Commit Graph

1765 Commits

Author SHA1 Message Date
Sean Christopherson
152482580a KVM: Call kvm_arch_memslots_updated() before updating memslots
kvm_arch_memslots_updated() is at this point in time an x86-specific
hook for handling MMIO generation wraparound.  x86 stashes 19 bits of
the memslots generation number in its MMIO sptes in order to avoid
full page fault walks for repeat faults on emulated MMIO addresses.
Because only 19 bits are used, wrapping the MMIO generation number is
possible, if unlikely.  kvm_arch_memslots_updated() alerts x86 that
the generation has changed so that it can invalidate all MMIO sptes in
case the effective MMIO generation has wrapped so as to avoid using a
stale spte, e.g. a (very) old spte that was created with generation==0.

Given that the purpose of kvm_arch_memslots_updated() is to prevent
consuming stale entries, it needs to be called before the new generation
is propagated to memslots.  Invalidating the MMIO sptes after updating
memslots means that there is a window where a vCPU could dereference
the new memslots generation, e.g. 0, and incorrectly reuse an old MMIO
spte that was created with (pre-wrap) generation==0.

Fixes: e59dbe09f8 ("KVM: Introduce kvm_arch_memslots_updated()")
Cc: <stable@vger.kernel.org>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-20 22:48:32 +01:00
Ben Gardon
b12ce36a43 kvm: Add memcg accounting to KVM allocations
There are many KVM kernel memory allocations which are tied to the life of
the VM process and should be charged to the VM process's cgroup. If the
allocations aren't tied to the process, the OOM killer will not know
that killing the process will free the associated kernel memory.
Add __GFP_ACCOUNT flags to many of the allocations which are not yet being
charged to the VM process's cgroup.

Tested:
	Ran all kvm-unit-tests on a 64 bit Haswell machine, the patch
	introduced no new failures.
	Ran a kernel memory accounting test which creates a VM to touch
	memory and then checks that the kernel memory allocated for the
	process is within certain bounds.
	With this patch we account for much more of the vmalloc and slab memory
	allocated for the VM.

There remain a few allocations which should be charged to the VM's
cgroup but are not. In they include:
        vcpu->run
        kvm->coalesced_mmio_ring
There allocations are unaccounted in this patch because they are mapped
to userspace, and accounting them to a cgroup causes problems. This
should be addressed in a future patch.

Signed-off-by: Ben Gardon <bgardon@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-20 22:48:29 +01:00
Gustavo A. R. Silva
90952cd388 kvm: Use struct_size() in kmalloc()
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-20 22:48:20 +01:00
Jann Horn
cfa3938117 kvm: fix kvm_ioctl_create_device() reference counting (CVE-2019-6974)
kvm_ioctl_create_device() does the following:

1. creates a device that holds a reference to the VM object (with a borrowed
   reference, the VM's refcount has not been bumped yet)
2. initializes the device
3. transfers the reference to the device to the caller's file descriptor table
4. calls kvm_get_kvm() to turn the borrowed reference to the VM into a real
   reference

The ownership transfer in step 3 must not happen before the reference to the VM
becomes a proper, non-borrowed reference, which only happens in step 4.
After step 3, an attacker can close the file descriptor and drop the borrowed
reference, which can cause the refcount of the kvm object to drop to zero.

This means that we need to grab a reference for the device before
anon_inode_getfd(), otherwise the VM can disappear from under us.

Fixes: 852b6d57dc ("kvm: add device control API")
Cc: stable@kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-07 19:02:38 +01:00
Tomas Bortoli
98938aa8ed KVM: validate userspace input in kvm_clear_dirty_log_protect()
The function at issue does not fully validate the content of the
structure pointed by the log parameter, though its content has just been
copied from userspace and lacks validation. Fix that.

Moreover, change the type of n to unsigned long as that is the type
returned by kvm_dirty_bitmap_bytes().

Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
Reported-by: syzbot+028366e52c9ace67deb3@syzkaller.appspotmail.com
[Squashed the fix from Paolo. - Radim.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2019-01-11 18:38:07 +01:00
Linus Torvalds
a65981109f Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:

 - procfs updates

 - various misc bits

 - lib/ updates

 - epoll updates

 - autofs

 - fatfs

 - a few more MM bits

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (58 commits)
  mm/page_io.c: fix polled swap page in
  checkpatch: add Co-developed-by to signature tags
  docs: fix Co-Developed-by docs
  drivers/base/platform.c: kmemleak ignore a known leak
  fs: don't open code lru_to_page()
  fs/: remove caller signal_pending branch predictions
  mm/: remove caller signal_pending branch predictions
  arch/arc/mm/fault.c: remove caller signal_pending_branch predictions
  kernel/sched/: remove caller signal_pending branch predictions
  kernel/locking/mutex.c: remove caller signal_pending branch predictions
  mm: select HAVE_MOVE_PMD on x86 for faster mremap
  mm: speed up mremap by 20x on large regions
  mm: treewide: remove unused address argument from pte_alloc functions
  initramfs: cleanup incomplete rootfs
  scripts/gdb: fix lx-version string output
  kernel/kcov.c: mark write_comp_data() as notrace
  kernel/sysctl: add panic_print into sysctl
  panic: add options to print system info when panic happens
  bfs: extra sanity checking and static inode bitmap
  exec: separate MM_ANONPAGES and RLIMIT_STACK accounting
  ...
2019-01-05 09:16:18 -08:00
Joel Fernandes (Google)
4cf5892495 mm: treewide: remove unused address argument from pte_alloc functions
Patch series "Add support for fast mremap".

