Commit Graph

1678 Commits

Author SHA1 Message Date
Nicholas Piggin
7c1bd80cc2 KVM: PPC: Book3S HV: Send kvmppc_bad_interrupt NMIs to Linux handlers
It's possible to take a SRESET or MCE in these paths due to a bug
in the host code or a NMI IPI, etc. A recent bug attempting to load
a virtual address from real mode gave th complete but cryptic error,
abridged:

      Oops: Bad interrupt in KVM entry/exit code, sig: 6 [#1]
      LE SMP NR_CPUS=2048 NUMA PowerNV
      CPU: 53 PID: 6582 Comm: qemu-system-ppc Not tainted
      NIP:  c0000000000155ac LR: c0000000000c2430 CTR: c000000000015580
      REGS: c000000fff76dd80 TRAP: 0200   Not tainted
      MSR:  9000000000201003 <SF,HV,ME,RI,LE>  CR: 48082222  XER: 00000000
      CFAR: 0000000102900ef0 DAR: d00017fffd941a28 DSISR: 00000040 SOFTE: 3
      NIP [c0000000000155ac] perf_trace_tlbie+0x2c/0x1a0
      LR [c0000000000c2430] do_tlbies+0x230/0x2f0

Sending the NMIs through the Linux handlers gives a nicer output:

      Severe Machine check interrupt [Not recovered]
        NIP [c0000000000155ac]: perf_trace_tlbie+0x2c/0x1a0
        Initiator: CPU
        Error type: Real address [Load (bad)]
          Effective address: d00017fffcc01a28
      opal: Machine check interrupt unrecoverable: MSR(RI=0)
      opal: Hardware platform error: Unrecoverable Machine Check exception
      CPU: 0 PID: 6700 Comm: qemu-system-ppc Tainted: G   M
      NIP:  c0000000000155ac LR: c0000000000c23c0 CTR: c000000000015580
      REGS: c000000fff9e9d80 TRAP: 0200   Tainted: G   M
      MSR:  9000000000201001 <SF,HV,ME,LE>  CR: 48082222  XER: 00000000
      CFAR: 000000010cbc1a30 DAR: d00017fffcc01a28 DSISR: 00000040 SOFTE: 3
      NIP [c0000000000155ac] perf_trace_tlbie+0x2c/0x1a0
      LR [c0000000000c23c0] do_tlbies+0x1c0/0x280

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:38:23 +10:00
Nicholas Piggin
eadce3b48b KVM: PPC: Book3S HV: Fix kvmppc_bad_host_intr for real mode interrupts
When CONFIG_RELOCATABLE=n, the Linux real mode interrupt handlers call
into KVM using real address. This needs to be translated to the kernel
linear effective address before the MMU is switched on.

kvmppc_bad_host_intr misses adding these bits, so when it is used to
handle a system reset interrupt (that always gets delivered in real
mode), it results in an instruction access fault immediately after
the MMU is turned on.

Fix this by ensuring the top 2 address bits are set when the MMU is
turned on.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:38:23 +10:00
Nicholas Piggin
878cf2bb2d KVM: PPC: Book3S HV: radix: Do not clear partition PTE when RC or write bits do not match
Adding the write bit and RC bits to pte permissions does not require a
pte clear and flush. There should not be other bits changed here,
because restricting access or changing the PFN must have already
invalidated any existing ptes (otherwise the race is already lost).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:38:23 +10:00
Nicholas Piggin
bc64dd0e1c KVM: PPC: Book3S HV: radix: Refine IO region partition scope attributes
When the radix fault handler has no page from the process address
space (e.g., for IO memory), it looks up the process pte and sets
partition table pte using that to get attributes like CI and guarded.
If the process table entry is to be writable, set _PAGE_DIRTY as well
to avoid an RC update. If not, then ensure _PAGE_DIRTY does not come
across. Set _PAGE_ACCESSED as well to avoid RC update.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:38:23 +10:00
Nicholas Piggin
9a4506e11b KVM: PPC: Book3S HV: Make radix handle process scoped LPID flush in C, with relocation on
The radix guest code can has fewer restrictions about what context it
can run in, so move this flushing out of assembly and have it use the
Linux TLB flush implementations introduced previously.

This allows powerpc:tlbie trace events to be used.

