Pull powerpc fixes from Michael Ellerman:
"Some more powerpc fixes for 4.16. Apologies if this is a bit big at
rc7, but they're all reasonably important fixes. None are actually for
new code, so they aren't indicative of 4.16 being in bad shape from
our point of view.
- Fix missing AT_BASE_PLATFORM (in auxv) when we're using a new
firmware interface for describing CPU features.
- Fix lost pending interrupts due to a race in our interrupt
soft-masking code.
- A workaround for a nest MMU bug with TLB invalidations on Power9.
- A workaround for broadcast TLB invalidations on Power9.
- Fix a bug in our instruction SLB miss handler, when handling bad
addresses (eg. >= TASK_SIZE), which could corrupt non-volatile user
GPRs.
Thanks to: Aneesh Kumar K.V, Balbir Singh, Benjamin Herrenschmidt,
Nicholas Piggin"
* tag 'powerpc-4.16-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/64s: Fix i-side SLB miss bad address handler saving nonvolatile GPRs
powerpc/mm: Fixup tlbie vs store ordering issue on POWER9
powerpc/mm/radix: Move the functions that does the actual tlbie closer
powerpc/mm/radix: Remove unused code
powerpc/mm: Workaround Nest MMU bug with TLB invalidations
powerpc/mm: Add tracking of the number of coprocessors using a context
powerpc/64s: Fix lost pending interrupt due to race causing lost update to irq_happened
powerpc/64s: Fix NULL AT_BASE_PLATFORM when using DT CPU features
Merge our fixes branch from the 4.16 cycle.
There were a number of important fixes merged, in particular some Power9
workarounds that we want in next for testing purposes. There's also been
some conflicting changes in the CPU features code which are best merged
and tested before going upstream.
This changes the hypervisor page fault handler for radix guests to use
the generic KVM __gfn_to_pfn_memslot() function instead of using
get_user_pages_fast() and then handling the case of VM_PFNMAP vmas
specially. The old code missed the case of VM_IO vmas; with this
change, VM_IO vmas will now be handled correctly by code within
__gfn_to_pfn_memslot.
Currently, __gfn_to_pfn_memslot calls hva_to_pfn, which only uses
__get_user_pages_fast for the initial lookup in the cases where
either atomic or async is set. Since we are not setting either
atomic or async, we do our own __get_user_pages_fast first, for now.
This also adds code to check for the KVM_MEM_READONLY flag on the
memslot. If it is set and this is a write access, we synthesize a
data storage interrupt for the guest.
In the case where the page is not normal RAM (i.e. page == NULL in
kvmppc_book3s_radix_page_fault(), we read the PTE from the Linux page
tables because we need the mapping attribute bits as well as the PFN.
(The mapping attribute bits indicate whether accesses have to be
non-cacheable and/or guarded.)
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
POWER9 with the DAWR disabled causes problems for partition
migration. Either we have to fail the migration (since we lose the
DAWR) or we silently drop the DAWR and allow the migration to pass.
This patch does the latter and allows the migration to pass (at the
cost of silently losing the DAWR). This is not ideal but hopefully the
best overall solution. This approach has been acked by Paulus.
With this patch kvmppc_set_one_reg() will store the DAWR in the vcpu
but won't actually set it on POWER9 hardware.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER7 compat mode guests can use h_set_dabr on POWER9. POWER9 should
use the DAWR but since it's disabled there we can't.
This returns H_UNSUPPORTED on a h_set_dabr() on POWER9 where the DAWR
is disabled.
Current Linux guests ignore this error, so they will silently not get
the DAWR (sigh). The same error code is being used by POWERVM in this
case.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Return H_P2 on a h_set_mode(SET_DAWR) on POWER9 where the DAWR is
disabled.
Current Linux guests ignore this error, so they will silently not get
the DAWR (sigh). The same error code is being used by POWERVM in this
case.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This works around a hardware bug in "Nimbus" POWER9 DD2.2 processors,
where the contents of the TEXASR can get corrupted while a thread is
in fake suspend state. The workaround is for the instruction emulation
code to use the value saved at the most recent guest exit in real
suspend mode. We achieve this by simply not saving the TEXASR into
the vcpu struct on an exit in fake suspend state. We also have to
take care to set the orig_texasr field only on guest exit in real
suspend state.