This series speeds up the mremap(2) syscall by copying page tables at
the PMD level even for non-THP systems.  There is concern that the extra
'address' argument that mremap passes to pte_alloc may do something
subtle architecture related in the future that may make the scheme not
work.  Also we find that there is no point in passing the 'address' to
pte_alloc since its unused.  This patch therefore removes this argument
tree-wide resulting in a nice negative diff as well.  Also ensuring
along the way that the enabled architectures do not do anything funky
with the 'address' argument that goes unnoticed by the optimization.

Build and boot tested on x86-64.  Build tested on arm64.  The config
enablement patch for arm64 will be posted in the future after more
testing.

The changes were obtained by applying the following Coccinelle script.
(thanks Julia for answering all Coccinelle questions!).
Following fix ups were done manually:
* Removal of address argument from  pte_fragment_alloc
* Removal of pte_alloc_one_fast definitions from m68k and microblaze.

// Options: --include-headers --no-includes
// Note: I split the 'identifier fn' line, so if you are manually
// running it, please unsplit it so it runs for you.

virtual patch

@pte_alloc_func_def depends on patch exists@
identifier E2;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
type T2;
@@

 fn(...
- , T2 E2
 )
 { ... }

@pte_alloc_func_proto_noarg depends on patch exists@
type T1, T2, T3, T4;
identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@

(
- T3 fn(T1, T2);
+ T3 fn(T1);
|
- T3 fn(T1, T2, T4);
+ T3 fn(T1, T2);
)

@pte_alloc_func_proto depends on patch exists@
identifier E1, E2, E4;
type T1, T2, T3, T4;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@

(
- T3 fn(T1 E1, T2 E2);
+ T3 fn(T1 E1);
|
- T3 fn(T1 E1, T2 E2, T4 E4);
+ T3 fn(T1 E1, T2 E2);
)

@pte_alloc_func_call depends on patch exists@
expression E2;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@

 fn(...
-,  E2
 )

@pte_alloc_macro depends on patch exists@
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
identifier a, b, c;
expression e;
position p;
@@

(
- #define fn(a, b, c) e
+ #define fn(a, b) e
|
- #define fn(a, b) e
+ #define fn(a) e
)

Link: http://lkml.kernel.org/r/20181108181201.88826-2-joelaf@google.com
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Suggested-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:47 -08:00
Linus Torvalds
96d4f267e4 Remove 'type' argument from access_ok() function
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-03 18:57:57 -08:00
Jérôme Glisse
5d6527a784 mm/mmu_notifier: use structure for invalidate_range_start/end callback
Patch series "mmu notifier contextual informations", v2.

This patchset adds contextual information, why an invalidation is
happening, to mmu notifier callback.  This is necessary for user of mmu
notifier that wish to maintains their own data structure without having to
add new fields to struct vm_area_struct (vma).

For instance device can have they own page table that mirror the process
address space.  When a vma is unmap (munmap() syscall) the device driver
can free the device page table for the range.

Today we do not have any information on why a mmu notifier call back is
happening and thus device driver have to assume that it is always an
munmap().  This is inefficient at it means that it needs to re-allocate
device page table on next page fault and rebuild the whole device driver
data structure for the range.

Other use case beside munmap() also exist, for instance it is pointless
for device driver to invalidate the device page table when the
invalidation is for the soft dirtyness tracking.  Or device driver can
optimize away mprotect() that change the page table permission access for
the range.

This patchset enables all this optimizations for device drivers.  I do not
include any of those in this series but another patchset I am posting will
leverage this.

The patchset is pretty simple from a code point of view.  The first two
patches consolidate all mmu notifier arguments into a struct so that it is
easier to add/change arguments.  The last patch adds the contextual
information (munmap, protection, soft dirty, clear, ...).

This patch (of 3):

To avoid having to change many callback definition everytime we want to
add a parameter use a structure to group all parameters for the
mmu_notifier invalidate_range_start/end callback.  No functional changes
with this patch.

[akpm@linux-foundation.org: fix drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c kerneldoc]
Link: http://lkml.kernel.org/r/20181205053628.3210-2-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Jason Gunthorpe <jgg@mellanox.com>	[infiniband]
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 12:11:50 -08:00
Linus Torvalds
792bf4d871 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "The biggest RCU changes in this cycle were:

   - Convert RCU's BUG_ON() and similar calls to WARN_ON() and similar.

   - Replace calls of RCU-bh and RCU-sched update-side functions to
     their vanilla RCU counterparts. This series is a step towards
     complete removal of the RCU-bh and RCU-sched update-side functions.

     ( Note that some of these conversions are going upstream via their
       respective maintainers. )

   - Documentation updates, including a number of flavor-consolidation
     updates from Joel Fernandes.

   - Miscellaneous fixes.

   - Automate generation of the initrd filesystem used for rcutorture
     testing.

   - Convert spin_is_locked() assertions to instead use lockdep.

     ( Note that some of these conversions are going upstream via their
       respective maintainers. )

   - SRCU updates, especially including a fix from Dennis Krein for a
     bag-on-head-class bug.

   - RCU torture-test updates"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (112 commits)
  rcutorture: Don't do busted forward-progress testing
  rcutorture: Use 100ms buckets for forward-progress callback histograms
  rcutorture: Recover from OOM during forward-progress tests
  rcutorture: Print forward-progress test age upon failure
  rcutorture: Print time since GP end upon forward-progress failure
  rcutorture: Print histogram of CB invocation at OOM time
  rcutorture: Print GP age upon forward-progress failure
  rcu: Print per-CPU callback counts for forward-progress failures
  rcu: Account for nocb-CPU callback counts in RCU CPU stall warnings
  rcutorture: Dump grace-period diagnostics upon forward-progress OOM
  rcutorture: Prepare for asynchronous access to rcu_fwd_startat
  torture: Remove unnecessary "ret" variables
  rcutorture: Affinity forward-progress test to avoid housekeeping CPUs
  rcutorture: Break up too-long rcu_torture_fwd_prog() function
  rcutorture: Remove cbflood facility
  torture: Bring any extra CPUs online during kernel startup
  rcutorture: Add call_rcu() flooding forward-progress tests
  rcutorture/formal: Replace synchronize_sched() with synchronize_rcu()
  tools/kernel.h: Replace synchronize_sched() with synchronize_rcu()
  net/decnet: Replace rcu_barrier_bh() with rcu_barrier()
  ...
2018-12-26 13:07:19 -08:00
Linus Torvalds
42b00f122c * ARM: selftests improvements, large PUD support for HugeTLB,
single-stepping fixes, improved tracing, various timer and vGIC
 fixes
 