This changes the tlbiel sequence to only execute RIC=2 flush once on
the first set flushed, then RIC=0 for the rest of the sets. The end
result of the flush should be unchanged. This matches the local PID
flush pattern that was introduced in a5998fcb92 ("powerpc/mm/radix:
Optimise tlbiel flush all case").

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:38:23 +10:00
Nicholas Piggin
d91cb39ffa KVM: PPC: Book3S HV: Make radix use the Linux translation flush functions for partition scope
This has the advantage of consolidating TLB flush code in fewer
places, and it also implements powerpc:tlbie trace events.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:38:23 +10:00
Nicholas Piggin
a5704e83aa KVM: PPC: Book3S HV: Recursively unmap all page table entries when unmapping
When partition scope mappings are unmapped with kvm_unmap_radix, the
pte is cleared, but the page table structure is left in place. If the
next page fault requests a different page table geometry (e.g., due to
THP promotion or split), kvmppc_create_pte is responsible for changing
the page tables.

When a page table entry is to be converted to a large pte, the page
table entry is cleared, the PWC flushed, then the page table it points
to freed. This will cause pte page tables to leak when a 1GB page is
to replace a pud entry points to a pmd table with pte tables under it:
The pmd table will be freed, but its pte tables will be missed.

Fix this by replacing the simple clear and free code with one that
walks down the page tables and frees children. Care must be taken to
clear the root entry being unmapped then flushing the PWC before
freeing any page tables, as explained in comments.

This requires PWC flush to logically become a flush-all-PWC (which it
already is in hardware, but the KVM API needs to be changed to avoid
confusion).

This code also checks that no unexpected pte entries exist in any page
table being freed, and unmaps those and emits a WARN. This is an
expensive operation for the pte page level, but partition scope
changes are rare, so it's unconditional for now to iron out bugs. It
can be put under a CONFIG option or removed after some time.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:38:23 +10:00
Nicholas Piggin
a5fad1e959 KVM: PPC: Book3S HV: Use a helper to unmap ptes in the radix fault path
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:38:23 +10:00
Nicholas Piggin
b755745147 KVM: PPC: Book3S HV: Lockless tlbie for HPT hcalls
tlbies to an LPAR do not have to be serialised since POWER4/PPC970,
after which the MMU_FTR_LOCKLESS_TLBIE feature was introduced to
avoid tlbie locking.

Since commit c17b98cf60 ("KVM: PPC: Book3S HV: Remove code for
PPC970 processors"), KVM no longer supports processors that do not
have this feature, so the tlbie locking can be removed completely.
A sanity check for the feature is put in kvmppc_mmu_hv_init.

Testing was done on a POWER9 system in HPT mode, with a -smp 32 guest
in HPT mode. 32 instances of the powerpc fork benchmark from selftests
were run with --fork, and the results measured.

Without this patch, total throughput was about 13.5K/sec, and this is
the top of the host profile:

   74.52%  [k] do_tlbies
    2.95%  [k] kvmppc_book3s_hv_page_fault
    1.80%  [k] calc_checksum
    1.80%  [k] kvmppc_vcpu_run_hv
    1.49%  [k] kvmppc_run_core

After this patch, throughput was about 51K/sec, with this profile:

   21.28%  [k] do_tlbies
    5.26%  [k] kvmppc_run_core
    4.88%  [k] kvmppc_book3s_hv_page_fault
    3.30%  [k] _raw_spin_lock_irqsave
    3.25%  [k] gup_pgd_range

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:38:23 +10:00
Simon Guo
f19d1f367a KVM: PPC: Fix a mmio_host_swabbed uninitialized usage issue
When KVM emulates VMX store, it will invoke kvmppc_get_vmx_data() to
retrieve VMX reg val. kvmppc_get_vmx_data() will check mmio_host_swabbed
to decide which double word of vr[] to be used. But the
mmio_host_swabbed can be uninitialized during VMX store procedure:

kvmppc_emulate_loadstore
	\- kvmppc_handle_store128_by2x64
		\- kvmppc_get_vmx_data

So vcpu->arch.mmio_host_swabbed is not meant to be used at all for
emulation of store instructions, and this patch makes that true for
VMX stores. This patch also initializes mmio_host_swabbed to avoid
possible future problems.

Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:38:23 +10:00
Simon Guo
173c520a04 KVM: PPC: Move nip/ctr/lr/xer registers to pt_regs in kvm_vcpu_arch
This patch moves nip/ctr/lr/xer registers from scattered places in
kvm_vcpu_arch to pt_regs structure.

cr register is "unsigned long" in pt_regs and u32 in vcpu->arch.
It will need more consideration and may move in later patches.

Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:38:23 +10:00
Simon Guo
1143a70665 KVM: PPC: Add pt_regs into kvm_vcpu_arch and move vcpu->arch.gpr[] into it
Current regs are scattered at kvm_vcpu_arch structure and it will
be more neat to organize them into pt_regs structure.

Also it will enable reimplementation of MMIO emulation code with
analyse_instr() later.

Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:38:23 +10:00
Paul Mackerras
9c9e9cf40a Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-next
This merges in the ppc-kvm topic branch of the powerpc repository
to get some changes on which future patches will depend, in particular
the definitions of various new TLB flushing functions.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-18 15:30:10 +10:00
Souptick Joarder
16d5c39d54 KVM: PPC: Book3S: Change return type to vm_fault_t
Use new return type vm_fault_t for fault handler
in struct vm_operations_struct. For now, this is
just documenting that the function returns a
VM_FAULT value rather than an errno.  Once all
instances are converted, vm_fault_t will become
a distinct type.

commit 1c8f422059 ("mm: change return type to
vm_fault_t")

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-17 16:41:51 +10:00
Alexey Kardashevskiy
e45719af1c KVM: PPC: Book3S: Check KVM_CREATE_SPAPR_TCE_64 parameters
Although it does not seem possible to break the host by passing bad
parameters when creating a TCE table in KVM, it is still better to get
an early clear indication of that than debugging weird effect this might
bring.

This adds some sanity checks that the page size is 4KB..16GB as this is
what the actual LoPAPR supports and that the window actually fits 64bit
space.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-17 16:41:51 +10:00
Alexey Kardashevskiy
ca1fc489cf KVM: PPC: Book3S: Allow backing bigger guest IOMMU pages with smaller physical pages
At the moment we only support in the host the IOMMU page sizes which
the guest is aware of, which is 4KB/64KB/16MB. However P9 does not support
16MB IOMMU pages, 2MB and 1GB pages are supported instead. We can still
emulate bigger guest pages (for example 16MB) with smaller host pages
(4KB/64KB/2MB).

This allows the physical IOMMU pages to use a page size smaller or equal
than the guest visible IOMMU page size.

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>
2018-05-17 16:41:51 +10:00
Alexey Kardashevskiy
c6b61661d2 KVM: PPC: Book3S: Use correct page shift in H_STUFF_TCE
The other TCE handlers use page shift from the guest visible TCE table
(described by kvmppc_spapr_tce_iommu_table) so let's make H_STUFF_TCE
handlers do the same thing.

This should cause no behavioral change now but soon we will allow
the iommu_table::it_page_shift being different from from the emulated
table page size so this will play a role.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-17 16:41:51 +10:00
Paul Mackerras
48e70b1ce6 KVM: PPC: Book3S HV: Fix inaccurate comment
We now have interrupts hard-disabled when coming back from
kvmppc_hv_entry_trampoline, so this changes the comment to reflect
that.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-17 16:36:56 +10:00
Paul Mackerras
7aa15842c1 KVM: PPC: Book3S HV: Set RWMR on POWER8 so PURR/SPURR count correctly
Although Linux doesn't use PURR and SPURR ((Scaled) Processor
Utilization of Resources Register), other OSes depend on them.
On POWER8 they count at a rate depending on whether the VCPU is
idle or running, the activity of the VCPU, and the value in the
RWMR (Region-Weighting Mode Register).  Hardware expects the
hypervisor to update the RWMR when a core is dispatched to reflect
the number of online VCPUs in the vcore.

This adds code to maintain a count in the vcore struct indicating
how many VCPUs are online.  In kvmppc_run_core we use that count
to set the RWMR register on POWER8.  If the core is split because
of a static or dynamic micro-threading mode, we use the value for
8 threads.  The RWMR value is not relevant when the host is
executing because Linux does not use the PURR or SPURR register,
so we don't bother saving and restoring the host value.

