MCE handling on pSeries platform fails as recent rework to use common
code for pSeries and PowerNV in machine check error handling tries to
access per-cpu variables in realmode. The per-cpu variables may be
outside the RMO region on pSeries platform and needs translation to be
enabled for access. Just moving these per-cpu variable into RMO region
did'nt help because we queue some work to workqueues in real mode, which
again tries to touch per-cpu variables. Also fwnmi_release_errinfo()
cannot be called when translation is not enabled.
This patch fixes this by enabling translation in the exception handler
when all required real mode handling is done. This change only affects
the pSeries platform.
Without this fix below kernel crash is seen on injecting
SLB multihit:
BUG: Unable to handle kernel data access on read at 0xc00000027b205950
Faulting instruction address: 0xc00000000003b7e0
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: mcetest_slb(OE+) af_packet(E) xt_tcpudp(E) ip6t_rpfilter(E) ip6t_REJECT(E) ipt_REJECT(E) xt_conntrack(E) ip_set(E) nfnetlink(E) ebtable_nat(E) ebtable_broute(E) ip6table_nat(E) ip6table_mangle(E) ip6table_raw(E) ip6table_security(E) iptable_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) iptable_mangle(E) iptable_raw(E) iptable_security(E) ebtable_filter(E) ebtables(E) ip6table_filter(E) ip6_tables(E) iptable_filter(E) ip_tables(E) x_tables(E) xfs(E) ibmveth(E) vmx_crypto(E) gf128mul(E) uio_pdrv_genirq(E) uio(E) crct10dif_vpmsum(E) rtc_generic(E) btrfs(E) libcrc32c(E) xor(E) zstd_decompress(E) zstd_compress(E) raid6_pq(E) sr_mod(E) sd_mod(E) cdrom(E) ibmvscsi(E) scsi_transport_srp(E) crc32c_vpmsum(E) dm_mod(E) sg(E) scsi_mod(E)
CPU: 34 PID: 8154 Comm: insmod Kdump: loaded Tainted: G OE 5.5.0-mahesh #1
NIP: c00000000003b7e0 LR: c0000000000f2218 CTR: 0000000000000000
REGS: c000000007dcb960 TRAP: 0300 Tainted: G OE (5.5.0-mahesh)
MSR: 8000000000001003 <SF,ME,RI,LE> CR: 28002428 XER: 20040000
CFAR: c0000000000f2214 DAR: c00000027b205950 DSISR: 40000000 IRQMASK: 0
GPR00: c0000000000f2218 c000000007dcbbf0 c000000001544800 c000000007dcbd70
GPR04: 0000000000000001 c000000007dcbc98 c008000000d00258 c0080000011c0000
GPR08: 0000000000000000 0000000300000003 c000000001035950 0000000003000048
GPR12: 000000027a1d0000 c000000007f9c000 0000000000000558 0000000000000000
GPR16: 0000000000000540 c008000001110000 c008000001110540 0000000000000000
GPR20: c00000000022af10 c00000025480fd70 c008000001280000 c00000004bfbb300
GPR24: c000000001442330 c00800000800000d c008000008000000 4009287a77000510
GPR28: 0000000000000000 0000000000000002 c000000001033d30 0000000000000001
NIP [c00000000003b7e0] save_mce_event+0x30/0x240
LR [c0000000000f2218] pseries_machine_check_realmode+0x2c8/0x4f0
Call Trace:
Instruction dump:
3c4c0151 38429050 7c0802a6 60000000 fbc1fff0 fbe1fff8 f821ffd1 3d42ffaf
3fc2ffaf e98d0030 394a1150 3bdef530 <7d6a62aa> 1d2b0048 2f8b0063 380b0001
---[ end trace 46fd63f36bbdd940 ]---
Fixes: 9ca766f989 ("powerpc/64s/pseries: machine check convert to use common event code")
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200320110119.10207-1-ganeshgr@linux.ibm.com
Commit 3282a3da25 ("powerpc/64: Implement soft interrupt replay in C")
broke the doorbell wakeup optimisation introduced by commit a9af97aa0a
("powerpc/64s: msgclr when handling doorbell exceptions from system
reset").
This patch restores the msgclr, in C code. It's now done in the system
reset wakeup path rather than doorbell interrupt replay where it used
to be, because it is always the right thing to do in the wakeup case,
but it may be rarely of use in other interrupt replay situations in
which case it's wasted work - we would have to run measurements to see
if that was a worthwhile optimisation, and I suspect it would not be.
The results are similar to those in the original commit, test on POWER8
of context_switch selftests benchmark with polling idle disabled (e.g.,
always nap, giving cross-CPU IPIs) gives the following results:
broken patched
Different threads, same core: 317k/s 375k/s +18.7%
Different cores: 280k/s 282k/s +1.0%
Fixes: 3282a3da25 ("powerpc/64: Implement soft interrupt replay in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200402121212.1118218-1-npiggin@gmail.com
This series focuses on corner case bug fixes and general clarity
improvements to hmm_range_fault().
- 9 bug fixes
- Allow pgmap to track the 'owner' of a DEVICE_PRIVATE - in this case the
owner tells the driver if it can understand the DEVICE_PRIVATE page or
not. Use this to resolve a bug in nouveau where it could touch
DEVICE_PRIVATE pages from other drivers.
- Remove a bunch of dead, redundant or unused code and flags
- Clarity improvements to hmm_range_fault()
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Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull hmm updates from Jason Gunthorpe:
"This series focuses on corner case bug fixes and general clarity
improvements to hmm_range_fault(). It arose from a review of
hmm_range_fault() by Christoph, Ralph and myself.
hmm_range_fault() is being used by these 'SVM' style drivers to
non-destructively read the page tables. It is very similar to
get_user_pages() except that the output is an array of PFNs and
per-pfn flags, and it has various modes of reading.
This is necessary before RDMA ODP can be converted, as we don't want
to have weird corner case regressions, which is still a looking
forward item. Ralph has a nice tester for this routine, but it is
waiting for feedback from the selftests maintainers.
Summary:
- 9 bug fixes
- Allow pgmap to track the 'owner' of a DEVICE_PRIVATE - in this case
the owner tells the driver if it can understand the DEVICE_PRIVATE
page or not. Use this to resolve a bug in nouveau where it could
touch DEVICE_PRIVATE pages from other drivers.
