Commit graph

1440 commits

Author SHA1 Message Date
Paul Mackerras 47c5310a8d KVM: PPC: Book3S: Fix race and leak in kvm_vm_ioctl_create_spapr_tce()
Nixiaoming pointed out that there is a memory leak in
kvm_vm_ioctl_create_spapr_tce() if the call to anon_inode_getfd()
fails; the memory allocated for the kvmppc_spapr_tce_table struct
is not freed, and nor are the pages allocated for the iommu
tables.  In addition, we have already incremented the process's
count of locked memory pages, and this doesn't get restored on
error.

David Hildenbrand pointed out that there is a race in that the
function checks early on that there is not already an entry in the
stt->iommu_tables list with the same LIOBN, but an entry with the
same LIOBN could get added between then and when the new entry is
added to the list.

This fixes all three problems.  To simplify things, we now call
anon_inode_getfd() before placing the new entry in the list.  The
check for an existing entry is done while holding the kvm->lock
mutex, immediately before adding the new entry to the list.
Finally, on failure we now call kvmppc_account_memlimit to
decrement the process's count of locked memory pages.

Reported-by: Nixiaoming <nixiaoming@huawei.com>
Reported-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-25 11:08:57 +02:00
Benjamin Herrenschmidt bb9b52bd51 KVM: PPC: Book3S HV: Add missing barriers to XIVE code and document them
This adds missing memory barriers to order updates/tests of
the virtual CPPR and MFRR, thus fixing a lost IPI problem.

While at it also document all barriers in this file.

This fixes a bug causing guest IPIs to occasionally get lost.  The
symptom then is hangs or stalls in the guest.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-24 20:02:01 +10:00
Benjamin Herrenschmidt 2c4fb78f78 KVM: PPC: Book3S HV: Workaround POWER9 DD1.0 bug causing IPB bit loss
This adds a workaround for a bug in POWER9 DD1 chips where changing
the CPPR (Current Processor Priority Register) can cause bits in the
IPB (Interrupt Pending Buffer) to get lost.  Thankfully it only
happens when manually manipulating CPPR which is quite rare.  When it
does happen it can cause interrupts to be delayed or lost.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-24 20:01:39 +10:00
Nicholas Piggin bd0fdb191c KVM: PPC: Book3S HV: Use msgsync with hypervisor doorbells on POWER9
When msgsnd is used for IPIs to other cores, msgsync must be executed by
the target to order stores performed on the source before its msgsnd
(provided the source executes the appropriate sync).

Fixes: 1704a81cce ("KVM: PPC: Book3S HV: Use msgsnd for IPIs to other cores on POWER9")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-24 20:01:39 +10:00
Linus Torvalds 8155469341 s390: SRCU fix.
PPC: host crash fixes.
 x86: bugfixes, including making nested posted interrupts really work.
 Generic: tweaks to kvm_stat and to uevents
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:
 "s390:
   - SRCU fix

  PPC:
   - host crash fixes

  x86:
   - bugfixes, including making nested posted interrupts really work

  Generic:
   - tweaks to kvm_stat and to uevents"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: LAPIC: Fix reentrancy issues with preempt notifiers
  tools/kvm_stat: add '-f help' to get the available event list
  tools/kvm_stat: use variables instead of hard paths in help output
  KVM: nVMX: Fix loss of L2's NMI blocking state
  KVM: nVMX: Fix posted intr delivery when vcpu is in guest mode
  x86: irq: Define a global vector for nested posted interrupts
  KVM: x86: do mask out upper bits of PAE CR3
  KVM: make pid available for uevents without debugfs
  KVM: s390: take srcu lock when getting/setting storage keys
  KVM: VMX: remove unused field
  KVM: PPC: Book3S HV: Fix host crash on changing HPT size
  KVM: PPC: Book3S HV: Enable TM before accessing TM registers
2017-07-28 13:36:56 -07:00
Linus Torvalds 080012bad6 powerpc fixes for 4.13 #4
The highlight is Ben's patch to work around a host killing bug when running KVM
 guests with the Radix MMU on Power9. See the long change log of that commit for
 more detail.
 
 And then three fairly minor fixes:
  - Fix of_node_put() underflow during reconfig remove, using old DLPAR tools.
  - Fix recently introduced ld version check with 64-bit LE-only toolchain.
  - Free the subpage_prot_table correctly, avoiding a memory leak.
 
 Thanks to:
   Aneesh Kumar K.V, Benjamin Herrenschmidt, Laurent Vivier.
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Merge tag 'powerpc-4.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "The highlight is Ben's patch to work around a host killing bug when
  running KVM guests with the Radix MMU on Power9. See the long change
  log of that commit for more detail.

  And then three fairly minor fixes:

   - fix of_node_put() underflow during reconfig remove, using old DLPAR
     tools.

   - fix recently introduced ld version check with 64-bit LE-only
     toolchain.

   - free the subpage_prot_table correctly, avoiding a memory leak.

  Thanks to: Aneesh Kumar K.V, Benjamin Herrenschmidt, Laurent Vivier"

* tag 'powerpc-4.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm/hash: Free the subpage_prot_table correctly
  powerpc/Makefile: Fix ld version check with 64-bit LE-only toolchain
  powerpc/pseries: Fix of_node_put() underflow during reconfig remove
  powerpc/mm/radix: Workaround prefetch issue with KVM
2017-07-28 13:25:15 -07:00
Benjamin Herrenschmidt a25bd72bad powerpc/mm/radix: Workaround prefetch issue with KVM
There's a somewhat architectural issue with Radix MMU and KVM.

When coming out of a guest with AIL (Alternate Interrupt Location, ie,
MMU enabled), we start executing hypervisor code with the PID register
still containing whatever the guest has been using.

The problem is that the CPU can (and will) then start prefetching or
speculatively load from whatever host context has that same PID (if
any), thus bringing translations for that context into the TLB, which
Linux doesn't know about.

This can cause stale translations and subsequent crashes.

Fixing this in a way that is neither racy nor a huge performance
impact is difficult. We could just make the host invalidations always
use broadcast forms but that would hurt single threaded programs for
example.

We chose to fix it instead by partitioning the PID space between guest
and host. This is possible because today Linux only use 19 out of the
20 bits of PID space, so existing guests will work if we make the host
use the top half of the 20 bits space.

We additionally add support for a property to indicate to Linux the
size of the PID register which will be useful if we eventually have
processors with a larger PID space available.

There is still an issue with malicious guests purposefully setting the
PID register to a value in the hosts PID range. Hopefully future HW
can prevent that, but in the meantime, we handle it with a pair of
kludges:

 - On the way out of a guest, before we clear the current VCPU in the
   PACA, we check the PID and if it's outside of the permitted range
   we flush the TLB for that PID.

 - When context switching, if the mm is "new" on that CPU (the
   corresponding bit was set for the first time in the mm cpumask), we
   check if any sibling thread is in KVM (has a non-NULL VCPU pointer
   in the PACA). If that is the case, we also flush the PID for that
   CPU (core).

This second part is needed to handle the case where a process is
migrated (or starts a new pthread) on a sibling thread of the CPU
coming out of KVM, as there's a window where stale translations can
exist before we detect it and flush them out.

A future optimization could be added by keeping track of whether the
PID has ever been used and avoid doing that for completely fresh PIDs.
We could similarily mark PIDs that have been the subject of a global
invalidation as "fresh". But for now this will do.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Rework the asm to build with CONFIG_PPC_RADIX_MMU=n, drop
      unneeded include of kvm_book3s_asm.h]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-07-26 16:41:52 +10:00
Paul Mackerras ef42719814 KVM: PPC: Book3S HV: Fix host crash on changing HPT size
Commit f98a8bf9ee ("KVM: PPC: Book3S HV: Allow KVM_PPC_ALLOCATE_HTAB
ioctl() to change HPT size", 2016-12-20) changed the behaviour of
the KVM_PPC_ALLOCATE_HTAB ioctl so that it now allocates a new HPT
and new revmap array if there was a previously-allocated HPT of a
different size from the size being requested.  In this case, we need
to reset the rmap arrays of the memslots, because the rmap arrays
will contain references to HPTEs which are no longer valid.  Worse,
these references are also references to slots in the new revmap
array (which parallels the HPT), and the new revmap array contains
random contents, since it doesn't get zeroed on allocation.

The effect of having these stale references to slots in the revmap
array that contain random contents is that subsequent calls to
functions such as kvmppc_add_revmap_chain will crash because they
will interpret the non-zero contents of the revmap array as HPTE
indexes and thus index outside of the revmap array.  This leads to
host crashes such as the following.