 * x86: Processor Tracing virtualization, STIBP support, some correctness fixes,
 refactorings and splitting of vmx.c, use the Hyper-V range TLB flush hypercall,
 reduce order of vcpu struct, WBNOINVD support, do not use -ftrace for __noclone
 functions, nested guest support for PAUSE filtering on AMD, more Hyper-V
 enlightenments (direct mode for synthetic timers)
 
 * PPC: nested VFIO
 
 * s390: bugfixes only this time
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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:
   - selftests improvements
   - large PUD support for HugeTLB
   - single-stepping fixes
   - improved tracing
   - various timer and vGIC fixes

  x86:
   - Processor Tracing virtualization
   - STIBP support
   - some correctness fixes
   - refactorings and splitting of vmx.c
   - use the Hyper-V range TLB flush hypercall
   - reduce order of vcpu struct
   - WBNOINVD support
   - do not use -ftrace for __noclone functions
   - nested guest support for PAUSE filtering on AMD
   - more Hyper-V enlightenments (direct mode for synthetic timers)

  PPC:
   -  nested VFIO

  s390:
   - bugfixes only this time"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (171 commits)
  KVM: x86: Add CPUID support for new instruction WBNOINVD
  kvm: selftests: ucall: fix exit mmio address guessing
  Revert "compiler-gcc: disable -ftracer for __noclone functions"
  KVM: VMX: Move VM-Enter + VM-Exit handling to non-inline sub-routines
  KVM: VMX: Explicitly reference RCX as the vmx_vcpu pointer in asm blobs
  KVM: x86: Use jmp to invoke kvm_spurious_fault() from .fixup
  MAINTAINERS: Add arch/x86/kvm sub-directories to existing KVM/x86 entry
  KVM/x86: Use SVM assembly instruction mnemonics instead of .byte streams
  KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range()
  KVM/MMU: Flush tlb directly in kvm_set_pte_rmapp()
  KVM/MMU: Move tlb flush in kvm_set_pte_rmapp() to kvm_mmu_notifier_change_pte()
  KVM: Make kvm_set_spte_hva() return int
  KVM: Replace old tlb flush function with new one to flush a specified range.
  KVM/MMU: Add tlb flush with range helper function
  KVM/VMX: Add hv tlb range flush support
  x86/hyper-v: Add HvFlushGuestAddressList hypercall support
  KVM: Add tlb_remote_flush_with_range callback in kvm_x86_ops
  KVM: x86: Disable Intel PT when VMXON in L1 guest
  KVM: x86: Set intercept for Intel PT MSRs read/write
  KVM: x86: Implement Intel PT MSRs read/write emulation
  ...
2018-12-26 11:46:28 -08:00
Linus Torvalds
5694cecdb0 arm64 festive updates for 4.21
In the end, we ended up with quite a lot more than I expected:
 
 - Support for ARMv8.3 Pointer Authentication in userspace (CRIU and
   kernel-side support to come later)
 
 - Support for per-thread stack canaries, pending an update to GCC that
   is currently undergoing review
 
 - Support for kexec_file_load(), which permits secure boot of a kexec
   payload but also happens to improve the performance of kexec
   dramatically because we can avoid the sucky purgatory code from
   userspace. Kdump will come later (requires updates to libfdt).
 
 - Optimisation of our dynamic CPU feature framework, so that all
   detected features are enabled via a single stop_machine() invocation
 
 - KPTI whitelisting of Cortex-A CPUs unaffected by Meltdown, so that
   they can benefit from global TLB entries when KASLR is not in use
 
 - 52-bit virtual addressing for userspace (kernel remains 48-bit)
 
 - Patch in LSE atomics for per-cpu atomic operations
 
 - Custom preempt.h implementation to avoid unconditional calls to
   preempt_schedule() from preempt_enable()
 
 - Support for the new 'SB' Speculation Barrier instruction
 
 - Vectorised implementation of XOR checksumming and CRC32 optimisations
 
 - Workaround for Cortex-A76 erratum #1165522
 
 - Improved compatibility with Clang/LLD
 
 - Support for TX2 system PMUS for profiling the L3 cache and DMC
 
 - Reflect read-only permissions in the linear map by default
 
 - Ensure MMIO reads are ordered with subsequent calls to Xdelay()
 
 - Initial support for memory hotplug
 
 - Tweak the threshold when we invalidate the TLB by-ASID, so that
   mremap() performance is improved for ranges spanning multiple PMDs.
 
 - Minor refactoring and cleanups
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 festive updates from Will Deacon:
 "In the end, we ended up with quite a lot more than I expected:

   - Support for ARMv8.3 Pointer Authentication in userspace (CRIU and
     kernel-side support to come later)

   - Support for per-thread stack canaries, pending an update to GCC
     that is currently undergoing review

   - Support for kexec_file_load(), which permits secure boot of a kexec
     payload but also happens to improve the performance of kexec
     dramatically because we can avoid the sucky purgatory code from
     userspace. Kdump will come later (requires updates to libfdt).