- Remove a bunch of dead, redundant or unused code and flags
- Clarity improvements to hmm_range_fault()"
* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (25 commits)
mm/hmm: return error for non-vma snapshots
mm/hmm: do not set pfns when returning an error code
mm/hmm: do not unconditionally set pfns when returning EBUSY
mm/hmm: use device_private_entry_to_pfn()
mm/hmm: remove HMM_FAULT_SNAPSHOT
mm/hmm: remove unused code and tidy comments
mm/hmm: return the fault type from hmm_pte_need_fault()
mm/hmm: remove pgmap checking for devmap pages
mm/hmm: check the device private page owner in hmm_range_fault()
mm: simplify device private page handling in hmm_range_fault
mm: handle multiple owners of device private pages in migrate_vma
memremap: add an owner field to struct dev_pagemap
mm: merge hmm_vma_do_fault into into hmm_vma_walk_hole_
mm/hmm: don't handle the non-fault case in hmm_vma_walk_hole_()
mm/hmm: simplify hmm_vma_walk_hugetlb_entry()
mm/hmm: remove the unused HMM_FAULT_ALLOW_RETRY flag
mm/hmm: don't provide a stub for hmm_range_fault()
mm/hmm: do not check pmd_protnone twice in hmm_vma_handle_pmd()
mm/hmm: add missing call to hmm_pte_need_fault in HMM_PFN_SPECIAL handling
mm/hmm: return -EFAULT when setting HMM_PFN_ERROR on requested valid pages
...
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>
Declaring setjmp()/longjmp() as taking longs makes the signature
non-standard, and makes clang complain. In the past, this has been
worked around by adding -ffreestanding to the compile flags.
The implementation looks like it only ever propagates the value
(in longjmp) or sets it to 1 (in setjmp), and we only call longjmp
with integer parameters.
This allows removing -ffreestanding from the compilation flags.
Fixes: c9029ef9c9 ("powerpc: Avoid clang warnings around setjmp and longjmp")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Clement Courbet <courbet@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200330080400.124803-1-courbet@google.com
Before checking for cpu_type == NULL, this same copy happens, so doing
it here will just write the same value to the t->oprofile_type
again.
Remove the repeated copy, as it is unnecessary.
Signed-off-by: Leonardo Bras <leonardo@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200215053637.280880-1-leonardo@linux.ibm.com
GCC v8 defaults to enabling -fasynchronous-unwind-tables due to
https://gcc.gnu.org/r259298, which results in .eh_frame section being
generated. This results in additional disk usage by the build, as well
as the kernel modules. Since the kernel has no use for this, this
section is discarded.
Add -fno-asynchronous-unwind-tables to KBUILD_CFLAGS to suppress
generation of .eh_frame section. Note that our VDSOs need .eh_frame, but
are not affected by this change since our VDSO code are all in assembly.
Reported-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1ed7cd84a7d1a3180b30c0c60e70eed8bb8b40c3.1583415544.git.naveen.n.rao@linux.vnet.ibm.com
The ISA_DMA_THRESHOLD variable is set by several platforms but never
referenced.
Remove it.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191125092033.20014-1-rppt@kernel.org
Relocatable kernel builds produce a warning about .gnu.hash being an
orphan section:
ld: warning: orphan section `.gnu.hash' from `linker stubs' being placed in section `.gnu.hash'
If we try to discard it the build fails:
ld -EL -m elf64lppc -pie --orphan-handling=warn --build-id -o
.tmp_vmlinux1 -T ./arch/powerpc/kernel/vmlinux.lds --whole-archive
arch/powerpc/kernel/head_64.o arch/powerpc/kernel/entry_64.o
...
sound/built-in.a net/built-in.a virt/built-in.a --no-whole-archive
--start-group lib/lib.a --end-group
ld: could not find section .gnu.hash
So add an entry to explicitly retain it, as we do for .hash.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200227045933.22967-1-mpe@ellerman.id.au
This reconciles interrupts in the system call case like all other
interrupts. This allows system_call_common to be shared with the scv
system call implementation in a subsequent patch.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-31-npiggin@gmail.com
Regular interrupt return restores NVGPRS whereas lite returns do not.
This is clumsy: most interrupts can return without restoring NVGPRS in
most of the time, but there are special cases that require it (when
registers have been modified by the kernel). So change interrupt
return to not restore NVGPRS, and have interrupt handlers restore them
explicitly in the cases that requires it.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-30-npiggin@gmail.com
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
When local_irq_enable() finds a pending soft-masked interrupt, it
"replays" it by setting up registers like the initial interrupt entry,
then calls into the low level handler to set up an interrupt stack
frame and process the interrupt.
This is not necessary, and uses more stack than needed. The high level
interrupt handler can be called directly from C, with just pt_regs set
up on stack. This should be faster and use less stack.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-28-npiggin@gmail.com
Kernel addresses and potentially other sensitive data could be leaked
in volatile registers after a syscall.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-27-npiggin@gmail.com
System call entry and particularly exit code is beyond the limit of
what is reasonable to implement in asm.
This conversion moves all conditional branches out of the asm code,
except for the case that all GPRs should be restored at exit.
Null syscall test is about 5% faster after this patch, because the
exit work is handled under local_irq_disable, and the hard mask and
pending interrupt replay is handled after that, which avoids games
with MSR.
mpe: Includes subsequent fixes from Nick:
This fixes 4 issues caught by TM selftests. First was a tm-syscall bug
that hit due to tabort_syscall being called after interrupts were
reconciled (in a subsequent patch), which led to interrupts being
enabled before tabort_syscall was called. Rather than going through an
un-reconciling interrupts for the return, I just go back to putting
the test early in asm, the C-ification of that wasn't a big win
anyway.
Second is the syscall return _TIF_USER_WORK_MASK check would go into
an infinite loop if _TIF_RESTORE_TM became set. The asm code uses
_TIF_USER_WORK_MASK to brach to slowpath which includes
restore_tm_state.
Third is system call return was not calling restore_tm_state, I missed
this completely (alhtough it's in the return from interrupt C
conversion because when the asm syscall code encountered problems it
would branch to the interrupt return code.
Fourth is MSR_VEC missing from restore_math, which was caught by
tm-unavailable selftest taking an unexpected facility unavailable
interrupt when testing VSX unavailble exception with MSR.FP=1
MSR.VEC=1. Fourth case also has a fixup in a subsequent patch.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-26-npiggin@gmail.com
powerpc has an optimisation where interrupts avoid saving the
non-volatile (or callee saved) registers to the interrupt stack frame
if they are not required.
Two problems with this are that an interrupt does not always know
whether it will need non-volatiles; and if it does need them, they can
only be saved from the entry-scoped asm code (because we don't control
what the C compiler does with these registers).
system calls are the most difficult: some system calls always require
all registers (e.g., fork, to copy regs into the child). Sometimes
registers are only required under certain conditions (e.g., tracing,
signal delivery). These cases require ugly logic in the call
chains (e.g., ppc_fork), and require a lot of logic to be implemented
in asm.
So remove the optimisation for system calls, and always save NVGPRs on
entry. Modern high performance CPUs are not so sensitive, because the
stores are dense in cache and can be hidden by other expensive work in
the syscall path -- the null syscall selftests benchmark on POWER9 is
not slowed (124.40ns before and 123.64ns after, i.e., within the
noise).
Other interrupts retain the NVGPR optimisation for now.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-24-npiggin@gmail.com
The soft NMI handler does not reconcile interrupt state, so it should
not return via the normal ret_from_except path. Return like other NMIs,
using the EXCEPTION_RESTORE_REGS macro.