[ 7072.862122] Unable to handle kernel paging request for data at address 0xd000000c250c00f8
[ 7072.862218] Faulting instruction address: 0xc0000000000e1c78
[ 7072.862233] Oops: Kernel access of bad area, sig: 11 [#1]
[ 7072.862286] SMP NR_CPUS=1024
[ 7072.862286] NUMA
[ 7072.862325] PowerNV
[ 7072.862378] Modules linked in: kvm_hv vhost_net vhost tap xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_mangle ip6table_security ip6table_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw ebtable_filter ebtables ip6table_filter ip6_tables rpcrdma ib_isert iscsi_target_mod ib_iser libiscsi scsi_transport_iscsi ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm iw_cxgb3 mlx5_ib ib_core ses enclosure scsi_transport_sas ipmi_powernv ipmi_devintf ipmi_msghandler powernv_op_panel i2c_opal nfsd auth_rpcgss oid_registry
[ 7072.863085]  nfs_acl lockd grace sunrpc kvm_pr kvm xfs libcrc32c scsi_dh_alua dm_service_time radeon lpfc nvme_fc nvme_fabrics nvme_core scsi_transport_fc i2c_algo_bit tg3 drm_kms_helper ptp pps_core syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm dm_multipath i2c_core cxgb3 mlx5_core mdio [last unloaded: kvm_hv]
[ 7072.863381] CPU: 72 PID: 56929 Comm: qemu-system-ppc Not tainted 4.12.0-kvm+ #59
[ 7072.863457] task: c000000fe29e7600 task.stack: c000001e3ffec000
[ 7072.863520] NIP: c0000000000e1c78 LR: c0000000000e2e3c CTR: c0000000000e25f0
[ 7072.863596] REGS: c000001e3ffef560 TRAP: 0300   Not tainted  (4.12.0-kvm+)
[ 7072.863658] MSR: 9000000100009033 <SF,HV,EE,ME,IR,DR,RI,LE,TM[E]>
[ 7072.863667]   CR: 44082882  XER: 20000000
[ 7072.863767] CFAR: c0000000000e2e38 DAR: d000000c250c00f8 DSISR: 42000000 SOFTE: 1
GPR00: c0000000000e2e3c c000001e3ffef7e0 c000000001407d00 d000000c250c00f0
GPR04: d00000006509fb70 d00000000b3d2048 0000000003ffdfb7 0000000000000000
GPR08: 00000001007fdfb7 00000000c000000f d0000000250c0000 000000000070f7bf
GPR12: 0000000000000008 c00000000fdad000 0000000010879478 00000000105a0d78
GPR16: 00007ffaf4080000 0000000000001190 0000000000000000 0000000000010000
GPR20: 4001ffffff000415 d00000006509fb70 0000000004091190 0000000ee1881190
GPR24: 0000000003ffdfb7 0000000003ffdfb7 00000000007fdfb7 c000000f5c958000
GPR28: d00000002d09fb70 0000000003ffdfb7 d00000006509fb70 d00000000b3d2048
[ 7072.864439] NIP [c0000000000e1c78] kvmppc_add_revmap_chain+0x88/0x130
[ 7072.864503] LR [c0000000000e2e3c] kvmppc_do_h_enter+0x84c/0x9e0
[ 7072.864566] Call Trace:
[ 7072.864594] [c000001e3ffef7e0] [c000001e3ffef830] 0xc000001e3ffef830 (unreliable)
[ 7072.864671] [c000001e3ffef830] [c0000000000e2e3c] kvmppc_do_h_enter+0x84c/0x9e0
[ 7072.864751] [c000001e3ffef920] [d00000000b38d878] kvmppc_map_vrma+0x168/0x200 [kvm_hv]
[ 7072.864831] [c000001e3ffef9e0] [d00000000b38a684] kvmppc_vcpu_run_hv+0x1284/0x1300 [kvm_hv]
[ 7072.864914] [c000001e3ffefb30] [d00000000f465664] kvmppc_vcpu_run+0x44/0x60 [kvm]
[ 7072.865008] [c000001e3ffefb60] [d00000000f461864] kvm_arch_vcpu_ioctl_run+0x114/0x290 [kvm]
[ 7072.865152] [c000001e3ffefbe0] [d00000000f453c98] kvm_vcpu_ioctl+0x598/0x7a0 [kvm]
[ 7072.865292] [c000001e3ffefd40] [c000000000389328] do_vfs_ioctl+0xd8/0x8c0
[ 7072.865410] [c000001e3ffefde0] [c000000000389be4] SyS_ioctl+0xd4/0x130
[ 7072.865526] [c000001e3ffefe30] [c00000000000b760] system_call+0x58/0x6c
[ 7072.865644] Instruction dump:
[ 7072.865715] e95b2110 793a0020 7b4926e4 7f8a4a14 409e0098 807c000c 786326e4 7c6a1a14
[ 7072.865857] 935e0008 7bbd0020 813c000c 913e000c <93a30008> 93bc000c 48000038 60000000
[ 7072.866001] ---[ end trace 627b6e4bf8080edc ]---

Note that to trigger this, it is necessary to use a recent upstream
QEMU (or other userspace that resizes the HPT at CAS time), specify
a maximum memory size substantially larger than the current memory
size, and boot a guest kernel that does not support HPT resizing.

This fixes the problem by resetting the rmap arrays when the old HPT
is freed.

Fixes: f98a8bf9ee ("KVM: PPC: Book3S HV: Allow KVM_PPC_ALLOCATE_HTAB ioctl() to change HPT size")
Cc: stable@vger.kernel.org # v4.11+
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-07-24 16:10:44 +10:00
Paul Mackerras e470571514 KVM: PPC: Book3S HV: Enable TM before accessing TM registers
Commit 46a704f840 ("KVM: PPC: Book3S HV: Preserve userspace HTM state
properly", 2017-06-15) added code to read transactional memory (TM)
registers but forgot to enable TM before doing so.  The result is
that if userspace does have live values in the TM registers, a KVM_RUN
ioctl will cause a host kernel crash like this:

[  181.328511] Unrecoverable TM Unavailable Exception f60 at d00000001e7d9980
[  181.328605] Oops: Unrecoverable TM Unavailable Exception, sig: 6 [#1]
[  181.328613] SMP NR_CPUS=2048
[  181.328613] NUMA
[  181.328618] PowerNV
[  181.328646] Modules linked in: vhost_net vhost tap nfs_layout_nfsv41_files rpcsec_gss_krb5 nfsv4 dns_resolver nfs
+fscache xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat
+nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 tun ebtable_filter ebtables
+ip6table_filter ip6_tables iptable_filter bridge stp llc kvm_hv kvm nfsd ses enclosure scsi_transport_sas ghash_generic
+auth_rpcgss gf128mul xts sg ctr nfs_acl lockd vmx_crypto shpchp ipmi_powernv i2c_opal grace ipmi_devintf i2c_core
+powernv_rng sunrpc ipmi_msghandler ibmpowernv uio_pdrv_genirq uio leds_powernv powernv_op_panel ip_tables xfs sd_mod
+lpfc ipr bnx2x libata mdio ptp pps_core scsi_transport_fc libcrc32c dm_mirror dm_region_hash dm_log dm_mod
[  181.329278] CPU: 40 PID: 9926 Comm: CPU 0/KVM Not tainted 4.12.0+ #1
[  181.329337] task: c000003fc6980000 task.stack: c000003fe4d80000
[  181.329396] NIP: d00000001e7d9980 LR: d00000001e77381c CTR: d00000001e7d98f0
[  181.329465] REGS: c000003fe4d837e0 TRAP: 0f60   Not tainted  (4.12.0+)
[  181.329523] MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE>
[  181.329527]   CR: 24022448  XER: 00000000
[  181.329608] CFAR: d00000001e773818 SOFTE: 1
[  181.329608] GPR00: d00000001e77381c c000003fe4d83a60 d00000001e7ef410 c000003fdcfe0000
[  181.329608] GPR04: c000003fe4f00000 0000000000000000 0000000000000000 c000003fd7954800
[  181.329608] GPR08: 0000000000000001 c000003fc6980000 0000000000000000 d00000001e7e2880
[  181.329608] GPR12: d00000001e7d98f0 c000000007b19000 00000001295220e0 00007fffc0ce2090
[  181.329608] GPR16: 0000010011886608 00007fff8c89f260 0000000000000001 00007fff8c080028
[  181.329608] GPR20: 0000000000000000 00000100118500a6 0000010011850000 0000010011850000
[  181.329608] GPR24: 00007fffc0ce1b48 0000010011850000 00000000d673b901 0000000000000000
[  181.329608] GPR28: 0000000000000000 c000003fdcfe0000 c000003fdcfe0000 c000003fe4f00000
[  181.330199] NIP [d00000001e7d9980] kvmppc_vcpu_run_hv+0x90/0x6b0 [kvm_hv]
[  181.330264] LR [d00000001e77381c] kvmppc_vcpu_run+0x2c/0x40 [kvm]
[  181.330322] Call Trace:
[  181.330351] [c000003fe4d83a60] [d00000001e773478] kvmppc_set_one_reg+0x48/0x340 [kvm] (unreliable)
[  181.330437] [c000003fe4d83b30] [d00000001e77381c] kvmppc_vcpu_run+0x2c/0x40 [kvm]
[  181.330513] [c000003fe4d83b50] [d00000001e7700b4] kvm_arch_vcpu_ioctl_run+0x114/0x2a0 [kvm]
[  181.330586] [c000003fe4d83bd0] [d00000001e7642f8] kvm_vcpu_ioctl+0x598/0x7a0 [kvm]
[  181.330658] [c000003fe4d83d40] [c0000000003451b8] do_vfs_ioctl+0xc8/0x8b0
[  181.330717] [c000003fe4d83de0] [c000000000345a64] SyS_ioctl+0xc4/0x120
[  181.330776] [c000003fe4d83e30] [c00000000000b004] system_call+0x58/0x6c
[  181.330833] Instruction dump:
[  181.330869] e92d0260 e9290b50 e9290108 792807e3 41820058 e92d0260 e9290b50 e9290108
[  181.330941] 792ae8a4 794a1f87 408204f4 e92d0260 <7d4022a6> f9490ff0 e92d0260 7d4122a6
[  181.331013] ---[ end trace 6f6ddeb4bfe92a92 ]---

The fix is just to turn on the TM bit in the MSR before accessing the
registers.

Cc: stable@vger.kernel.org # v3.14+
Fixes: 46a704f840 ("KVM: PPC: Book3S HV: Preserve userspace HTM state properly")
Reported-by: Jan Stancek <jstancek@redhat.com>
Tested-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-07-24 16:10:44 +10:00
Michal Hocko dcda9b0471 mm, tree wide: replace __GFP_REPEAT by __GFP_RETRY_MAYFAIL with more useful semantic
__GFP_REPEAT was designed to allow retry-but-eventually-fail semantic to
the page allocator.  This has been true but only for allocations
requests larger than PAGE_ALLOC_COSTLY_ORDER.  It has been always
ignored for smaller sizes.  This is a bit unfortunate because there is
no way to express the same semantic for those requests and they are
considered too important to fail so they might end up looping in the
page allocator for ever, similarly to GFP_NOFAIL requests.