This also means that on guest entry in fake suspend state, TEXASR
will be restored to the value it had on the last exit in real suspend
state, effectively counteracting any hardware-caused corruption. This
works because TEXASR may not be written in suspend state.
With this, the guest might see the wrong values in TEXASR if it reads
it while in suspend state, but will see the correct value in
non-transactional state (e.g. after a treclaim), and treclaim will
work correctly.
With this workaround, the code will actually run slightly faster, and
will operate correctly on systems without the TEXASR bug (since TEXASR
may not be written in suspend state, and is only changed by failure
recording, which will have already been done before we get into fake
suspend state). Therefore these changes are not made subject to a CPU
feature bit.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This works around a hardware bug in "Nimbus" POWER9 DD2.2 processors,
where a treclaim performed in fake suspend mode can cause subsequent
reads from the XER register to return inconsistent values for the SO
(summary overflow) bit. The inconsistent SO bit state can potentially
be observed on any thread in the core. We have to do the treclaim
because that is the only way to get the thread out of suspend state
(fake or real) and into non-transactional state.
The workaround for the bug is to force the core into SMT4 mode before
doing the treclaim. This patch adds the code to do that, conditional
on the CPU_FTR_P9_TM_XER_SO_BUG feature bit.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER9 has hardware bugs relating to transactional memory and thread
reconfiguration (changes to hardware SMT mode). Specifically, the core
does not have enough storage to store a complete checkpoint of all the
architected state for all four threads. The DD2.2 version of POWER9
includes hardware modifications designed to allow hypervisor software
to implement workarounds for these problems. This patch implements
those workarounds in KVM code so that KVM guests see a full, working
transactional memory implementation.
The problems center around the use of TM suspended state, where the
CPU has a checkpointed state but execution is not transactional. The
workaround is to implement a "fake suspend" state, which looks to the
guest like suspended state but the CPU does not store a checkpoint.
In this state, any instruction that would cause a transition to
transactional state (rfid, rfebb, mtmsrd, tresume) or would use the
checkpointed state (treclaim) causes a "soft patch" interrupt (vector
0x1500) to the hypervisor so that it can be emulated. The trechkpt
instruction also causes a soft patch interrupt.
On POWER9 DD2.2, we avoid returning to the guest in any state which
would require a checkpoint to be present. The trechkpt in the guest
entry path which would normally create that checkpoint is replaced by
either a transition to fake suspend state, if the guest is in suspend
state, or a rollback to the pre-transactional state if the guest is in
transactional state. Fake suspend state is indicated by a flag in the
PACA plus a new bit in the PSSCR. The new PSSCR bit is write-only and
reads back as 0.
On exit from the guest, if the guest is in fake suspend state, we still
do the treclaim instruction as we would in real suspend state, in order
to get into non-transactional state, but we do not save the resulting
register state since there was no checkpoint.
Emulation of the instructions that cause a softpatch interrupt is
handled in two paths. If the guest is in real suspend mode, we call
kvmhv_p9_tm_emulation_early() to handle the cases where the guest is
transitioning to transactional state. This is called before we do the
treclaim in the guest exit path; because we haven't done treclaim, we
can get back to the guest with the transaction still active. If the
instruction is a case that kvmhv_p9_tm_emulation_early() doesn't
handle, or if the guest is in fake suspend state, then we proceed to
do the complete guest exit path and subsequently call
kvmhv_p9_tm_emulation() in host context with the MMU on. This handles
all the cases including the cases that generate program interrupts
(illegal instruction or TM Bad Thing) and facility unavailable
interrupts.
The emulation is reasonably straightforward and is mostly concerned
with checking for exception conditions and updating the state of
registers such as MSR and CR0. The treclaim emulation takes care to
ensure that the TEXASR register gets updated as if it were the guest
treclaim instruction that had done failure recording, not the treclaim
done in hypervisor state in the guest exit path.