This becomes important when the scv interrupt is implemented, which
must handle soft-masked interrupts that have r13 set to something
other than the PACA -- returning to kernel in this case must restore
r13.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-23-npiggin@gmail.com
This adds IRQ_HARD_DIS to irq_happened. Although it doesn't seem to
matter much because we're not allowed to enable irqs in an NMI
handler, the soft-irq debugging code is becoming more strict about
ensuring IRQ_HARD_DIS is in sync with MSR[EE], this may help avoid
asserts or other issues.
Add a comment explaining why MCE does not have this. Early machine
check is generally much smaller and more contained code which will
explode if you look at it wrong anyway as it runs in real mode, though
there's an argument that we should do similar reconciling for the MCE
as well.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-22-npiggin@gmail.com
Apart from SRESET, MCE, and syscall (hcall variant), the SRR type
interrupts are not escalated to hypervisor mode, so are delivered to
the OS.
When running PR KVM, the OS is the hypervisor, and the guest runs with
MSR[PR]=1 (ie. usermode), so these interrupts must test if a guest was
running when interrupted. These tests are required at the real-mode
entry points because the PR KVM host runs with LPCR[AIL]=0.
In HV KVM and nested HV KVM, the guest always receives these
interrupts, so there is no need for the host to make this test. So
remove the tests if PR KVM is not configured.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-21-npiggin@gmail.com
A few of the non-standard handlers are left uncommented. Some more
description could be added to some.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-20-npiggin@gmail.com
The hdec interrupt handler is reported to sometimes fire in Linux if
KVM leaves it pending after a guest exists. This is harmless, so there
is a no-op handler for it.
The interrupt handler currently uses the regular kernel stack. Change
this to avoid touching the stack entirely.
This should be the last place where the regular Linux stack can be
accessed with asynchronous interrupts (including PMI) soft-masked.
It might be possible to take advantage of this invariant, e.g., to
context switch the kernel stack SLB entry without clearing MSR[EE].
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-17-npiggin@gmail.com
Replace IEARLY=1 and IEARLY=2 with IBRANCH_COMMON, which controls if
the entry code branches to a common handler; and IREALMODE_COMMON,
which controls whether the common handler should remain in real mode.
These special cases no longer avoid loading the SRR registers, there
is no point as most of them load the registers immediately anyway.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-14-npiggin@gmail.com
This allows more code to be moved out of unrelocated regions. The
system call KVMTEST is changed to be open-coded and remain in the
tramp area to avoid having to move it to entry_64.S. The custom nature
of the system call entry code means the hcall case can be made more
streamlined than regular interrupt handlers.
mpe: Incorporate fix from Nick:
Moving KVM test to the common entry code missed the case of HMI and
MCE, which do not do __GEN_COMMON_ENTRY (because they don't want to
switch to virt mode).
This means a MCE or HMI exception that is taken while KVM is running a
guest context will not be switched out of that context, and KVM won't
be notified. Found by running sigfuz in guest with patched host on
POWER9 DD2.3, which causes some TM related HMI interrupts (which are
expected and supposed to be handled by KVM).
This fix adds a __GEN_REALMODE_COMMON_ENTRY for those handlers to add
the KVM test. This makes them look a little more like other handlers
that all use __GEN_COMMON_ENTRY.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-13-npiggin@gmail.com
As well as moving code out of the unrelocated vectors, this allows the
masked handlers to be moved to common code, and allows the soft_nmi
handler to be generated more like a regular handler.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-12-npiggin@gmail.com
The real mode interrupt entry points currently use rfid to branch to
the common handler in virtual mode. This is a significant amount of
code, and forces other code (notably the KVM test) to live in the
real mode handler.
In the interest of minimising the amount of code that runs unrelocated
move the switch to virt mode into the common code, and do it with
mtmsrd, which avoids clobbering SRRs (although the post-KVMTEST
performance of real-mode interrupt handlers is not a big concern these
days).
This requires CTR to always be saved (real-mode needs to reach 0xc...)
but that's not a huge impact these days. It could be optimized away in
future.
mpe: Incorporate fix from Nick:
It's possible for interrupts to be replayed when TM is enabled and
suspended, for example rt_sigreturn, where the mtmsrd MSR_KERNEL in
the real-mode entry point to the common handler causes a TM Bad Thing
exception (due to attempting to clear suspended).
The fix for this is to have replay interrupts go to the _virt entry
point and skip the mtmsrd, which matches what happens before this
patch.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-11-npiggin@gmail.com
Aside from label names and BUG line numbers, the generated code change
is an additional HMI KVM handler added for the "late" KVM handler,
because early and late HMI generation is achieved by defining two
different interrupt types.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-6-npiggin@gmail.com
These don't provide a large amount of code sharing. Removing them
makes code easier to shuffle around. For example, some of the common
instructions will be moved into the common code gen macro.
No generated code change.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-5-npiggin@gmail.com
The code generation macro arguments are difficult to read, and
defaults can't easily be used.
This introduces a block where parameters can be set for interrupt
handler code generation by the subsequent macros, and adds the first
generation macro for interrupt entry.
One interrupt handler is converted to the new macros to demonstrate
the change, the rest will be coverted all at once.
No generated code change.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-2-npiggin@gmail.com
In restore_tm_sigcontexts() we take the trap value directly from the
user sigcontext with no checking:
err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]);
This means we can be in the kernel with an arbitrary regs->trap value.
Although that's not immediately problematic, there is a risk we could
trigger one of the uses of CHECK_FULL_REGS():
#define CHECK_FULL_REGS(regs) BUG_ON(regs->trap & 1)
It can also cause us to unnecessarily save non-volatile GPRs again in
save_nvgprs(), which shouldn't be problematic but is still wrong.
It's also possible it could trick the syscall restart machinery, which
relies on regs->trap not being == 0xc00 (see 9a81c16b52 ("powerpc:
fix double syscall restarts")), though I haven't been able to make
that happen.
Finally it doesn't match the behaviour of the non-TM case, in
restore_sigcontext() which zeroes regs->trap.
So change restore_tm_sigcontexts() to zero regs->trap.
This was discovered while testing Nick's upcoming rewrite of the
syscall entry path. In that series the call to save_nvgprs() prior to
signal handling (do_notify_resume()) is removed, which leaves the
low-bit of regs->trap uncleared which can then trigger the FULL_REGS()
WARNs in setup_tm_sigcontexts().
Fixes: 2b0a576d15 ("powerpc: Add new transactional memory state to the signal context")
Cc: stable@vger.kernel.org # v3.9+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200401023836.3286664-1-mpe@ellerman.id.au
Pull networking updates from David Miller:
"Highlights:
1) Fix the iwlwifi regression, from Johannes Berg.
2) Support BSS coloring and 802.11 encapsulation offloading in
hardware, from John Crispin.
3) Fix some potential Spectre issues in qtnfmac, from Sergey
Matyukevich.
4) Add TTL decrement action to openvswitch, from Matteo Croce.