Now that the whole tree has been cleaned up and accidental or misled
usage of __GFP_REPEAT flag has been removed for !costly requests we can
give the original flag a better name and more importantly a more useful
semantic.  Let's rename it to __GFP_RETRY_MAYFAIL which tells the user
that the allocator would try really hard but there is no promise of a
success.  This will work independent of the order and overrides the
default allocator behavior.  Page allocator users have several levels of
guarantee vs.  cost options (take GFP_KERNEL as an example)

 - GFP_KERNEL & ~__GFP_RECLAIM - optimistic allocation without _any_
   attempt to free memory at all. The most light weight mode which even
   doesn't kick the background reclaim. Should be used carefully because
   it might deplete the memory and the next user might hit the more
   aggressive reclaim

 - GFP_KERNEL & ~__GFP_DIRECT_RECLAIM (or GFP_NOWAIT)- optimistic
   allocation without any attempt to free memory from the current
   context but can wake kswapd to reclaim memory if the zone is below
   the low watermark. Can be used from either atomic contexts or when
   the request is a performance optimization and there is another
   fallback for a slow path.

 - (GFP_KERNEL|__GFP_HIGH) & ~__GFP_DIRECT_RECLAIM (aka GFP_ATOMIC) -
   non sleeping allocation with an expensive fallback so it can access
   some portion of memory reserves. Usually used from interrupt/bh
   context with an expensive slow path fallback.

 - GFP_KERNEL - both background and direct reclaim are allowed and the
   _default_ page allocator behavior is used. That means that !costly
   allocation requests are basically nofail but there is no guarantee of
   that behavior so failures have to be checked properly by callers
   (e.g. OOM killer victim is allowed to fail currently).

 - GFP_KERNEL | __GFP_NORETRY - overrides the default allocator behavior
   and all allocation requests fail early rather than cause disruptive
   reclaim (one round of reclaim in this implementation). The OOM killer
   is not invoked.

 - GFP_KERNEL | __GFP_RETRY_MAYFAIL - overrides the default allocator
   behavior and all allocation requests try really hard. The request
   will fail if the reclaim cannot make any progress. The OOM killer
   won't be triggered.

 - GFP_KERNEL | __GFP_NOFAIL - overrides the default allocator behavior
   and all allocation requests will loop endlessly until they succeed.
   This might be really dangerous especially for larger orders.

Existing users of __GFP_REPEAT are changed to __GFP_RETRY_MAYFAIL
because they already had their semantic.  No new users are added.
__alloc_pages_slowpath is changed to bail out for __GFP_RETRY_MAYFAIL if
there is no progress and we have already passed the OOM point.

This means that all the reclaim opportunities have been exhausted except
the most disruptive one (the OOM killer) and a user defined fallback
behavior is more sensible than keep retrying in the page allocator.

[akpm@linux-foundation.org: fix arch/sparc/kernel/mdesc.c]
[mhocko@suse.com: semantic fix]
  Link: http://lkml.kernel.org/r/20170626123847.GM11534@dhcp22.suse.cz
[mhocko@kernel.org: address other thing spotted by Vlastimil]
  Link: http://lkml.kernel.org/r/20170626124233.GN11534@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20170623085345.11304-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alex Belits <alex.belits@cavium.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: NeilBrown <neilb@suse.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:03 -07:00
Linus Torvalds d691b7e7d1 powerpc updates for 4.13
Highlights include:
 
  - Support for STRICT_KERNEL_RWX on 64-bit server CPUs.
 
  - Platform support for FSP2 (476fpe) board
 
  - Enable ZONE_DEVICE on 64-bit server CPUs.
 
  - Generic & powerpc spin loop primitives to optimise busy waiting
 
  - Convert VDSO update function to use new update_vsyscall() interface
 
  - Optimisations to hypercall/syscall/context-switch paths
 
  - Improvements to the CPU idle code on Power8 and Power9.
 
 As well as many other fixes and improvements.
 
 Thanks to:
   Akshay Adiga, Andrew Donnellan, Andrew Jeffery, Anshuman Khandual, Anton
   Blanchard, Balbir Singh, Benjamin Herrenschmidt, Christophe Leroy, Christophe
   Lombard, Colin Ian King, Dan Carpenter, Gautham R. Shenoy, Hari Bathini, Ian
   Munsie, Ivan Mikhaylov, Javier Martinez Canillas, Madhavan Srinivasan,
   Masahiro Yamada, Matt Brown, Michael Neuling, Michal Suchanek, Murilo
   Opsfelder Araujo, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Paul
   Mackerras, Pavel Machek, Russell Currey, Santosh Sivaraj, Stephen Rothwell,
   Thiago Jung Bauermann, Yang Li.
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Merge tag 'powerpc-4.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Highlights include:

   - Support for STRICT_KERNEL_RWX on 64-bit server CPUs.

   - Platform support for FSP2 (476fpe) board

   - Enable ZONE_DEVICE on 64-bit server CPUs.

   - Generic & powerpc spin loop primitives to optimise busy waiting

   - Convert VDSO update function to use new update_vsyscall() interface

   - Optimisations to hypercall/syscall/context-switch paths

   - Improvements to the CPU idle code on Power8 and Power9.

  As well as many other fixes and improvements.

  Thanks to: Akshay Adiga, Andrew Donnellan, Andrew Jeffery, Anshuman
  Khandual, Anton Blanchard, Balbir Singh, Benjamin Herrenschmidt,
  Christophe Leroy, Christophe Lombard, Colin Ian King, Dan Carpenter,
  Gautham R. Shenoy, Hari Bathini, Ian Munsie, Ivan Mikhaylov, Javier
  Martinez Canillas, Madhavan Srinivasan, Masahiro Yamada, Matt Brown,
  Michael Neuling, Michal Suchanek, Murilo Opsfelder Araujo, Naveen N.
  Rao, Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Pavel Machek,
  Russell Currey, Santosh Sivaraj, Stephen Rothwell, Thiago Jung
  Bauermann, Yang Li"

* tag 'powerpc-4.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (158 commits)
  powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs
  powerpc/mm/radix: Implement STRICT_RWX/mark_rodata_ro() for Radix
  powerpc/mm/hash: Implement mark_rodata_ro() for hash
  powerpc/vmlinux.lds: Align __init_begin to 16M
  powerpc/lib/code-patching: Use alternate map for patch_instruction()
  powerpc/xmon: Add patch_instruction() support for xmon
  powerpc/kprobes/optprobes: Use patch_instruction()
  powerpc/kprobes: Move kprobes over to patch_instruction()
  powerpc/mm/radix: Fix execute permissions for interrupt_vectors
  powerpc/pseries: Fix passing of pp0 in updatepp() and updateboltedpp()
  powerpc/64s: Blacklist rtas entry/exit from kprobes
  powerpc/64s: Blacklist functions invoked on a trap
  powerpc/64s: Un-blacklist system_call() from kprobes
  powerpc/64s: Move system_call() symbol to just after setting MSR_EE
  powerpc/64s: Blacklist system_call() and system_call_common() from kprobes
  powerpc/64s: Convert .L__replay_interrupt_return to a local label
  powerpc64/elfv1: Only dereference function descriptor for non-text symbols
  cxl: Export library to support IBM XSL
  powerpc/dts: Use #include "..." to include local DT
  powerpc/perf/hv-24x7: Aggregate result elements on POWER9 SMT8
  ...
2017-07-07 13:55:45 -07:00
Linus Torvalds c136b84393 PPC:
- Better machine check handling for HV KVM
 - Ability to support guests with threads=2, 4 or 8 on POWER9
 - Fix for a race that could cause delayed recognition of signals
 - Fix for a bug where POWER9 guests could sleep with interrupts pending.
 
 ARM:
 - VCPU request overhaul
 - allow timer and PMU to have their interrupt number selected from userspace
 - workaround for Cavium erratum 30115
 - handling of memory poisonning
 - the usual crop of fixes and cleanups
 
 s390:
 - initial machine check forwarding
 - migration support for the CMMA page hinting information
 - cleanups and fixes
 
 x86:
 - nested VMX bugfixes and improvements
 - more reliable NMI window detection on AMD
 - APIC timer optimizations
 
 Generic:
 - VCPU request overhaul + documentation of common code patterns
 - kvm_stat improvements
 
 There is a small conflict in arch/s390 due to an arch-wide field rename.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "PPC:
   - Better machine check handling for HV KVM
   - Ability to support guests with threads=2, 4 or 8 on POWER9
   - Fix for a race that could cause delayed recognition of signals
   - Fix for a bug where POWER9 guests could sleep with interrupts pending.

  ARM:
   - VCPU request overhaul
   - allow timer and PMU to have their interrupt number selected from userspace
   - workaround for Cavium erratum 30115
   - handling of memory poisonning
   - the usual crop of fixes and cleanups

  s390:
   - initial machine check forwarding
   - migration support for the CMMA page hinting information
   - cleanups and fixes

  x86:
   - nested VMX bugfixes and improvements
   - more reliable NMI window detection on AMD
   - APIC timer optimizations

  Generic:
   - VCPU request overhaul + documentation of common code patterns
   - kvm_stat improvements"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (124 commits)
  Update my email address
  kvm: vmx: allow host to access guest MSR_IA32_BNDCFGS
  x86: kvm: mmu: use ept a/d in vmcs02 iff used in vmcs12
  kvm: x86: mmu: allow A/D bits to be disabled in an mmu
  x86: kvm: mmu: make spte mmio mask more explicit
  x86: kvm: mmu: dead code thanks to access tracking
  KVM: PPC: Book3S: Fix typo in XICS-on-XIVE state saving code
  KVM: PPC: Book3S HV: Close race with testing for signals on guest entry
  KVM: PPC: Book3S HV: Simplify dynamic micro-threading code
  KVM: x86: remove ignored type attribute
  KVM: LAPIC: Fix lapic timer injection delay
  KVM: lapic: reorganize restart_apic_timer
  KVM: lapic: reorganize start_hv_timer
  kvm: nVMX: Check memory operand to INVVPID
  KVM: s390: Inject machine check into the nested guest
  KVM: s390: Inject machine check into the guest
  tools/kvm_stat: add new interactive command 'b'
  tools/kvm_stat: add new command line switch '-i'
  tools/kvm_stat: fix error on interactive command 'g'
  KVM: SVM: suppress unnecessary NMI singlestep on GIF=0 and nested exit
  ...
2017-07-06 18:38:31 -07:00
Linus Torvalds 9a9594efe5 Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP hotplug updates from Thomas Gleixner:
 "This update is primarily a cleanup of the CPU hotplug locking code.

  The hotplug locking mechanism is an open coded RWSEM, which allows
  recursive locking. The main problem with that is the recursive nature
  as it evades the full lockdep coverage and hides potential deadlocks.

