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2017-04-25powerpc/xmon: Deindent the SLB dumping logicMichael Ellerman
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>
2017-04-25Merge branch 'topic/kprobes' into nextMichael Ellerman
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.
2017-04-24powerpc/kprobes: Prefer ftrace when probing function entryNaveen N. Rao
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>
2017-04-24powerpc: Introduce a new helper to obtain function entry pointsNaveen N. Rao
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>
2017-04-24powerpc/kprobes: Add support for KPROBES_ON_FTRACENaveen N. Rao
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>
2017-04-24powerpc/ftrace: Restore LR from pt_regsNaveen N. Rao
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>
2017-04-23powerpc/kprobes: Blacklist common exception handlersNaveen N. Rao
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>
2017-04-23powerpc/kprobes: Blacklist exception handlersNaveen N. Rao
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>
2017-04-23powerpc/kprobes: Convert __kprobes to NOKPROBE_SYMBOL()Naveen N. Rao
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>
2017-04-23powerpc/ftrace: Move stack setup and teardown code into ftrace_graph_caller()Naveen N. Rao
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>
2017-04-23powerpc/kprobes: Remove duplicate saving of MSRNaveen N. Rao
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>
2017-04-23powerpc/64s: Simplify POWER9 DD1 idle workaround codeNicholas Piggin
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>
2017-04-23powerpc/64s: Idle POWER8 avoid full state loss recovery where possibleNicholas Piggin
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>
2017-04-23powerpc/64s: Idle do not hold reservation longer than requiredNicholas Piggin
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>
2017-04-23powerpc/64s: Expand core idle state bitsNicholas Piggin
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>
2017-04-23powerpc/64s: Fix POWER9 machine check handler from stop stateNicholas Piggin
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>
2017-04-23powerpc/64s: Use alternative feature patchingNicholas Piggin
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>
2017-04-23powerpc/64s: Stop using bit in HSPRG0 to test winkleNicholas Piggin
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>
2017-04-23powerpc/64s: Move remaining system reset idle code into idle_book3s.SNicholas Piggin
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>
2017-04-23Revert "x86/mm/gup: Switch GUP to the generic get_user_page_fast() ↵Ingo Molnar
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>
2017-04-23Merge branch 'for-mingo' of ↵Ingo Molnar
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>
2017-04-23powerpc/64s: Remove unnecessary relocation branch from idle handlerNicholas Piggin
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>
2017-04-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
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>
2017-04-21Merge tag 'powerpc-4.11-8' of ↵Linus Torvalds
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
2017-04-21powerpc/mm: Add support for runtime configuration of ASLR limitsMichael Ellerman
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>
2017-04-21crypto: crct10dif-vpmsum - Fix missing preempt_disable()Michael Ellerman
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>
2017-04-21powerpc/mm: Wire up ioremap_cache()Oliver O'Halloran
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>
2017-04-20PCI: Add BAR index argument to pci_mmap_page_range()David Woodhouse
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>
2017-04-20powerpc/kprobes: Emulate instructions on kprobe handler re-entryNaveen N. Rao
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>
2017-04-20powerpc/kprobes: Factor out code to emulate instruction into a helperNaveen N. Rao
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>
2017-04-20powerpc/kretprobes: Override default function entry offsetNaveen N. Rao
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>
2017-04-20powerpc/kprobes: Fix handling of function offsets on ABIv2Naveen N. Rao
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>
2017-04-20kprobes: Convert kprobe_lookup_name() to a functionNaveen N. Rao
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>
2017-04-20powerpc/64s: Use relon prolog for EXC_VIRT_OOL_MASKABLE_HV handlersNicholas Piggin
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>
2017-04-20powerpc/xive: Fix missing check of rc != OPAL_BUSYMichael Ellerman
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>
2017-04-20KVM: PPC: Book3S PR: Do not fail emulation with mtspr/mfspr for unknown SPRsThomas Huth
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>
2017-04-20KVM: PPC: VFIO: Add in-kernel acceleration for VFIOAlexey Kardashevskiy
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>
2017-04-20KVM: PPC: iommu: Unify TCE checkingAlexey Kardashevskiy
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>
2017-04-20KVM: PPC: Use preregistered memory API to access TCE listAlexey Kardashevskiy
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>
2017-04-20KVM: PPC: Pass kvm* to kvmppc_find_table()Alexey Kardashevskiy
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>
2017-04-20KVM: PPC: Enable IOMMU_API for KVM_BOOK3S_64 permanentlyAlexey Kardashevskiy
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>
2017-04-20Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-nextPaul Mackerras
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>
2017-04-20KVM: PPC: Align the table size to system page sizeAlexey Kardashevskiy
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>
2017-04-20KVM: PPC: Book3S PR: Preserve storage control bitsAlexey Kardashevskiy
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>
2017-04-20KVM: PPC: Book3S PR: Exit KVM on failed mappingAlexey Kardashevskiy
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>
2017-04-20KVM: PPC: Book3S PR: Get rid of unused local variableAlexey Kardashevskiy
@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>
2017-04-20KVM: PPC: e500: Use kcalloc() in e500_mmu_host_init()Markus Elfring
* 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>
2017-04-20KVM: PPC: Book3S HV: Use common error handling code in kvmppc_clr_passthru_irq()Markus Elfring
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>
2017-04-20KVM: PPC: Add MMIO emulation for remaining floating-point instructionsPaul Mackerras
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>
2017-04-20KVM: PPC: Emulation for more integer loads and storesPaul Mackerras
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>