This helps preventing a BUG* or WARN* in some static inline from
preventing that (or one of its callers) being inlined, so should allow
gcc to make better informed inlining decisions.
For example, with gcc 9.2, tcp_fastopen_no_cookie() vanishes from
net/ipv4/tcp_fastopen.o. It does not itself have any BUG or WARN, but
it calls dst_metric() which has a WARN_ON_ONCE - and despite that
WARN_ON_ONCE vanishing since the condition is compile-time false,
dst_metric() is apparently sufficiently "large" that when it gets
inlined into tcp_fastopen_no_cookie(), the latter becomes too large
for inlining.
Overall, if one asks size(1), .text decreases a little and .data
increases by about the same amount (x86-64 defconfig)
$ size vmlinux.{before,after}
text data bss dec hex filename
19709726 5202600 1630280 26542606 195020e vmlinux.before
19709330 5203068 1630280 26542678 1950256 vmlinux.after
while bloat-o-meter says
add/remove: 10/28 grow/shrink: 103/51 up/down: 3669/-2854 (815)
...
Total: Before=14783683, After=14784498, chg +0.01%
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Most, if not all, uses of the alternative* family just provide one or
two instructions in .text, but the string literal can be quite large,
causing gcc to overestimate the size of the generated code. That in
turn affects its decisions about inlining of the function containing
the alternative() asm statement.
New enough versions of gcc allow one to overrule the estimated size by
using "asm inline" instead of just "asm". So replace asm by the helper
asm_inline, which for older gccs just expands to asm.
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Pull kvm fixes from Paolo Bonzini:
"The main change here is a revert of reverts. We recently simplified
some code that was thought unnecessary; however, since then KVM has
grown quite a few cond_resched()s and for that reason the simplified
code is prone to livelocks---one CPUs tries to empty a list of guest
page tables while the others keep adding to them. This adds back the
generation-based zapping of guest page tables, which was not
unnecessary after all.
On top of this, there is a fix for a kernel memory leak and a couple
of s390 fixlets as well"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86/mmu: Reintroduce fast invalidate/zap for flushing memslot
KVM: x86: work around leak of uninitialized stack contents
KVM: nVMX: handle page fault in vmread
KVM: s390: Do not leak kernel stack data in the KVM_S390_INTERRUPT ioctl
KVM: s390: kvm_s390_vm_start_migration: check dirty_bitmap before using it as target for memset()
Pull RISC-V fix from Paul Walmsley:
"Last week, Palmer and I learned that there was an error in the RISC-V
kernel image header format that could make it less compatible with the
ARM64 kernel image header format. I had missed this error during my
original reviews of the patch.
The kernel image header format is an interface that impacts
bootloaders, QEMU, and other user tools. Those packages must be
updated to align with whatever is merged in the kernel. We would like
to avoid proliferating these image formats by keeping the RISC-V
header as close as possible to the existing ARM64 header. Since the
arch/riscv patch that adds support for the image header was merged
with our v5.3-rc1 pull request as commit 0f327f2aaa ("RISC-V: Add
an Image header that boot loader can parse."), we think it wise to try
to fix this error before v5.3 is released.
The fix itself should be backwards-compatible with any project that
has already merged support for premature versions of this interface.
It primarily involves ensuring that the RISC-V image header has
something useful in the same field as the ARM64 image header"
* tag 'riscv/for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: modify the Image header to improve compatibility with the ARM64 header
James Harvey reported a livelock that was introduced by commit
d012a06ab1 ("Revert "KVM: x86/mmu: Zap only the relevant pages when
removing a memslot"").
The livelock occurs because kvm_mmu_zap_all() as it exists today will
voluntarily reschedule and drop KVM's mmu_lock, which allows other vCPUs
to add shadow pages. With enough vCPUs, kvm_mmu_zap_all() can get stuck
in an infinite loop as it can never zap all pages before observing lock
contention or the need to reschedule. The equivalent of kvm_mmu_zap_all()
that was in use at the time of the reverted commit (4e103134b8, "KVM:
x86/mmu: Zap only the relevant pages when removing a memslot") employed
a fast invalidate mechanism and was not susceptible to the above livelock.
There are three ways to fix the livelock:
- Reverting the revert (commit d012a06ab1) is not a viable option as
the revert is needed to fix a regression that occurs when the guest has
one or more assigned devices. It's unlikely we'll root cause the device
assignment regression soon enough to fix the regression timely.