  The rework replaces the open coded RWSEM with a percpu RWSEM and
  establishes full lockdep coverage that way.

  The bulk of the changes fix up recursive locking issues and address
  the now fully reported potential deadlocks all over the place. Some of
  these deadlocks have been observed in the RT tree, but on mainline the
  probability was low enough to hide them away."

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
  cpu/hotplug: Constify attribute_group structures
  powerpc: Only obtain cpu_hotplug_lock if called by rtasd
  ARM/hw_breakpoint: Fix possible recursive locking for arch_hw_breakpoint_init
  cpu/hotplug: Remove unused check_for_tasks() function
  perf/core: Don't release cred_guard_mutex if not taken
  cpuhotplug: Link lock stacks for hotplug callbacks
  acpi/processor: Prevent cpu hotplug deadlock
  sched: Provide is_percpu_thread() helper
  cpu/hotplug: Convert hotplug locking to percpu rwsem
  s390: Prevent hotplug rwsem recursion
  arm: Prevent hotplug rwsem recursion
  arm64: Prevent cpu hotplug rwsem recursion
  kprobes: Cure hotplug lock ordering issues
  jump_label: Reorder hotplug lock and jump_label_lock
  perf/tracing/cpuhotplug: Fix locking order
  ACPI/processor: Use cpu_hotplug_disable() instead of get_online_cpus()
  PCI: Replace the racy recursion prevention
  PCI: Use cpu_hotplug_disable() instead of get_online_cpus()
  perf/x86/intel: Drop get_online_cpus() in intel_snb_check_microcode()
  x86/perf: Drop EXPORT of perf_check_microcode
  ...
2017-07-03 18:08:06 -07:00
Michael Ellerman 218ea31039 Merge branch 'fixes' into next
Merge our fixes branch, a few of them are tripping people up while
working on top of next, and we also have a dependency between the CXL
fixes and new CXL code we want to merge into next.
2017-07-03 23:05:43 +10:00
Paolo Bonzini 8a53e7e572 Merge branch 'kvm-ppc-next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD
- Better machine check handling for HV KVM
- Ability to support guests with threads=2, 4 or 8 on POWER9
- Fix for a race that could cause delayed recognition of signals
- Fix for a bug where POWER9 guests could sleep with interrupts
  pending.
2017-07-03 10:41:59 +02:00
Paul Mackerras 00c14757f6 KVM: PPC: Book3S: Fix typo in XICS-on-XIVE state saving code
This fixes a typo where the wrong loop index was used to index
the kvmppc_xive_vcpu.queues[] array in xive_pre_save_scan().
The variable i contains the vcpu number; we need to index queues[]
using j, which iterates from 0 to KVMPPC_XIVE_Q_COUNT-1.

The effect of this bug is that things that save the interrupt
controller state, such as "virsh dump", on a VM with more than
8 vCPUs, result in xive_pre_save_queue() getting called on a
bogus queue structure, usually resulting in a crash like this:

[  501.821107] Unable to handle kernel paging request for data at address 0x00000084
[  501.821212] Faulting instruction address: 0xc008000004c7c6f8
[  501.821234] Oops: Kernel access of bad area, sig: 11 [#1]
[  501.821305] SMP NR_CPUS=1024
[  501.821307] NUMA
[  501.821376] PowerNV
[  501.821470] Modules linked in: vhost_net vhost tap xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_mangle ip6table_security ip6table_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack libcrc32c iptable_mangle iptable_security iptable_raw ebtable_filter ebtables ip6table_filter ip6_tables ses enclosure scsi_transport_sas ipmi_powernv ipmi_devintf ipmi_msghandler powernv_op_panel kvm_hv nfsd auth_rpcgss oid_registry nfs_acl lockd grace sunrpc kvm tg3 ptp pps_core
[  501.822477] CPU: 3 PID: 3934 Comm: live_migration Not tainted 4.11.0-4.git8caa70f.el7.centos.ppc64le #1
[  501.822633] task: c0000003f9e3ae80 task.stack: c0000003f9ed4000
[  501.822745] NIP: c008000004c7c6f8 LR: c008000004c7c628 CTR: 0000000030058018
[  501.822877] REGS: c0000003f9ed7980 TRAP: 0300   Not tainted  (4.11.0-4.git8caa70f.el7.centos.ppc64le)
[  501.823030] MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE>
[  501.823047]   CR: 28022244  XER: 00000000
[  501.823203] CFAR: c008000004c7c77c DAR: 0000000000000084 DSISR: 40000000 SOFTE: 1
[  501.823203] GPR00: c008000004c7c628 c0000003f9ed7c00 c008000004c91450 00000000000000ff
[  501.823203] GPR04: c0000003f5580000 c0000003f559bf98 9000000000009033 0000000000000000
[  501.823203] GPR08: 0000000000000084 0000000000000000 00000000000001e0 9000000000001003
[  501.823203] GPR12: c00000000008a7d0 c00000000fdc1b00 000000000a9a0000 0000000000000000
[  501.823203] GPR16: 00000000402954e8 000000000a9a0000 0000000000000004 0000000000000000
[  501.823203] GPR20: 0000000000000008 c000000002e8f180 c000000002e8f1e0 0000000000000001
[  501.823203] GPR24: 0000000000000008 c0000003f5580008 c0000003f4564018 c000000002e8f1e8
[  501.823203] GPR28: 00003ff6e58bdc28 c0000003f4564000 0000000000000000 0000000000000000
[  501.825441] NIP [c008000004c7c6f8] xive_get_attr+0x3b8/0x5b0 [kvm]
[  501.825671] LR [c008000004c7c628] xive_get_attr+0x2e8/0x5b0 [kvm]
[  501.825887] Call Trace:
[  501.825991] [c0000003f9ed7c00] [c008000004c7c628] xive_get_attr+0x2e8/0x5b0 [kvm] (unreliable)
[  501.826312] [c0000003f9ed7cd0] [c008000004c62ec4] kvm_device_ioctl_attr+0x64/0xa0 [kvm]
[  501.826581] [c0000003f9ed7d20] [c008000004c62fcc] kvm_device_ioctl+0xcc/0xf0 [kvm]
[  501.826843] [c0000003f9ed7d40] [c000000000350c70] do_vfs_ioctl+0xd0/0x8c0
[  501.827060] [c0000003f9ed7de0] [c000000000351534] SyS_ioctl+0xd4/0xf0
[  501.827282] [c0000003f9ed7e30] [c00000000000b8e0] system_call+0x38/0xfc
[  501.827496] Instruction dump:
[  501.827632] 419e0078 3b760008 e9160008 83fb000c 83db0010 80fb0008 2f280000 60000000
[  501.827901] 60000000 60420000 419a0050 7be91764 <7d284c2c> 552a0ffe 7f8af040 419e003c
[  501.828176] ---[ end trace 2d0529a5bbbbafed ]---

Cc: stable@vger.kernel.org
Fixes: 5af5099385 ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller")
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-07-03 10:40:22 +02:00
Paul Mackerras 8b24e69fc4 KVM: PPC: Book3S HV: Close race with testing for signals on guest entry
At present, interrupts are hard-disabled fairly late in the guest
entry path, in the assembly code.  Since we check for pending signals
for the vCPU(s) task(s) earlier in the guest entry path, it is
possible for a signal to be delivered before we enter the guest but
not be noticed until after we exit the guest for some other reason.

Similarly, it is possible for the scheduler to request a reschedule
while we are in the guest entry path, and we won't notice until after
we have run the guest, potentially for a whole timeslice.

Furthermore, with a radix guest on POWER9, we can take the interrupt
with the MMU on.  In this case we end up leaving interrupts
hard-disabled after the guest exit, and they are likely to stay
hard-disabled until we exit to userspace or context-switch to
another process.  This was masking the fact that we were also not
setting the RI (recoverable interrupt) bit in the MSR, meaning
that if we had taken an interrupt, it would have crashed the host
kernel with an unrecoverable interrupt message.

To close these races, we need to check for signals and reschedule
requests after hard-disabling interrupts, and then keep interrupts
hard-disabled until we enter the guest.  If there is a signal or a
reschedule request from another CPU, it will send an IPI, which will
cause a guest exit.

This puts the interrupt disabling before we call kvmppc_start_thread()
for all the secondary threads of this core that are going to run vCPUs.
The reason for that is that once we have started the secondary threads
there is no easy way to back out without going through at least part
of the guest entry path.  However, kvmppc_start_thread() includes some
code for radix guests which needs to call smp_call_function(), which
must be called with interrupts enabled.  To solve this problem, this
patch moves that code into a separate function that is called earlier.

When the guest exit is caused by an external interrupt, a hypervisor
doorbell or a hypervisor maintenance interrupt, we now handle these
using the replay facility.  __kvmppc_vcore_entry() now returns the
trap number that caused the exit on this thread, and instead of the
assembly code jumping to the handler entry, we return to C code with
interrupts still hard-disabled and set the irq_happened flag in the
PACA, so that when we do local_irq_enable() the appropriate handler
gets called.

With all this, we now have the interrupt soft-enable flag clear while
we are in the guest.  This is useful because code in the real-mode
hypercall handlers that checks whether interrupts are enabled will
now see that they are disabled, which is correct, since interrupts
are hard-disabled in the real-mode code.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-07-01 18:59:38 +10:00
Paul Mackerras 898b25b202 KVM: PPC: Book3S HV: Simplify dynamic micro-threading code
Since commit b009031f74 ("KVM: PPC: Book3S HV: Take out virtual
core piggybacking code", 2016-09-15), we only have at most one
vcore per subcore.  Previously, the fact that there might be more
than one vcore per subcore meant that we had the notion of a
"master vcore", which was the vcore that controlled thread 0 of
the subcore.  We also needed a list per subcore in the core_info
struct to record which vcores belonged to each subcore.  Now that
there can only be one vcore in the subcore, we can replace the
list with a simple pointer and get rid of the notion of the
master vcore (and in fact treat every vcore as a master vcore).

