Schnelle <schnelle@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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It is trivial to implement an inline to do this, so provide it in the s390
headers. Like the 64 bit version it should just invoke zpci_memcpy_toio()
with the correct size.
Link: https://lore.kernel.org/r/2-v3-1893cd8b9369+1925-mlx5_arm_wc_jgg@nvidia.com
Acked-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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commit fa41ba0d08de ("s390/mm: avoid empty zero pages for KVM guests to
avoid postcopy hangs") introduced an undesired side effect when combined
with memory ballooning and VM migration: memory part of the inflated
memory balloon will consume memory.
Assuming we have a 100GiB VM and inflated the balloon to 40GiB. Our VM
will consume ~60GiB of memory. If we now trigger a VM migration,
hypervisors like QEMU will read all VM memory. As s390x does not support
the shared zeropage, we'll end up allocating for all previously-inflated
memory part of the memory balloon: 50 GiB. So we might easily
(unexpectedly) crash the VM on the migration source.
Even worse, hypervisors like QEMU optimize for zeropage migration to not
consume memory on the migration destination: when migrating a
"page full of zeroes", on the migration destination they check whether the
target memory is already zero (by reading the destination memory) and avoid
writing to the memory to not allocate memory: however, s390x will also
allocate memory here, implying that also on the migration destination, we
will end up allocating all previously-inflated memory part of the memory
balloon.
This is especially bad if actual memory overcommit was not desired, when
memory ballooning is used for dynamic VM memory resizing, setting aside
some memory during boot that can be added later on demand. Alternatives
like virtio-mem that would avoid this issue are not yet available on
s390x.
There could be ways to optimize some cases in user space: before reading
memory in an anonymous private mapping on the migration source, check via
/proc/self/pagemap if anything is already populated. Similarly check on
the migration destination before reading. While that would avoid
populating tables full of shared zeropages on all architectures, it's
harder to get right and performant, and requires user space changes.
Further, with posctopy live migration we must place a page, so there,
"avoid touching memory to avoid allocating memory" is not really
possible. (Note that a previously we would have falsely inserted
shared zeropages into processes using UFFDIO_ZEROPAGE where
mm_forbids_zeropage() would have actually forbidden it)
PV is currently incompatible with memory ballooning, and in the common
case, KVM guests don't make use of storage keys. Instead of zapping
zeropages when enabling storage keys / PV, that turned out to be
problematic in the past, let's do exactly the same we do with KSM pages:
trigger unsharing faults to replace the shared zeropages by proper
anonymous folios.
What about added latency when enabling storage kes? Having a lot of
zeropages in applicable environments (PV, legacy guests, unittests) is
unexpected. Further, KSM could today already unshare the zeropages
and unmerging KSM pages when enabling storage kets would unshare the
KSM-placed zeropages in the same way, resulting in the same latency.
[ agordeev: Fixed sparse and checkpatch complaints and error handling ]
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Fixes: fa41ba0d08de ("s390/mm: avoid empty zero pages for KVM guests to avoid postcopy hangs")
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20240411161441.910170-3-david@redhat.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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Currently, kernel modules contain their own set of expoline thunks. In
the case of EXPOLINE_EXTERN, this involves postlinking of precompiled
expoline.o. expoline.o is also necessary for out-of-source tree module
builds.
Now that the kernel modules area is less than 4 GB away from
kernel expoline thunks, make modules use kernel expolines. Also make
EXPOLINE_EXTERN the default if the compiler supports it. This simplifies
build and aligns with the approach adopted by other architectures.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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The .vmlinux.relocs section is moved in front of the compressed
kernel. The interim section rescue step is avoided as result.
Suggested-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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Rework deployment of kernel image for both compressed and
uncompressed variants as defined by CONFIG_KERNEL_UNCOMPRESSED
kernel configuration variable.
In case CONFIG_KERNEL_UNCOMPRESSED is disabled avoid uncompressing
the kernel to a temporary buffer and copying it to the target
address. Instead, uncompress it directly to the target destination.
In case CONFIG_KERNEL_UNCOMPRESSED is enabled avoid moving the
kernel to default 0x100000 location when KASLR is disabled or
failed. Instead, use the uncompressed kernel image directly.
In case KASLR is disabled or failed .amode31 section location in
memory is not randomized and precedes the kernel image. In case
CONFIG_KERNEL_UNCOMPRESSED is disabled that location overlaps the
area used by the decompression algorithm. That is fine, since that
area is not used after the decompression finished and the size of
.amode31 section is not expected to exceed BOOT_HEAP_SIZE ever.
There is no decompression in case CONFIG_KERNEL_UNCOMPRESSED is
enabled. Therefore, rename decompress_kernel() to deploy_kernel(),
which better describes both uncompressed and compressed cases.
Introduce AMODE31_SIZE macro to avoid immediate value of 0x3000
(the size of .amode31 section) in the decompressor linker script.
Modify the vmlinux linker script to force the size of .amode31
section to AMODE31_SIZE (the value of (_eamode31 - _samode31)
could otherwise differ as result of compiler options used).
Introduce __START_KERNEL macro that defines the kernel ELF image
entry point and set it to the currrent value of 0x100000.
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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Since kernel virtual and physical address spaces are
uncoupled the kernel is mapped at the top of the virtual
address space in case KASLR is disabled.
That does not pose any issue with regard to the kernel
booting and operation, but makes it difficult to use a
generated vmlinux with some debugging tools (e.g. gdb),
because the exact location of the kernel image in virtual
memory is unknown. Make that location known and introduce
CONFIG_KERNEL_IMAGE_BASE configuration option.
A custom CONFIG_KERNEL_IMAGE_BASE value that would break
the virtual memory layout leads to a build error.
The kernel image size is defined by KERNEL_IMAGE_SIZE
macro and set to 512 MB, by analogy with x86.