5) Allow paralleization through flow_action setup by not taking the
RTNL mutex, from Vlad Buslov.
6) A lot of zero-length array to flexible-array conversions, from
Gustavo A. R. Silva.
7) Align XDP statistics names across several drivers for consistency,
from Lorenzo Bianconi.
8) Add various pieces of infrastructure for offloading conntrack, and
make use of it in mlx5 driver, from Paul Blakey.
9) Allow using listening sockets in BPF sockmap, from Jakub Sitnicki.
10) Lots of parallelization improvements during configuration changes
in mlxsw driver, from Ido Schimmel.
11) Add support to devlink for generic packet traps, which report
packets dropped during ACL processing. And use them in mlxsw
driver. From Jiri Pirko.
12) Support bcmgenet on ACPI, from Jeremy Linton.
13) Make BPF compatible with RT, from Thomas Gleixnet, Alexei
Starovoitov, and your's truly.
14) Support XDP meta-data in virtio_net, from Yuya Kusakabe.
15) Fix sysfs permissions when network devices change namespaces, from
Christian Brauner.
16) Add a flags element to ethtool_ops so that drivers can more simply
indicate which coalescing parameters they actually support, and
therefore the generic layer can validate the user's ethtool
request. Use this in all drivers, from Jakub Kicinski.
17) Offload FIFO qdisc in mlxsw, from Petr Machata.
18) Support UDP sockets in sockmap, from Lorenz Bauer.
19) Fix stretch ACK bugs in several TCP congestion control modules,
from Pengcheng Yang.
20) Support virtual functiosn in octeontx2 driver, from Tomasz
Duszynski.
21) Add region operations for devlink and use it in ice driver to dump
NVM contents, from Jacob Keller.
22) Add support for hw offload of MACSEC, from Antoine Tenart.
23) Add support for BPF programs that can be attached to LSM hooks,
from KP Singh.
24) Support for multiple paths, path managers, and counters in MPTCP.
From Peter Krystad, Paolo Abeni, Florian Westphal, Davide Caratti,
and others.
25) More progress on adding the netlink interface to ethtool, from
Michal Kubecek"
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2121 commits)
net: ipv6: rpl_iptunnel: Fix potential memory leak in rpl_do_srh_inline
cxgb4/chcr: nic-tls stats in ethtool
net: dsa: fix oops while probing Marvell DSA switches
net/bpfilter: remove superfluous testing message
net: macb: Fix handling of fixed-link node
net: dsa: ksz: Select KSZ protocol tag
netdevsim: dev: Fix memory leak in nsim_dev_take_snapshot_write
net: stmmac: add EHL 2.5Gbps PCI info and PCI ID
net: stmmac: add EHL PSE0 & PSE1 1Gbps PCI info and PCI ID
net: stmmac: create dwmac-intel.c to contain all Intel platform
net: dsa: bcm_sf2: Support specifying VLAN tag egress rule
net: dsa: bcm_sf2: Add support for matching VLAN TCI
net: dsa: bcm_sf2: Move writing of CFP_DATA(5) into slicing functions
net: dsa: bcm_sf2: Check earlier for FLOW_EXT and FLOW_MAC_EXT
net: dsa: bcm_sf2: Disable learning for ASP port
net: dsa: b53: Deny enslaving port 7 for 7278 into a bridge
net: dsa: b53: Prevent tagged VLAN on port 7 for 7278
net: dsa: b53: Restore VLAN entries upon (re)configuration
net: dsa: bcm_sf2: Fix overflow checks
hv_netvsc: Remove unnecessary round_up for recv_completion_cnt
...
Currently, kernel shows the below values
"persistence_domain":"cpu_cache"
"persistence_domain":"memory_controller"
"persistence_domain":"unknown"
"cpu_cache" indicates no extra instructions is needed to ensure the persistence
of data in the pmem media on power failure.
"memory_controller" indicates cpu cache flush instructions are required to flush
the data. Platform provides mechanisms to automatically flush outstanding
write data from memory controler to pmem on system power loss.
Based on the above use memory_controller for non volatile regions on ppc64.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/20200324034821.60869-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Pass @opaque to kvm_arch_hardware_setup() and
kvm_arch_check_processor_compat() to allow architecture specific code to
reference @opaque without having to stash it away in a temporary global
variable. This will enable x86 to separate its vendor specific callback
ops, which are passed via @opaque, into "init" and "runtime" ops without
having to stash away the "init" ops.
No functional change intended.
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Tested-by: Cornelia Huck <cohuck@redhat.com> #s390
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200321202603.19355-2-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* Add a capability for enabling secure guests under the Protected
Execution Framework ultravisor
* Various bug fixes and cleanups.
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Merge tag 'kvm-ppc-next-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD
KVM PPC update for 5.7
* Add a capability for enabling secure guests under the Protected
Execution Framework ultravisor
* Various bug fixes and cleanups.
- Remove TIF_NOHZ from 3 architectures
These architectures use a static key to decide whether context tracking
needs to be invoked and the TIF_NOHZ flag just causes a pointless
slowpath execution for nothing.
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Merge tag 'timers-nohz-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull NOHZ update from Thomas Gleixner:
"Remove TIF_NOHZ from three architectures
These architectures use a static key to decide whether context
tracking needs to be invoked and the TIF_NOHZ flag just causes a
pointless slowpath execution for nothing"
* tag 'timers-nohz-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
arm64: Remove TIF_NOHZ
arm: Remove TIF_NOHZ
x86: Remove TIF_NOHZ
context-tracking: Introduce CONFIG_HAVE_TIF_NOHZ
x86/entry: Remove _TIF_NOHZ from _TIF_WORK_SYSCALL_ENTRY
- Support for locked CSD objects in smp_call_function_single_async()
which allows to simplify callsites in the scheduler core and MIPS
- Treewide consolidation of CPU hotplug functions which ensures the
consistency between the sysfs interface and kernel state. The low level
functions cpu_up/down() are now confined to the core code and not
longer accessible from random code.
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Merge tag 'smp-core-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core SMP updates from Thomas Gleixner:
"CPU (hotplug) updates:
- Support for locked CSD objects in smp_call_function_single_async()
which allows to simplify callsites in the scheduler core and MIPS
- Treewide consolidation of CPU hotplug functions which ensures the
consistency between the sysfs interface and kernel state. The low
level functions cpu_up/down() are now confined to the core code and
not longer accessible from random code"
* tag 'smp-core-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
cpu/hotplug: Ignore pm_wakeup_pending() for disable_nonboot_cpus()
cpu/hotplug: Hide cpu_up/down()
cpu/hotplug: Move bringup of secondary CPUs out of smp_init()
torture: Replace cpu_up/down() with add/remove_cpu()
firmware: psci: Replace cpu_up/down() with add/remove_cpu()
xen/cpuhotplug: Replace cpu_up/down() with device_online/offline()
parisc: Replace cpu_up/down() with add/remove_cpu()
sparc: Replace cpu_up/down() with add/remove_cpu()
powerpc: Replace cpu_up/down() with add/remove_cpu()
x86/smp: Replace cpu_up/down() with add/remove_cpu()
arm64: hibernate: Use bringup_hibernate_cpu()
cpu/hotplug: Provide bringup_hibernate_cpu()
arm64: Use reboot_cpu instead of hardconding it to 0
arm64: Don't use disable_nonboot_cpus()
ARM: Use reboot_cpu instead of hardcoding it to 0
ARM: Don't use disable_nonboot_cpus()
ia64: Replace cpu_down() with smp_shutdown_nonboot_cpus()
cpu/hotplug: Create a new function to shutdown nonboot cpus
cpu/hotplug: Add new {add,remove}_cpu() functions
sched/core: Remove rq.hrtick_csd_pending
...