We can also get rid of the subcore_vm[] field in the core_info
struct since it is never read.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-07-01 18:59:01 +10:00
Paolo Bonzini 04a7ea04d5 KVM/ARM updates for 4.13
- vcpu request overhaul
 - allow timer and PMU to have their interrupt number
   selected from userspace
 - workaround for Cavium erratum 30115
 - handling of memory poisonning
 - the usual crop of fixes and cleanups
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Merge tag 'kvmarm-for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/ARM updates for 4.13

- vcpu request overhaul
- allow timer and PMU to have their interrupt number
  selected from userspace
- workaround for Cavium erratum 30115
- handling of memory poisonning
- the usual crop of fixes and cleanups

Conflicts:
	arch/s390/include/asm/kvm_host.h
2017-06-30 12:38:26 +02:00
Balbir Singh 0428491cba powerpc/mm: Trace tlbie(l) instructions
Add a trace point for tlbie(l) (Translation Lookaside Buffer Invalidate
Entry (Local)) instructions.

The tlbie instruction has changed over the years, so not all versions
accept the same operands. Use the ISA v3 field operands because they are
the most verbose, we may change them in future.

Example output:

  qemu-system-ppc-5371  [016]  1412.369519: tlbie:
  	tlbie with lpid 0, local 1, rb=67bd8900174c11c1, rs=0, ric=0 prs=0 r=0

Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Add some missing trace_tlbie()s, reword change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-06-23 21:14:49 +10:00
Paul Mackerras 2ed4f9dd19 KVM: PPC: Book3S HV: Add capability to report possible virtual SMT modes
Now that userspace can set the virtual SMT mode by enabling the
KVM_CAP_PPC_SMT capability, it is useful for userspace to be able
to query the set of possible virtual SMT modes.  This provides a
new capability, KVM_CAP_PPC_SMT_POSSIBLE, to provide this
information.  The return value is a bitmap of possible modes, with
bit N set if virtual SMT mode 2^N is available.  That is, 1 indicates
SMT1 is available, 2 indicates that SMT2 is available, 3 indicates
that both SMT1 and SMT2 are available, and so on.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-22 11:25:31 +10:00
Aravinda Prasad e20bbd3d8d KVM: PPC: Book3S HV: Exit guest upon MCE when FWNMI capability is enabled
Enhance KVM to cause a guest exit with KVM_EXIT_NMI
exit reason upon a machine check exception (MCE) in
the guest address space if the KVM_CAP_PPC_FWNMI
capability is enabled (instead of delivering a 0x200
interrupt to guest). This enables QEMU to build error
log and deliver machine check exception to guest via
guest registered machine check handler.

This approach simplifies the delivery of machine
check exception to guest OS compared to the earlier
approach of KVM directly invoking 0x200 guest interrupt
vector.

This design/approach is based on the feedback for the
QEMU patches to handle machine check exception. Details
of earlier approach of handling machine check exception
in QEMU and related discussions can be found at:

https://lists.nongnu.org/archive/html/qemu-devel/2014-11/msg00813.html

Note:

This patch now directly invokes machine_check_print_event_info()
from kvmppc_handle_exit_hv() to print the event to host console
at the time of guest exit before the exception is passed on to the
guest. Hence, the host-side handling which was performed earlier
via machine_check_fwnmi is removed.

The reasons for this approach is (i) it is not possible
to distinguish whether the exception occurred in the
guest or the host from the pt_regs passed on the
machine_check_exception(). Hence machine_check_exception()
calls panic, instead of passing on the exception to
the guest, if the machine check exception is not
recoverable. (ii) the approach introduced in this
patch gives opportunity to the host kernel to perform
actions in virtual mode before passing on the exception
to the guest. This approach does not require complex
tweaks to machine_check_fwnmi and friends.

Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-22 11:24:57 +10:00
Aravinda Prasad 134764ed6e KVM: PPC: Book3S HV: Add new capability to control MCE behaviour
This introduces a new KVM capability to control how KVM behaves
on machine check exception (MCE) in HV KVM guests.

If this capability has not been enabled, KVM redirects machine check
exceptions to guest's 0x200 vector, if the address in error belongs to
the guest. With this capability enabled, KVM will cause a guest exit
with the exit reason indicating an NMI.

The new capability is required to avoid problems if a new kernel/KVM
is used with an old QEMU, running a guest that doesn't issue
"ibm,nmi-register".  As old QEMU does not understand the NMI exit
type, it treats it as a fatal error.  However, the guest could have
handled the machine check error if the exception was delivered to
guest's 0x200 interrupt vector instead of NMI exit in case of old
QEMU.

[paulus@ozlabs.org - Reworded the commit message to be clearer,
 enable only on HV KVM.]

Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-21 13:37:08 +10:00
Radim Krčmář c72544d85f Merge branch 'kvm-ppc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
* fix problems that could cause hangs or crashes in the host on POWER9
* fix problems that could allow guests to potentially affect or disrupt
  the execution of the controlling userspace
2017-06-20 14:32:57 +02:00
Paul Mackerras ee3308a254 KVM: PPC: Book3S HV: Don't sleep if XIVE interrupt pending on POWER9
On a POWER9 system, it is possible for an interrupt to become pending
for a VCPU when that VCPU is about to cede (execute a H_CEDE hypercall)
and has already disabled interrupts, or in the H_CEDE processing up
to the point where the XIVE context is pulled from the hardware.  In
such a case, the H_CEDE should not sleep, but should return immediately
to the guest.  However, the conditions tested in kvmppc_vcpu_woken()
don't include the condition that a XIVE interrupt is pending, so the
VCPU could sleep until the next decrementer interrupt.

To fix this, we add a new xive_interrupt_pending() helper which looks
in the XIVE context that was pulled from the hardware to see if the
priority of any pending interrupt is higher (numerically lower than)
the CPU priority.  If so then kvmppc_vcpu_woken() will return true.
If the XIVE context has never been used, then both the pipr and the
cppr fields will be zero and the test will indicate that no interrupt
is pending.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-20 15:46:12 +10:00
Nicholas Piggin 9d29250136 powerpc/64s/idle: Avoid SRR usage in idle sleep/wake paths
Idle code now always runs at the 0xc... effective address whether
in real or virtual mode. This means rfid can be ditched, along
with a lot of SRR manipulations.

In the wakeup path, carry SRR1 around in r12. Use mtmsrd to change
MSR states as required.

This also balances the return prediction for the idle call, by
doing blr rather than rfid to return to the idle caller.

On POWER9, 2-process context switch on different cores, with snooze
disabled, increases performance by 2%.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Incorporate v2 fixes from Nick]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-06-19 19:46:29 +10:00
Paul Mackerras 579006944e KVM: PPC: Book3S HV: Virtualize doorbell facility on POWER9
On POWER9, we no longer have the restriction that we had on POWER8
where all threads in a core have to be in the same partition, so
the CPU threads are now independent.  However, we still want to be
able to run guests with a virtual SMT topology, if only to allow
migration of guests from POWER8 systems to POWER9.

A guest that has a virtual SMT mode greater than 1 will expect to
be able to use the doorbell facility; it will expect the msgsndp
and msgclrp instructions to work appropriately and to be able to read
sensible values from the TIR (thread identification register) and
DPDES (directed privileged doorbell exception status) special-purpose
registers.  However, since each CPU thread is a separate sub-processor
in POWER9, these instructions and registers can only be used within
a single CPU thread.

In order for these instructions to appear to act correctly according
to the guest's virtual SMT mode, we have to trap and emulate them.
We cause them to trap by clearing the HFSCR_MSGP bit in the HFSCR
register.  The emulation is triggered by the hypervisor facility
unavailable interrupt that occurs when the guest uses them.

To cause a doorbell interrupt to occur within the guest, we set the
DPDES register to 1.  If the guest has interrupts enabled, the CPU
will generate a doorbell interrupt and clear the DPDES register in
hardware.  The DPDES hardware register for the guest is saved in the
vcpu->arch.vcore->dpdes field.  Since this gets written by the guest
exit code, other VCPUs wishing to cause a doorbell interrupt don't
write that field directly, but instead set a vcpu->arch.doorbell_request
flag.  This is consumed and set to 0 by the guest entry code, which
then sets DPDES to 1.

Emulating reads of the DPDES register is somewhat involved, because
it requires reading the doorbell pending interrupt status of all of the
VCPU threads in the virtual core, and if any of those VCPUs are
running, their doorbell status is only up-to-date in the hardware
DPDES registers of the CPUs where they are running.  In order to get
a reasonable approximation of the current doorbell status, we send
those CPUs an IPI, causing an exit from the guest which will update
the vcpu->arch.vcore->dpdes field.  We then use that value in
constructing the emulated DPDES register value.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-19 14:34:37 +10:00
Paul Mackerras 3c31352460 KVM: PPC: Book3S HV: Allow userspace to set the desired SMT mode
This allows userspace to set the desired virtual SMT (simultaneous
multithreading) mode for a VM, that is, the number of VCPUs that
get assigned to each virtual core.  Previously, the virtual SMT mode
was fixed to the number of threads per subcore, and if userspace
wanted to have fewer vcpus per vcore, then it would achieve that by
using a sparse CPU numbering.  This had the disadvantage that the
vcpu numbers can get quite large, particularly for SMT1 guests on
a POWER8 with 8 threads per core.  With this patch, userspace can
set its desired virtual SMT mode and then use contiguous vcpu
numbering.

On POWER8, where the threading mode is "strict", the virtual SMT mode
must be less than or equal to the number of threads per subcore.  On
POWER9, which implements a "loose" threading mode, the virtual SMT
mode can be any power of 2 between 1 and 8, even though there is
effectively one thread per subcore, since the threads are independent
and can all be in different partitions.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-19 14:34:20 +10:00
Paul Mackerras 769377f77c KVM: PPC: Book3S HV: Context-switch HFSCR between host and guest on POWER9
This adds code to allow us to use a different value for the HFSCR
(Hypervisor Facilities Status and Control Register) when running the
guest from that which applies in the host.  The reason for doing this
is to allow us to trap the msgsndp instruction and related operations
in future so that they can be virtualized.  We also save the value of
HFSCR when a hypervisor facility unavailable interrupt occurs, because
the high byte of HFSCR indicates which facility the guest attempted to
access.

We save and restore the host value on guest entry/exit because some
bits of it affect host userspace execution.