Suggested-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
|
The uncoupling physical vs virtual address spaces brings
the following benefits to s390:
- virtual memory layout flexibility;
- closes the address gap between kernel and modules, it
caused s390-only problems in the past (e.g. 'perf' bugs);
- allows getting rid of trampolines used for module calls
into kernel;
- allows simplifying BPF trampoline;
- minor performance improvement in branch prediction;
- kernel randomization entropy is magnitude bigger, as it is
derived from the amount of available virtual, not physical
memory;
The whole change could be described in two pictures below:
before and after the change.
Some aspects of the virtual memory layout setup are not
clarified (number of page levels, alignment, DMA memory),
since these are not a part of this change or secondary
with regard to how the uncoupling itself is implemented.
The focus of the pictures is to explain why __va() and __pa()
macros are implemented the way they are.
Memory layout in V==R mode:
| Physical | Virtual |
+- 0 --------------+- 0 --------------+ identity mapping start
| | S390_lowcore | Low-address memory
| +- 8 KB -----------+
| | |
| | identity | phys == virt
| | mapping | virt == phys
| | |
+- AMODE31_START --+- AMODE31_START --+ .amode31 rand. phys/virt start
|.amode31 text/data|.amode31 text/data|
+- AMODE31_END ----+- AMODE31_END ----+ .amode31 rand. phys/virt start
| | |
| | |
+- __kaslr_offset, __kaslr_offset_phys| kernel rand. phys/virt start
| | |
| kernel text/data | kernel text/data | phys == kvirt
| | |
+------------------+------------------+ kernel phys/virt end
| | |
| | |
| | |
| | |
+- ident_map_size -+- ident_map_size -+ identity mapping end
| |
| ... unused gap |
| |
+---- vmemmap -----+ 'struct page' array start
| |
| virtually mapped |
| memory map |
| |
+- __abs_lowcore --+
| |
| Absolute Lowcore |
| |
+- __memcpy_real_area
| |
| Real Memory Copy|
| |
+- VMALLOC_START --+ vmalloc area start
| |
| vmalloc area |
| |
+- MODULES_VADDR --+ modules area start
| |
| modules area |
| |
+------------------+ UltraVisor Secure Storage limit
| |
| ... unused gap |
| |
+KASAN_SHADOW_START+ KASAN shadow memory start
| |
| KASAN shadow |
| |
+------------------+ ASCE limit
Memory layout in V!=R mode:
| Physical | Virtual |
+- 0 --------------+- 0 --------------+
| | S390_lowcore | Low-address memory
| +- 8 KB -----------+
| | |
| | |
| | ... unused gap |
| | |
+- AMODE31_START --+- AMODE31_START --+ .amode31 rand. phys/virt start
|.amode31 text/data|.amode31 text/data|
+- AMODE31_END ----+- AMODE31_END ----+ .amode31 rand. phys/virt end (<2GB)
| | |
| | |
+- __kaslr_offset_phys | kernel rand. phys start
| | |
| kernel text/data | |
| | |
+------------------+ | kernel phys end
| | |
| | |
| | |
| | |
+- ident_map_size -+ |
| |
| ... unused gap |
| |
+- __identity_base + identity mapping start (>= 2GB)
| |
| identity | phys == virt - __identity_base
| mapping | virt == phys + __identity_base
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
+---- vmemmap -----+ 'struct page' array start
| |
| virtually mapped |
| memory map |
| |
+- __abs_lowcore --+
| |
| Absolute Lowcore |
| |
+- __memcpy_real_area
| |
| Real Memory Copy|
| |
+- VMALLOC_START --+ vmalloc area start
| |
| vmalloc area |
| |
+- MODULES_VADDR --+ modules area start
| |
| modules area |
| |
+- __kaslr_offset -+ kernel rand. virt start
| |
| kernel text/data | phys == (kvirt - __kaslr_offset) +
| | __kaslr_offset_phys
+- kernel .bss end + kernel rand. virt end
| |
| ... unused gap |
| |
+------------------+ UltraVisor Secure Storage limit
| |
| ... unused gap |
| |
+KASAN_SHADOW_START+ KASAN shadow memory start
| |
| KASAN shadow |
| |
+------------------+ ASCE limit
Unused gaps in the virtual memory layout could be present
or not - depending on how partucular system is configured.
No page tables are created for the unused gaps.
The relative order of vmalloc, modules and kernel image in
virtual memory is defined by following considerations:
- start of the modules area and end of the kernel should reside
within 4GB to accommodate relative 32-bit jumps. The best way
to achieve that is to place kernel next to modules;
- vmalloc and module areas should locate next to each other
to prevent failures and extra reworks in user level tools
(makedumpfile, crash, etc.) which treat vmalloc and module
addresses similarily;
- kernel needs to be the last area in the virtual memory
layout to easily distinguish between kernel and non-kernel
virtual addresses. That is needed to (again) simplify
handling of addresses in user level tools and make __pa()
macro faster (see below);
Concluding the above, the relative order of the considered
virtual areas in memory is: vmalloc - modules - kernel.
Therefore, the only change to the current memory layout is
moving kernel to the end of virtual address space.
With that approach the implementation of __pa() macro is
straightforward - all linear virtual addresses less than
kernel base are considered identity mapping:
phys == virt - __identity_base
All addresses greater than kernel base are kernel ones:
phys == (kvirt - __kaslr_offset) + __kaslr_offset_phys
By contrast, __va() macro deals only with identity mapping
addresses:
virt == phys + __identity_base
.amode31 section is mapped separately and is not covered by
__pa() macro. In fact, it could have been handled easily by
checking whether a virtual address is within the section or
not, but there is no need for that. Thus, let __pa() code
do as little machine cycles as possible.
The KASAN shadow memory is located at the very end of the
virtual memory layout, at addresses higher than the kernel.
However, that is not a linear mapping and no code other than
KASAN instrumentation or API is expected to access it.