Pull perf updates from Ingo Molnar:
"The main changes in this cycle were:
Kernel side changes:
- A couple of x86/cpu cleanups and changes were grandfathered in due
to patch dependencies. These clean up the set of CPU model/family
matching macros with a consistent namespace and C99 initializer
style.
- A bunch of updates to various low level PMU drivers:
* AMD Family 19h L3 uncore PMU
* Intel Tiger Lake uncore support
* misc fixes to LBR TOS sampling
- optprobe fixes
- perf/cgroup: optimize cgroup event sched-in processing
- misc cleanups and fixes
Tooling side changes are to:
- perf {annotate,expr,record,report,stat,test}
- perl scripting
- libapi, libperf and libtraceevent
- vendor events on Intel and S390, ARM cs-etm
- Intel PT updates
- Documentation changes and updates to core facilities
- misc cleanups, fixes and other enhancements"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (89 commits)
cpufreq/intel_pstate: Fix wrong macro conversion
x86/cpu: Cleanup the now unused CPU match macros
hwrng: via_rng: Convert to new X86 CPU match macros
crypto: Convert to new CPU match macros
ASoC: Intel: Convert to new X86 CPU match macros
powercap/intel_rapl: Convert to new X86 CPU match macros
PCI: intel-mid: Convert to new X86 CPU match macros
mmc: sdhci-acpi: Convert to new X86 CPU match macros
intel_idle: Convert to new X86 CPU match macros
extcon: axp288: Convert to new X86 CPU match macros
thermal: Convert to new X86 CPU match macros
hwmon: Convert to new X86 CPU match macros
platform/x86: Convert to new CPU match macros
EDAC: Convert to new X86 CPU match macros
cpufreq: Convert to new X86 CPU match macros
ACPI: Convert to new X86 CPU match macros
x86/platform: Convert to new CPU match macros
x86/kernel: Convert to new CPU match macros
x86/kvm: Convert to new CPU match macros
x86/perf/events: Convert to new CPU match macros
...
Pull locking updates from Ingo Molnar:
"The main changes in this cycle were:
- Continued user-access cleanups in the futex code.
- percpu-rwsem rewrite that uses its own waitqueue and atomic_t
instead of an embedded rwsem. This addresses a couple of
weaknesses, but the primary motivation was complications on the -rt
kernel.
- Introduce raw lock nesting detection on lockdep
(CONFIG_PROVE_RAW_LOCK_NESTING=y), document the raw_lock vs. normal
lock differences. This too originates from -rt.
- Reuse lockdep zapped chain_hlocks entries, to conserve RAM
footprint on distro-ish kernels running into the "BUG:
MAX_LOCKDEP_CHAIN_HLOCKS too low!" depletion of the lockdep
chain-entries pool.
- Misc cleanups, smaller fixes and enhancements - see the changelog
for details"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (55 commits)
fs/buffer: Make BH_Uptodate_Lock bit_spin_lock a regular spinlock_t
thermal/x86_pkg_temp: Make pkg_temp_lock a raw_spinlock_t
Documentation/locking/locktypes: Minor copy editor fixes
Documentation/locking/locktypes: Further clarifications and wordsmithing
m68knommu: Remove mm.h include from uaccess_no.h
x86: get rid of user_atomic_cmpxchg_inatomic()
generic arch_futex_atomic_op_inuser() doesn't need access_ok()
x86: don't reload after cmpxchg in unsafe_atomic_op2() loop
x86: convert arch_futex_atomic_op_inuser() to user_access_begin/user_access_end()
objtool: whitelist __sanitizer_cov_trace_switch()
[parisc, s390, sparc64] no need for access_ok() in futex handling
sh: no need of access_ok() in arch_futex_atomic_op_inuser()
futex: arch_futex_atomic_op_inuser() calling conventions change
completion: Use lockdep_assert_RT_in_threaded_ctx() in complete_all()
lockdep: Add posixtimer context tracing bits
lockdep: Annotate irq_work
lockdep: Add hrtimer context tracing bits
lockdep: Introduce wait-type checks
completion: Use simple wait queues
sched/swait: Prepare usage in completions
...
Move access_ok() in and pagefault_enable()/pagefault_disable() out.
Mechanical conversion only - some instances don't really need
a separate access_ok() at all (e.g. the ones only using
get_user()/put_user(), or architectures where access_ok()
is always true); we'll deal with that in followups.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
As per ISA an isync is only needed on instruction cache block
invalidate. Remove the same from dcache invalidate.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200320103242.229223-1-aneesh.kumar@linux.ibm.com
.globl sets the symbol binding to STB_GLOBAL while .weak sets the
binding to STB_WEAK. GNU as let .weak override .globl since
binutils-gdb 5ca547dc2399a0a5d9f20626d4bf5547c3ccfddd (1996). Clang
integrated assembler let the last win but it may error in the future.
Since it is a convention that only one binding directive is used, just
delete .globl.
Fixes: ee9d21b3b3 ("powerpc/boot: Ensure _zimage_start is a weak symbol")
Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200325164257.170229-1-maskray@google.com
memcpy_mcsafe has been implemented for power machines which is used
by pmem infrastructure, so that an UE encountered during memcpy from
pmem devices would not result in panic instead a right error code
is returned. The implementation expects machine check handler to ignore
the event and set nip to continue the execution from fixup code.
Appropriate changes are already made to powernv machine check handler,
make similar changes to pseries machine check handler to ignore the
the event and set nip to continue execution at the fixup entry if we
hit UE at an instruction with a fixup entry.
while we are at it, have a common function which searches the exception
table entry and updates nip with fixup address, and any future common
changes can be made in this function that are valid for both architectures.
powernv changes are made by
commit 895e3dceeb ("powerpc/mce: Handle UE event for memcpy_mcsafe")
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Santosh S <santosh@fossix.org>
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200326184916.31172-1-ganeshgr@linux.ibm.com
Add a new src_owner field to struct migrate_vma. If the field is set,
only device private pages with page->pgmap->owner equal to that field are
migrated. If the field is not set only "normal" pages are migrated.
