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Currently the code that dumps SLB entries uses a double-nested if. This
means the actual dumping logic is a bit squashed. Deindent it by using
continue.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Although most of these kprobes patches are powerpc specific, there's a couple
that touch generic code (with Acks). At the moment there's one conflict with
acme's tree, but it's not too bad. Still just in case some other conflicts show
up, we've put these in a topic branch so another tree could merge some or all of
it if necessary.
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KPROBES_ON_FTRACE avoids much of the overhead of regular kprobes as it
eliminates the need for a trap, as well as the need to emulate or single-step
instructions.
Though OPTPROBES provides us with similar performance, we have limited
optprobes trampoline slots. As such, when asked to probe at a function
entry, default to using the ftrace infrastructure.
With:
# cd /sys/kernel/debug/tracing
# echo 'p _do_fork' > kprobe_events
before patch:
# cat ../kprobes/list
c0000000000daf08 k _do_fork+0x8 [DISABLED]
c000000000044fc0 k kretprobe_trampoline+0x0 [OPTIMIZED]
and after patch:
# cat ../kprobes/list
c0000000000d074c k _do_fork+0xc [DISABLED][FTRACE]
c0000000000412b0 k kretprobe_trampoline+0x0 [OPTIMIZED]
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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kprobe_lookup_name() is specific to the kprobe subsystem and may not always
return the function entry point (in a subsequent patch for KPROBES_ON_FTRACE).
For looking up function entry points, introduce a separate helper and use it
in optprobes.c
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Allow kprobes to be placed on ftrace _mcount() call sites. This optimization
avoids the use of a trap, by riding on ftrace infrastructure.
This depends on HAVE_DYNAMIC_FTRACE_WITH_REGS which depends on MPROFILE_KERNEL,
which is only currently enabled on powerpc64le with newer toolchains.
Based on the x86 code by Masami.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Pass the real LR to the ftrace handler. This is needed for KPROBES_ON_FTRACE for
the pre handlers.
Also, with KPROBES_ON_FTRACE, the link register may be updated by the pre
handlers or by a registed kretprobe. Honor updated LR by restoring it from
pt_regs, rather than from the stack save area.
Live patch and function graph continue to work fine with this change.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Blacklist all the exception common/OOL handlers as the kernel stack is not yet
setup, which means we can't take a trap at this point.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Introduce __head_end to mark end of the early fixed sections and use it to
blacklist all exception handlers from kprobes.
mpe: We do not need to do anything special for relocatable kernels, where the
exception vectors are split from the main kernel, as the split vectors are
already excluded by the check for kernel_text_address().
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
[mpe: Move __head_end outside #ifdef 64-bit to unbreak the 32-bit build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Along similar lines as commit 9326638cbee2 ("kprobes, x86: Use NOKPROBE_SYMBOL()
instead of __kprobes annotation"), convert __kprobes annotation to either
NOKPROBE_SYMBOL() or nokprobe_inline. The latter forces inlining, in which case
the caller needs to be added to NOKPROBE_SYMBOL().
Also:
- blacklist arch_deref_entry_point(), and
- convert a few regular inlines to nokprobe_inline in lib/sstep.c
A key benefit is the ability to detect such symbols as being
blacklisted. Before this patch:
$ cat /sys/kernel/debug/kprobes/blacklist | grep read_mem
$ perf probe read_mem
Failed to write event: Invalid argument
Error: Failed to add events.
$ dmesg | tail -1
[ 3736.112815] Could not insert probe at _text+10014968: -22
After patch:
$ cat /sys/kernel/debug/kprobes/blacklist | grep read_mem
0xc000000000072b50-0xc000000000072d20 read_mem
$ perf probe read_mem
read_mem is blacklisted function, skip it.
Added new events:
(null):(null) (on read_mem)
probe:read_mem (on read_mem)
You can now use it in all perf tools, such as:
perf record -e probe:read_mem -aR sleep 1
$ grep " read_mem" /proc/kallsyms
c000000000072b50 t read_mem
c0000000005f3b40 t read_mem
$ cat /sys/kernel/debug/kprobes/list
c0000000005f3b48 k read_mem+0x8 [DISABLED]
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
[mpe: Minor change log formatting, fix up some conflicts]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Move the stack setup and teardown code into ftrace_graph_caller(). This way, we
don't incur the cost of setting it up unless function graph is enabled for this
function.