With this, the KVM_CAP_PPC_HTM capability returns true (1) even if
transactional memory is not available to host userspace.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On POWER9, under some circumstances, a broadcast TLB invalidation
might complete before all previous stores have drained, potentially
allowing stale stores from becoming visible after the invalidation.
This works around it by doubling up those TLB invalidations which was
verified by HW to be sufficient to close the risk window.
This will be documented in a yet-to-be-published errata.
Fixes: 1a472c9dba ("powerpc/mm/radix: Add tlbflush routines")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Enable the feature in the DT CPU features code for all Power9,
rename the feature to CPU_FTR_P9_TLBIE_BUG per benh.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Since commit 6964e6a4e4 ("KVM: PPC: Book3S HV: Do SLB load/unload
with guest LPCR value loaded", 2018-01-11), we have been seeing
occasional machine check interrupts on POWER8 systems when running
KVM guests, due to SLB multihit errors.
This turns out to be due to the guest exit code reloading the host
SLB entries from the SLB shadow buffer when the SLB was not previously
cleared in the guest entry path. This can happen because the path
which skips from the guest entry code to the guest exit code without
entering the guest now does the skip before the SLB is cleared and
loaded with guest values, but the host values are loaded after the
point in the guest exit path that we skip to.
To fix this, we move the code that reloads the host SLB values up
so that it occurs just before the point in the guest exit code (the
label guest_bypass:) where we skip to from the guest entry path.
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Fixes: 6964e6a4e4 ("KVM: PPC: Book3S HV: Do SLB load/unload with guest LPCR value loaded")
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This adds code to the radix hypervisor page fault handler to handle the
case where the guest memory is backed by 1GB hugepages, and put them
into the partition-scoped radix tree at the PUD level. The code is
essentially analogous to the code for 2MB pages. This also rearranges
kvmppc_create_pte() to make it easier to follow.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
When using the radix MMU, we can get hypervisor page fault interrupts
with the DSISR_SET_RC bit set in DSISR/HSRR1, indicating that an
attempt to set the R (reference) or C (change) bit in a PTE atomically
failed. Previously we would find the corresponding Linux PTE and
check the permission and dirty bits there, but this is not really
necessary since we only need to do what the hardware was trying to
do, namely set R or C atomically. This removes the code that reads
the Linux PTE and just update the partition-scoped PTE, having first
checked that it is still present, and if the access is a write, that
the PTE still has write permission.
Furthermore, we now check whether any other relevant bits are set
in DSISR, and if there are, then we proceed with the rest of the
function in order to handle whatever condition they represent,
instead of returning to the guest as we did previously.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This improves the handling of transparent huge pages in the radix
hypervisor page fault handler. Previously, if a small page is faulted
in to a 2MB region of guest physical space, that means that there is
a page table pointer at the PMD level, which could never be replaced
by a leaf (2MB) PMD entry. This adds the code to clear the PMD,
invlidate the page walk cache and free the page table page in this
situation, so that the leaf PMD entry can be created.
This also adds code to check whether a PMD or PTE being inserted is
the same as is already there (because of a race with another CPU that
faulted on the same page) and if so, we don't replace the existing
entry, meaning that we don't invalidate the PTE or PMD and do a TLB
invalidation.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Since commit fb1522e099 ("KVM: update to new mmu_notifier semantic
v2", 2017-08-31), the MMU notifier code in KVM no longer calls the
kvm_unmap_hva callback. This removes the PPC implementations of
kvm_unmap_hva().
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This fixes a bug where the trap number that is returned by
__kvmppc_vcore_entry gets corrupted. The effect of the corruption
is that IPIs get ignored on POWER9 systems when the IPI is sent via
a doorbell interrupt to a CPU which is executing in a KVM guest.
The effect of the IPI being ignored is often that another CPU locks
up inside smp_call_function_many() (and if that CPU is holding a
spinlock, other CPUs then lock up inside raw_spin_lock()).