Fixes: df6ad69838 ("mm/device-public-memory: device memory cache coherent with CPU")
Link: https://lore.kernel.org/r/20200316193216.920734-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Tested-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Add a new opaque owner field to struct dev_pagemap, which will allow the
hmm and migrate_vma code to identify who owns ZONE_DEVICE memory, and
refuse to work on mappings not owned by the calling entity.
Link: https://lore.kernel.org/r/20200316193216.920734-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Tested-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
We can avoid the #ifdef by using IS_ENABLED() in the existing
condition check.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200313112020.28235-2-mpe@ellerman.id.au
We don't need the NULL check of np, the result is the same because the
OF helpers cope with NULL, of_node_to_nid(NULL) == NUMA_NO_NODE (-1).
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200313112020.28235-1-mpe@ellerman.id.au
The reason debuggers add an ASCII dump to other types of memory dumps
is to give the user visual reference points in the case that ASCII
strings are adjacent to other structures or element. For example,
when examining the task_struct structure one can look for the comm[]
string and use it to locate other important elements.
ASCII strings do not have endianess, they exist in memory in the same
order regardless of CPU endianess. ASCII strings are, by definition,
human readable and so should be presented in a human readable format.
For these reasons, the supplemental ASCII dump does not re-order
the strings from memory to match the endianess of the corresponding
16, 32, or 64 bit words. That would make the ASCII dump much less
useful.
Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1488205694-13337-1-git-send-email-dougmill@linux.vnet.ibm.com
As does XMON, the debugfs file /sys/kernel/debug/powerpc/xive exposes
the XIVE internal state of the machine CPUs and interrupts. Available
on the PowerNV and sPAPR platforms.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
[mpe: Make the debugfs file 0400]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306150143.5551-5-clg@kaod.org
Some firmwares or hypervisors can advertise different source
characteristics. Track their value under XMON. What we are mostly
interested in is the StoreEOI flag.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306150143.5551-4-clg@kaod.org
The PowerNV platform has multiple IRQ chips and the xmon command
dumping the state of the XIVE interrupt should only operate on the
XIVE IRQ chip.
Fixes: 5896163f7f ("powerpc/xmon: Improve output of XIVE interrupts")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306150143.5551-3-clg@kaod.org
When a CPU is brought up, an IPI number is allocated and recorded
under the XIVE CPU structure. Invalid IPI numbers are tracked with
interrupt number 0x0.
On the PowerNV platform, the interrupt number space starts at 0x10 and
this works fine. However, on the sPAPR platform, it is possible to
allocate the interrupt number 0x0 and this raises an issue when CPU 0
is unplugged. The XIVE spapr driver tracks allocated interrupt numbers
in a bitmask and it is not correctly updated when interrupt number 0x0
is freed. It stays allocated and it is then impossible to reallocate.
Fix by using the XIVE_BAD_IRQ value instead of zero on both platforms.
Reported-by: David Gibson <david@gibson.dropbear.id.au>
Fixes: eac1e731b5 ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Tested-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306150143.5551-2-clg@kaod.org
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
[mpe: Drop changes to a/p/boot which doesn't use linux headers]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190812215052.71840-10-ndesaulniers@google.com
At present, on Power systems with Protected Execution Facility
hardware and an ultravisor, a KVM guest can transition to being a
secure guest at will. Userspace (QEMU) has no way of knowing
whether a host system is capable of running secure guests. This
will present a problem in future when the ultravisor is capable of
migrating secure guests from one host to another, because
virtualization management software will have no way to ensure that
secure guests only run in domains where all of the hosts can
support secure guests.
This adds a VM capability which has two functions: (a) userspace
can query it to find out whether the host can support secure guests,
and (b) userspace can enable it for a guest, which allows that
guest to become a secure guest. If userspace does not enable it,
KVM will return an error when the ultravisor does the hypercall
that indicates that the guest is starting to transition to a
secure guest. The ultravisor will then abort the transition and
the guest will terminate.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Ram Pai <linuxram@us.ibm.com>
The core device API performs extra housekeeping bits that are missing
from directly calling cpu_up/down.
See commit a6717c01dd ("powerpc/rtas: use device model APIs and
serialization during LPM") for an example description of what might go
wrong.
This also prepares to make cpu_up/down() a private interface of the CPU
subsystem.
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lkml.kernel.org/r/20200323135110.30522-11-qais.yousef@arm.com
When a program check exception happens while MMU translation is
disabled, following Oops happens in kprobe_handler() in the following
code:
} else if (*addr != BREAKPOINT_INSTRUCTION) {
BUG: Unable to handle kernel data access on read at 0x0000e268
Faulting instruction address: 0xc000ec34
Oops: Kernel access of bad area, sig: 11 [#1]
BE PAGE_SIZE=16K PREEMPT CMPC885
Modules linked in:
CPU: 0 PID: 429 Comm: cat Not tainted 5.6.0-rc1-s3k-dev-00824-g84195dc6c58a #3267
NIP: c000ec34 LR: c000ecd8 CTR: c019cab8
REGS: ca4d3b58 TRAP: 0300 Not tainted (5.6.0-rc1-s3k-dev-00824-g84195dc6c58a)
MSR: 00001032 <ME,IR,DR,RI> CR: 2a4d3c52 XER: 00000000
DAR: 0000e268 DSISR: c0000000
GPR00: c000b09c ca4d3c10 c66d0620 00000000 ca4d3c60 00000000 00009032 00000000
GPR08: 00020000 00000000 c087de44 c000afe0 c66d0ad0 100d3dd6 fffffff3 00000000
GPR16: 00000000 00000041 00000000 ca4d3d70 00000000 00000000 0000416d 00000000
GPR24: 00000004 c53b6128 00000000 0000e268 00000000 c07c0000 c07bb6fc ca4d3c60
NIP [c000ec34] kprobe_handler+0x128/0x290
LR [c000ecd8] kprobe_handler+0x1cc/0x290
Call Trace:
[ca4d3c30] [c000b09c] program_check_exception+0xbc/0x6fc
[ca4d3c50] [c000e43c] ret_from_except_full+0x0/0x4
--- interrupt: 700 at 0xe268
Instruction dump:
913e0008 81220000 38600001 3929ffff 91220000 80010024 bb410008 7c0803a6
38210020 4e800020 38600000 4e800020 <813b0000> 6d2a7fe0 2f8a0008 419e0154
---[ end trace 5b9152d4cdadd06d ]---
kprobe is not prepared to handle events in real mode and functions
running in real mode should have been blacklisted, so kprobe_handler()
can safely bail out telling 'this trap is not mine' for any trap that
happened while in real-mode.
If the trap happened with MSR_IR or MSR_DR cleared, return 0
immediately.
Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
Fixes: 6cc89bad60 ("powerpc/kprobes: Invoke handlers directly")
Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/424331e2006e7291a1bfe40e7f3fa58825f565e1.1582054578.git.christophe.leroy@c-s.fr
When building ppc64 defconfig, Clang errors (trimmed for brevity):
arch/powerpc/platforms/maple/setup.c:365:1: error: attribute declaration
must precede definition [-Werror,-Wignored-attributes]
machine_device_initcall(maple, maple_cpc925_edac_setup);
^
machine_device_initcall expands to __define_machine_initcall, which in
turn has the macro machine_is used in it, which declares mach_##name
with an __attribute__((weak)). define_machine actually defines
mach_##name, which in this file happens before the declaration, hence
the warning.