   - Optimisation of our dynamic CPU feature framework, so that all
     detected features are enabled via a single stop_machine()
     invocation

   - KPTI whitelisting of Cortex-A CPUs unaffected by Meltdown, so that
     they can benefit from global TLB entries when KASLR is not in use

   - 52-bit virtual addressing for userspace (kernel remains 48-bit)

   - Patch in LSE atomics for per-cpu atomic operations

   - Custom preempt.h implementation to avoid unconditional calls to
     preempt_schedule() from preempt_enable()

   - Support for the new 'SB' Speculation Barrier instruction

   - Vectorised implementation of XOR checksumming and CRC32
     optimisations

   - Workaround for Cortex-A76 erratum #1165522

   - Improved compatibility with Clang/LLD

   - Support for TX2 system PMUS for profiling the L3 cache and DMC

   - Reflect read-only permissions in the linear map by default

   - Ensure MMIO reads are ordered with subsequent calls to Xdelay()

   - Initial support for memory hotplug

   - Tweak the threshold when we invalidate the TLB by-ASID, so that
     mremap() performance is improved for ranges spanning multiple PMDs.

   - Minor refactoring and cleanups"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (125 commits)
  arm64: kaslr: print PHYS_OFFSET in dump_kernel_offset()
  arm64: sysreg: Use _BITUL() when defining register bits
  arm64: cpufeature: Rework ptr auth hwcaps using multi_entry_cap_matches
  arm64: cpufeature: Reduce number of pointer auth CPU caps from 6 to 4
  arm64: docs: document pointer authentication
  arm64: ptr auth: Move per-thread keys from thread_info to thread_struct
  arm64: enable pointer authentication
  arm64: add prctl control for resetting ptrauth keys
  arm64: perf: strip PAC when unwinding userspace
  arm64: expose user PAC bit positions via ptrace
  arm64: add basic pointer authentication support
  arm64/cpufeature: detect pointer authentication
  arm64: Don't trap host pointer auth use to EL2
  arm64/kvm: hide ptrauth from guests
  arm64/kvm: consistently handle host HCR_EL2 flags
  arm64: add pointer authentication register bits
  arm64: add comments about EC exception levels
  arm64: perf: Treat EXCLUDE_EL* bit definitions as unsigned
  arm64: kpti: Whitelist Cortex-A CPUs that don't implement the CSV3 field
  arm64: enable per-task stack canaries
  ...
2018-12-25 17:41:56 -08:00
Lan Tianyu
0cf853c5e2 KVM/MMU: Move tlb flush in kvm_set_pte_rmapp() to kvm_mmu_notifier_change_pte()
This patch is to move tlb flush in kvm_set_pte_rmapp() to
kvm_mmu_notifier_change_pte() in order to avoid redundant tlb flush.

Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21 11:28:42 +01:00
Lan Tianyu
748c0e312f KVM: Make kvm_set_spte_hva() return int
The patch is to make kvm_set_spte_hva() return int and caller can
check return value to determine flush tlb or not.

Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21 11:28:41 +01:00
Wei Yang
bdd303cb1b KVM: fix some typos
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
[Preserved the iff and a probably intentional weird bracket notation.
 Also dropped the style change to make a single-purpose patch. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-12-21 11:28:26 +01:00
Jim Mattson
7a86dab8cf kvm: Change offset in kvm_write_guest_offset_cached to unsigned
Since the offset is added directly to the hva from the
gfn_to_hva_cache, a negative offset could result in an out of bounds
write. The existing BUG_ON only checks for addresses beyond the end of
the gfn_to_hva_cache, not for addresses before the start of the
gfn_to_hva_cache.

Note that all current call sites have non-negative offsets.

Fixes: 4ec6e86362 ("kvm: Introduce kvm_write_guest_offset_cached()")
Reported-by: Cfir Cohen <cfir@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Cfir Cohen <cfir@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-12-21 11:28:22 +01:00
Jim Mattson
f1b9dd5eb8 kvm: Disallow wraparound in kvm_gfn_to_hva_cache_init
Previously, in the case where (gpa + len) wrapped around, the entire
region was not validated, as the comment claimed. It doesn't actually
seem that wraparound should be allowed here at all.

Furthermore, since some callers don't check the return code from this
function, it seems prudent to clear ghc->memslot in the event of an
error.

Fixes: 8f964525a1 ("KVM: Allow cross page reads and writes from cached translations.")
Reported-by: Cfir Cohen <cfir@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Cfir Cohen <cfir@google.com>
Reviewed-by: Marc Orr <marcorr@google.com>
Cc: Andrew Honig <ahonig@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-12-21 11:28:22 +01:00
Paolo Bonzini
8c5e14f438 KVM/arm updates for 4.21
- Large PUD support for HugeTLB
 - Single-stepping fixes
 - Improved tracing
 - Various timer and vgic fixups
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Merge tag 'kvmarm-for-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm updates for 4.21

- Large PUD support for HugeTLB
- Single-stepping fixes
- Improved tracing
- Various timer and vgic fixups
2018-12-19 20:33:55 +01:00
Marc Zyngier
58466766cd arm/arm64: KVM: Add ARM_EXCEPTION_IS_TRAP macro
32 and 64bit use different symbols to identify the traps.
32bit has a fine grained approach (prefetch abort, data abort and HVC),
while 64bit is pretty happy with just "trap".

This has been fine so far, except that we now need to decode some
of that in tracepoints that are common to both architectures.

Introduce ARM_EXCEPTION_IS_TRAP which abstracts the trap symbols
and make the tracepoint use it.

Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19 17:47:53 +00:00
Christoffer Dall
6794ad5443 KVM: arm/arm64: Fix unintended stage 2 PMD mappings
There are two things we need to take care of when we create block
mappings in the stage 2 page tables:

  (1) The alignment within a PMD between the host address range and the
  guest IPA range must be the same, since otherwise we end up mapping
  pages with the wrong offset.