We only do all this on POWER9, not on POWER8, because we are not
intending to virtualize any of the facilities controlled by HFSCR on
POWER8.  In particular, the HFSCR bit that controls execution of
msgsndp and related operations does not exist on POWER8.  The HFSCR
doesn't exist at all on POWER7.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-19 14:08:02 +10:00
Paul Mackerras 1da4e2f4fb KVM: PPC: Book3S HV: Don't let VCPU sleep if it has a doorbell pending
It is possible, through a narrow race condition, for a VCPU to exit
the guest with a H_CEDE hypercall while it has a doorbell interrupt
pending.  In this case, the H_CEDE should return immediately, but in
fact it puts the VCPU to sleep until some other interrupt becomes
pending or a prod is received (via another VCPU doing H_PROD).

This fixes it by checking the DPDES (Directed Privileged Doorbell
Exception Status) bit for the thread along with the other interrupt
pending bits.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-19 14:05:22 +10:00
Paul Mackerras 1bc3fe818c KVM: PPC: Book3S HV: Enable guests to use large decrementer mode on POWER9
This allows userspace (e.g. QEMU) to enable large decrementer mode for
the guest when running on a POWER9 host, by setting the LPCR_LD bit in
the guest LPCR value.  With this, the guest exit code saves 64 bits of
the guest DEC value on exit.  Other places that use the guest DEC
value check the LPCR_LD bit in the guest LPCR value, and if it is set,
omit the 32-bit sign extension that would otherwise be done.

This doesn't change the DEC emulation used by PR KVM because PR KVM
is not supported on POWER9 yet.

This is partly based on an earlier patch by Oliver O'Halloran.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-19 14:02:04 +10:00
Linus Torvalds 5ac447d268 powerpc fixes for 4.12 #6
Three small fixes for recently merged code:
 
  - remove a spurious WARN_ON when a PCI device has no of_node, it's allowed in
    some circumstances for there to be no of_node.
 
  - fix the offset for store EOI MMIOs in the XIVE interrupt controller.
 
  - fix non-const WARN_ONs which were becoming BUGs due to them losing
    BUGFLAG_WARNING in a recent cleanup patch.
 
 Thanks to:
   Alexey Kardashevskiy, Alistair Popple, Benjamin Herrenschmidt.
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Merge tag 'powerpc-4.12-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "Three small fixes for recently merged code:

   - remove a spurious WARN_ON when a PCI device has no of_node, it's
     allowed in some circumstances for there to be no of_node.

   - fix the offset for store EOI MMIOs in the XIVE interrupt
     controller.

   - fix non-const WARN_ONs which were becoming BUGs due to them losing
     BUGFLAG_WARNING in a recent cleanup patch.

  Thanks to: Alexey Kardashevskiy, Alistair Popple, Benjamin
  Herrenschmidt"

* tag 'powerpc-4.12-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/debug: Add missing warn flag to WARN_ON's non-builtin path
  powerpc/xive: Fix offset for store EOI MMIOs
  powerpc/npu-dma: Remove spurious WARN_ON when a PCI device has no of_node
2017-06-17 05:57:54 +09:00
Paul Mackerras 3d3efb68c1 KVM: PPC: Book3S HV: Ignore timebase offset on POWER9 DD1
POWER9 DD1 has an erratum where writing to the TBU40 register, which
is used to apply an offset to the timebase, can cause the timebase to
lose counts.  This results in the timebase on some CPUs getting out of
sync with other CPUs, which then results in misbehaviour of the
timekeeping code.

To work around the problem, we make KVM ignore the timebase offset for
all guests on POWER9 DD1 machines.  This means that live migration
cannot be supported on POWER9 DD1 machines.

Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-16 16:04:57 +10:00
Paul Mackerras 7ceaa6dcd8 KVM: PPC: Book3S HV: Save/restore host values of debug registers
At present, HV KVM on POWER8 and POWER9 machines loses any instruction
or data breakpoint set in the host whenever a guest is run.
Instruction breakpoints are currently only used by xmon, but ptrace
and the perf_event subsystem can set data breakpoints as well as xmon.

To fix this, we save the host values of the debug registers (CIABR,
DAWR and DAWRX) before entering the guest and restore them on exit.
To provide space to save them in the stack frame, we expand the stack
frame allocated by kvmppc_hv_entry() from 112 to 144 bytes.

Fixes: b005255e12 ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs", 2014-01-08)
Cc: stable@vger.kernel.org # v3.14+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-16 11:53:19 +10:00
Benjamin Herrenschmidt 25642705b2 powerpc/xive: Fix offset for store EOI MMIOs
Architecturally we should apply a 0x400 offset for these. Not doing
it will break future HW implementations.

The offset of 0 is supposed to remain for "triggers" though not all
sources support both trigger and store EOI, and in P9 specifically,
some sources will treat 0 as a store EOI. But future chips will not.
So this makes us use the properly architected offset which should work
always.

Fixes: 243e25112d ("powerpc/xive: Native exploitation of the XIVE interrupt controller")
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-06-15 23:29:39 +10:00
Paul Mackerras 46a704f840 KVM: PPC: Book3S HV: Preserve userspace HTM state properly
If userspace attempts to call the KVM_RUN ioctl when it has hardware
transactional memory (HTM) enabled, the values that it has put in the
HTM-related SPRs TFHAR, TFIAR and TEXASR will get overwritten by
guest values.  To fix this, we detect this condition and save those
SPR values in the thread struct, and disable HTM for the task.  If
userspace goes to access those SPRs or the HTM facility in future,
a TM-unavailable interrupt will occur and the handler will reload
those SPRs and re-enable HTM.

If userspace has started a transaction and suspended it, we would
currently lose the transactional state in the guest entry path and
would almost certainly get a "TM Bad Thing" interrupt, which would
cause the host to crash.  To avoid this, we detect this case and
return from the KVM_RUN ioctl with an EINVAL error, with the KVM
exit reason set to KVM_EXIT_FAIL_ENTRY.

Fixes: b005255e12 ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs", 2014-01-08)
Cc: stable@vger.kernel.org # v3.14+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-15 16:18:17 +10:00
Paul Mackerras 4c3bb4ccd0 KVM: PPC: Book3S HV: Restore critical SPRs to host values on guest exit
This restores several special-purpose registers (SPRs) to sane values
on guest exit that were missed before.

TAR and VRSAVE are readable and writable by userspace, and we need to
save and restore them to prevent the guest from potentially affecting
userspace execution (not that TAR or VRSAVE are used by any known
program that run uses the KVM_RUN ioctl).  We save/restore these
in kvmppc_vcpu_run_hv() rather than on every guest entry/exit.

FSCR affects userspace execution in that it can prohibit access to
certain facilities by userspace.  We restore it to the normal value
for the task on exit from the KVM_RUN ioctl.

IAMR is normally 0, and is restored to 0 on guest exit.  However,
with a radix host on POWER9, it is set to a value that prevents the
kernel from executing user-accessible memory.  On POWER9, we save
IAMR on guest entry and restore it on guest exit to the saved value
rather than 0.  On POWER8 we continue to set it to 0 on guest exit.

PSPB is normally 0.  We restore it to 0 on guest exit to prevent
userspace taking advantage of the guest having set it non-zero
(which would allow userspace to set its SMT priority to high).

UAMOR is normally 0.  We restore it to 0 on guest exit to prevent
the AMR from being used as a covert channel between userspace
processes, since the AMR is not context-switched at present.

Fixes: b005255e12 ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs", 2014-01-08)
Cc: stable@vger.kernel.org # v3.14+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-15 16:17:09 +10:00
Paul Mackerras ca8efa1df1 KVM: PPC: Book3S HV: Context-switch EBB registers properly
This adds code to save the values of three SPRs (special-purpose
registers) used by userspace to control event-based branches (EBBs),
which are essentially interrupts that get delivered directly to
userspace.  These registers are loaded up with guest values when
entering the guest, and their values are saved when exiting the
guest, but we were not saving the host values and restoring them
before going back to userspace.

On POWER8 this would only affect userspace programs which explicitly
request the use of EBBs and also use the KVM_RUN ioctl, since the
only source of EBBs on POWER8 is the PMU, and there is an explicit
enable bit in the PMU registers (and those PMU registers do get
properly context-switched between host and guest).  On POWER9 there
is provision for externally-generated EBBs, and these are not subject
to the control in the PMU registers.

Since these registers only affect userspace, we can save them when
we first come in from userspace and restore them before returning to
userspace, rather than saving/restoring the host values on every
guest entry/exit.  Similarly, we don't need to worry about their
values on offline secondary threads since they execute in the context
of the idle task, which never executes in userspace.

Fixes: b005255e12 ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs", 2014-01-08)
Cc: stable@vger.kernel.org # v3.14+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-13 14:12:02 +10:00
Radim Krčmář 2fa6e1e12a KVM: add kvm_request_pending
A first step in vcpu->requests encapsulation.  Additionally, we now
use READ_ONCE() when accessing vcpu->requests, which ensures we
always load vcpu->requests when it's accessed.  This is important as
other threads can change it any time.  Also, READ_ONCE() documents
that vcpu->requests is used with other threads, likely requiring
memory barriers, which it does.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
[ Documented the new use of READ_ONCE() and converted another check
  in arch/mips/kvm/vz.c ]
Signed-off-by: Andrew Jones <drjones@redhat.com>
Acked-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-04 16:53:00 +02:00
Paul Mackerras 2f2724630f KVM: PPC: Book3S HV: Cope with host using large decrementer mode
POWER9 introduces a new mode for the decrementer register, called
large decrementer mode, in which the decrementer counter is 56 bits
wide rather than 32, and reads are sign-extended rather than
zero-extended.  For the decrementer, this new mode is optional and
controlled by a bit in the LPCR.  The hypervisor decrementer (HDEC)
is 56 bits wide on POWER9 and has no mode control.

Since KVM code reads and writes the decrementer and hypervisor
decrementer registers in a few places, it needs to be aware of the
need to treat the decrementer value as a 64-bit quantity, and only do
a 32-bit sign extension when large decrementer mode is not in effect.
Similarly, the HDEC should always be treated as a 64-bit quantity on
POWER9.  We define a new EXTEND_HDEC macro to encapsulate the feature
test for POWER9 and the sign extension.