To fix this, move define_machine after machine_device_initcall so that
the declaration occurs before the definition, which matches how
machine_device_initcall and define_machine work throughout
arch/powerpc.
While we're here, remove some spaces before tabs.
Fixes: 8f101a051e ("edac: cpc925 MC platform device setup")
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Ilie Halip <ilie.halip@gmail.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200323222729.15365-1-natechancellor@gmail.com
With the EEH early probe now being pseries specific there's no need for
eeh_ops->probe() to take a pci_dn. Instead, we can make it take a pci_dev
and use the probe function to map a pci_dev to an eeh_dev. This allows
the platform to implement it's own method for finding (or creating) an
eeh_dev for a given pci_dev which also removes a use of pci_dn in
generic EEH code.
This patch also renames eeh_device_add_late() to eeh_device_probe(). This
better reflects what it does does and removes the last vestiges of the
early/late EEH probe split.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-6-oohall@gmail.com
The eeh_ops->probe() function is called from two different contexts:
1. On pseries, where we set EEH_PROBE_MODE_DEVTREE, it's called in
eeh_add_device_early() which is supposed to run before we create
a pci_dev.
2. On PowerNV, where we set EEH_PROBE_MODE_DEV, it's called in
eeh_device_add_late() which is supposed to run *after* the
pci_dev is created.
The "early" probe is required because PAPR requires that we perform an RTAS
call to enable EEH support on a device before we start interacting with it
via config space or MMIO. This requirement doesn't exist on PowerNV and
shoehorning two completely separate initialisation paths into a common
interface just results in a convoluted code everywhere.
Additionally the early probe requires the probe function to take an pci_dn
rather than a pci_dev argument. We'd like to make pci_dn a pseries specific
data structure since there's no real requirement for them on PowerNV. To
help both goals move the early probe into the pseries containment zone
so the platform depedence is more explicit.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-5-oohall@gmail.com
This check for a missing PHB has existing in various forms since the
initial PPC64 port was upstreamed in 2002. The idea seems to be that we
need to guard against creating pci-specific data structures for the non-pci
children of a PCI device tree node (e.g. USB devices). However, we only
create pci_dn structures for DT nodes that correspond to PCI devices so
there's not much point in doing this check in the eeh_probe path.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-4-oohall@gmail.com
The pci hotplug helper (pci_hp_add_devices()) calls
eeh_add_device_tree_early() to scan the device-tree for new PCI devices and
do the early EEH probe before the device is scanned. This early probe is a
no-op in a lot of cases because:
a) The early init is only required to satisfy a PAPR requirement that EEH
be configured before we start doing config accesses. On PowerNV it is
a no-op.
b) It's a no-op for devices that have already had their eeh_dev
initialised.
There are four callers of pci_hp_add_devices():
1. arch/powerpc/kernel/eeh_driver.c
Here the hotplug helper is called when re-scanning pci_devs that
were removed during an EEH recovery pass. The EEH stat for each
removed device (the eeh_dev) is retained across a recovery pass
so the early init is a no-op in this case.
2. drivers/pci/hotplug/pnv_php.c
This is also a no-op since the PowerNV hotplug driver is, suprisingly,
PowerNV specific.
3. drivers/pci/hotplug/rpaphp_core.c
4. drivers/pci/hotplug/rpaphp_pci.c
In these two cases new devices have been hotplugged and FW has
provided new DT nodes for each. These are the only two cases where
the EEH we might have new PCI device nodes in the DT so these are
the only two cases where the early EEH probe needs to be done.
We can move the calls to eeh_add_device_tree_early() to the locations where
it's needed and remove it from the generic path. This is preparation for
making the early EEH probe pseries specific.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-3-oohall@gmail.com
On pseries and PowerNV pcibios_bus_add_device() calls eeh_add_device_late()
so there's no need to do a separate tree traversal to bind the eeh_dev and
pci_dev together setting up the PHB at boot. As a result we can remove
eeh_add_device_tree_late().
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-2-oohall@gmail.com
Move creating the EEH specific sysfs files into eeh_add_device_late()
rather than being open-coded all over the place. Calling the function is
generally done immediately after calling eeh_add_device_late() anyway. This
is also a correctness fix since currently the sysfs files will be added
even if the EEH probe happens to fail.
Similarly, on pseries we currently add the sysfs files before calling
eeh_add_device_late(). This is flat-out broken since the sysfs files
require the pci_dev->dev.archdata.edev pointer to be set, and that is done
in eeh_add_device_late().
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-1-oohall@gmail.com
The previous commit reduced the amount of code that is run before we
setup a paca. However there are still a few remaining functions that
run with no paca, or worse, with an arbitrary value in r13 that will
be used as a paca pointer.
In particular the stack protector canary is stored in the paca, so if
stack protector is activated for any of these functions we will read
the stack canary from wherever r13 points. If r13 happens to point
outside of memory we will get a machine check / checkstop.
For example if we modify initialise_paca() to trigger stack
protection, and then boot in the mambo simulator with r13 poisoned in
skiboot before calling the kernel:
DEBUG: 19952232: (19952232): INSTRUCTION: PC=0xC0000000191FC1E8: [0x3C4C006D]: addis r2,r12,0x6D [fetch]
DEBUG: 19952236: (19952236): INSTRUCTION: PC=0xC00000001807EAD8: [0x7D8802A6]: mflr r12 [fetch]
FATAL ERROR: 19952276: (19952276): Check Stop for 0:0: Machine Check with ME bit of MSR off
DEBUG: 19952276: (19952276): INSTRUCTION: PC=0xC0000000191FCA7C: [0xE90D0CF8]: ld r8,0xCF8(r13) [Instruction Failed]
INFO: 19952276: (19952277): ** Execution stopped: Mambo Error, Machine Check Stop, **
systemsim % bt
pc: 0xC0000000191FCA7C initialise_paca+0x54
lr: 0xC0000000191FC22C early_setup+0x44
stack:0x00000000198CBED0 0x0 +0x0
stack:0x00000000198CBF00 0xC0000000191FC22C early_setup+0x44
stack:0x00000000198CBF90 0x1801C968 +0x1801C968
So annotate the relevant functions to ensure stack protection is never
enabled for them.
Fixes: 06ec27aea9 ("powerpc/64: add stack protector support")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200320032116.1024773-2-mpe@ellerman.id.au
Currently we set up the paca after parsing the device tree for CPU
features. Prior to that, r13 contains random data, which means there
is random data in r13 while we're running the generic dt parsing code.
This random data varies depending on whether we boot through a vmlinux
or a zImage: for the vmlinux case it's usually around zero, but for
zImages we see random values like 912a72603d420015.