For the sake of old userspace which does not set the KVM_REG_PPC_ONLINE
register, we set online to 1 if it was 0 at the time of a KVM_RUN
ioctl.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-17 16:36:48 +10:00
Paul Mackerras
a1f158262a KVM: PPC: Book3S HV: Add 'online' register to ONE_REG interface
This adds a new KVM_REG_PPC_ONLINE register which userspace can set
to 0 or 1 via the GET/SET_ONE_REG interface to indicate whether it
considers the VCPU to be offline (0), that is, not currently running,
or online (1).  This will be used in a later patch to configure the
register which controls PURR and SPURR accumulation.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-17 16:36:36 +10:00
Paul Mackerras
df158189db KVM: PPC: Book 3S HV: Do ptesync in radix guest exit path
A radix guest can execute tlbie instructions to invalidate TLB entries.
After a tlbie or a group of tlbies, it must then do the architected
sequence eieio; tlbsync; ptesync to ensure that the TLB invalidation
has been processed by all CPUs in the system before it can rely on
no CPU using any translation that it just invalidated.

In fact it is the ptesync which does the actual synchronization in
this sequence, and hardware has a requirement that the ptesync must
be executed on the same CPU thread as the tlbies which it is expected
to order.  Thus, if a vCPU gets moved from one physical CPU to
another after it has done some tlbies but before it can get to do the
ptesync, the ptesync will not have the desired effect when it is
executed on the second physical CPU.

To fix this, we do a ptesync in the exit path for radix guests.  If
there are any pending tlbies, this will wait for them to complete.
If there aren't, then ptesync will just do the same as sync.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-17 15:17:13 +10:00
Benjamin Herrenschmidt
9dc81d6b0f KVM: PPC: Book3S HV: XIVE: Resend re-routed interrupts on CPU priority change
When a vcpu priority (CPPR) is set to a lower value (masking more
interrupts), we stop processing interrupts already in the queue
for the priorities that have now been masked.

If those interrupts were previously re-routed to a different
CPU, they might still be stuck until the older one that has
them in its queue processes them. In the case of guest CPU
unplug, that can be never.

To address that without creating additional overhead for
the normal interrupt processing path, this changes H_CPPR
handling so that when such a priority change occurs, we
scan the interrupt queue for that vCPU, and for any
interrupt in there that has been re-routed, we replace it
with a dummy and force a re-trigger.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-17 15:17:06 +10:00
Nicholas Piggin
7e3d9a1d0f KVM: PPC: Book3S HV: Make radix clear pte when unmapping
The current partition table unmap code clears the _PAGE_PRESENT bit
out of the pte, which leaves pud_huge/pmd_huge true and does not
clear pud_present/pmd_present.  This can confuse subsequent page
faults and possibly lead to the guest looping doing continual
hypervisor page faults.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-17 15:16:59 +10:00
Nicholas Piggin
e2560b108f KVM: PPC: Book3S HV: Make radix use correct tlbie sequence in kvmppc_radix_tlbie_page
The standard eieio ; tlbsync ; ptesync must follow tlbie to ensure it
is ordered with respect to subsequent operations.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-17 15:16:53 +10:00
Paul Mackerras
57b8daa70a KVM: PPC: Book3S HV: Snapshot timebase offset on guest entry
Currently, the HV KVM guest entry/exit code adds the timebase offset
from the vcore struct to the timebase on guest entry, and subtracts
it on guest exit.  Which is fine, except that it is possible for
userspace to change the offset using the SET_ONE_REG interface while
the vcore is running, as there is only one timebase offset per vcore
but potentially multiple VCPUs in the vcore.  If that were to happen,
KVM would subtract a different offset on guest exit from that which
it had added on guest entry, leading to the timebase being out of sync
between cores in the host, which then leads to bad things happening
such as hangs and spurious watchdog timeouts.

To fix this, we add a new field 'tb_offset_applied' to the vcore struct
which stores the offset that is currently applied to the timebase.
This value is set from the vcore tb_offset field on guest entry, and
is what is subtracted from the timebase on guest exit.  Since it is
zero when the timebase offset is not applied, we can simplify the
logic in kvmhv_start_timing and kvmhv_accumulate_time.