When KASLR mode is enabled the kernel base address randomized
within a memory window that spans whole unused virtual address
space. The size of that window depends from the amount of
physical memory available to the system, the limit imposed by
UltraVisor (if present) and the vmalloc area size as provided
by vmalloc= kernel command line parameter.
In case the virtual memory is exhausted the minimum size of
the randomization window is forcefully set to 2GB, which
amounts to in 15 bits of entropy if KASAN is enabled or 17
bits of entropy in default configuration.
The default kernel offset 0x100000 is used as a magic value
both in the decompressor code and vmlinux linker script, but
it will be removed with a follow-up change.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
|
This is a preparatory rework to allow uncoupling virtual
and physical addresses spaces.
The vmcore ELF program headers describe virtual memory
regions of a crashed kernel. User level tools use that
information for the kernel text and data analysis (e.g
vmcore-dmesg extracts the kernel log).
Currently the kernel image is covered by program headers
describing the identity mapping regions. But in the future
the kernel image will be mapped into separate region outside
of the identity mapping. Create the additional ELF program
header that covers kernel image only, so that vmcore tools
could locate kernel text and data.
Further, the identity mapping in crashed and capture kernels
will have different base address. Due to that __va() macro
can not be used in the capture kernel. Instead, read crashed
kernel identity mapping base address from os_info and use
it for PT_LOAD type program headers creation.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
|
This is a preparatory rework to allow uncoupling virtual
and physical addresses spaces.
The virtual memory layout will be read out by makedumpfile,
crash and other user tools for virtual address translation.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
|
Introduce entries that do not reference any data in memory,
but rather provide values. Set the size of such entries to
zero and do not compute checksum for them, since there is no
data which integrity needs to be checked. The integrity of
the value entries itself is still covered by the os_info
checksum.
Reserve the lowest unused entry index OS_INFO_RESERVED for
future use - presumably for the number of entries present.
That could later be used by user level tools. The existing
tools would not notice any difference.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
|
This is a preparatory rework to allow uncoupling virtual
and physical addresses spaces.
Introduce .amode31 section address range AMODE31_START
and AMODE31_END macros for later use.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
|
This is a preparatory rework to allow uncoupling virtual
and physical addresses spaces.
Currently the identity mapping base address is implicit
and is always set to zero. Make it explicit by putting
into __identity_base persistent boot variable and use it
in proper context - which is the value of PAGE_OFFSET.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
|
This is a preparatory rework to allow uncoupling virtual
and physical addresses spaces.
Currently __kaslr_offset is the kernel offset in both
physical memory on boot and in virtual memory after DAT
mode is enabled.
Uncouple these offsets and rename the physical address
space variant to __kaslr_offset_phys while keep the name
__kaslr_offset for the offset in virtual address space.
Do not use __kaslr_offset_phys after DAT mode is enabled
just yet, but still make it a persistent boot variable
for later use.
Use __kaslr_offset and __kaslr_offset_phys offsets in
proper contexts and alter handle_relocs() function to
distinguish between the two.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
|
This is a preparatory rework to allow uncoupling virtual
and physical addresses spaces.
Put virtual memory layout information into a structure
to improve code generation when accessing the structure
members, which are currently only ident_map_size and
__kaslr_offset.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
|
Move everyting KASLR related to <asm/page.h>,
similarly to many other architectures.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
|
The maximum mappable physical address (as returned by
arch_get_mappable_range() callback) is limited by the
value of (1UL << MAX_PHYSMEM_BITS).
The maximum physical address available to a DCSS segment
is 512GB.
In case the available online or offline memory size is less
than the DCSS limit arch_get_mappable_range() would include
never used [512GB..(1UL << MAX_PHYSMEM_BITS)] range.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
|
__ARCH_HAS_VTIME_TASK_SWITCH macro is not used anymore.
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Link: https://lore.kernel.org/r/b1055852eab0ffea33ad16c92d6a825c83037c3e.1712760275.git.agordeev@linux.ibm.com
|
|
The direct dependency of chsc and the AP bus prevents the
modularization of ap bus. Introduce a notifier interface for AP
changes, which decouples the producer of the change events (chsc) from
the consumer (ap_bus).
Remove the ap_cfg_chg() interface and replace it with the notifier
invocation. The ap bus module registers a notification handler, which
triggers the AP bus scan.
Cc: Vineeth Vijayan <vneethv@linux.ibm.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Acked-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
|
Since qci is available on most of the current machines, move away from
the dynamic buffers for qci information and store it instead in a
statically defined buffer.
The new flags member in struct ap_config_info is now used as an
indicator, if qci is available in the system (at least one of these
bits is set).
Suggested-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
|
Consolidate vdso_calc_delta(), in preparation for further simplification.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240325064023.2997-2-adrian.hunter@intel.com
|
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preempt_count-related functions are quite ubiquitous and may be called
by noinstr ones, introducing unwanted instrumentation. Here is one
example call chain:
irqentry_nmi_enter() # noinstr
lockdep_hardirqs_enabled()
this_cpu_read()
__pcpu_size_call_return()
this_cpu_read_*()
this_cpu_generic_read()
__this_cpu_generic_read_nopreempt()
preempt_disable_notrace()
__preempt_count_inc()
__preempt_count_add()
They are very small, so there are no significant downsides to
force-inlining them.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20240320230007.4782-3-iii@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
|
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Atomic functions are quite ubiquitous and may be called by noinstr
ones, introducing unwanted instrumentation. They are very small, so
there are no significant downsides to force-inlining them.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20240320230007.4782-2-iii@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
|
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git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull more s390 updates from Heiko Carstens:
- Various virtual vs physical address usage fixes
- Add new bitwise types and helper functions and use them in s390
specific drivers and code to make it easier to find virtual vs
physical address usage bugs.