To enable the sign extension to be removed in large decrementer mode,
we test the LPCR_LD bit in the host LPCR image stored in the struct
kvm for the guest.  If is set then large decrementer mode is enabled
and the sign extension should be skipped.

This is partly based on an earlier patch by Oliver O'Halloran.

Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-05-29 16:01:26 +10:00
Sebastian Andrzej Siewior 419af25fa4 KVM/PPC/Book3S HV: Use cpuhp_setup_state_nocalls_cpuslocked()
kvmppc_alloc_host_rm_ops() holds get_online_cpus() while invoking
cpuhp_setup_state_nocalls().

cpuhp_setup_state_nocalls() invokes get_online_cpus() as well. This is
correct, but prevents the conversion of the hotplug locking to a percpu
rwsem.

Use cpuhp_setup_state_nocalls_cpuslocked() to avoid the nested
call. Convert *_online_cpus() to the new interfaces while at it.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: kvm@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: kvm-ppc@vger.kernel.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Alexander Graf <agraf@suse.com>
Link: http://lkml.kernel.org/r/20170524081547.809616236@linutronix.de
2017-05-26 10:10:39 +02:00
Paul Mackerras 76d837a4c0 KVM: PPC: Book3S PR: Don't include SPAPR TCE code on non-pseries platforms
Commit e91aa8e6ec ("KVM: PPC: Enable IOMMU_API for KVM_BOOK3S_64
permanently", 2017-03-22) enabled the SPAPR TCE code for all 64-bit
Book 3S kernel configurations in order to simplify the code and
reduce #ifdefs.  However, 64-bit Book 3S PPC platforms other than
pseries and powernv don't implement the necessary IOMMU callbacks,
leading to build failures like the following (for a pasemi config):

scripts/kconfig/conf  --silentoldconfig Kconfig
warning: (KVM_BOOK3S_64) selects SPAPR_TCE_IOMMU which has unmet direct dependencies (IOMMU_SUPPORT && (PPC_POWERNV || PPC_PSERIES))

...

  CC [M]  arch/powerpc/kvm/book3s_64_vio.o
/home/paulus/kernel/kvm/arch/powerpc/kvm/book3s_64_vio.c: In function ‘kvmppc_clear_tce’:
/home/paulus/kernel/kvm/arch/powerpc/kvm/book3s_64_vio.c:363:2: error: implicit declaration of function ‘iommu_tce_xchg’ [-Werror=implicit-function-declaration]
  iommu_tce_xchg(tbl, entry, &hpa, &dir);
  ^

To fix this, we make the inclusion of the SPAPR TCE support, and the
code that uses it in book3s_vio.c and book3s_vio_hv.c, depend on
the inclusion of support for the pseries and/or powernv platforms.
This means that when running a 'pseries' guest on those platforms,
the guest won't have in-kernel acceleration of the PAPR TCE hypercalls,
but at least now they compile.

Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-05-12 15:32:30 +10:00
Paul Mackerras 67325e988f KVM: PPC: Book3S PR: Check copy_to/from_user return values
The PR KVM implementation of the PAPR HPT hypercalls (H_ENTER etc.)
access an image of the HPT in userspace memory using copy_from_user
and copy_to_user.  Recently, the declarations of those functions were
annotated to indicate that the return value must be checked.  Since
this code doesn't currently check the return value, this causes
compile warnings like the ones shown below, and since on PPC the
default is to compile arch/powerpc with -Werror, this causes the
build to fail.

To fix this, we check the return values, and if non-zero, fail the
hypercall being processed with a H_FUNCTION error return value.
There is really no good error return value to use since PAPR didn't
envisage the possibility that the hypervisor may not be able to access
the guest's HPT, and H_FUNCTION (function not supported) seems as
good as any.

The typical compile warnings look like this:

  CC      arch/powerpc/kvm/book3s_pr_papr.o
/home/paulus/kernel/kvm/arch/powerpc/kvm/book3s_pr_papr.c: In function ‘kvmppc_h_pr_enter’:
/home/paulus/kernel/kvm/arch/powerpc/kvm/book3s_pr_papr.c:53:2: error: ignoring return value of ‘copy_from_user’, declared with attribute warn_unused_result [-Werror=unused-result]
  copy_from_user(pteg, (void __user *)pteg_addr, sizeof(pteg));
  ^
/home/paulus/kernel/kvm/arch/powerpc/kvm/book3s_pr_papr.c:74:2: error: ignoring return value of ‘copy_to_user’, declared with attribute warn_unused_result [-Werror=unused-result]
  copy_to_user((void __user *)pteg_addr, hpte, HPTE_SIZE);
  ^

... etc.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-05-12 15:09:03 +10:00
Paul Mackerras acde25726b KVM: PPC: Book3S HV: Add radix checks in real-mode hypercall handlers
POWER9 running a radix guest will take some hypervisor interrupts
without going to real mode (turning off the MMU).  This means that
early hypercall handlers may now be called in virtual mode.  Most of
the handlers work just fine in both modes, but there are some that
can crash the host if called in virtual mode, notably the TCE (IOMMU)
hypercalls H_PUT_TCE, H_STUFF_TCE and H_PUT_TCE_INDIRECT.  These
already have both a real-mode and a virtual-mode version, so we
arrange for the real-mode version to return H_TOO_HARD for radix
guests, which will result in the virtual-mode version being called.

The other hypercall which is sensitive to the MMU mode is H_RANDOM.
It doesn't have a virtual-mode version, so this adds code to enable
it to be called in either mode.

An alternative solution was considered which would refuse to call any
of the early hypercall handlers when doing a virtual-mode exit from a
radix guest.  However, the XICS-on-XIVE code depends on the XICS
hypercalls being handled early even for virtual-mode exits, because
the handlers need to be called before the XIVE vCPU state has been
pulled off the hardware.  Therefore that solution would have become
quite invasive and complicated, and was rejected in favour of the
simpler, though less elegant, solution presented here.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Tested-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-05-12 15:08:09 +10:00
Paolo Bonzini 4415b33528 Merge branch 'kvm-ppc-next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD
The main thing here is a new implementation of the in-kernel
XICS interrupt controller emulation for POWER9 machines, from Ben
Herrenschmidt.

POWER9 has a new interrupt controller called XIVE (eXternal Interrupt
Virtualization Engine) which is able to deliver interrupts directly
to guest virtual CPUs in hardware without hypervisor intervention.
With this new code, the guest still sees the old XICS interface but
performance is better because the XICS emulation in the host uses the
XIVE directly rather than going through a XICS emulation in firmware.

Conflicts:
	arch/powerpc/kernel/cpu_setup_power.S [cherry-picked fix]
	arch/powerpc/kvm/book3s_xive.c [include asm/debugfs.h]
2017-05-09 11:50:01 +02:00
Linus Torvalds 2d3e4866de * ARM: HYP mode stub supports kexec/kdump on 32-bit; improved PMU
support; virtual interrupt controller performance improvements; support
 for userspace virtual interrupt controller (slower, but necessary for
 KVM on the weird Broadcom SoCs used by the Raspberry Pi 3)
 
 * MIPS: basic support for hardware virtualization (ImgTec
 P5600/P6600/I6400 and Cavium Octeon III)
 
 * PPC: in-kernel acceleration for VFIO
 
 * s390: support for guests without storage keys; adapter interruption
 suppression
 
 * x86: usual range of nVMX improvements, notably nested EPT support for
 accessed and dirty bits; emulation of CPL3 CPUID faulting
 
 * generic: first part of VCPU thread request API; kvm_stat improvements
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "ARM:
   - HYP mode stub supports kexec/kdump on 32-bit
   - improved PMU support
   - virtual interrupt controller performance improvements
   - support for userspace virtual interrupt controller (slower, but
     necessary for KVM on the weird Broadcom SoCs used by the Raspberry
     Pi 3)

  MIPS:
   - basic support for hardware virtualization (ImgTec P5600/P6600/I6400
     and Cavium Octeon III)

  PPC:
   - in-kernel acceleration for VFIO

  s390:
   - support for guests without storage keys
   - adapter interruption suppression

  x86:
   - usual range of nVMX improvements, notably nested EPT support for
     accessed and dirty bits
   - emulation of CPL3 CPUID faulting

  generic:
   - first part of VCPU thread request API
   - kvm_stat improvements"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (227 commits)
  kvm: nVMX: Don't validate disabled secondary controls
  KVM: put back #ifndef CONFIG_S390 around kvm_vcpu_kick
  Revert "KVM: Support vCPU-based gfn->hva cache"
  tools/kvm: fix top level makefile
  KVM: x86: don't hold kvm->lock in KVM_SET_GSI_ROUTING
  KVM: Documentation: remove VM mmap documentation
  kvm: nVMX: Remove superfluous VMX instruction fault checks
  KVM: x86: fix emulation of RSM and IRET instructions
  KVM: mark requests that need synchronization
  KVM: return if kvm_vcpu_wake_up() did wake up the VCPU
  KVM: add explicit barrier to kvm_vcpu_kick
  KVM: perform a wake_up in kvm_make_all_cpus_request
  KVM: mark requests that do not need a wakeup
  KVM: remove #ifndef CONFIG_S390 around kvm_vcpu_wake_up
  KVM: x86: always use kvm_make_request instead of set_bit
  KVM: add kvm_{test,clear}_request to replace {test,clear}_bit
  s390: kvm: Cpu model support for msa6, msa7 and msa8
  KVM: x86: remove irq disablement around KVM_SET_CLOCK/KVM_GET_CLOCK
  kvm: better MWAIT emulation for guests
  KVM: x86: virtualize cpuid faulting
  ...
2017-05-08 12:37:56 -07:00
Linus Torvalds c6a677c6f3 Staging/IIO patches for 4.12-rc1
Here is the big staging tree update for 4.12-rc1.  And it's a big one,
 adding about 350k new lines of crap^Wcode, mostly all in a big dump of
 media drivers from Intel.  But there's other new drivers in here as
 well, yet-another-wifi driver, new IIO drivers, and a new crypto
 accelerator.  We also deleted a bunch of stuff, mostly in patch
 cleanups, but also the Android ION code has shrunk a lot, and the
 Android low memory killer driver was finally deleted, much to the
 celebration of the -mm developers.
 