In addition, we had secondary threads reading the timebase while
running concurrently with code on the primary thread which would
eventually add or subtract the timebase offset from the timebase.
This occurred while saving or restoring the DEC register value on
the secondary threads.  Although no specific incorrect behaviour has
been observed, this is a race which should be fixed.  To fix it, we
move the DEC saving code to just before we call kvmhv_commence_exit,
and the DEC restoring code to after the point where we have waited
for the primary thread to switch the MMU context and add the timebase
offset.  That way we are sure that the timebase contains the guest
timebase value in both cases.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-05-17 15:16:45 +10:00
Michael Ellerman
a42ae34f71 Merge branch 'topic/ppc-kvm' into next
This brings in one commit that we may want to share with the kvm-ppc
tree, to avoid merge conflicts and get wider testing.
2018-05-15 22:28:19 +10:00
Aneesh Kumar K.V
21828c99ee powerpc/kvm: Switch kvm pmd allocator to custom allocator
In the next set of patches, we will switch pmd allocator to use page fragments
and the locking will be updated to split pmd ptlock. We want to avoid using
fragments for partition-scoped table. Use slab cache similar to level 4 table

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15 22:27:06 +10:00
Naveen N. Rao
a4bc64d305 powerpc64/ftrace: Disable ftrace during kvm entry/exit
During guest entry/exit, we switch over to/from the guest MMU context
and we cannot take exceptions in the hypervisor code.

Since ftrace may be enabled and since it can result in us taking a trap,
disable ftrace by setting paca->ftrace_enabled to zero. There are two
paths through which we enter/exit a guest:
1. If we are the vcore runner, then we enter the guest via
__kvmppc_vcore_entry() and we disable ftrace around this. This is always
the case for Power9, and for the primary thread on Power8.
2. If we are a secondary thread in Power8, then we would be in nap due
to SMT being disabled. We are woken up by an IPI to enter the guest. In
this scenario, we enter the guest through kvm_start_guest(). We disable
ftrace at this point. In this scenario, ftrace would only get re-enabled
on the secondary thread when SMT is re-enabled (via start_secondary()).

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 22:32:27 +10:00
Laurentiu Tudor
b2d7ecbe35 powerpc/kvm/booke: Fix altivec related build break
Add missing "altivec unavailable" interrupt injection helper
thus fixing the linker error below:

  arch/powerpc/kvm/emulate_loadstore.o: In function `kvmppc_check_altivec_disabled':
  arch/powerpc/kvm/emulate_loadstore.c: undefined reference to `.kvmppc_core_queue_vec_unavail'

Fixes: 09f984961c ("KVM: PPC: Book3S: Add MMIO emulation for VMX instructions")
Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-27 16:36:03 +10:00
Linus Torvalds
b1cb4f93b5 Merge tag 'powerpc-4.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:

 - Fix crashes when loading modules built with a different
   CONFIG_RELOCATABLE value by adding CONFIG_RELOCATABLE to vermagic.

 - Fix busy loops in the OPAL NVRAM driver if we get certain error
   conditions from firmware.

 - Remove tlbie trace points from KVM code that's called in real mode,
   because it causes crashes.

 - Fix checkstops caused by invalid tlbiel on Power9 Radix.

 - Ensure the set of CPU features we "know" are always enabled is
   actually the minimal set when we build with support for firmware
   supplied CPU features.

Thanks to: Aneesh Kumar K.V, Anshuman Khandual, Nicholas Piggin.

* tag 'powerpc-4.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: Fix CPU_FTRS_ALWAYS vs DT CPU features
  powerpc/mm/radix: Fix checkstops caused by invalid tlbiel
  KVM: PPC: Book3S HV: trace_tlbie must not be called in realmode
  powerpc/8xx: Fix build with hugetlbfs enabled
  powerpc/powernv: Fix OPAL NVRAM driver OPAL_BUSY loops
  powerpc/powernv: define a standard delay for OPAL_BUSY type retry loops
  powerpc/fscr: Enable interrupts earlier before calling get_user()
  powerpc/64s: Fix section mismatch warnings from setup_rfi_flush()
  powerpc/modules: Fix crashes by adding CONFIG_RELOCATABLE to vermagic
2018-04-15 11:57:12 -07:00
Nicholas Piggin
19ce7909ed KVM: PPC: Book3S HV: trace_tlbie must not be called in realmode
This crashes with a "Bad real address for load" attempting to load
from the vmalloc region in realmode (faulting address is in DAR).