- Remove the conditional reschedule from kvm_mmu_zap_all(). However, although
removing the reschedule would be a smaller code change, it's less safe
in the sense that the resulting kvm_mmu_zap_all() hasn't been used in
the wild for flushing memslots since the fast invalidate mechanism was
introduced by commit 6ca18b6950 ("KVM: x86: use the fast way to
invalidate all pages"), back in 2013.
- Reintroduce the fast invalidate mechanism and use it when zapping shadow
pages in response to a memslot being deleted/moved, which is what this
patch does.
For all intents and purposes, this is a revert of commit ea145aacf4
("Revert "KVM: MMU: fast invalidate all pages"") and a partial revert of
commit 7390de1e99 ("Revert "KVM: x86: use the fast way to invalidate
all pages""), i.e. restores the behavior of commit 5304b8d37c ("KVM:
MMU: fast invalidate all pages") and commit 6ca18b6950 ("KVM: x86:
use the fast way to invalidate all pages") respectively.
Fixes: d012a06ab1 ("Revert "KVM: x86/mmu: Zap only the relevant pages when removing a memslot"")
Reported-by: James Harvey <jamespharvey20@gmail.com>
Cc: Alex Willamson <alex.williamson@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Emulation of VMPTRST can incorrectly inject a page fault
when passed an operand that points to an MMIO address.
The page fault will use uninitialized kernel stack memory
as the CR2 and error code.
The right behavior would be to abort the VM with a KVM_EXIT_INTERNAL_ERROR
exit to userspace; however, it is not an easy fix, so for now just ensure
that the error code and CR2 are zero.
Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Cc: stable@vger.kernel.org
[add comment]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The implementation of vmread to memory is still incomplete, as it
lacks the ability to do vmread to I/O memory just like vmptrst.
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Part of the intention during the definition of the RISC-V kernel image
header was to lay the groundwork for a future merge with the ARM64
image header. One error during my original review was not noticing
that the RISC-V header's "magic" field was at a different size and
position than the ARM64's "magic" field. If the existing ARM64 Image
header parsing code were to attempt to parse an existing RISC-V kernel
image header format, it would see a magic number 0. This is
undesirable, since it's our intention to align as closely as possible
with the ARM64 header format. Another problem was that the original
"res3" field was not being initialized correctly to zero.
Address these issues by creating a 32-bit "magic2" field in the RISC-V
header which matches the ARM64 "magic" field. RISC-V binaries will
store "RSC\x05" in this field. The intention is that the use of the
existing 64-bit "magic" field in the RISC-V header will be deprecated
over time. Increment the minor version number of the file format to
indicate this change, and update the documentation accordingly. Fix
the assembler directives in head.S to ensure that reserved fields are
properly zero-initialized.
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Reported-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Atish Patra <atish.patra@wdc.com>
Cc: Karsten Merker <merker@debian.org>
Link: https://lore.kernel.org/linux-riscv/194c2f10c9806720623430dbf0cc59a965e50448.camel@wdc.com/T/#u
Link: https://lore.kernel.org/linux-riscv/mhng-755b14c4-8f35-4079-a7ff-e421fd1b02bc@palmer-si-x1e/T/#t
IPI shorthand is supported now by linux apic/x2apic driver, switch to
IPI shorthand for all excluding self and all including self destination
shorthand in kvm guest, to avoid splitting the target mask into several
PV IPI hypercalls. This patch removes the kvm_send_ipi_all() and
kvm_send_ipi_allbutself() since the callers in APIC codes have already
taken care of apic_use_ipi_shorthand and fallback to ->send_IPI_mask
and ->send_IPI_mask_allbutself if it is false.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Nadav Amit <namit@vmware.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When dumping the XIVE state of an CPU IPI, xmon does not check if the
CPU is started or not which can cause an error. Add a check for that
and change the output to be on one line just as the XIVE interrupts of
the machine.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190910081850.26038-3-clg@kaod.org
Booting a POWER9 PowerNV system generates a few messages below with
"____ptrval____" due to the pointers printed without a specifier
extension (i.e unadorned %p) are hashed to prevent leaking information
about the kernel memory layout.
radix-mmu: Initializing Radix MMU
radix-mmu: Partition table (____ptrval____)
radix-mmu: Mapped 0x0000000000000000-0x0000000040000000 with 1.00 GiB
pages (exec)
radix-mmu: Mapped 0x0000000040000000-0x0000002000000000 with 1.00 GiB
pages
radix-mmu: Mapped 0x0000200000000000-0x0000202000000000 with 1.00 GiB
pages
radix-mmu: Process table (____ptrval____) and radix root for kernel:
(____ptrval____)
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1566570120-16529-1-git-send-email-cai@lca.pw
OPAL loads kernel & initrd at 512MB offset (256MB size), also exported
as ibm,opal/dump/fw-load-area. So, if boot memory size of FADump is
less than 768MB, kernel memory to be exported as '/proc/vmcore' would
be overwritten by f/w while loading kernel & initrd. To avoid such a
scenario, enforce a minimum boot memory size of 768MB on OPAL platform
and skip using FADump if a newer F/W version loads kernel & initrd
above 768MB.