Right now virtual and physical addresses are identical for s390,
except for module, vmalloc, and similar areas. This will be changed,
hopefully with the next merge window, so that e.g. the kernel image
and modules will be located close to each other, allowing for direct
branches and also for some other simplifications.
As a prerequisite this requires to fix all misuses of virtual and
physical addresses. As it turned out people are so used to the
concept that virtual and physical addresses are the same, that new
bugs got added to code which was already fixed. In order to avoid
that even more code gets merged which adds such bugs add and use new
bitwise types, so that sparse can be used to find such usage bugs.
Most likely the new types can go away again after some time
- Provide a simple ARCH_HAS_DEBUG_VIRTUAL implementation
- Fix kprobe branch handling: if an out-of-line single stepped relative
branch instruction has a target address within a certain address area
in the entry code, the program check handler may incorrectly execute
cleanup code as if KVM code was executed, leading to crashes
- Fix reference counting of zcrypt card objects
- Various other small fixes and cleanups
* tag 's390-6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (41 commits)
s390/entry: compare gmap asce to determine guest/host fault
s390/entry: remove OUTSIDE macro
s390/entry: add CIF_SIE flag and remove sie64a() address check
s390/cio: use while (i--) pattern to clean up
s390/raw3270: make class3270 constant
s390/raw3270: improve raw3270_init() readability
s390/tape: make tape_class constant
s390/vmlogrdr: make vmlogrdr_class constant
s390/vmur: make vmur_class constant
s390/zcrypt: make zcrypt_class constant
s390/mm: provide simple ARCH_HAS_DEBUG_VIRTUAL support
s390/vfio_ccw_cp: use new address translation helpers
s390/iucv: use new address translation helpers
s390/ctcm: use new address translation helpers
s390/lcs: use new address translation helpers
s390/qeth: use new address translation helpers
s390/zfcp: use new address translation helpers
s390/tape: fix virtual vs physical address confusion
s390/3270: use new address translation helpers
s390/3215: use new address translation helpers
...
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With the current implementation, there are some cornercases where
a host fault would be treated as a guest fault, for example
when the sie instruction causes a program check. Therefore store
the gmap asce in ptregs, and use that to compare the primary asce
from the fault instead of matching instruction addresses.
Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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When a program check, interrupt or machine check is triggered, the
PSW address is compared to a certain range of the sie64a() function
to figure out whether SIE was interrupted and a cleanup of SIE is
needed.
This doesn't work with kprobes: If kprobes probes an instruction, it
copies the instruction to the kprobes instruction page and overwrites the
original instruction with an undefind instruction (Opcode 00). When this
instruction is hit later, kprobes single-steps the instruction on the
kprobes_instruction page.
However, if this instruction is a relative branch instruction it will now
point to a different location in memory due to being moved to the kprobes
instruction page. If the new branch target points into sie64a() the kernel
assumes it interrupted SIE when processing the breakpoint and will crash
trying to access the SIE control block.
Instead of comparing the address, introduce a new CIF_SIE flag which
indicates whether SIE was interrupted.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Pull kvm updates from Paolo Bonzini:
"S390:
- Changes to FPU handling came in via the main s390 pull request
- Only deliver to the guest the SCLP events that userspace has
requested
- More virtual vs physical address fixes (only a cleanup since
virtual and physical address spaces are currently the same)
- Fix selftests undefined behavior
x86:
- Fix a restriction that the guest can't program a PMU event whose
encoding matches an architectural event that isn't included in the
guest CPUID. The enumeration of an architectural event only says
that if a CPU supports an architectural event, then the event can
be programmed *using the architectural encoding*. The enumeration
does NOT say anything about the encoding when the CPU doesn't
report support the event *in general*. It might support it, and it
might support it using the same encoding that made it into the
architectural PMU spec
- Fix a variety of bugs in KVM's emulation of RDPMC (more details on
individual commits) and add a selftest to verify KVM correctly
emulates RDMPC, counter availability, and a variety of other
PMC-related behaviors that depend on guest CPUID and therefore are
easier to validate with selftests than with custom guests (aka
kvm-unit-tests)
- Zero out PMU state on AMD if the virtual PMU is disabled, it does
not cause any bug but it wastes time in various cases where KVM
would check if a PMC event needs to be synthesized
- Optimize triggering of emulated events, with a nice ~10%
performance improvement in VM-Exit microbenchmarks when a vPMU is
exposed to the guest
- Tighten the check for "PMI in guest" to reduce false positives if
an NMI arrives in the host while KVM is handling an IRQ VM-Exit
- Fix a bug where KVM would report stale/bogus exit qualification
information when exiting to userspace with an internal error exit
code
- Add a VMX flag in /proc/cpuinfo to report 5-level EPT support
- Rework TDP MMU root unload, free, and alloc to run with mmu_lock
held for read, e.g. to avoid serializing vCPUs when userspace
deletes a memslot
- Tear down TDP MMU page tables at 4KiB granularity (used to be
1GiB). KVM doesn't support yielding in the middle of processing a
zap, and 1GiB granularity resulted in multi-millisecond lags that
are quite impolite for CONFIG_PREEMPT kernels
- Allocate write-tracking metadata on-demand to avoid the memory
overhead when a kernel is built with i915 virtualization support
but the workloads use neither shadow paging nor i915 virtualization
- Explicitly initialize a variety of on-stack variables in the