  (2) The head and tail of a memory slot may not cover a full block
  size, and we have to take care to not map those with block
  descriptors, since we could expose memory to the guest that the host
  did not intend to expose.

So far, we have been taking care of (1), but not (2), and our commentary
describing (1) was somewhat confusing.

This commit attempts to factor out the checks of both into a common
function, and if we don't pass the check, we won't attempt any PMD
mappings for neither hugetlbfs nor THP.

Note that we used to only check the alignment for THP, not for
hugetlbfs, but as far as I can tell the check needs to be applied to
both scenarios.

Cc: Ralph Palutke <ralph.palutke@fau.de>
Cc: Lukas Braun <koomi@moshbit.net>
Reported-by: Lukas Braun <koomi@moshbit.net>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19 17:47:52 +00:00
Marc Zyngier
107352a249 arm/arm64: KVM: vgic: Force VM halt when changing the active state of GICv3 PPIs/SGIs
We currently only halt the guest when a vCPU messes with the active
state of an SPI. This is perfectly fine for GICv2, but isn't enough
for GICv3, where all vCPUs can access the state of any other vCPU.

Let's broaden the condition to include any GICv3 interrupt that
has an active state (i.e. all but LPIs).

Cc: stable@vger.kernel.org
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19 17:47:08 +00:00
Christoffer Dall
6e14ef1d12 KVM: arm/arm64: arch_timer: Simplify kvm_timer_vcpu_terminate
kvm_timer_vcpu_terminate can only be called in two scenarios:

 1. As part of cleanup during a failed VCPU create
 2. As part of freeing the whole VM (struct kvm refcount == 0)

In the first case, we cannot have programmed any timers or mapped any
IRQs, and therefore we do not have to cancel anything or unmap anything.

In the second case, the VCPU will have gone through kvm_timer_vcpu_put,
which will have canceled the emulated physical timer's hrtimer, and we
do not need to that here as well.  We also do not care if the irq is
recorded as mapped or not in the VGIC data structure, because the whole
VM is going away.  That leaves us only with having to ensure that we
cancel the bg_timer if we were blocking the last time we called
kvm_timer_vcpu_put().

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19 17:47:07 +00:00
Christoffer Dall
8a411b060f KVM: arm/arm64: Remove arch timer workqueue
The use of a work queue in the hrtimer expire function for the bg_timer
is a leftover from the time when we would inject interrupts when the
bg_timer expired.

Since we are no longer doing that, we can instead call
kvm_vcpu_wake_up() directly from the hrtimer function and remove all
workqueue functionality from the arch timer code.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19 17:47:07 +00:00
Christoffer Dall
71a7e47f39 KVM: arm/arm64: Fixup the kvm_exit tracepoint
The kvm_exit tracepoint strangely always reported exits as being IRQs.
This seems to be because either the __print_symbolic or the tracepoint
macros use a variable named idx.

Take this chance to update the fields in the tracepoint to reflect the
concepts in the arm64 architecture that we pass to the tracepoint and
move the exception type table to the same location and header files as
the exits code.

We also clear out the exception code to 0 for IRQ exits (which
translates to UNKNOWN in text) to make it slighyly less confusing to
parse the trace output.

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19 17:47:06 +00:00
Christoffer Dall
9009782a49 KVM: arm/arm64: vgic: Consider priority and active state for pending irq
When checking if there are any pending IRQs for the VM, consider the
active state and priority of the IRQs as well.

Otherwise we could be continuously scheduling a guest hypervisor without
it seeing an IRQ.

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19 17:47:06 +00:00
Gustavo A. R. Silva
c23b2e6fc4 KVM: arm/arm64: vgic: Fix off-by-one bug in vgic_get_irq()
When using the nospec API, it should be taken into account that:

"...if the CPU speculates past the bounds check then
 * array_index_nospec() will clamp the index within the range of [0,
 * size)."

The above is part of the header for macro array_index_nospec() in
linux/nospec.h

Now, in this particular case, if intid evaluates to exactly VGIC_MAX_SPI
or to exaclty VGIC_MAX_PRIVATE, the array_index_nospec() macro ends up
returning VGIC_MAX_SPI - 1 or VGIC_MAX_PRIVATE - 1 respectively, instead
of VGIC_MAX_SPI or VGIC_MAX_PRIVATE, which, based on the original logic:

	/* SGIs and PPIs */
	if (intid <= VGIC_MAX_PRIVATE)
 		return &vcpu->arch.vgic_cpu.private_irqs[intid];

 	/* SPIs */
	if (intid <= VGIC_MAX_SPI)
 		return &kvm->arch.vgic.spis[intid - VGIC_NR_PRIVATE_IRQS];

are valid values for intid.

Fix this by calling array_index_nospec() macro with VGIC_MAX_PRIVATE + 1
and VGIC_MAX_SPI + 1 as arguments for its parameter size.

Fixes: 41b87599c7 ("KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_get_irq()")
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
[dropped the SPI part which was fixed separately]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19 17:46:07 +00:00
Eric Biggers
987d1149be KVM: fix unregistering coalesced mmio zone from wrong bus
If you register a kvm_coalesced_mmio_zone with '.pio = 0' but then
unregister it with '.pio = 1', KVM_UNREGISTER_COALESCED_MMIO will try to
unregister it from KVM_PIO_BUS rather than KVM_MMIO_BUS, which is a
no-op.  But it frees the kvm_coalesced_mmio_dev anyway, causing a
use-after-free.

Fix it by only unregistering and freeing the zone if the correct value
of 'pio' is provided.

