Commit Graph

22 Commits

Author SHA1 Message Date
Alexey Kardashevskiy
8f6a9f0d06 KVM: PPC: Book3S: Protect kvmppc_gpa_to_ua() with SRCU
kvmppc_gpa_to_ua() accesses KVM memory slot array via
srcu_dereference_check() and this produces warnings from RCU like below.

This extends the existing srcu_read_lock/unlock to cover that
kvmppc_gpa_to_ua() as well.

We did not hit this before as this lock is not needed for the realmode
handlers and hash guests would use the realmode path all the time;
however the radix guests are always redirected to the virtual mode
handlers and hence the warning.

[   68.253798] ./include/linux/kvm_host.h:575 suspicious rcu_dereference_check() usage!
[   68.253799]
               other info that might help us debug this:

[   68.253802]
               rcu_scheduler_active = 2, debug_locks = 1
[   68.253804] 1 lock held by qemu-system-ppc/6413:
[   68.253806]  #0:  (&vcpu->mutex){+.+.}, at: [<c00800000e3c22f4>] vcpu_load+0x3c/0xc0 [kvm]
[   68.253826]
               stack backtrace:
[   68.253830] CPU: 92 PID: 6413 Comm: qemu-system-ppc Tainted: G        W       4.14.0-rc3-00553-g432dcba58e9c-dirty #72
[   68.253833] Call Trace:
[   68.253839] [c000000fd3d9f790] [c000000000b7fcc8] dump_stack+0xe8/0x160 (unreliable)
[   68.253845] [c000000fd3d9f7d0] [c0000000001924c0] lockdep_rcu_suspicious+0x110/0x180
[   68.253851] [c000000fd3d9f850] [c0000000000e825c] kvmppc_gpa_to_ua+0x26c/0x2b0
[   68.253858] [c000000fd3d9f8b0] [c00800000e3e1984] kvmppc_h_put_tce+0x12c/0x2a0 [kvm]

Fixes: 121f80ba68 ("KVM: PPC: VFIO: Add in-kernel acceleration for VFIO")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-10-14 11:35:41 +11:00
Paul Mackerras
edd03602d9 KVM: PPC: Book3S HV: Protect updates to spapr_tce_tables list
Al Viro pointed out that while one thread of a process is executing
in kvm_vm_ioctl_create_spapr_tce(), another thread could guess the
file descriptor returned by anon_inode_getfd() and close() it before
the first thread has added it to the kvm->arch.spapr_tce_tables list.
That highlights a more general problem: there is no mutual exclusion
between writers to the spapr_tce_tables list, leading to the
possibility of the list becoming corrupted, which could cause a
host kernel crash.

To fix the mutual exclusion problem, we add a mutex_lock/unlock
pair around the list_del_rce in kvm_spapr_tce_release().  Also,
this moves the call to anon_inode_getfd() inside the region
protected by the kvm->lock mutex, after we have done the check for
a duplicate LIOBN.  This means that if another thread does guess the
file descriptor and closes it, its call to kvm_spapr_tce_release()
will not do any harm because it will have to wait until the first
thread has released kvm->lock.  With this, there are no failure
points in kvm_vm_ioctl_create_spapr_tce() after the call to
anon_inode_getfd().

The other things that the second thread could do with the guessed
file descriptor are to mmap it or to pass it as a parameter to a
KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE ioctl on a KVM device fd.  An mmap
call won't cause any harm because kvm_spapr_tce_mmap() and
kvm_spapr_tce_fault() don't access the spapr_tce_tables list or
the kvmppc_spapr_tce_table.list field, and the fields that they do use
have been properly initialized by the time of the anon_inode_getfd()
call.

The KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE ioctl calls
kvm_spapr_tce_attach_iommu_group(), which scans the spapr_tce_tables
list looking for the kvmppc_spapr_tce_table struct corresponding to
the fd given as the parameter.  Either it will find the new entry
or it won't; if it doesn't, it just returns an error, and if it
does, it will function normally.  So, in each case there is no
harmful effect.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-30 14:59:31 +10:00
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
Alexey Kardashevskiy
121f80ba68 KVM: PPC: VFIO: Add in-kernel acceleration for VFIO
This allows the host kernel to handle H_PUT_TCE, H_PUT_TCE_INDIRECT
and H_STUFF_TCE requests targeted an IOMMU TCE table used for VFIO
without passing them to user space which saves time on switching
to user space and back.