The trap number is currently held in register r12 for most of the
assembly-language part of the guest exit path. In that path, we
call kvmppc_subcore_exit_guest(), which is a C function, without
restoring r12 afterwards. Depending on the kernel config and the
compiler, it may modify r12 or it may not, so some config/compiler
combinations see the bug and others don't.
To fix this, we arrange for the trap number to be stored on the
stack from the 'guest_bypass:' label until the end of the function,
then the trap number is loaded and returned in r12 as before.
Cc: stable@vger.kernel.org # v4.8+
Fixes: fd7bacbca4 ("KVM: PPC: Book3S HV: Fix TB corruption in guest exit path on HMI interrupt")
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Fixes for PPC KVM:
- Fix guest time accounting in the host
- Fix large-page backing for radix guests on POWER9
- Fix HPT guests on POWER9 backed by 2M or 1G pages
- Compile fixes for some configs and gcc versions
Since commit 8b24e69fc4 ("KVM: PPC: Book3S HV: Close race with testing
for signals on guest entry"), if CONFIG_VIRT_CPU_ACCOUNTING_GEN is set, the
guest time is not accounted to guest time and user time, but instead to
system time.
This is because guest_enter()/guest_exit() are called while interrupts
are disabled and the tick counter cannot be updated between them.
To fix that, move guest_exit() after local_irq_enable(), and as
guest_enter() is called with IRQ disabled, call guest_enter_irqoff()
instead.
Fixes: 8b24e69fc4 ("KVM: PPC: Book3S HV: Close race with testing for signals on guest entry")
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The current code for initializing the VRMA (virtual real memory area)
for HPT guests requires the page size of the backing memory to be one
of 4kB, 64kB or 16MB. With a radix host we have the possibility that
the backing memory page size can be 2MB or 1GB. In these cases, if the
guest switches to HPT mode, KVM will not initialize the VRMA and the
guest will fail to run.
In fact it is not necessary that the VRMA page size is the same as the
backing memory page size; any VRMA page size less than or equal to the
backing memory page size is acceptable. Therefore we now choose the
largest page size out of the set {4k, 64k, 16M} which is not larger
than the backing memory page size.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This fixes several bugs in the radix page fault handler relating to
the way large pages in the memory backing the guest were handled.
First, the check for large pages only checked for explicit huge pages
and missed transparent huge pages. Then the check that the addresses
(host virtual vs. guest physical) had appropriate alignment was
wrong, meaning that the code never put a large page in the partition
scoped radix tree; it was always demoted to a small page.
Fixing this exposed bugs in kvmppc_create_pte(). We were never
invalidating a 2MB PTE, which meant that if a page was initially
faulted in without write permission and the guest then attempted
to store to it, we would never update the PTE to have write permission.
If we find a valid 2MB PTE in the PMD, we need to clear it and
do a TLB invalidation before installing either the new 2MB PTE or
a pointer to a page table page.
This also corrects an assumption that get_user_pages_fast would set
the _PAGE_DIRTY bit if we are writing, which is not true. Instead we
mark the page dirty explicitly with set_page_dirty_lock(). This
also means we don't need the dirty bit set on the host PTE when
providing write access on a read fault.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
On lkml suggestions were made to split up such trivial typo fixes into per subsystem
patches:
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -439,7 +439,7 @@ setup_uga32(void **uga_handle, unsigned long size, u32 *width, u32 *height)
struct efi_uga_draw_protocol *uga = NULL, *first_uga;
efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
unsigned long nr_ugas;
- u32 *handles = (u32 *)uga_handle;;
+ u32 *handles = (u32 *)uga_handle;
efi_status_t status = EFI_INVALID_PARAMETER;
int i;
This patch is the result of the following script:
$ sed -i 's/;;$/;/g' $(git grep -E ';;$' | grep "\.[ch]:" | grep -vwE 'for|ia64' | cut -d: -f1 | sort | uniq)
... followed by manual review to make sure it's all good.
Splitting this up is just crazy talk, let's get over with this and just do it.
Reported-by: Pavel Machek <pavel@ucw.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Some versions of gcc generate a warning that the variable "emulated"
may be used uninitialized in function kvmppc_handle_load128_by2x64().