Also, irrespective of RMA size, set the minimum boot memory size
expected on pseries platform at 320MB. This is to avoid inflating the
minimum memory requirements on systems with 512M/1024M RMA size.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821381414.5656.1592867278535469652.stgit@hbathini.in.ibm.com
Export /sys/firmware/opal/core file to analyze opal crashes. Since OPAL
core can be generated independent of CONFIG_FA_DUMP support in kernel,
add this support under a new kernel config option CONFIG_OPAL_CORE.
Also, avoid code duplication by moving common code used while exporting
/proc/vmcore and/or /sys/firmware/opal/core file(s).
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821378503.5656.3693769384945087756.stgit@hbathini.in.ibm.com
Add a new kernel config option, CONFIG_PRESERVE_FA_DUMP that ensures
that crash data, from previously crash'ed kernel, is preserved. This
helps in cases where FADump is not enabled but the subsequent memory
preserving kernel boot is likely to process this crash data. One
typical usecase for this config option is petitboot kernel.
As OPAL allows registering address with it in the first kernel and
retrieving it after MPIPL, use it to store the top of boot memory.
A kernel that intends to preserve crash data retrieves it and avoids
using memory beyond this address.
Move arch_reserved_kernel_pages() function as it is needed for both
FA_DUMP and PRESERVE_FA_DUMP configurations.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821375751.5656.11459483669542541602.stgit@hbathini.in.ibm.com
Commit 0962e8004e ("powerpc/prom: Scan reserved-ranges node for
memory reservations") enabled support to parse 'reserved-ranges' DT
node to reserve kernel memory falling in these ranges for firmware
purposes. Along with the preserved area memory, ensure memory in
reserved ranges is not overlapped with memory released by capture
kernel aftering saving vmcore. Also, fix the off-by-one error in
fadump_release_reserved_area function while releasing memory.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821371358.5656.6061214942558818661.stgit@hbathini.in.ibm.com
Firmware uses a 32-bit field for size while copying/backing-up memory
during MPIPL. So, the maximum value that could be represented with
a PAGE_SIZE aligned 32-bit field will be the maximum copy size for a
region but FADump capture kernel usually needs more memory than that
to be preserved to avoid running into out of memory errors.
So, request firmware to copy multiple kernel boot memory regions
instead of just one (which worked fine for pseries as 64-bit field
was used for size there).
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821350193.5656.3664853158523582019.stgit@hbathini.in.ibm.com
MPIPL is Memory Preserving IPL supported from POWER9. This enables the
kernel to reset the system with memory 'preserved'. Also, it supports
copying memory from a source address to some destination address during
MPIPL boot. Add MPIPL interface definitions here to leverage these f/w
features in adding FADump support for PowerNV platform.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821340710.5656.10071829040515662624.stgit@hbathini.in.ibm.com
Except for Reserved dump area (see Documentation/powerpc/firmware-
assisted-dump.rst) which is permanent reserved, all memory above boot
memory size, where boot memory size is the memory required for the
kernel to boot successfully when booted with restricted memory (memory
for capture kernel), is released when the dump is invalidated. Make
this a bit more explicit in the code.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821336092.5656.1079046285366041687.stgit@hbathini.in.ibm.com
Add helper functions to setup & free CPU notes buffer and to find if a
given memory area is contiguous. Also, use boolean as return type for
the function that finds if boot memory area is contiguous. While at
it, save the virtual address of CPU notes buffer instead of physical
address as virtual address is used often.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821318971.5656.9281936950510635858.stgit@hbathini.in.ibm.com
This slightly improves the prom_init_check rule.
[1] Avoid needless check
Currently, prom_init_check.sh is invoked every time you run 'make'
even if you have changed nothing in prom_init.c. With this commit,
the script is re-run only when prom_init.o is recompiled.
[2] Beautify the build log
Currently, the O= build shows the absolute path to the script:
CALL /abs/path/to/source/of/linux/arch/powerpc/kernel/prom_init_check.sh
With this commit, it is always a relative path to the timestamp file:
PROMCHK arch/powerpc/kernel/prom_init_check
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190912074037.13813-1-yamada.masahiro@socionext.com