This adds H_PUT_TCE/H_PUT_TCE_INDIRECT/H_STUFF_TCE handlers to KVM.
KVM tries to handle a TCE request in the real mode, if failed
it passes the request to the virtual mode to complete the operation.
If it a virtual mode handler fails, the request is passed to
the user space; this is not expected to happen though.

To avoid dealing with page use counters (which is tricky in real mode),
this only accelerates SPAPR TCE IOMMU v2 clients which are required
to pre-register the userspace memory. The very first TCE request will
be handled in the VFIO SPAPR TCE driver anyway as the userspace view
of the TCE table (iommu_table::it_userspace) is not allocated till
the very first mapping happens and we cannot call vmalloc in real mode.

If we fail to update a hardware IOMMU table unexpected reason, we just
clear it and move on as there is nothing really we can do about it -
for example, if we hot plug a VFIO device to a guest, existing TCE tables
will be mirrored automatically to the hardware and there is no interface
to report to the guest about possible failures.

This adds new attribute - KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE - to
the VFIO KVM device. It takes a VFIO group fd and SPAPR TCE table fd
and associates a physical IOMMU table with the SPAPR TCE table (which
is a guest view of the hardware IOMMU table). The iommu_table object
is cached and referenced so we do not have to look up for it in real mode.

This does not implement the UNSET counterpart as there is no use for it -
once the acceleration is enabled, the existing userspace won't
disable it unless a VFIO container is destroyed; this adds necessary
cleanup to the KVM_DEV_VFIO_GROUP_DEL handler.

This advertises the new KVM_CAP_SPAPR_TCE_VFIO capability to the user
space.

This adds real mode version of WARN_ON_ONCE() as the generic version
causes problems with rcu_sched. Since we testing what vmalloc_to_phys()
returns in the code, this also adds a check for already existing
vmalloc_to_phys() call in kvmppc_rm_h_put_tce_indirect().

This finally makes use of vfio_external_user_iommu_id() which was
introduced quite some time ago and was considered for removal.

Tests show that this patch increases transmission speed from 220MB/s
to 750..1020MB/s on 10Gb network (Chelsea CXGB3 10Gb ethernet card).

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-04-20 11:39:26 +10:00
Alexey Kardashevskiy
503bfcbe18 KVM: PPC: Pass kvm* to kvmppc_find_table()
The guest view TCE tables are per KVM anyway (not per VCPU) so pass kvm*
there. This will be used in the following patches where we will be
attaching VFIO containers to LIOBNs via ioctl() to KVM (rather than
to VCPU).

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-04-20 11:39:12 +10:00
Alexey Kardashevskiy
3762d45aa7 KVM: PPC: Align the table size to system page size
At the moment the userspace can request a table smaller than a page size
and this value will be stored as kvmppc_spapr_tce_table::size.
However the actual allocated size will still be aligned to the system
page size as alloc_page() is used there.

This aligns the table size up to the system page size. It should not
change the existing behaviour but when in-kernel TCE acceleration patchset
reaches the upstream kernel, this will allow small TCE tables be
accelerated as well: PCI IODA iommu_table allocator already aligns
the size and, without this patch, an IOMMU group won't attach to LIOBN
due to the mismatching table size.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-04-20 11:38:20 +10:00
Ingo Molnar
3f07c01441 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h>
We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:29 +01:00
Dave Jiang
11bac80004 mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmf
->fault(), ->page_mkwrite(), and ->pfn_mkwrite() calls do not need to
take a vma and vmf parameter when the vma already resides in vmf.

Remove the vma parameter to simplify things.

[arnd@arndb.de: fix ARM build]
  Link: http://lkml.kernel.org/r/20170125223558.1451224-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/148521301778.19116.10840599906674778980.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24 17:46:54 -08:00
Wei Yongjun
5982f0849e KVM: PPC: Book 3S: Fix error return in kvm_vm_ioctl_create_spapr_tce()
Fix to return error code -ENOMEM from the memory alloc error handling
case instead of 0, as done elsewhere in this function.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-02-09 22:06:28 +11:00
Daniel Axtens
f8750513b7 powerpc/kvm: Clarify __user annotations
kvmppc_h_put_tce_indirect labels a u64 pointer as __user. It also
labelled the u64 where get_user puts the result as __user. This isn't
a pointer and so doesn't need to be labelled __user.