Reported-by: syzbot+f87f60bb6f13f39b54e3@syzkaller.appspotmail.com
Fixes: 0804c849f1 ("kvm/x86 : add coalesced pio support")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-18 22:07:25 +01:00
Marc Zyngier
bea2ef803a KVM: arm/arm64: vgic: Cap SPIs to the VM-defined maximum
SPIs should be checked against the VMs specific configuration, and
not the architectural maximum.

Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:50 +00:00
Christoffer Dall
6992195cc6 KVM: arm64: Clarify explanation of STAGE2_PGTABLE_LEVELS
In attempting to re-construct the logic for our stage 2 page table
layout I found the reasoning in the comment explaining how we calculate
the number of levels used for stage 2 page tables a bit backwards.

This commit attempts to clarify the comment, to make it slightly easier
to read without having the Arm ARM open on the right page.

While we're at it, fixup a typo in a comment that was recently changed.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:50 +00:00
Julien Thierry
2e2f6c3c0b KVM: arm/arm64: vgic: Do not cond_resched_lock() with IRQs disabled
To change the active state of an MMIO, halt is requested for all vcpus of
the affected guest before modifying the IRQ state. This is done by calling
cond_resched_lock() in vgic_mmio_change_active(). However interrupts are
disabled at this point and we cannot reschedule a vcpu.

We actually don't need any of this, as kvm_arm_halt_guest ensures that
all the other vcpus are out of the guest. Let's just drop that useless
code.

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Suggested-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:49 +00:00
Punit Agrawal
b8e0ba7c8b KVM: arm64: Add support for creating PUD hugepages at stage 2
KVM only supports PMD hugepages at stage 2. Now that the various page
handling routines are updated, extend the stage 2 fault handling to
map in PUD hugepages.

Addition of PUD hugepage support enables additional page sizes (e.g.,
1G with 4K granule) which can be useful on cores that support mapping
larger block sizes in the TLB entries.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[ Replace BUG() => WARN_ON(1) for arm32 PUD helpers ]
Signed-off-by: Suzuki Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:49 +00:00
Punit Agrawal
35a6396619 KVM: arm64: Update age handlers to support PUD hugepages
In preparation for creating larger hugepages at Stage 2, add support
to the age handling notifiers for PUD hugepages when encountered.

Provide trivial helpers for arm32 to allow sharing code.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[ Replaced BUG() => WARN_ON(1) for arm32 PUD helpers ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:48 +00:00
Punit Agrawal
eb3f0624ea KVM: arm64: Support handling access faults for PUD hugepages
In preparation for creating larger hugepages at Stage 2, extend the
access fault handling at Stage 2 to support PUD hugepages when
encountered.

Provide trivial helpers for arm32 to allow sharing of code.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[ Replaced BUG() => WARN_ON(1) in PUD helpers ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:48 +00:00
Punit Agrawal
86d1c55ea6 KVM: arm64: Support PUD hugepage in stage2_is_exec()
In preparation for creating PUD hugepages at stage 2, add support for
detecting execute permissions on PUD page table entries. Faults due to
lack of execute permissions on page table entries is used to perform
i-cache invalidation on first execute.

Provide trivial implementations of arm32 helpers to allow sharing of
code.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[ Replaced BUG() => WARN_ON(1) in arm32 PUD helpers ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:48 +00:00
Punit Agrawal
4ea5af5311 KVM: arm64: Support dirty page tracking for PUD hugepages
In preparation for creating PUD hugepages at stage 2, add support for
write protecting PUD hugepages when they are encountered. Write
protecting guest tables is used to track dirty pages when migrating
VMs.

Also, provide trivial implementations of required kvm_s2pud_* helpers
to allow sharing of code with arm32.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[ Replaced BUG() => WARN_ON() in arm32 pud helpers ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:47 +00:00
Punit Agrawal
f8df73388e KVM: arm/arm64: Introduce helpers to manipulate page table entries
Introduce helpers to abstract architectural handling of the conversion
of pfn to page table entries and marking a PMD page table entry as a
block entry.

The helpers are introduced in preparation for supporting PUD hugepages
at stage 2 - which are supported on arm64 but do not exist on arm.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:47 +00:00
Punit Agrawal
6396b852e4 KVM: arm/arm64: Re-factor setting the Stage 2 entry to exec on fault
Stage 2 fault handler marks a page as executable if it is handling an
execution fault or if it was a permission fault in which case the
executable bit needs to be preserved.

The logic to decide if the page should be marked executable is
duplicated for PMD and PTE entries. To avoid creating another copy
when support for PUD hugepages is introduced refactor the code to
share the checks needed to mark a page table entry as executable.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:47 +00:00
Punit Agrawal
3f58bf6345 KVM: arm/arm64: Share common code in user_mem_abort()
The code for operations such as marking the pfn as dirty, and
dcache/icache maintenance during stage 2 fault handling is duplicated
between normal pages and PMD hugepages.

Instead of creating another copy of the operations when we introduce
PUD hugepages, let's share them across the different pagesizes.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:46 +00:00
Christoffer Dall
60c3ab30d8 KVM: arm/arm64: vgic-v2: Set active_source to 0 when restoring state
When restoring the active state from userspace, we don't know which CPU
was the source for the active state, and this is not architecturally
exposed in any of the register state.

Set the active_source to 0 in this case.  In the future, we can expand
on this and exposse the information as additional information to
userspace for GICv2 if anyone cares.

Cc: stable@vger.kernel.org
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:46 +00:00
Christoffer Dall
fb544d1ca6 KVM: arm/arm64: Fix VMID alloc race by reverting to lock-less
We recently addressed a VMID generation race by introducing a read/write
lock around accesses and updates to the vmid generation values.

However, kvm_arch_vcpu_ioctl_run() also calls need_new_vmid_gen() but
does so without taking the read lock.