It would be used uninitialized if kvmppc_handle_load128_by2x64 was
ever called with vcpu->arch.mmio_vmx_copy_nums == 0, but neither of
the callers ever do that, so there is no actual bug. When gcc
generates a warning, it causes the build to fail because arch/powerpc
is compiled with -Werror.
This silences the warning by initializing "emulated" to EMULATE_DONE.
Fixes: 09f984961c ("KVM: PPC: Book3S: Add MMIO emulation for VMX instructions")
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Commit accb757d79 ("KVM: Move vcpu_load to arch-specific
kvm_arch_vcpu_ioctl_run", 2017-12-04) added a "goto out"
statement and an "out:" label to kvm_arch_vcpu_ioctl_run().
Since the only "goto out" is inside a CONFIG_VSX block,
compiling with CONFIG_VSX=n gives a warning that label "out"
is defined but not used, and because arch/powerpc is compiled
with -Werror, that becomes a compile error that makes the kernel
build fail.
Merge commit 1ab03c072f ("Merge tag 'kvm-ppc-next-4.16-2' of
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc",
2018-02-09) added a similar block of code inside a #ifdef
CONFIG_ALTIVEC, with a "goto out" statement.
In order to make the build succeed, this adds a #ifdef around the
"out:" label. This is a minimal, ugly fix, to be replaced later
by a refactoring of the code. Since CONFIG_VSX depends on
CONFIG_ALTIVEC, it is sufficient to use #ifdef CONFIG_ALTIVEC here.
Fixes: accb757d79 ("KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_run")
Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Pull KVM updates from Radim Krčmář:
"ARM:
- icache invalidation optimizations, improving VM startup time
- support for forwarded level-triggered interrupts, improving
performance for timers and passthrough platform devices
- a small fix for power-management notifiers, and some cosmetic
changes
PPC:
- add MMIO emulation for vector loads and stores
- allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
requiring the complex thread synchronization of older CPU versions
- improve the handling of escalation interrupts with the XIVE
interrupt controller
- support decrement register migration
- various cleanups and bugfixes.
s390:
- Cornelia Huck passed maintainership to Janosch Frank
- exitless interrupts for emulated devices
- cleanup of cpuflag handling
- kvm_stat counter improvements
- VSIE improvements
- mm cleanup
x86:
- hypervisor part of SEV
- UMIP, RDPID, and MSR_SMI_COUNT emulation
- paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit
- allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more
AVX512 features
- show vcpu id in its anonymous inode name
- many fixes and cleanups
- per-VCPU MSR bitmaps (already merged through x86/pti branch)
- stable KVM clock when nesting on Hyper-V (merged through
x86/hyperv)"
* tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (197 commits)
KVM: PPC: Book3S: Add MMIO emulation for VMX instructions
KVM: PPC: Book3S HV: Branch inside feature section
KVM: PPC: Book3S HV: Make HPT resizing work on POWER9
KVM: PPC: Book3S HV: Fix handling of secondary HPTEG in HPT resizing code
KVM: PPC: Book3S PR: Fix broken select due to misspelling
KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs()
KVM: PPC: Book3S PR: Fix svcpu copying with preemption enabled
KVM: PPC: Book3S HV: Drop locks before reading guest memory
kvm: x86: remove efer_reload entry in kvm_vcpu_stat
KVM: x86: AMD Processor Topology Information
x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested
kvm: embed vcpu id to dentry of vcpu anon inode
kvm: Map PFN-type memory regions as writable (if possible)
x86/kvm: Make it compile on 32bit and with HYPYERVISOR_GUEST=n
KVM: arm/arm64: Fixup userspace irqchip static key optimization
KVM: arm/arm64: Fix userspace_irqchip_in_use counting
KVM: arm/arm64: Fix incorrect timer_is_pending logic
MAINTAINERS: update KVM/s390 maintainers
MAINTAINERS: add Halil as additional vfio-ccw maintainer
MAINTAINERS: add David as a reviewer for KVM/s390
...