Split the u64 value definition onto a new line to make it clear that
it doesn't get the annotation.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-14 20:43:50 +10:00
Alexey Kardashevskiy
31217db720 KVM: PPC: Create a virtual-mode only TCE table handlers
Upcoming in-kernel VFIO acceleration needs different handling in real
and virtual modes which makes it hard to support both modes in
the same handler.

This creates a copy of kvmppc_rm_h_stuff_tce and kvmppc_rm_h_put_tce
in addition to the existing kvmppc_rm_h_put_tce_indirect.

This also fixes linker breakage when only PR KVM was selected (leaving
HV KVM off): the kvmppc_h_put_tce/kvmppc_h_stuff_tce functions
would not compile at all and the linked would fail.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 12:02:51 +01:00
Linus Torvalds
d5e2d00898 powerpc updates for 4.6
Highlights:
  - Restructure Linux PTE on Book3S/64 to Radix format from Paul Mackerras
  - Book3s 64 MMU cleanup in preparation for Radix MMU from Aneesh Kumar K.V
  - Add POWER9 cputable entry from Michael Neuling
  - FPU/Altivec/VSX save/restore optimisations from Cyril Bur
  - Add support for new ftrace ABI on ppc64le from Torsten Duwe
 
 Various cleanups & minor fixes from:
  - Adam Buchbinder, Andrew Donnellan, Balbir Singh, Christophe Leroy, Cyril
    Bur, Luis Henriques, Madhavan Srinivasan, Pan Xinhui, Russell Currey,
    Sukadev Bhattiprolu, Suraj Jitindar Singh.
 
 General:
  - atomics: Allow architectures to define their own __atomic_op_* helpers from
    Boqun Feng
  - Implement atomic{, 64}_*_return_* variants and acquire/release/relaxed
    variants for (cmp)xchg from Boqun Feng
  - Add powernv_defconfig from Jeremy Kerr
  - Fix BUG_ON() reporting in real mode from Balbir Singh
  - Add xmon command to dump OPAL msglog from Andrew Donnellan
  - Add xmon command to dump process/task similar to ps(1) from Douglas Miller
  - Clean up memory hotplug failure paths from David Gibson
 
 pci/eeh:
  - Redesign SR-IOV on PowerNV to give absolute isolation between VFs from Wei
    Yang.
  - EEH Support for SRIOV VFs from Wei Yang and Gavin Shan.
  - PCI/IOV: Rename and export virtfn_{add, remove} from Wei Yang
  - PCI: Add pcibios_bus_add_device() weak function from Wei Yang
  - MAINTAINERS: Update EEH details and maintainership from Russell Currey
 
 cxl:
  - Support added to the CXL driver for running on both bare-metal and
    hypervisor systems, from Christophe Lombard and Frederic Barrat.
  - Ignore probes for virtual afu pci devices from Vaibhav Jain
 
 perf:
  - Export Power8 generic and cache events to sysfs from Sukadev Bhattiprolu
  - hv-24x7: Fix usage with chip events, display change in counter values,
    display domain indices in sysfs, eliminate domain suffix in event names,
    from Sukadev Bhattiprolu
 
 Freescale:
  - Updates from Scott: "Highlights include 8xx optimizations, 32-bit checksum
    optimizations, 86xx consolidation, e5500/e6500 cpu hotplug, more fman and
    other dt bits, and minor fixes/cleanup."
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Merge tag 'powerpc-4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "This was delayed a day or two by some build-breakage on old toolchains
  which we've now fixed.

  There's two PCI commits both acked by Bjorn.

  There's one commit to mm/hugepage.c which is (co)authored by Kirill.

  Highlights:
   - Restructure Linux PTE on Book3S/64 to Radix format from Paul
     Mackerras
   - Book3s 64 MMU cleanup in preparation for Radix MMU from Aneesh
     Kumar K.V
   - Add POWER9 cputable entry from Michael Neuling
   - FPU/Altivec/VSX save/restore optimisations from Cyril Bur
   - Add support for new ftrace ABI on ppc64le from Torsten Duwe

  Various cleanups & minor fixes from:
   - Adam Buchbinder, Andrew Donnellan, Balbir Singh, Christophe Leroy,
     Cyril Bur, Luis Henriques, Madhavan Srinivasan, Pan Xinhui, Russell
     Currey, Sukadev Bhattiprolu, Suraj Jitindar Singh.