Also, remove the extraneous LR restore code after the function graph stub. LR
has previously been restored and neither livepatch_handler() nor
ftrace_graph_caller() return back here.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
[mpe: Drop bad change to non-mprofile-kernel version of ftrace_graph_caller]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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set_current_kprobe() already saves regs->msr into kprobe_saved_msr. Remove the
redundant save.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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The idle workaround does not need to load PACATOC, and it does not
need to be called within a nested function that requires LR to be
saved.
Load the PACATOC at entry to the idle wakeup. It does not matter which
PACA this comes from, so it's okay to call before the workaround. Then
apply the workaround to get the right PACA.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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If not all threads were in winkle, full state loss recovery is not
necessary and can be avoided. A previous patch removed this optimisation
due to some complexity with the implementation. Re-implement it by
counting the number of threads in winkle with the per-core idle state.
Only restore full state loss if all threads were in winkle.
This has a small window of false positives right before threads execute
winkle and just after they wake up, when the winkle count does not
reflect the true number of threads in winkle. This is not a significant
problem in comparison with even the minimum winkle duration. For
correctness, a false positive is not a problem (only false negatives
would be).
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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When taking the core idle state lock, grab it immediately like a regular
lock, rather than adding more tests in there. Holding the lock keeps it
stable, so there is no need to do it whole holding the reservation.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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In preparation for adding more bits to the core idle state word, move
the lock bit up, and unlock by flipping the lock bit rather than masking
off all but the thread bits.
Add branch hints for atomic operations while we're here.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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The ISA specifies power save wakeup due to a machine check exception can
cause a machine check interrupt (rather than the usual system reset
interrupt).
The machine check handler copes with this by doing low level machine
check recovery without restoring full state from idle, then queues up a
machine check event for logging, then directly executes the same idle
instruction it woke from. This minimises the work done before recovery
is performed.
The problem is that it requires machine specific instructions and
knowledge of the book3s idle code. Currently it only has code to handle
POWER8 idle, so POWER9 crashes when trying to execute the P8 idle
instructions which don't exist in ISAv3.0B.
cpu 0x0: Vector: e40 (Emulation Assist) at [c0000000008f3810]
pc: c000000000008380: machine_check_handle_early+0x130/0x2f0
lr: c00000000053a098: stop_loop+0x68/0xd0
sp: c0000000008f3a90
msr: 9000000000081001
current = 0xc0000000008a1080
paca = 0xc00000000ffd0000 softe: 0 irq_happened: 0x01
pid = 0, comm = swapper/0
Instead of going to sleep after recovery, do the usual idle wakeup and
state restoration by calling into the normal idle wakeup path. This
reuses the normal idle wakeup paths.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Reviewed-by: Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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This reduces the number of nops for POWER8.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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The POWER8 idle code has a neat trick of programming the power on engine
to restore a low bit into HSPRG0, so idle wakeup code can test and see
if it has been programmed this way and therefore lost all state. Restore
time can be reduced if winkle has not been reached.
However this messes with our r13 PACA pointer, and requires HSPRG0 to be
written to. It also optimizes the slowest and most uncommon case at the
expense of another SPR write in the common nap state wakeup.
Remove this complexity and assume winkle sleeps always require a state
restore. This speedup could be made entirely contained within the winkle
idle code by counting per-core winkles and setting a thread bitmap when
all have gone to winkle.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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No functional change.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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implementation"
This reverts commit 2947ba054a4dabbd82848728d765346886050029.
Dan Williams reported dax-pmem kernel warnings with the following signature:
WARNING: CPU: 8 PID: 245 at lib/percpu-refcount.c:155 percpu_ref_switch_to_atomic_rcu+0x1f5/0x200
percpu ref (dax_pmem_percpu_release [dax_pmem]) <= 0 (0) after switching to atomic
... and bisected it to this commit, which suggests possible memory corruption
caused by the x86 fast-GUP conversion.
He also pointed out:
"
This is similar to the backtrace when we were not properly handling
pud faults and was fixed with this commit: 220ced1676c4 "mm: fix
get_user_pages() vs device-dax pud mappings"
I've found some missing _devmap checks in the generic
get_user_pages_fast() path, but this does not fix the regression
[...]
"
So given that there are known bugs, and a pretty robust looking bisection
points to this commit suggesting that are unknown bugs in the conversion
as well, revert it for the time being - we'll re-try in v4.13.
Reported-by: Dan Williams <dan.j.williams@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: aneesh.kumar@linux.vnet.ibm.com
Cc: dann.frazier@canonical.com
Cc: dave.hansen@intel.com
Cc: steve.capper@linaro.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:
- Documentation updates.
- Miscellaneous fixes.
- Parallelize SRCU callback handling (plus overlapping patches).