Second PPC KVM update for 4.16
Seven fixes that are either trivial or that address bugs that people
are actually hitting. The main ones are:
- Drop spinlocks before reading guest memory
- Fix a bug causing corruption of VCPU state in PR KVM with preemption
enabled
- Make HPT resizing work on POWER9
- Add MMIO emulation for vector loads and stores, because guests now
use these instructions in memcpy and similar routines.
This patch provides the MMIO load/store vector indexed
X-Form emulation.
Instructions implemented:
lvx: the quadword in storage addressed by the result of EA &
0xffff_ffff_ffff_fff0 is loaded into VRT.
stvx: the contents of VRS are stored into the quadword in storage
addressed by the result of EA & 0xffff_ffff_ffff_fff0.
Reported-by: Gopesh Kumar Chaudhary <gopchaud@in.ibm.com>
Reported-by: Balamuruhan S <bala24@linux.vnet.ibm.com>
Signed-off-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
We ended up with code that did a conditional branch inside a feature
section to code outside of the feature section. Depending on how the
object file gets organized, that might mean we exceed the 14bit
relocation limit for conditional branches:
arch/powerpc/kvm/built-in.o:arch/powerpc/kvm/book3s_hv_rmhandlers.S:416:(__ftr_alt_97+0x8): relocation truncated to fit: R_PPC64_REL14 against `.text'+1ca4
So instead of doing a conditional branch outside of the feature section,
let's just jump at the end of the same, making the branch very short.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This adds code to enable the HPT resizing code to work on POWER9,
which uses a slightly modified HPT entry format compared to POWER8.
On POWER9, we convert HPTEs read from the HPT from the new format to
the old format so that the rest of the HPT resizing code can work as
before. HPTEs written to the new HPT are converted to the new format
as the last step before writing them into the new HPT.
This takes out the checks added by commit bcd3bb63db ("KVM: PPC:
Book3S HV: Disable HPT resizing on POWER9 for now", 2017-02-18),
now that HPT resizing works on POWER9.
On POWER9, when we pivot to the new HPT, we now call
kvmppc_setup_partition_table() to update the partition table in order
to make the hardware use the new HPT.
[paulus@ozlabs.org - added kvmppc_setup_partition_table() call,
wrote commit message.]
Tested-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This fixes the computation of the HPTE index to use when the HPT
resizing code encounters a bolted HPTE which is stored in its
secondary HPTE group. The code inverts the HPTE group number, which
is correct, but doesn't then mask it with new_hash_mask. As a result,
new_pteg will be effectively negative, resulting in new_hptep
pointing before the new HPT, which will corrupt memory.
In addition, this removes two BUG_ON statements. The condition that
the BUG_ONs were testing -- that we have computed the hash value
incorrectly -- has never been observed in testing, and if it did
occur, would only affect the guest, not the host. Given that
BUG_ON should only be used in conditions where the kernel (i.e.
the host kernel, in this case) can't possibly continue execution,
it is not appropriate here.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Pull powerpc updates from Michael Ellerman:
"Highlights:
- Enable support for memory protection keys aka "pkeys" on Power7/8/9
when using the hash table MMU.
- Extend our interrupt soft masking to support masking PMU interrupts
as well as "normal" interrupts, and then use that to implement
local_t for a ~4x speedup vs the current atomics-based
implementation.
- A new driver "ocxl" for "Open Coherent Accelerator Processor
Interface (OpenCAPI)" devices.
- Support for new device tree properties on PowerVM to describe
hotpluggable memory and devices.
- Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE to the 64-bit
VDSO.
- Freescale updates from Scott: fixes for CPM GPIO and an FSL PCI
erratum workaround, plus a minor cleanup patch.
As well as quite a lot of other changes all over the place, and small
fixes and cleanups as always.
Thanks to: Alan Modra, Alastair D'Silva, Alexey Kardashevskiy,
Alistair Popple, Andreas Schwab, Andrew Donnellan, Aneesh Kumar K.V,
Anju T Sudhakar, Anshuman Khandual, Anton Blanchard, Arnd Bergmann,
Balbir Singh, Benjamin Herrenschmidt, Bhaktipriya Shridhar, Bryant G.