  General:
   - atomics: Allow architectures to define their own __atomic_op_*
     helpers from Boqun Feng
   - Implement atomic{, 64}_*_return_* variants and acquire/release/
     relaxed variants for (cmp)xchg from Boqun Feng
   - Add powernv_defconfig from Jeremy Kerr
   - Fix BUG_ON() reporting in real mode from Balbir Singh
   - Add xmon command to dump OPAL msglog from Andrew Donnellan
   - Add xmon command to dump process/task similar to ps(1) from Douglas
     Miller
   - Clean up memory hotplug failure paths from David Gibson

  pci/eeh:
   - Redesign SR-IOV on PowerNV to give absolute isolation between VFs
     from Wei Yang.
   - EEH Support for SRIOV VFs from Wei Yang and Gavin Shan.
   - PCI/IOV: Rename and export virtfn_{add, remove} from Wei Yang
   - PCI: Add pcibios_bus_add_device() weak function from Wei Yang
   - MAINTAINERS: Update EEH details and maintainership from Russell
     Currey

  cxl:
   - Support added to the CXL driver for running on both bare-metal and
     hypervisor systems, from Christophe Lombard and Frederic Barrat.
   - Ignore probes for virtual afu pci devices from Vaibhav Jain

  perf:
   - Export Power8 generic and cache events to sysfs from Sukadev
     Bhattiprolu
   - hv-24x7: Fix usage with chip events, display change in counter
     values, display domain indices in sysfs, eliminate domain suffix in
     event names, from Sukadev Bhattiprolu

  Freescale:
   - Updates from Scott: "Highlights include 8xx optimizations, 32-bit
     checksum optimizations, 86xx consolidation, e5500/e6500 cpu
     hotplug, more fman and other dt bits, and minor fixes/cleanup"

* tag 'powerpc-4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (179 commits)
  powerpc: Fix unrecoverable SLB miss during restore_math()
  powerpc/8xx: Fix do_mtspr_cpu6() build on older compilers
  powerpc/rcpm: Fix build break when SMP=n
  powerpc/book3e-64: Use hardcoded mttmr opcode
  powerpc/fsl/dts: Add "jedec,spi-nor" flash compatible
  powerpc/T104xRDB: add tdm riser card node to device tree
  powerpc32: PAGE_EXEC required for inittext
  powerpc/mpc85xx: Add pcsphy nodes to FManV3 device tree
  powerpc/mpc85xx: Add MDIO bus muxing support to the board device tree(s)
  powerpc/86xx: Introduce and use common dtsi
  powerpc/86xx: Update device tree
  powerpc/86xx: Move dts files to fsl directory
  powerpc/86xx: Switch to kconfig fragments approach
  powerpc/86xx: Update defconfigs
  powerpc/86xx: Consolidate common platform code
  powerpc32: Remove one insn in mulhdu
  powerpc32: small optimisation in flush_icache_range()
  powerpc: Simplify test in __dma_sync()
  powerpc32: move xxxxx_dcache_range() functions inline
  powerpc32: Remove clear_pages() and define clear_page() inline
  ...
2016-03-19 15:38:41 -07:00
Aneesh Kumar K.V
f64e8084c9 powerpc/mm: Move hash related mmu-*.h headers to book3s/
No code changes.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-03 21:19:21 +11:00
Alexey Kardashevskiy
58ded4201f KVM: PPC: Add support for 64bit TCE windows
The existing KVM_CREATE_SPAPR_TCE only supports 32bit windows which is not
enough for directly mapped windows as the guest can get more than 4GB.

This adds KVM_CREATE_SPAPR_TCE_64 ioctl and advertises it
via KVM_CAP_SPAPR_TCE_64 capability. The table size is checked against
the locked memory limit.

Since 64bit windows are to support Dynamic DMA windows (DDW), let's add
@bus_offset and @page_shift which are also required by DDW.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2016-03-02 09:56:50 +11:00
Alexey Kardashevskiy
fe26e52712 KVM: PPC: Add @page_shift to kvmppc_spapr_tce_table
At the moment the kvmppc_spapr_tce_table struct can only describe
4GB windows and handle fixed size (4K) pages. Dynamic DMA windows
support more so these limits need to be extended.