emulator that triggered KMSAN false positives
- Fix the debugregs ABI for 32-bit KVM
- Rework the "force immediate exit" code so that vendor code
ultimately decides how and when to force the exit, which allowed
some optimization for both Intel and AMD
- Fix a long-standing bug where kvm_has_noapic_vcpu could be left
elevated if vCPU creation ultimately failed, causing extra
unnecessary work
- Cleanup the logic for checking if the currently loaded vCPU is
in-kernel
- Harden against underflowing the active mmu_notifier invalidation
count, so that "bad" invalidations (usually due to bugs elsehwere
in the kernel) are detected earlier and are less likely to hang the
kernel
x86 Xen emulation:
- Overlay pages can now be cached based on host virtual address,
instead of guest physical addresses. This removes the need to
reconfigure and invalidate the cache if the guest changes the gpa
but the underlying host virtual address remains the same
- When possible, use a single host TSC value when computing the
deadline for Xen timers in order to improve the accuracy of the
timer emulation
- Inject pending upcall events when the vCPU software-enables its
APIC to fix a bug where an upcall can be lost (and to follow Xen's
behavior)
- Fall back to the slow path instead of warning if "fast" IRQ
delivery of Xen events fails, e.g. if the guest has aliased xAPIC
IDs
RISC-V:
- Support exception and interrupt handling in selftests
- New self test for RISC-V architectural timer (Sstc extension)
- New extension support (Ztso, Zacas)
- Support userspace emulation of random number seed CSRs
ARM:
- Infrastructure for building KVM's trap configuration based on the
architectural features (or lack thereof) advertised in the VM's ID
registers
- Support for mapping vfio-pci BARs as Normal-NC (vaguely similar to
x86's WC) at stage-2, improving the performance of interacting with
assigned devices that can tolerate it
- Conversion of KVM's representation of LPIs to an xarray, utilized
to address serialization some of the serialization on the LPI
injection path
- Support for _architectural_ VHE-only systems, advertised through
the absence of FEAT_E2H0 in the CPU's ID register
- Miscellaneous cleanups, fixes, and spelling corrections to KVM and
selftests
LoongArch:
- Set reserved bits as zero in CPUCFG
- Start SW timer only when vcpu is blocking
- Do not restart SW timer when it is expired
- Remove unnecessary CSR register saving during enter guest
- Misc cleanups and fixes as usual
Generic:
- Clean up Kconfig by removing CONFIG_HAVE_KVM, which was basically
always true on all architectures except MIPS (where Kconfig
determines the available depending on CPU capabilities). It is
replaced either by an architecture-dependent symbol for MIPS, and
IS_ENABLED(CONFIG_KVM) everywhere else
- Factor common "select" statements in common code instead of
requiring each architecture to specify it
- Remove thoroughly obsolete APIs from the uapi headers
- Move architecture-dependent stuff to uapi/asm/kvm.h
- Always flush the async page fault workqueue when a work item is
being removed, especially during vCPU destruction, to ensure that
there are no workers running in KVM code when all references to
KVM-the-module are gone, i.e. to prevent a very unlikely
use-after-free if kvm.ko is unloaded
- Grab a reference to the VM's mm_struct in the async #PF worker
itself instead of gifting the worker a reference, so that there's
no need to remember to *conditionally* clean up after the worker
Selftests:
- Reduce boilerplate especially when utilize selftest TAP
infrastructure
- Add basic smoke tests for SEV and SEV-ES, along with a pile of
library support for handling private/encrypted/protected memory
- Fix benign bugs where tests neglect to close() guest_memfd files"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (246 commits)
selftests: kvm: remove meaningless assignments in Makefiles
KVM: riscv: selftests: Add Zacas extension to get-reg-list test
RISC-V: KVM: Allow Zacas extension for Guest/VM
KVM: riscv: selftests: Add Ztso extension to get-reg-list test
RISC-V: KVM: Allow Ztso extension for Guest/VM
RISC-V: KVM: Forward SEED CSR access to user space
KVM: riscv: selftests: Add sstc timer test
KVM: riscv: selftests: Change vcpu_has_ext to a common function
KVM: riscv: selftests: Add guest helper to get vcpu id
KVM: riscv: selftests: Add exception handling support
LoongArch: KVM: Remove unnecessary CSR register saving during enter guest
LoongArch: KVM: Do not restart SW timer when it is expired
LoongArch: KVM: Start SW timer only when vcpu is blocking
LoongArch: KVM: Set reserved bits as zero in CPUCFG
KVM: selftests: Explicitly close guest_memfd files in some gmem tests
KVM: x86/xen: fix recursive deadlock in timer injection
KVM: pfncache: simplify locking and make more self-contained
KVM: x86/xen: remove WARN_ON_ONCE() with false positives in evtchn delivery
KVM: x86/xen: inject vCPU upcall vector when local APIC is enabled
KVM: x86/xen: improve accuracy of Xen timers
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- Kuan-Wei Chiu has developed the well-named series "lib min_heap: Min
heap optimizations".
- Kuan-Wei Chiu has also sped up the library sorting code in the series
"lib/sort: Optimize the number of swaps and comparisons".
- Alexey Gladkov has added the ability for code running within an IPC
namespace to alter its IPC and MQ limits. The series is "Allow to
change ipc/mq sysctls inside ipc namespace".
- Geert Uytterhoeven has contributed some dhrystone maintenance work in
the series "lib: dhry: miscellaneous cleanups".
- Ryusuke Konishi continues nilfs2 maintenance work in the series
"nilfs2: eliminate kmap and kmap_atomic calls"
"nilfs2: fix kernel bug at submit_bh_wbc()"
- Nathan Chancellor has updated our build tools requirements in the
series "Bump the minimum supported version of LLVM to 13.0.1".
- Muhammad Usama Anjum continues with the selftests maintenance work in
the series "selftests/mm: Improve run_vmtests.sh".
- Oleg Nesterov has done some maintenance work against the signal code
in the series "get_signal: minor cleanups and fix".
Plus the usual shower of singleton patches in various parts of the tree.
Please see the individual changelogs for details.