As far as I can tell, this can lead to the same kind of race:

  VM 0, VCPU 0			VM 0, VCPU 1
  ------------			------------
  update_vttbr (vmid 254)
  				update_vttbr (vmid 1) // roll over
				read_lock(kvm_vmid_lock);
				force_vm_exit()
  local_irq_disable
  need_new_vmid_gen == false //because vmid gen matches

  enter_guest (vmid 254)
  				kvm_arch.vttbr = <PGD>:<VMID 1>
				read_unlock(kvm_vmid_lock);

  				enter_guest (vmid 1)

Which results in running two VCPUs in the same VM with different VMIDs
and (even worse) other VCPUs from other VMs could now allocate clashing
VMID 254 from the new generation as long as VCPU 0 is not exiting.

Attempt to solve this by making sure vttbr is updated before another CPU
can observe the updated VMID generation.

Cc: stable@vger.kernel.org
Fixes: f0cf47d939 "KVM: arm/arm64: Close VMID generation race"
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:45 +00:00
Mark Rutland
bd7d95cafb arm64: KVM: Consistently advance singlestep when emulating instructions
When we emulate a guest instruction, we don't advance the hardware
singlestep state machine, and thus the guest will receive a software
step exception after a next instruction which is not emulated by the
host.

We bodge around this in an ad-hoc fashion. Sometimes we explicitly check
whether userspace requested a single step, and fake a debug exception
from within the kernel. Other times, we advance the HW singlestep state
rely on the HW to generate the exception for us. Thus, the observed step
behaviour differs for host and guest.

Let's make this simpler and consistent by always advancing the HW
singlestep state machine when we skip an instruction. Thus we can rely
on the hardware to generate the singlestep exception for us, and never
need to explicitly check for an active-pending step, nor do we need to
fake a debug exception from the guest.

Cc: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 14:11:37 +00:00
Mark Rutland
0d640732db arm64: KVM: Skip MMIO insn after emulation
When we emulate an MMIO instruction, we advance the CPU state within
decode_hsr(), before emulating the instruction effects.

Having this logic in decode_hsr() is opaque, and advancing the state
before emulation is problematic. It gets in the way of applying
consistent single-step logic, and it prevents us from being able to fail
an MMIO instruction with a synchronous exception.

Clean this up by only advancing the CPU state *after* the effects of the
instruction are emulated.

Cc: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 14:10:36 +00:00
Paolo Bonzini
2a31b9db15 kvm: introduce manual dirty log reprotect
There are two problems with KVM_GET_DIRTY_LOG.  First, and less important,
it can take kvm->mmu_lock for an extended period of time.  Second, its user
can actually see many false positives in some cases.  The latter is due
to a benign race like this:

  1. KVM_GET_DIRTY_LOG returns a set of dirty pages and write protects
     them.
  2. The guest modifies the pages, causing them to be marked ditry.
  3. Userspace actually copies the pages.
  4. KVM_GET_DIRTY_LOG returns those pages as dirty again, even though
     they were not written to since (3).

This is especially a problem for large guests, where the time between
(1) and (3) can be substantial.  This patch introduces a new
capability which, when enabled, makes KVM_GET_DIRTY_LOG not
write-protect the pages it returns.  Instead, userspace has to
explicitly clear the dirty log bits just before using the content
of the page.  The new KVM_CLEAR_DIRTY_LOG ioctl can also operate on a
64-page granularity rather than requiring to sync a full memslot;
this way, the mmu_lock is taken for small amounts of time, and
only a small amount of time will pass between write protection
of pages and the sending of their content.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 12:34:19 +01:00
Paolo Bonzini
8fe65a8299 kvm: rename last argument to kvm_get_dirty_log_protect
When manual dirty log reprotect will be enabled, kvm_get_dirty_log_protect's
pointer argument will always be false on exit, because no TLB flush is needed
until the manual re-protection operation.  Rename it from "is_dirty" to "flush",
which more accurately tells the caller what they have to do with it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 12:34:18 +01:00
Paolo Bonzini
e5d83c74a5 kvm: make KVM_CAP_ENABLE_CAP_VM architecture agnostic
The first such capability to be handled in virt/kvm/ will be manual
dirty page reprotection.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 12:34:18 +01:00
Marc Zyngier
33e5f4e509 KVM: arm64: Rework detection of SVE, !VHE systems
An SVE system is so far the only case where we mandate VHE. As we're
starting to grow this requirements, let's slightly rework the way we
deal with that situation, allowing for easy extension of this check.

Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-10 11:57:52 +00:00
Lance Roy
d4d592a6ee KVM: arm/arm64: vgic: Replace spin_is_locked() with lockdep
lockdep_assert_held() is better suited to checking locking requirements,
since it only checks if the current thread holds the lock regardless of
whether someone else does. This is also a step towards possibly removing
spin_is_locked().

Signed-off-by: Lance Roy <ldr709@gmail.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: <kvmarm@lists.cs.columbia.edu>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
2018-11-12 09:06:22 -08:00
Michal Hocko
4e15a073a1 Revert "mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks"
Revert 5ff7091f5a ("mm, mmu_notifier: annotate mmu notifiers with
blockable invalidate callbacks").

MMU_INVALIDATE_DOES_NOT_BLOCK flags was the only one used and it is no
longer needed since 93065ac753 ("mm, oom: distinguish blockable mode for
mmu notifiers").  We now have a full support for per range !blocking
behavior so we can drop the stop gap workaround which the per notifier
flag was used for.

Link: http://lkml.kernel.org/r/20180827112623.8992-4-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-26 16:25:19 -07:00
Linus Torvalds
0d1e8b8d2b KVM updates for v4.20
ARM:
  - Improved guest IPA space support (32 to 52 bits)
 
  - RAS event delivery for 32bit
 
  - PMU fixes
 
  - Guest entry hardening
 
  - Various cleanups
 
  - Port of dirty_log_test selftest
 
 PPC:
  - Nested HV KVM support for radix guests on POWER9.  The performance is
    much better than with PR KVM.  Migration and arbitrary level of
    nesting is supported.
 