This replaces window_size (in bytes, 4GB max) with page_shift (32bit)
and size (64bit, in pages).

This should cause no behavioural change as this is changing
the internal structures only - the user interface still only
allows one to create a 32-bit table with 4KiB pages at this stage.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2016-03-02 09:56:50 +11:00
Alexey Kardashevskiy
d3695aa4f4 KVM: PPC: Add support for multiple-TCE hcalls
This adds real and virtual mode handlers for the H_PUT_TCE_INDIRECT and
H_STUFF_TCE hypercalls for user space emulated devices such as IBMVIO
devices or emulated PCI. These calls allow adding multiple entries
(up to 512) into the TCE table in one call which saves time on
transition between kernel and user space.

The current implementation of kvmppc_h_stuff_tce() allows it to be
executed in both real and virtual modes so there is one helper.
The kvmppc_rm_h_put_tce_indirect() needs to translate the guest address
to the host address and since the translation is different, there are
2 helpers - one for each mode.

This implements the KVM_CAP_PPC_MULTITCE capability. When present,
the kernel will try handling H_PUT_TCE_INDIRECT and H_STUFF_TCE if these
are enabled by the userspace via KVM_CAP_PPC_ENABLE_HCALL.
If they can not be handled by the kernel, they are passed on to
the user space. The user space still has to have an implementation
for these.

Both HV and PR-syle KVM are supported.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2016-02-16 13:44:26 +11:00
Alexey Kardashevskiy
462ee11e58 KVM: PPC: Replace SPAPR_TCE_SHIFT with IOMMU_PAGE_SHIFT_4K
SPAPR_TCE_SHIFT is used in few places only and since IOMMU_PAGE_SHIFT_4K
can be easily used instead, remove SPAPR_TCE_SHIFT.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2016-02-16 13:44:26 +11:00
Alexey Kardashevskiy
f8626985c7 KVM: PPC: Account TCE-containing pages in locked_vm
At the moment pages used for TCE tables (in addition to pages addressed
by TCEs) are not counted in locked_vm counter so a malicious userspace
tool can call ioctl(KVM_CREATE_SPAPR_TCE) as many times as
RLIMIT_NOFILE and lock a lot of memory.

This adds counting for pages used for TCE tables.

This counts the number of pages required for a table plus pages for
the kvmppc_spapr_tce_table struct (TCE table descriptor) itself.

This changes release_spapr_tce_table() to store @npages on stack to
avoid calling kvmppc_stt_npages() in the loop (tiny optimization,
probably).

This does not change the amount of used memory.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2016-02-16 13:44:26 +11:00
Alexey Kardashevskiy
366baf28ee KVM: PPC: Use RCU for arch.spapr_tce_tables
At the moment only spapr_tce_tables updates are protected against races
but not lookups. This fixes missing protection by using RCU for the list.
As lookups also happen in real mode, this uses
list_for_each_entry_lockless() (which is expected not to access any
vmalloc'd memory).

This converts release_spapr_tce_table() to a RCU scheduled handler.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2016-02-16 13:44:26 +11:00
Yann Droneaud
2f84d5ea6f ppc: kvm: use anon_inode_getfd() with O_CLOEXEC flag
KVM uses anon_inode_get() to allocate file descriptors as part
of some of its ioctls. But those ioctls are lacking a flag argument
allowing userspace to choose options for the newly opened file descriptor.

In such case it's advised to use O_CLOEXEC by default so that
userspace is allowed to choose, without race, if the file descriptor
is going to be inherited across exec().

This patch set O_CLOEXEC flag on all file descriptors created
with anon_inode_getfd() to not leak file descriptors across exec().

Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Link: http://lkml.kernel.org/r/cover.1377372576.git.ydroneaud@opteya.com
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-08-26 13:19:56 +03:00
Al Viro
75ef9de126 constify a bunch of struct file_operations instances
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 14:16:20 -04:00
Benjamin Herrenschmidt
f31e65e117 kvm/book3s: Make kernel emulated H_PUT_TCE available for "PR" KVM
There is nothing in the code for emulating TCE tables in the kernel
that prevents it from working on "PR" KVM... other than ifdef's and
location of the code.

This and moves the bulk of the code there to a new file called
book3s_64_vio.c.

This speeds things up a bit on my G5.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[agraf: fix for hv kvm, 32bit, whitespace]
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-06 16:19:11 +02:00