* tag 'mm-nonmm-stable-2024-03-14-09-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits)
nilfs2: prevent kernel bug at submit_bh_wbc()
nilfs2: fix failure to detect DAT corruption in btree and direct mappings
ocfs2: enable ocfs2_listxattr for special files
ocfs2: remove SLAB_MEM_SPREAD flag usage
assoc_array: fix the return value in assoc_array_insert_mid_shortcut()
buildid: use kmap_local_page()
watchdog/core: remove sysctl handlers from public header
nilfs2: use div64_ul() instead of do_div()
mul_u64_u64_div_u64: increase precision by conditionally swapping a and b
kexec: copy only happens before uchunk goes to zero
get_signal: don't initialize ksig->info if SIGNAL_GROUP_EXIT/group_exec_task
get_signal: hide_si_addr_tag_bits: fix the usage of uninitialized ksig
get_signal: don't abuse ksig->info.si_signo and ksig->sig
const_structs.checkpatch: add device_type
Normalise "name (ad@dr)" MODULE_AUTHORs to "name <ad@dr>"
dyndbg: replace kstrdup() + strchr() with kstrdup_and_replace()
list: leverage list_is_head() for list_entry_is_head()
nilfs2: MAINTAINERS: drop unreachable project mirror site
smp: make __smp_processor_id() 0-argument macro
fat: fix uninitialized field in nostale filehandles
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
from hotplugged memory rather than only from main memory. Series
"implement "memmap on memory" feature on s390".
- More folio conversions from Matthew Wilcox in the series
"Convert memcontrol charge moving to use folios"
"mm: convert mm counter to take a folio"
- Chengming Zhou has optimized zswap's rbtree locking, providing
significant reductions in system time and modest but measurable
reductions in overall runtimes. The series is "mm/zswap: optimize the
scalability of zswap rb-tree".
- Chengming Zhou has also provided the series "mm/zswap: optimize zswap
lru list" which provides measurable runtime benefits in some
swap-intensive situations.
- And Chengming Zhou further optimizes zswap in the series "mm/zswap:
optimize for dynamic zswap_pools". Measured improvements are modest.
- zswap cleanups and simplifications from Yosry Ahmed in the series
"mm: zswap: simplify zswap_swapoff()".
- In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
contributed several DAX cleanups as well as adding a sysfs tunable to
control the memmap_on_memory setting when the dax device is
hotplugged as system memory.
- Johannes Weiner has added the large series "mm: zswap: cleanups",
which does that.
- More DAMON work from SeongJae Park in the series
"mm/damon: make DAMON debugfs interface deprecation unignorable"
"selftests/damon: add more tests for core functionalities and corner cases"
"Docs/mm/damon: misc readability improvements"
"mm/damon: let DAMOS feeds and tame/auto-tune itself"
- In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
extension" Rakie Kim has developed a new mempolicy interleaving
policy wherein we allocate memory across nodes in a weighted fashion
rather than uniformly. This is beneficial in heterogeneous memory
environments appearing with CXL.
- Christophe Leroy has contributed some cleanup and consolidation work
against the ARM pagetable dumping code in the series "mm: ptdump:
Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".
- Luis Chamberlain has added some additional xarray selftesting in the
series "test_xarray: advanced API multi-index tests".
- Muhammad Usama Anjum has reworked the selftest code to make its
human-readable output conform to the TAP ("Test Anything Protocol")
format. Amongst other things, this opens up the use of third-party
tools to parse and process out selftesting results.
- Ryan Roberts has added fork()-time PTE batching of THP ptes in the
series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
targeted at arm64, this significantly speeds up fork() when the
process has a large number of pte-mapped folios.
- David Hildenbrand also gets in on the THP pte batching game in his
series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
implements batching during munmap() and other pte teardown
situations. The microbenchmark improvements are nice.
- And in the series "Transparent Contiguous PTEs for User Mappings"
Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte
mappings"). Kernel build times on arm64 improved nicely. Ryan's
series "Address some contpte nits" provides some followup work.
- In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
fixed an obscure hugetlb race which was causing unnecessary page
faults. He has also added a reproducer under the selftest code.
- In the series "selftests/mm: Output cleanups for the compaction
test", Mark Brown did what the title claims.
- Kinsey Ho has added the series "mm/mglru: code cleanup and
refactoring".
- Even more zswap material from Nhat Pham. The series "fix and extend
zswap kselftests" does as claimed.
- In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
regression" Mathieu Desnoyers has cleaned up and fixed rather a mess
in our handling of DAX on archiecctures which have virtually aliasing
data caches. The arm architecture is the main beneficiary.
- Lokesh Gidra's series "per-vma locks in userfaultfd" provides
dramatic improvements in worst-case mmap_lock hold times during
certain userfaultfd operations.
- Some page_owner enhancements and maintenance work from Oscar Salvador
in his series
"page_owner: print stacks and their outstanding allocations"
"page_owner: Fixup and cleanup"
- Uladzislau Rezki has contributed some vmalloc scalability
improvements in his series "Mitigate a vmap lock contention". It
realizes a 12x improvement for a certain microbenchmark.
- Some kexec/crash cleanup work from Baoquan He in the series "Split
crash out from kexec and clean up related config items".
- Some zsmalloc maintenance work from Chengming Zhou in the series
"mm/zsmalloc: fix and optimize objects/page migration"
"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"
- Zi Yan has taught the MM to perform compaction on folios larger than
order=0. This a step along the path to implementaton of the merging
of large anonymous folios. The series is named "Enable >0 order folio
memory compaction".
- Christoph Hellwig has done quite a lot of cleanup work in the
pagecache writeback code in his series "convert write_cache_pages()
to an iterator".
- Some modest hugetlb cleanups and speedups in Vishal Moola's series
"Handle hugetlb faults under the VMA lock".
- Zi Yan has changed the page splitting code so we can split huge pages
into sizes other than order-0 to better utilize large folios. The
series is named "Split a folio to any lower order folios".
- David Hildenbrand has contributed the series "mm: remove
total_mapcount()", a cleanup.
- Matthew Wilcox has sought to improve the performance of bulk memory
freeing in his series "Rearrange batched folio freeing".
- Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
provides large improvements in bootup times on large machines which
are configured to use large numbers of hugetlb pages.
- Matthew Wilcox's series "PageFlags cleanups" does that.
- Qi Zheng's series "minor fixes and supplement for ptdesc" does that
also. S390 is affected.
- Cleanups to our pagemap utility functions from Peter Xu in his series
"mm/treewide: Replace pXd_large() with pXd_leaf()".
- Nico Pache has fixed a few things with our hugepage selftests in his
series "selftests/mm: Improve Hugepage Test Handling in MM
Selftests".
- Also, of course, many singleton patches to many things. Please see
the individual changelogs for details.
* tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits)
mm/zswap: remove the memcpy if acomp is not sleepable
crypto: introduce: acomp_is_async to expose if comp drivers might sleep
memtest: use {READ,WRITE}_ONCE in memory scanning
mm: prohibit the last subpage from reusing the entire large folio
mm: recover pud_leaf() definitions in nopmd case
selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements
selftests/mm: skip uffd hugetlb tests with insufficient hugepages
selftests/mm: dont fail testsuite due to a lack of hugepages
mm/huge_memory: skip invalid debugfs new_order input for folio split
mm/huge_memory: check new folio order when split a folio
mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure
mm: add an explicit smp_wmb() to UFFDIO_CONTINUE
mm: fix list corruption in put_pages_list
mm: remove folio from deferred split list before uncharging it
filemap: avoid unnecessary major faults in filemap_fault()
mm,page_owner: drop unnecessary check
mm,page_owner: check for null stack_record before bumping its refcount
mm: swap: fix race between free_swap_and_cache() and swapoff()
mm/treewide: align up pXd_leaf() retval across archs
mm/treewide: drop pXd_large()
...
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Provide a very simple ARCH_HAS_DEBUG_VIRTUAL implementation.
For now errors are only reported for the following cases:
- Trying to translate a vmalloc or module address to a physical address
- Translating a supposed to be ZONE_DMA virtual address into a physical
address, and the resulting physical address is larger than two GiB
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Fix virtual vs physical address confusion. This does not fix a bug since
virtual and physical address spaces are currently the same.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Only the last 12 bits of virtual / physical addresses are used when masking
with IDA_BLOCK_SIZE - 1. Given that the bits are the same regardless of
virtual or physical address, remove the virtual to physical address
conversion.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Adjust coding style, partially refactor code, and use kcalloc()
instead of kmalloc() to allocate an idaw array.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Change and use ccw_device_dma_zalloc() so it returns a virtual address like
before, which can be used to access data. However also pass a new dma32_t
pointer type handle, which correlates to the returned virtual address.
This pointer is used to directly pass/set the DMA handle as returned by the
DMA API.
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Change types of I/O structure members which contain physical addresses to
dma32_t and dma64_t bitwise types.
This allows to make use of sparse (aka "make C=1") to find incorrect usage
of physical addresses.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Introduce dma32_t and dma64_t bitwise types, which are supposed to be used
for 31 and 64 bit DMA capable addresses. This allows to use sparse (make
C=1) for type checking, so that incorrect usages can be easily found.
Also add a couple of helper functions which
- convert virtual to DMA addresses and vice versa
- allow for simple logical and arithmetic operations on DMA addresses
- convert DMA addresses to plain u32 and u64 values
All helper functions exist to avoid excessive casting in C code.
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Co-developed-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening updates from Kees Cook:
"As is pretty normal for this tree, there are changes all over the
place, especially for small fixes, selftest improvements, and improved
macro usability.
Some header changes ended up landing via this tree as they depended on
the string header cleanups. Also, a notable set of changes is the work
for the reintroduction of the UBSAN signed integer overflow sanitizer
so that we can continue to make improvements on the compiler side to
make this sanitizer a more viable future security hardening option.
Summary:
- string.h and related header cleanups (Tanzir Hasan, Andy
Shevchenko)
- VMCI memcpy() usage and struct_size() cleanups (Vasiliy Kovalev,
Harshit Mogalapalli)
- selftests/powerpc: Fix load_unaligned_zeropad build failure
(Michael Ellerman)
- hardened Kconfig fragment updates (Marco Elver, Lukas Bulwahn)
- Handle tail call optimization better in LKDTM (Douglas Anderson)
- Use long form types in overflow.h (Andy Shevchenko)
- Add flags param to string_get_size() (Andy Shevchenko)
- Add Coccinelle script for potential struct_size() use (Jacob
Keller)
- Fix objtool corner case under KCFI (Josh Poimboeuf)
- Drop 13 year old backward compat CAP_SYS_ADMIN check (Jingzi Meng)
- Add str_plural() helper (Michal Wajdeczko, Kees Cook)
- Ignore relocations in .notes section
- Add comments to explain how __is_constexpr() works
- Fix m68k stack alignment expectations in stackinit Kunit test
- Convert string selftests to KUnit
- Add KUnit tests for fortified string functions
- Improve reporting during fortified string warnings
- Allow non-type arg to type_max() and type_min()
- Allow strscpy() to be called with only 2 arguments
- Add binary mode to leaking_addresses scanner
- Various small cleanups to leaking_addresses scanner
- Adding wrapping_*() arithmetic helper
- Annotate initial signed integer wrap-around in refcount_t
- Add explicit UBSAN section to MAINTAINERS
- Fix UBSAN self-test warnings
- Simplify UBSAN build via removal of CONFIG_UBSAN_SANITIZE_ALL
- Reintroduce UBSAN's signed overflow sanitizer"
* tag 'hardening-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (51 commits)
selftests/powerpc: Fix load_unaligned_zeropad build failure
string: Convert helpers selftest to KUnit
string: Convert selftest to KUnit
sh: Fix build with CONFIG_UBSAN=y
compiler.h: Explain how __is_constexpr() works
overflow: Allow non-type arg to type_max() and type_min()
VMCI: Fix possible memcpy() run-time warning in vmci_datagram_invoke_guest_handler()
lib/string_helpers: Add flags param to string_get_size()
x86, relocs: Ignore relocations in .notes section
objtool: Fix UNWIND_HINT_{SAVE,RESTORE} across basic blocks
overflow: Use POD in check_shl_overflow()
lib: stackinit: Adjust target string to 8 bytes for m68k
sparc: vdso: Disable UBSAN instrumentation
kernel.h: Move lib/cmdline.c prototypes to string.h
leaking_addresses: Provide mechanism to scan binary files
leaking_addresses: Ignore input device status lines
leaking_addresses: Use File::Temp for /tmp files
MAINTAINERS: Update LEAKING_ADDRESSES details
fortify: Improve buffer overflow reporting
fortify: Add KUnit tests for runtime overflows
...