  Oops: Bad interrupt in KVM entry/exit code, sig: 6 [#1]
  LE SMP NR_CPUS=2048 NUMA PowerNV
  CPU: 53 PID: 6582 Comm: qemu-system-ppc Not tainted 4.16.0-01530-g43d1859f0994
  NIP:  c0000000000155ac LR: c0000000000c2430 CTR: c000000000015580
  REGS: c000000fff76dd80 TRAP: 0200   Not tainted  (4.16.0-01530-g43d1859f0994)
  MSR:  9000000000201003 <SF,HV,ME,RI,LE>  CR: 48082222  XER: 00000000
  CFAR: 0000000102900ef0 DAR: d00017fffd941a28 DSISR: 00000040 SOFTE: 3
  NIP [c0000000000155ac] perf_trace_tlbie+0x2c/0x1a0
  LR [c0000000000c2430] do_tlbies+0x230/0x2f0

I suspect the reason is the per-cpu data is not in the linear chunk.
This could be restored if that was able to be fixed, but for now,
just remove the tracepoints.

Fixes: 0428491cba ("powerpc/mm: Trace tlbie(l) instructions")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-11 12:35:33 +10:00
Linus Torvalds
d8312a3f61 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
 "ARM:
   - VHE optimizations

   - EL2 address space randomization

   - speculative execution mitigations ("variant 3a", aka execution past
     invalid privilege register access)

   - bugfixes and cleanups

  PPC:
   - improvements for the radix page fault handler for HV KVM on POWER9

  s390:
   - more kvm stat counters

   - virtio gpu plumbing

   - documentation

   - facilities improvements

  x86:
   - support for VMware magic I/O port and pseudo-PMCs

   - AMD pause loop exiting

   - support for AMD core performance extensions

   - support for synchronous register access

   - expose nVMX capabilities to userspace

   - support for Hyper-V signaling via eventfd

   - use Enlightened VMCS when running on Hyper-V

   - allow userspace to disable MWAIT/HLT/PAUSE vmexits

   - usual roundup of optimizations and nested virtualization bugfixes

  Generic:
   - API selftest infrastructure (though the only tests are for x86 as
     of now)"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (174 commits)
  kvm: x86: fix a prototype warning
  kvm: selftests: add sync_regs_test
  kvm: selftests: add API testing infrastructure
  kvm: x86: fix a compile warning
  KVM: X86: Add Force Emulation Prefix for "emulate the next instruction"
  KVM: X86: Introduce handle_ud()
  KVM: vmx: unify adjacent #ifdefs
  x86: kvm: hide the unused 'cpu' variable
  KVM: VMX: remove bogus WARN_ON in handle_ept_misconfig
  Revert "KVM: X86: Fix SMRAM accessing even if VM is shutdown"
  kvm: Add emulation for movups/movupd
  KVM: VMX: raise internal error for exception during invalid protected mode state
  KVM: nVMX: Optimization: Dont set KVM_REQ_EVENT when VMExit with nested_run_pending
  KVM: nVMX: Require immediate-exit when event reinjected to L2 and L1 event pending
  KVM: x86: Fix misleading comments on handling pending exceptions
  KVM: x86: Rename interrupt.pending to interrupt.injected
  KVM: VMX: No need to clear pending NMI/interrupt on inject realmode interrupt
  x86/kvm: use Enlightened VMCS when running on Hyper-V
  x86/hyper-v: detect nested features
  x86/hyper-v: define struct hv_enlightened_vmcs and clean field bits
  ...
2018-04-09 11:42:31 -07:00
Linus Torvalds
49a695ba72 Merge tag 'powerpc-4.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - Support for 4PB user address space on 64-bit, opt-in via mmap().

   - Removal of POWER4 support, which was accidentally broken in 2016
     and no one noticed, and blocked use of some modern instructions.

   - Workarounds so that the hypervisor can enable Transactional Memory
     on Power9.

   - A series to disable the DAWR (Data Address Watchpoint Register) on
     Power9.

   - More information displayed in the meltdown/spectre_v1/v2 sysfs
     files.

   - A vpermxor (Power8 Altivec) implementation for the raid6 Q
     Syndrome.

   - A big series to make the allocation of our pacas (per cpu area),
     kernel page tables, and per-cpu stacks NUMA aware when using the
     Radix MMU on Power9.

  And as usual many fixes, reworks and cleanups.