Ly, Cédric Le Goater, Christophe Leroy, Christophe Lombard, Cyril Bur,
David Gibson, Desnes A. Nunes do Rosario, Dmitry Torokhov, Frederic
Barrat, Geert Uytterhoeven, Guilherme G. Piccoli, Gustavo A. R. Silva,
Gustavo Romero, Ivan Mikhaylov, Joakim Tjernlund, Joe Perches, Josh
Poimboeuf, Juan J. Alvarez, Julia Cartwright, Kamalesh Babulal,
Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu Malaterre, Michael
Bringmann, Michael Hanselmann, Michael Neuling, Nathan Fontenot,
Naveen N. Rao, Nicholas Piggin, Paul Mackerras, Philippe Bergheaud,
Ram Pai, Russell Currey, Santosh Sivaraj, Scott Wood, Seth Forshee,
Simon Guo, Stewart Smith, Sukadev Bhattiprolu, Thiago Jung Bauermann,
Vaibhav Jain, Vasyl Gomonovych"
* tag 'powerpc-4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (199 commits)
powerpc/mm/radix: Fix build error when RADIX_MMU=n
macintosh/ams-input: Use true and false for boolean values
macintosh: change some data types from int to bool
powerpc/watchdog: Print the NIP in soft_nmi_interrupt()
powerpc/watchdog: regs can't be null in soft_nmi_interrupt()
powerpc/watchdog: Tweak watchdog printks
powerpc/cell: Remove axonram driver
rtc-opal: Fix handling of firmware error codes, prevent busy loops
powerpc/mpc52xx_gpt: make use of raw_spinlock variants
macintosh/adb: Properly mark continued kernel messages
powerpc/pseries: Fix cpu hotplug crash with memoryless nodes
powerpc/numa: Ensure nodes initialized for hotplug
powerpc/numa: Use ibm,max-associativity-domains to discover possible nodes
powerpc/kernel: Block interrupts when updating TIDR
powerpc/powernv/idoa: Remove unnecessary pcidev from pci_dn
powerpc/mm/nohash: do not flush the entire mm when range is a single page
powerpc/pseries: Add Initialization of VF Bars
powerpc/pseries/pci: Associate PEs to VFs in configure SR-IOV
powerpc/eeh: Add EEH notify resume sysfs
powerpc/eeh: Add EEH operations to notify resume
...
PPC KVM update for 4.16
- Allow HPT guests to run on a radix host on POWER9 v2.2 CPUs
without requiring the complex thread synchronization that earlier
CPU versions required.
- A series from Ben Herrenschmidt to improve the handling of
escalation interrupts with the XIVE interrupt controller.
- Provide for the decrementer register to be copied across on
migration.
- Various minor cleanups and bugfixes.
Pull asm/uaccess.h whack-a-mole from Al Viro:
"It's linux/uaccess.h, damnit... Oh, well - eventually they'll stop
cropping up..."
* 'work.whack-a-mole' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
asm-prototypes.h: use linux/uaccess.h, not asm/uaccess.h
riscv: use linux/uaccess.h, not asm/uaccess.h...
ppc: for put_user() pull linux/uaccess.h, not asm/uaccess.h
When copying between the vcpu and svcpu, we may get scheduled away onto
a different host CPU which in turn means our svcpu pointer may change.
That means we need to atomically copy to and from the svcpu with preemption
disabled, so that all code around it always sees a coherent state.
Reported-by: Simon Guo <wei.guo.simon@gmail.com>
Fixes: 3d3319b45e ("KVM: PPC: Book3S: PR: Enable interrupts earlier")
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Running with CONFIG_DEBUG_ATOMIC_SLEEP reveals that HV KVM tries to
read guest memory, in order to emulate guest instructions, while
preempt is disabled and a vcore lock is held. This occurs in
kvmppc_handle_exit_hv(), called from post_guest_process(), when
emulating guest doorbell instructions on POWER9 systems, and also
when checking whether we have hit a hypervisor breakpoint.