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The system reset idle handler system_reset_idle_common is relocated, so
relocation is not required to branch to kvm_start_guest. The superfluous
relocation does not result in incorrect code, but it does not compile
outside of exception-64s.S (with fixed section definitions).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Both conflict were simple overlapping changes.
In the kaweth case, Eric Dumazet's skb_cow() bug fix overlapped the
conversion of the driver in net-next to use in-netdev stats.
Signed-off-by: David S. Miller <davem@davemloft.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"Just two fixes.
The first fixes kprobing a stdu, and is marked for stable as it's been
broken for ~ever. In hindsight this could have gone in next.
The other is a fix for a change we merged this cycle, where if we take
a certain exception when the kernel is running relocated (currently
only used for kdump), we checkstop the box.
Thanks to Ravi Bangoria"
* tag 'powerpc-4.11-8' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/64: Fix HMI exception on LE with CONFIG_RELOCATABLE=y
powerpc/kprobe: Fix oops when kprobed on 'stdu' instruction
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Add powerpc support for mmap_rnd_bits and mmap_rnd_compat_bits, which are two
sysctls that allow a user to configure the number of bits of randomness used for
ASLR.
Because of the way the Kconfig for ARCH_MMAP_RND_BITS is defined, we have to
construct at least the MIN value in Kconfig, vs in a header which would be more
natural. Given that we just go ahead and do it all in Kconfig.
At least according to the code (the documentation makes no mention of it), the
value is defined as the number of bits of randomisation *of the page*, not the
address. This makes some sense, with larger page sizes more of the low bits are
forced to zero, which would reduce the randomisation if we didn't take the
PAGE_SIZE into account. However it does mean the min/max values have to change
depending on the PAGE_SIZE in order to actually limit the amount of address
space consumed by the randomisation.
The result of that is that we have to define the default values based on both
32-bit vs 64-bit, but also the configured PAGE_SIZE. Furthermore now that we
have 128TB address space support on Book3S, we also have to take that into
account.
Finally we can wire up the value in arch_mmap_rnd().
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
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In crct10dif_vpmsum() we call enable_kernel_altivec() without first
disabling preemption, which is not allowed.
It used to be sufficient just to call pagefault_disable(), because that
also disabled preemption. But the two were decoupled in commit 8222dbe21e79
("sched/preempt, mm/fault: Decouple preemption from the page fault
logic") in mid 2015.
The crct10dif-vpmsum code inherited this bug from the crc32c-vpmsum code
on which it was modelled.
So add the missing preempt_disable/enable(). We should also call
disable_kernel_fp(), although it does nothing by default, there is a
debug switch to make it active and all enables should be paired with
disables.
Fixes: b01df1c16c9a ("crypto: powerpc - Add CRC-T10DIF acceleration")
Acked-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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The default implementation of ioremap_cache() is aliased to ioremap().
On powerpc ioremap() creates cache-inhibited mappings by default which
is almost certainly not what you wanted.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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In all cases we know which BAR it is. Passing it in means that arch code
(or generic code; watch this space) won't have to go looking for it again.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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On kprobe handler re-entry, try to emulate the instruction rather than single
stepping always.
Acked-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Factor out code to emulate instruction into a try_to_emulate()
helper function. This makes no functional changes.
Acked-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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With ABIv2, we offset 8 bytes into a function to get at the local entry
point.
mpe: NB this function is currently not called, the change to generic code to
call it is being merged via the tip tree.
Acked-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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commit 239aeba76409 ("perf powerpc: Fix kprobe and kretprobe handling with
kallsyms on ppc64le") changed how we use the offset field in struct kprobe on
ABIv2. perf now offsets from the global entry point if an offset is specified
and otherwise chooses the local entry point.
Fix the same in kernel for kprobe API users. We do this by extending
kprobe_lookup_name() to accept an additional parameter to indicate the offset
specified with the kprobe registration. If offset is 0, we return the local
function entry and return the global entry point otherwise.
With:
# cd /sys/kernel/debug/tracing/
# echo "p _do_fork" >> kprobe_events
# echo "p _do_fork+0x10" >> kprobe_events
before this patch:
# cat ../kprobes/list
c0000000000d0748 k _do_fork+0x8 [DISABLED]
c0000000000d0758 k _do_fork+0x18 [DISABLED]
c0000000000412b0 k kretprobe_trampoline+0x0 [OPTIMIZED]
and after:
# cat ../kprobes/list
c0000000000d04c8 k _do_fork+0x8 [DISABLED]
c0000000000d04d0 k _do_fork+0x10 [DISABLED]
c0000000000412b0 k kretprobe_trampoline+0x0 [OPTIMIZED]
Acked-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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The macro is now pretty long and ugly on powerpc. In the light of further
changes needed here, convert it to a __weak variant to be over-ridden with a
nicer looking function.
Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Hypervisor Virtualization and Directed Hypervisor Doorbell interrupt handlers
use the macro EXC_VIRT_OOL_MASKABLE_HV for their relocation-on handlers, which
calls MASKABLE_RELON_EXCEPTION_HV_OOL, which uses the *real mode* interrupt
prolog. This means we needlessly rfid from virtual mode to virtual mode.
For POWER8 it only affects doorbell IPIs. Context switch microbenchmark between
threads with snooze disabled (which causes IPI) gets about 3% faster, about 370
cycles. Should be more important on POWER9 with global doorbells and HVI for
host interrupts.
Use the RELON variant instead to reduce overhead.
Fixes: 1707dd1613 ("powerpc: Save CFAR before branching in interrupt entry paths")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fold some more detail into the change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Dan Carpenter noticed that the code in __xive_native_disable_queue() has a for
loop with an unconditional break in the middle, which doesn't make a lot of
sense.
What the code's supposed to do is loop as long as OPAL says it's busy, if we get
any other return code, either success or failure, then we should break the loop.
So add the missing check.
Fixes: 243e25112d06 ("powerpc/xive: Native exploitation of the XIVE interrupt controller")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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According to the PowerISA 2.07, mtspr and mfspr should not always
generate an illegal instruction exception when being used with an
undefined SPR, but rather treat the instruction as a NOP or inject a
privilege exception in some cases, too - depending on the SPR number.
Also turn the printk here into a ratelimited print statement, so that
the guest can not flood the dmesg log of the host by issueing lots of
illegal mtspr/mfspr instruction here.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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This allows the host kernel to handle H_PUT_TCE, H_PUT_TCE_INDIRECT
and H_STUFF_TCE requests targeted an IOMMU TCE table used for VFIO
without passing them to user space which saves time on switching
to user space and back.
This adds H_PUT_TCE/H_PUT_TCE_INDIRECT/H_STUFF_TCE handlers to KVM.
KVM tries to handle a TCE request in the real mode, if failed
it passes the request to the virtual mode to complete the operation.
If it a virtual mode handler fails, the request is passed to
the user space; this is not expected to happen though.
To avoid dealing with page use counters (which is tricky in real mode),
this only accelerates SPAPR TCE IOMMU v2 clients which are required
to pre-register the userspace memory. The very first TCE request will
be handled in the VFIO SPAPR TCE driver anyway as the userspace view
of the TCE table (iommu_table::it_userspace) is not allocated till
the very first mapping happens and we cannot call vmalloc in real mode.
If we fail to update a hardware IOMMU table unexpected reason, we just
clear it and move on as there is nothing really we can do about it -
for example, if we hot plug a VFIO device to a guest, existing TCE tables
will be mirrored automatically to the hardware and there is no interface
to report to the guest about possible failures.
This adds new attribute - KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE - to
the VFIO KVM device. It takes a VFIO group fd and SPAPR TCE table fd
and associates a physical IOMMU table with the SPAPR TCE table (which
is a guest view of the hardware IOMMU table). The iommu_table object
is cached and referenced so we do not have to look up for it in real mode.
This does not implement the UNSET counterpart as there is no use for it -
once the acceleration is enabled, the existing userspace won't
disable it unless a VFIO container is destroyed; this adds necessary
cleanup to the KVM_DEV_VFIO_GROUP_DEL handler.
This advertises the new KVM_CAP_SPAPR_TCE_VFIO capability to the user
space.
This adds real mode version of WARN_ON_ONCE() as the generic version
causes problems with rcu_sched. Since we testing what vmalloc_to_phys()
returns in the code, this also adds a check for already existing
vmalloc_to_phys() call in kvmppc_rm_h_put_tce_indirect().
This finally makes use of vfio_external_user_iommu_id() which was
introduced quite some time ago and was considered for removal.
Tests show that this patch increases transmission speed from 220MB/s
to 750..1020MB/s on 10Gb network (Chelsea CXGB3 10Gb ethernet card).
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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This reworks helpers for checking TCE update parameters in way they
can be used in KVM.
This should cause no behavioral change.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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VFIO on sPAPR already implements guest memory pre-registration
when the entire guest RAM gets pinned. This can be used to translate
the physical address of a guest page containing the TCE list
from H_PUT_TCE_INDIRECT.