  Thanks to: Aaro Koskinen, Alexandre Belloni, Alexey Kardashevskiy,
  Alistair Popple, Andy Shevchenko, Aneesh Kumar K.V, Anshuman Khandual,
  Balbir Singh, Benjamin Herrenschmidt, Christophe Leroy, Christophe
  Lombard, Cyril Bur, Daniel Axtens, Dave Young, Finn Thain, Frederic
  Barrat, Gustavo Romero, Horia Geantă, Jonathan Neuschäfer, Kees Cook,
  Larry Finger, Laurent Dufour, Laurent Vivier, Logan Gunthorpe,
  Madhavan Srinivasan, Mark Greer, Mark Hairgrove, Markus Elfring,
  Mathieu Malaterre, Matt Brown, Matt Evans, Mauricio Faria de Oliveira,
  Michael Neuling, Naveen N. Rao, Nicholas Piggin, Paul Mackerras,
  Philippe Bergheaud, Ram Pai, Rob Herring, Sam Bobroff, Segher
  Boessenkool, Simon Guo, Simon Horman, Stewart Smith, Sukadev
  Bhattiprolu, Suraj Jitindar Singh, Thiago Jung Bauermann, Vaibhav
  Jain, Vaidyanathan Srinivasan, Vasant Hegde, Wei Yongjun"

* tag 'powerpc-4.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (207 commits)
  powerpc/64s/idle: Fix restore of AMOR on POWER9 after deep sleep
  powerpc/64s: Fix POWER9 DD2.2 and above in cputable features
  powerpc/64s: Fix pkey support in dt_cpu_ftrs, add CPU_FTR_PKEY bit
  powerpc/64s: Fix dt_cpu_ftrs to have restore_cpu clear unwanted LPCR bits
  Revert "powerpc/64s/idle: POWER9 ESL=0 stop avoid save/restore overhead"
  powerpc: iomap.c: introduce io{read|write}64_{lo_hi|hi_lo}
  powerpc: io.h: move iomap.h include so that it can use readq/writeq defs
  cxl: Fix possible deadlock when processing page faults from cxllib
  powerpc/hw_breakpoint: Only disable hw breakpoint if cpu supports it
  powerpc/mm/radix: Update command line parsing for disable_radix
  powerpc/mm/radix: Parse disable_radix commandline correctly.
  powerpc/mm/hugetlb: initialize the pagetable cache correctly for hugetlb
  powerpc/mm/radix: Update pte fragment count from 16 to 256 on radix
  powerpc/mm/keys: Update documentation and remove unnecessary check
  powerpc/64s/idle: POWER9 ESL=0 stop avoid save/restore overhead
  powerpc/64s/idle: Consolidate power9_offline_stop()/power9_idle_stop()
  powerpc/powernv: Always stop secondaries before reboot/shutdown
  powerpc: hard disable irqs in smp_send_stop loop
  powerpc: use NMI IPI for smp_send_stop
  powerpc/powernv: Fix SMT4 forcing idle code
  ...
2018-04-07 12:08:19 -07:00
Nicholas Piggin
e303c08787 KVM: PPC: Book3S HV: Fix ppc_breakpoint_available compile error
arch/powerpc/kvm/book3s_hv.c: In function ‘kvmppc_h_set_mode’:
arch/powerpc/kvm/book3s_hv.c:745:8: error: implicit declaration of function ‘ppc_breakpoint_available’
   if (!ppc_breakpoint_available())
        ^~~~~~~~~~~~~~~~~~~~~~~~

Fixes: 398e712c00 ("KVM: PPC: Book3S HV: Return error from h_set_mode(SET_DAWR) on POWER9")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-03 21:50:07 +10:00
Nicholas Piggin
471d7ff8b5 powerpc/64s: Remove POWER4 support
POWER4 has been broken since at least the change 49d09bf2a6
("powerpc/64s: Optimise MSR handling in exception handling"), which
requires mtmsrd L=1 support. This was introduced in ISA v2.01, and
POWER4 supports ISA v2.00.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-01 00:47:50 +11:00
Aneesh Kumar K.V
ca9a16c3bc powerpc/kvm: Fix guest boot failure on Power9 since DAWR changes
SLOF checks for 'sc 1' (hypercall) support by issuing a hcall with
H_SET_DABR. Since the recent commit e8ebedbf31 ("KVM: PPC: Book3S
HV: Return error from h_set_dabr() on POWER9") changed H_SET_DABR to
return H_UNSUPPORTED on Power9, we see guest boot failures, the
symptom is the boot seems to just stop in SLOF, eg:

  SLOF ***************************************************************
  QEMU Starting
   Build Date = Sep 24 2017 12:23:07
   FW Version = buildd@ release 20170724
  <no further output>

SLOF can cope if H_SET_DABR returns H_HARDWARE. So wwitch the return
value to H_HARDWARE instead of H_UNSUPPORTED so that we don't break
the guest boot.