Reading guest memory can cause a page fault and thus cause the
task to sleep, so we need to avoid reading guest memory while
holding a spinlock or when preempt is disabled.
To fix this, we move the preempt_enable() in kvmppc_run_core() to
before the loop that calls post_guest_process() for each vcore that
has just run, and we drop and re-take the vcore lock around the calls
to kvmppc_emulate_debug_inst() and kvmppc_emulate_doorbell_instr().
Dropping the lock is safe with respect to the iteration over the
runnable vcpus in post_guest_process(); for_each_runnable_thread
is actually safe to use locklessly. It is possible for a vcpu
to become runnable and add itself to the runnable_threads array
(code near the beginning of kvmppc_run_vcpu()) and then get included
in the iteration in post_guest_process despite the fact that it
has not just run. This is benign because vcpu->arch.trap and
vcpu->arch.ceded will be zero.
Cc: stable@vger.kernel.org # v4.13+
Fixes: 579006944e ("KVM: PPC: Book3S HV: Virtualize doorbell facility on POWER9")
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Symbolic macros are unintuitive and hard to read, whereas octal constants
are much easier to interpret. Replace macros for the basic permission
flags (user/group/other read/write/execute) with numeric constants
instead, across the whole powerpc tree.
Introducing a significant number of changes across the tree for no runtime
benefit isn't exactly desirable, but so long as these macros are still
used in the tree people will keep sending patches that add them. Not only
are they hard to parse at a glance, there are multiple ways of coming to
the same value (as you can see with 0444 and 0644 in this patch) which
hurts readability.
Signed-off-by: Russell Currey <ruscur@russell.cc>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Merge our fixes branch from the 4.15 cycle.
Unusually the fixes branch saw some significant features merged,
notably the RFI flush patches, so we want the code in next to be
tested against that, to avoid any surprises when the two are merged.
There's also some other work on the panic handling that was reverted
in fixes and we now want to do properly in next, which would conflict.
And we also fix a few other minor merge conflicts.
Merge the topic branch we share with kvm-ppc, this brings in two xive
commits, one from Paul to rework HMI handling, and a minor cleanup to
drop an unused flag.
Rename the paca->soft_enabled to paca->irq_soft_mask as it is no
longer used as a flag for interrupt state, but a mask.
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds a new ioctl, KVM_PPC_GET_CPU_CHAR, that gives userspace
information about the underlying machine's level of vulnerability
to the recently announced vulnerabilities CVE-2017-5715,
CVE-2017-5753 and CVE-2017-5754, and whether the machine provides
instructions to assist software to work around the vulnerabilities.
The ioctl returns two u64 words describing characteristics of the
CPU and required software behaviour respectively, plus two mask
words which indicate which bits have been filled in by the kernel,
for extensibility. The bit definitions are the same as for the
new H_GET_CPU_CHARACTERISTICS hypercall.
There is also a new capability, KVM_CAP_PPC_GET_CPU_CHAR, which
indicates whether the new ioctl is available.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This works on top of the single escalation support. When in single
escalation, with this change, we will keep the escalation interrupt
disabled unless the VCPU is in H_CEDE (idle). In any other case, we
know the VCPU will be rescheduled and thus there is no need to take
escalation interrupts in the host whenever a guest interrupt fires.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The prodded flag is only cleared at the beginning of H_CEDE,
so every time we have an escalation, we will cause the *next*
H_CEDE to return immediately.
Instead use a dedicated "irq_pending" flag to indicate that
a guest interrupt is pending for the VCPU. We don't reuse the
existing exception bitmap so as to avoid expensive atomic ops.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
That feature, provided by Power9 DD2.0 and later, when supported
by newer OPAL versions, allows us to sacrifice a queue (priority 7)
in favor of merging all the escalation interrupts of the queues
of a single VP into a single interrupt.
This reduces the number of host interrupts used up by KVM guests
especially when those guests use multiple priorities.
It will also enable a future change to control the masking of the
escalation interrupts more precisely to avoid spurious ones.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