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git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull asm-generic updates from Arnd Bergmann:
"Just two small updates this time:
- A series I did to unify the definition of PAGE_SIZE through
Kconfig, intended to help with a vdso rework that needs the
constant but cannot include the normal kernel headers when building
the compat VDSO on arm64 and potentially others
- a patch from Yan Zhao to remove the pfn_to_virt() definitions from
a couple of architectures after finding they were both incorrect
and entirely unused"
* tag 'asm-generic-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
arch: define CONFIG_PAGE_SIZE_*KB on all architectures
arch: simplify architecture specific page size configuration
arch: consolidate existing CONFIG_PAGE_SIZE_*KB definitions
mm: Remove broken pfn_to_virt() on arch csky/hexagon/openrisc
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git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Heiko Carstens:
- Various virtual vs physical address usage fixes
- Fix error handling in Processor Activity Instrumentation device
driver, and export number of counters with a sysfs file
- Allow for multiple events when Processor Activity Instrumentation
counters are monitored in system wide sampling
- Change multiplier and shift values of the Time-of-Day clock source to
improve steering precision
- Remove a couple of unneeded GFP_DMA flags from allocations
- Disable mmap alignment if randomize_va_space is also disabled, to
avoid a too small heap
- Various changes to allow s390 to be compiled with LLVM=1, since
ld.lld and llvm-objcopy will have proper s390 support witch clang 19
- Add __uninitialized macro to Compiler Attributes. This is helpful
with s390's FPU code where some users have up to 520 byte stack
frames. Clearing such stack frames (if INIT_STACK_ALL_PATTERN or
INIT_STACK_ALL_ZERO is enabled) before they are used contradicts the
intention (performance improvement) of such code sections.
- Convert switch_to() to an out-of-line function, and use the generic
switch_to header file
- Replace the usage of s390's debug feature with pr_debug() calls
within the zcrypt device driver
- Improve hotplug support of the Adjunct Processor device driver
- Improve retry handling in the zcrypt device driver
- Various changes to the in-kernel FPU code:
- Make in-kernel FPU sections preemptible
- Convert various larger inline assemblies and assembler files to
C, mainly by using singe instruction inline assemblies. This
increases readability, but also allows makes it easier to add
proper instrumentation hooks
- Cleanup of the header files
- Provide fast variants of csum_partial() and
csum_partial_copy_nocheck() based on vector instructions
- Introduce and use a lock to synchronize accesses to zpci device data
structures to avoid inconsistent states caused by concurrent accesses
- Compile the kernel without -fPIE. This addresses the following
problems if the kernel is compiled with -fPIE:
- It uses dynamic symbols (.dynsym), for which the linker refuses
to allow more than 64k sections. This can break features which
use '-ffunction-sections' and '-fdata-sections', including
kpatch-build and function granular KASLR
- It unnecessarily uses GOT relocations, adding an extra layer of
indirection for many memory accesses
- Fix shared_cpu_list for CPU private L2 caches, which incorrectly were
reported as globally shared
* tag 's390-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (117 commits)
s390/tools: handle rela R_390_GOTPCDBL/R_390_GOTOFF64
s390/cache: prevent rebuild of shared_cpu_list
s390/crypto: remove retry loop with sleep from PAES pkey invocation
s390/pkey: improve pkey retry behavior
s390/zcrypt: improve zcrypt retry behavior
s390/zcrypt: introduce retries on in-kernel send CPRB functions
s390/ap: introduce mutex to lock the AP bus scan
s390/ap: rework ap_scan_bus() to return true on config change
s390/ap: clarify AP scan bus related functions and variables
s390/ap: rearm APQNs bindings complete completion
s390/configs: increase number of LOCKDEP_BITS
s390/vfio-ap: handle hardware checkstop state on queue reset operation
s390/pai: change sampling event assignment for PMU device driver
s390/boot: fix minor comment style damages
s390/boot: do not check for zero-termination relocation entry
s390/boot: make type of __vmlinux_relocs_64_start|end consistent
s390/boot: sanitize kaslr_adjust_relocs() function prototype
s390/boot: simplify GOT handling
s390: vmlinux.lds.S: fix .got.plt assertion
s390/boot: workaround current 'llvm-objdump -t -j ...' behavior
...
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https://github.com/kvm-x86/linux into HEAD
KVM GUEST_MEMFD fixes for 6.8:
- Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY to
avoid creating ABI that KVM can't sanely support.
- Update documentation for KVM_SW_PROTECTED_VM to make it abundantly
clear that such VMs are purely a development and testing vehicle, and
come with zero guarantees.
- Limit KVM_SW_PROTECTED_VM guests to the TDP MMU, as the long term plan
is to support confidential VMs with deterministic private memory (SNP
and TDX) only in the TDP MMU.
- Fix a bug in a GUEST_MEMFD negative test that resulted in false passes
when verifying that KVM_MEM_GUEST_MEMFD memslots can't be dirty logged.
|