That does mean we return a different error to PowerVM in this case,
but that's probably not a big concern.

Fixes: e8ebedbf31 ("KVM: PPC: Book3S HV: Return error from h_set_dabr() on POWER9")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-01 00:47:13 +11:00
Michael Ellerman
f437c51748 Merge branch 'topic/paca' into next
Bring in yet another series that touches KVM code, and might need to
be merged into the kvm-ppc branch to resolve conflicts.

This required some changes in pnv_power9_force_smt4_catch/release()
due to the paca array becomming an array of pointers.
2018-03-31 09:09:36 +11:00
Linus Torvalds
72573481eb Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Radim Krčmář:
 "PPC:
   - Fix a bug causing occasional machine check exceptions on POWER8
     hosts (introduced in 4.16-rc1)

  x86:
   - Fix a guest crashing regression with nested VMX and restricted
     guest (introduced in 4.16-rc1)

   - Fix dependency check for pv tlb flush (the wrong dependency that
     effectively disabled the feature was added in 4.16-rc4, the
     original feature in 4.16-rc1, so it got decent testing)"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: Fix pv tlb flush dependencies
  KVM: nVMX: sync vmcs02 segment regs prior to vmx_set_cr0
  KVM: PPC: Book3S HV: Fix duplication of host SLB entries
2018-03-30 07:24:14 -10:00
Nicholas Piggin
499dcd4137 powerpc/64s: Allocate LPPACAs individually
We no longer allocate lppacas in an array, so this patch removes the
1kB static alignment for the structure, and enforces the PAPR
alignment requirements at allocation time. We can not reduce the 1kB
allocation size however, due to existing KVM hypervisors.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-30 23:34:24 +11:00
Nicholas Piggin
d2e60075a3 powerpc/64: Use array of paca pointers and allocate pacas individually
Change the paca array into an array of pointers to pacas. Allocate
pacas individually.

This allows flexibility in where the PACAs are allocated. Future work
will allocate them node-local. Platforms that don't have address limits
on PACAs would be able to defer PACA allocations until later in boot
rather than allocate all possible ones up-front then freeing unused.

This is slightly more overhead (one additional indirection) for cross
CPU paca references, but those aren't too common.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-30 23:34:23 +11:00
Nicholas Piggin
8e0b634b13 powerpc/64s: Do not allocate lppaca if we are not virtualized
The "lppaca" is a structure registered with the hypervisor. This is
unnecessary when running on non-virtualised platforms. One field from
the lppaca (pmcregs_in_use) is also used by the host, so move the host
part out into the paca (lppaca field is still updated in
guest mode).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fix non-pseries build with some #ifdefs]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-30 23:34:22 +11:00
Linus Torvalds
a2601d78b7 Merge tag 'powerpc-4.16-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
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
2018-03-28 13:54:03 -10:00
Michael Ellerman
95dff480bb Merge branch 'fixes' into next
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.
2018-03-28 22:59:50 +11:00
Paul Mackerras
31c8b0d069 KVM: PPC: Book3S HV: Use __gfn_to_pfn_memslot() in page fault handler
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>
2018-03-28 08:27:58 +11:00
Michael Ellerman
c0b346729b Merge branch 'topic/ppc-kvm' into next
Merge the DAWR series, which touches arch code and KVM code and may need
to be merged into the kvm-ppc tree.
2018-03-27 23:55:49 +11:00
Michael Neuling
b53221e704 KVM: PPC: Book3S HV: Handle migration with POWER9 disabled DAWR
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>
2018-03-27 23:55:33 +11:00
Michael Neuling
e8ebedbf31 KVM: PPC: Book3S HV: Return error from h_set_dabr() on POWER9
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>
2018-03-27 23:55:32 +11:00
Michael Neuling
398e712c00 KVM: PPC: Book3S HV: Return error from h_set_mode(SET_DAWR) on POWER9
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>
2018-03-27 23:55:32 +11:00
Michael Ellerman
a26cf1c9fe Merge branch 'topic/ppc-kvm' into next
This brings in two series from Paul, one of which touches KVM code and
may need to be merged into the kvm-ppc tree to resolve conflicts.
2018-03-24 08:43:18 +11:00
Paul Mackerras
681c617b7c KVM: PPC: Book3S HV: Work around TEXASR bug in fake suspend state
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>
2018-03-24 00:39:17 +11:00