This is poor practice, and can also lead to difficult-to-debug
crashes. For example, when kcov is enabled, the kcov instrumentation
attempts to read preempt_count out of the current task, which goes via
the paca. This then crashes in the zImage case.
Similarly stack protector can cause crashes if r13 is bogus, by
reading from the stack canary in the paca.
To resolve this:
- move the paca setup to before the CPU feature parsing.
- because we no longer have access to CPU feature flags in paca
setup, change the HV feature test in the paca setup path to consider
the actual value of the MSR rather than the CPU feature.
Translations get switched on once we leave early_setup, so I think
we'd already catch any other cases where the paca or task aren't set
up.
Boot tested on a P9 guest and host.
Fixes: fb0b0a73b2 ("powerpc: Enable kcov")
Fixes: 06ec27aea9 ("powerpc/64: add stack protector support")
Cc: stable@vger.kernel.org # v4.20+
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Daniel Axtens <dja@axtens.net>
[mpe: Reword comments & change log a bit to mention stack protector]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200320032116.1024773-1-mpe@ellerman.id.au
H_PAGE_THP_HUGE is used to differentiate between a THP hugepage and
hugetlb hugepage entries. The difference is WRT how we handle hash
fault on these address. THP address enables MPSS in segments. We want
to manage devmap hugepage entries similar to THP pt entries. Hence use
H_PAGE_THP_HUGE for devmap huge PTE entries.
With current code while handling hash PTE fault, we do set is_thp =
true when finding devmap PTE huge PTE entries.
Current code also does the below sequence we setting up huge devmap
entries.
entry = pmd_mkhuge(pfn_t_pmd(pfn, prot));
if (pfn_t_devmap(pfn))
entry = pmd_mkdevmap(entry);
In that case we would find both H_PAGE_THP_HUGE and PAGE_DEVMAP set
for huge devmap PTE entries. This results in false positive error like
below.
kernel BUG at /home/kvaneesh/src/linux/mm/memory.c:4321!
Oops: Exception in kernel mode, sig: 5 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Modules linked in:
CPU: 56 PID: 67996 Comm: t_mmap_dio Not tainted 5.6.0-rc4-59640-g371c804dedbc #128
....
NIP [c00000000044c9e4] __follow_pte_pmd+0x264/0x900
LR [c0000000005d45f8] dax_writeback_one+0x1a8/0x740
Call Trace:
str_spec.74809+0x22ffb4/0x2d116c (unreliable)
dax_writeback_one+0x1a8/0x740
dax_writeback_mapping_range+0x26c/0x700
ext4_dax_writepages+0x150/0x5a0
do_writepages+0x68/0x180
__filemap_fdatawrite_range+0x138/0x180
file_write_and_wait_range+0xa4/0x110
ext4_sync_file+0x370/0x6e0
vfs_fsync_range+0x70/0xf0
sys_msync+0x220/0x2e0
system_call+0x5c/0x68
This is because our pmd_trans_huge check doesn't exclude _PAGE_DEVMAP.
To make this all consistent, update pmd_mkdevmap to set
H_PAGE_THP_HUGE and pmd_trans_huge check now excludes _PAGE_DEVMAP
correctly.
Fixes: ebd3119793 ("powerpc/mm: Add devmap support for ppc64")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200313094842.351830-1-aneesh.kumar@linux.ibm.com
Reorder Linux PTE bits to (almost) match Hash PTE bits.
RW Kernel : PP = 00
RO Kernel : PP = 00
RW User : PP = 01
RO User : PP = 11
So naturally, we should have
_PAGE_USER = 0x001
_PAGE_RW = 0x002
Today 0x001 and 0x002 and _PAGE_PRESENT and _PAGE_HASHPTE which
both are software only bits.
Switch _PAGE_USER and _PAGE_PRESET
Switch _PAGE_RW and _PAGE_HASHPTE
This allows to remove a few insns.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c4d6c18a7f8d9d3b899bc492f55fbc40ef38896a.1583861325.git.christophe.leroy@c-s.fr
At the time being we have something like
if (something) {
p = get();
if (p) {
if (something_wrong)
goto out;
...
return;
} else if (a != b) {
if (some_error)
goto out;
...
}
goto out;
}
p = get();
if (!p) {
if (a != b) {
if (some_error)
goto out;
...
}
goto out;
}
This is similar to
p = get();
if (!p) {
if (a != b) {
if (some_error)
goto out;
...
}
goto out;
}
if (something) {
if (something_wrong)
goto out;
...
return;
}
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Reflow the comment that was moved]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/07a17425743600460ce35fa9432d42487a825583.1582099499.git.christophe.leroy@c-s.fr
We currently have two section mismatch warnings:
The function __boot_from_prom() references
the function __init prom_init().
The function start_here_common() references
the function __init start_kernel().
The warnings are correct, we do have branches from non-init code into
init code, which is freed after boot. But we don't expect to ever
execute any of that early boot code after boot, if we did that would
be a bug. In particular calling into OF after boot would be fatal
because OF is no longer resident.
So for now fix the warnings by marking the relevant functions as
__REF, which puts them in the ".ref.text" section.
This causes some reordering of the functions in the final link:
@@ -217,10 +217,9 @@
c00000000000b088 t generic_secondary_common_init
c00000000000b124 t __mmu_off
c00000000000b14c t __start_initialization_multiplatform
-c00000000000b1ac t __boot_from_prom
-c00000000000b1ec t __after_prom_start
-c00000000000b260 t p_end
-c00000000000b27c T copy_and_flush
+c00000000000b1ac t __after_prom_start
+c00000000000b220 t p_end
+c00000000000b23c T copy_and_flush
c00000000000b300 T __secondary_start
c00000000000b300 t copy_to_here
c00000000000b344 t start_secondary_prolog
@@ -228,8 +227,9 @@
c00000000000b36c t enable_64b_mode
c00000000000b388 T relative_toc
c00000000000b3a8 t p_toc
-c00000000000b3b0 t start_here_common
-c00000000000b3d0 t start_here_multiplatform
+c00000000000b3b0 t __boot_from_prom
+c00000000000b3f0 t start_here_multiplatform
+c00000000000b480 t start_here_common
c00000000000b880 T system_call_common
c00000000000b974 t system_call
c00000000000b9dc t system_call_exit
In particular __boot_from_prom moves after copy_to_here, which means
it's not copied to zero in the first stage of copy of the kernel to
zero.
But that's OK, because we only call __boot_from_prom before we do the
copy, so it makes no difference when it's copied. The call sequence
is:
__start
-> __start_initialization_multiplatform
-> __boot_from_prom
-> __start
-> __start_initialization_multiplatform
-> __after_prom_start
-> copy_and_flush
-> copy_and_flush (relocated to 0)
-> start_here_multiplatform
-> early_setup
Reported-by: Mauricio Faria de Oliveira <mauricfo@linux.ibm.com>
Reported-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225031328.14676-1-mpe@ellerman.id.au
Ganesh Goudar