 All of these have been in linux-next with a few build issues that will
 show up when you merge to your tree, I'll follow up with fixes for those
 after this gets merged.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'staging-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging/IIO updates from Greg KH:
 "Here is the big staging tree update for 4.12-rc1.

  It's a big one, adding about 350k new lines of crap^Wcode, mostly all
  in a big dump of media drivers from Intel. But there's other new
  drivers in here as well, yet-another-wifi driver, new IIO drivers, and
  a new crypto accelerator.

  We also deleted a bunch of stuff, mostly in patch cleanups, but also
  the Android ION code has shrunk a lot, and the Android low memory
  killer driver was finally deleted, much to the celebration of the -mm
  developers.

  All of these have been in linux-next with a few build issues that will
  show up when you merge to your tree"

Merge conflicts in the new rtl8723bs driver (due to the wifi changes
this merge window) handled as per linux-next, courtesy of Stephen
Rothwell.

* tag 'staging-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1182 commits)
  staging: fsl-mc/dpio: add cpu <--> LE conversion for dpaa2_fd
  staging: ks7010: remove line continuations in quoted strings
  staging: vt6656: use tabs instead of spaces
  staging: android: ion: Fix unnecessary initialization of static variable
  staging: media: atomisp: fix range checking on clk_num
  staging: media: atomisp: fix misspelled word in comment
  staging: media: atomisp: kmap() can't fail
  staging: atomisp: remove #ifdef for runtime PM functions
  staging: atomisp: satm include directory is gone
  atomisp: remove some more unused files
  atomisp: remove hmm_load/store/clear indirections
  atomisp: kill off mmgr_free
  atomisp: clean up the hmm init/cleanup indirections
  atomisp: handle allocation calls before init in the hmm layer
  staging: fsl-dpaa2/eth: Add maintainer for Ethernet driver
  staging: fsl-dpaa2/eth: Add TODO file
  staging: fsl-dpaa2/eth: Add trace points
  staging: fsl-dpaa2/eth: Add driver specific stats
  staging: fsl-dpaa2/eth: Add ethtool support
  staging: fsl-dpaa2/eth: Add Freescale DPAA2 Ethernet driver
  ...
2017-05-05 18:16:23 -07:00
Linus Torvalds 7246f60068 powerpc updates for 4.12 part 1.
Highlights include:
 
  - Larger virtual address space on 64-bit server CPUs. By default we use a 128TB
    virtual address space, but a process can request access to the full 512TB by
    passing a hint to mmap().
 
  - Support for the new Power9 "XIVE" interrupt controller.
 
  - TLB flushing optimisations for the radix MMU on Power9.
 
  - Support for CAPI cards on Power9, using the "Coherent Accelerator Interface
    Architecture 2.0".
 
  - The ability to configure the mmap randomisation limits at build and runtime.
 
  - Several small fixes and cleanups to the kprobes code, as well as support for
    KPROBES_ON_FTRACE.
 
  - Major improvements to handling of system reset interrupts, correctly treating
    them as NMIs, giving them a dedicated stack and using a new hypervisor call
    to trigger them, all of which should aid debugging and robustness.
 
 Many fixes and other minor enhancements.
 
 Thanks to:
   Alastair D'Silva, Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan,
   Aneesh Kumar K.V, Anshuman Khandual, Anton Blanchard, Balbir Singh, Ben
   Hutchings, Benjamin Herrenschmidt, Bhupesh Sharma, Chris Packham, Christian
   Zigotzky, Christophe Leroy, Christophe Lombard, Daniel Axtens, David Gibson,
   Gautham R. Shenoy, Gavin Shan, Geert Uytterhoeven, Guilherme G. Piccoli,
   Hamish Martin, Hari Bathini, Kees Cook, Laurent Dufour, Madhavan Srinivasan,
   Mahesh J Salgaonkar, Mahesh Salgaonkar, Masami Hiramatsu, Matt Brown, Matthew
   R. Ochs, Michael Neuling, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran,
   Pan Xinhui, Paul Mackerras, Rashmica Gupta, Russell Currey, Sukadev
   Bhattiprolu, Thadeu Lima de Souza Cascardo, Tobin C. Harding, Tyrel Datwyler,
   Uma Krishnan, Vaibhav Jain, Vipin K Parashar, Yang Shi.
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Merge tag 'powerpc-4.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Highlights include:

   - Larger virtual address space on 64-bit server CPUs. By default we
     use a 128TB virtual address space, but a process can request access
     to the full 512TB by passing a hint to mmap().

   - Support for the new Power9 "XIVE" interrupt controller.

   - TLB flushing optimisations for the radix MMU on Power9.

   - Support for CAPI cards on Power9, using the "Coherent Accelerator
     Interface Architecture 2.0".

   - The ability to configure the mmap randomisation limits at build and
     runtime.

   - Several small fixes and cleanups to the kprobes code, as well as
     support for KPROBES_ON_FTRACE.

   - Major improvements to handling of system reset interrupts,
     correctly treating them as NMIs, giving them a dedicated stack and
     using a new hypervisor call to trigger them, all of which should
     aid debugging and robustness.

   - Many fixes and other minor enhancements.

  Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Alistair Popple,
  Andrew Donnellan, Aneesh Kumar K.V, Anshuman Khandual, Anton
  Blanchard, Balbir Singh, Ben Hutchings, Benjamin Herrenschmidt,
  Bhupesh Sharma, Chris Packham, Christian Zigotzky, Christophe Leroy,
  Christophe Lombard, Daniel Axtens, David Gibson, Gautham R. Shenoy,
  Gavin Shan, Geert Uytterhoeven, Guilherme G. Piccoli, Hamish Martin,
  Hari Bathini, Kees Cook, Laurent Dufour, Madhavan Srinivasan, Mahesh J
  Salgaonkar, Mahesh Salgaonkar, Masami Hiramatsu, Matt Brown, Matthew
  R. Ochs, Michael Neuling, Naveen N. Rao, Nicholas Piggin, Oliver
  O'Halloran, Pan Xinhui, Paul Mackerras, Rashmica Gupta, Russell
  Currey, Sukadev Bhattiprolu, Thadeu Lima de Souza Cascardo, Tobin C.
  Harding, Tyrel Datwyler, Uma Krishnan, Vaibhav Jain, Vipin K Parashar,
  Yang Shi"

* tag 'powerpc-4.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (214 commits)
  powerpc/64s: Power9 has no LPCR[VRMASD] field so don't set it
  powerpc/powernv: Fix TCE kill on NVLink2
  powerpc/mm/radix: Drop support for CPUs without lockless tlbie
  powerpc/book3s/mce: Move add_taint() later in virtual mode
  powerpc/sysfs: Move #ifdef CONFIG_HOTPLUG_CPU out of the function body
  powerpc/smp: Document irq enable/disable after migrating IRQs
  powerpc/mpc52xx: Don't select user-visible RTAS_PROC
  powerpc/powernv: Document cxl dependency on special case in pnv_eeh_reset()
  powerpc/eeh: Clean up and document event handling functions
  powerpc/eeh: Avoid use after free in eeh_handle_special_event()
  cxl: Mask slice error interrupts after first occurrence
  cxl: Route eeh events to all drivers in cxl_pci_error_detected()
  cxl: Force context lock during EEH flow
  powerpc/64: Allow CONFIG_RELOCATABLE if COMPILE_TEST
  powerpc/xmon: Teach xmon oops about radix vectors
  powerpc/mm/hash: Fix off-by-one in comment about kernel contexts ids
  powerpc/pseries: Enable VFIO
  powerpc/powernv: Fix iommu table size calculation hook for small tables
  powerpc/powernv: Check kzalloc() return value in pnv_pci_table_alloc
  powerpc: Add arch/powerpc/tools directory
  ...
2017-05-05 11:36:44 -07:00
Paul Mackerras fb7dcf723d Merge remote-tracking branch 'remotes/powerpc/topic/xive' into kvm-ppc-next
This merges in the powerpc topic/xive branch to bring in the code for
the in-kernel XICS interrupt controller emulation to use the new XIVE
(eXternal Interrupt Virtualization Engine) hardware in the POWER9 chip
directly, rather than via a XICS emulation in firmware.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-04-28 08:23:16 +10:00
Denis Kirjanov db4b0dfab7 KVM: PPC: Book3S HV: Avoid preemptibility warning in module initialization
With CONFIG_DEBUG_PREEMPT, get_paca() produces the following warning
in kvmppc_book3s_init_hv() since it calls debug_smp_processor_id().

There is no real issue with the xics_phys field.
If paca->kvm_hstate.xics_phys is non-zero on one cpu, it will be
non-zero on them all.  Therefore this is not fixing any actual
problem, just the warning.

[  138.521188] BUG: using smp_processor_id() in preemptible [00000000] code: modprobe/5596
[  138.521308] caller is .kvmppc_book3s_init_hv+0x184/0x350 [kvm_hv]
[  138.521404] CPU: 5 PID: 5596 Comm: modprobe Not tainted 4.11.0-rc3-00022-gc7e790c #1
[  138.521509] Call Trace:
[  138.521563] [c0000007d018b810] [c0000000023eef10] .dump_stack+0xe4/0x150 (unreliable)
[  138.521694] [c0000007d018b8a0] [c000000001f6ec04] .check_preemption_disabled+0x134/0x150
[  138.521829] [c0000007d018b940] [d00000000a010274] .kvmppc_book3s_init_hv+0x184/0x350 [kvm_hv]
[  138.521963] [c0000007d018ba00] [c00000000191d5cc] .do_one_initcall+0x5c/0x1c0
[  138.522082] [c0000007d018bad0] [c0000000023e9494] .do_init_module+0x84/0x240
[  138.522201] [c0000007d018bb70] [c000000001aade18] .load_module+0x1f68/0x2a10
[  138.522319] [c0000007d018bd20] [c000000001aaeb30] .SyS_finit_module+0xc0/0xf0
[  138.522439] [c0000007d018be30] [c00000000191baec] system_call+0x38/0xfc

Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-04-28 08:21:51 +10:00