This makes use of the pre-registrered memory API to access TCE list
pages in order to avoid unnecessary locking on the KVM memory
reverse map as we know that all of guest memory is pinned and
we have a flat array mapping GPA to HPA which makes it simpler and
quicker to index into that array (even with looking up the
kernel page tables in vmalloc_to_phys) than it is to find the memslot,
lock the rmap entry, look up the user page tables, and unlock the rmap
entry. Note that the rmap pointer is initialized to NULL
where declared (not in this patch).
If a requested chunk of memory has not been preregistered, this will
fall back to non-preregistered case and lock rmap.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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The guest view TCE tables are per KVM anyway (not per VCPU) so pass kvm*
there. This will be used in the following patches where we will be
attaching VFIO containers to LIOBNs via ioctl() to KVM (rather than
to VCPU).
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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It does not make much sense to have KVM in book3s-64 and
not to have IOMMU bits for PCI pass through support as it costs little
and allows VFIO to function on book3s KVM.
Having IOMMU_API always enabled makes it unnecessary to have a lot of
"#ifdef IOMMU_API" in arch/powerpc/kvm/book3s_64_vio*. With those
ifdef's we could have only user space emulated devices accelerated
(but not VFIO) which do not seem to be very useful.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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This merges in the commits in the topic/ppc-kvm branch of the powerpc
tree to get the changes to arch/powerpc which subsequent patches will
rely on.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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At the moment the userspace can request a table smaller than a page size
and this value will be stored as kvmppc_spapr_tce_table::size.
However the actual allocated size will still be aligned to the system
page size as alloc_page() is used there.
This aligns the table size up to the system page size. It should not
change the existing behaviour but when in-kernel TCE acceleration patchset
reaches the upstream kernel, this will allow small TCE tables be
accelerated as well: PCI IODA iommu_table allocator already aligns
the size and, without this patch, an IOMMU group won't attach to LIOBN
due to the mismatching table size.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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PR KVM page fault handler performs eaddr to pte translation for a guest,
however kvmppc_mmu_book3s_64_xlate() does not preserve WIMG bits
(storage control) in the kvmppc_pte struct. If PR KVM is running as
a second level guest under HV KVM, and PR KVM tries inserting HPT entry,
this fails in HV KVM if it already has this mapping.
This preserves WIMG bits between kvmppc_mmu_book3s_64_xlate() and
kvmppc_mmu_map_page().
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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At the moment kvmppc_mmu_map_page() returns -1 if
mmu_hash_ops.hpte_insert() fails for any reason so the page fault handler
resumes the guest and it faults on the same address again.
This adds distinction to kvmppc_mmu_map_page() to return -EIO if
mmu_hash_ops.hpte_insert() failed for a reason other than full pteg.
At the moment only pSeries_lpar_hpte_insert() returns -2 if
plpar_pte_enter() failed with a code other than H_PTEG_FULL.
Other mmu_hash_ops.hpte_insert() instances can only fail with
-1 "full pteg".
With this change, if PR KVM fails to update HPT, it can signal
the userspace about this instead of returning to guest and having
the very same page fault over and over again.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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@is_mmio has never been used since introduction in
commit 2f4cf5e42d13 ("Add book3s.c") from 2009.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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* A multiplication for the size determination of a memory allocation
indicated that an array data structure should be processed.
Thus use the corresponding function "kcalloc".
This issue was detected by using the Coccinelle software.
* Replace the specification of a data type by a pointer dereference
to make the corresponding size determination a bit safer according to
the Linux coding style convention.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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Add a jump target so that a bit of exception handling can be better reused
at the end of this function.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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For completeness, this adds emulation of the lfiwax and lfiwzx
instructions. With this, all floating-point load and store instructions
as of Power ISA V2.07 are emulated.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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This adds emulation for the following integer loads and stores,
thus enabling them to be used in a guest for accessing emulated
MMIO locations.
- lhaux
- lwaux
- lwzux
- ldu
- lwa
- stdux
- stwux
- stdu
- ldbrx
- stdbrx
Previously, most of these would cause an emulation failure exit to
userspace, though ldu and lwa got treated incorrectly as ld, and
stdu got treated incorrectly as std.
This also tidies up some of the formatting and updates the comment
listing instructions that still need to be implemented.
With this, all integer loads and stores that are defined in the Power
ISA v2.07 are emulated, except for those that are permitted to trap
when used on cache-inhibited or write-through mappings (and which do
in fact trap on POWER8), that is, lmw/stmw, lswi/stswi, lswx/stswx,
lq/stq, and l[bhwdq]arx/st[bhwdq]cx.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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