  - Disable nested HV-KVM on early POWER9 chips that need a particular hardware
    bug workaround
 
  - One VM per core mode to prevent potential data leaks
 
  - PCI pass-through optimization
 
  - merge ppc-kvm topic branch and kvm-ppc-fixes to get a better base
 
 s390:
  - Initial version of AP crypto virtualization via vfio-mdev
 
  - Improvement for vfio-ap
 
  - Set the host program identifier
 
  - Optimize page table locking
 
 x86:
  - Enable nested virtualization by default
 
  - Implement Hyper-V IPI hypercalls
 
  - Improve #PF and #DB handling
 
  - Allow guests to use Enlightened VMCS
 
  - Add migration selftests for VMCS and Enlightened VMCS
 
  - Allow coalesced PIO accesses
 
  - Add an option to perform nested VMCS host state consistency check
    through hardware
 
  - Automatic tuning of lapic_timer_advance_ns
 
  - Many fixes, minor improvements, and cleanups
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Merge tag 'kvm-4.20-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Radim Krčmář:
 "ARM:
   - Improved guest IPA space support (32 to 52 bits)

   - RAS event delivery for 32bit

   - PMU fixes

   - Guest entry hardening

   - Various cleanups

   - Port of dirty_log_test selftest

  PPC:
   - Nested HV KVM support for radix guests on POWER9. The performance
     is much better than with PR KVM. Migration and arbitrary level of
     nesting is supported.

   - Disable nested HV-KVM on early POWER9 chips that need a particular
     hardware bug workaround

   - One VM per core mode to prevent potential data leaks

   - PCI pass-through optimization

   - merge ppc-kvm topic branch and kvm-ppc-fixes to get a better base

  s390:
   - Initial version of AP crypto virtualization via vfio-mdev

   - Improvement for vfio-ap

   - Set the host program identifier

   - Optimize page table locking

  x86:
   - Enable nested virtualization by default

   - Implement Hyper-V IPI hypercalls

   - Improve #PF and #DB handling

   - Allow guests to use Enlightened VMCS

   - Add migration selftests for VMCS and Enlightened VMCS

   - Allow coalesced PIO accesses

   - Add an option to perform nested VMCS host state consistency check
     through hardware

   - Automatic tuning of lapic_timer_advance_ns

   - Many fixes, minor improvements, and cleanups"

* tag 'kvm-4.20-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (204 commits)
  KVM/nVMX: Do not validate that posted_intr_desc_addr is page aligned
  Revert "kvm: x86: optimize dr6 restore"
  KVM: PPC: Optimize clearing TCEs for sparse tables
  x86/kvm/nVMX: tweak shadow fields
  selftests/kvm: add missing executables to .gitignore
  KVM: arm64: Safety check PSTATE when entering guest and handle IL
  KVM: PPC: Book3S HV: Don't use streamlined entry path on early POWER9 chips
  arm/arm64: KVM: Enable 32 bits kvm vcpu events support
  arm/arm64: KVM: Rename function kvm_arch_dev_ioctl_check_extension()
  KVM: arm64: Fix caching of host MDCR_EL2 value
  KVM: VMX: enable nested virtualization by default
  KVM/x86: Use 32bit xor to clear registers in svm.c
  kvm: x86: Introduce KVM_CAP_EXCEPTION_PAYLOAD
  kvm: vmx: Defer setting of DR6 until #DB delivery
  kvm: x86: Defer setting of CR2 until #PF delivery
  kvm: x86: Add payload operands to kvm_multiple_exception
  kvm: x86: Add exception payload fields to kvm_vcpu_events
  kvm: x86: Add has_payload and payload to kvm_queued_exception
  KVM: Documentation: Fix omission in struct kvm_vcpu_events
  KVM: selftests: add Enlightened VMCS test
  ...
2018-10-25 17:57:35 -07:00
Linus Torvalds
ba9f6f8954 Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull siginfo updates from Eric Biederman:
 "I have been slowly sorting out siginfo and this is the culmination of
  that work.

  The primary result is in several ways the signal infrastructure has
  been made less error prone. The code has been updated so that manually
  specifying SEND_SIG_FORCED is never necessary. The conversion to the
  new siginfo sending functions is now complete, which makes it
  difficult to send a signal without filling in the proper siginfo
  fields.

  At the tail end of the patchset comes the optimization of decreasing
  the size of struct siginfo in the kernel from 128 bytes to about 48
  bytes on 64bit. The fundamental observation that enables this is by
  definition none of the known ways to use struct siginfo uses the extra
  bytes.

  This comes at the cost of a small user space observable difference.
  For the rare case of siginfo being injected into the kernel only what
  can be copied into kernel_siginfo is delivered to the destination, the
  rest of the bytes are set to 0. For cases where the signal and the
  si_code are known this is safe, because we know those bytes are not
  used. For cases where the signal and si_code combination is unknown
  the bits that won't fit into struct kernel_siginfo are tested to
  verify they are zero, and the send fails if they are not.

  I made an extensive search through userspace code and I could not find
  anything that would break because of the above change. If it turns out
  I did break something it will take just the revert of a single change
  to restore kernel_siginfo to the same size as userspace siginfo.

  Testing did reveal dependencies on preferring the signo passed to
  sigqueueinfo over si->signo, so bit the bullet and added the
  complexity necessary to handle that case.

  Testing also revealed bad things can happen if a negative signal
  number is passed into the system calls. Something no sane application
  will do but something a malicious program or a fuzzer might do. So I
  have fixed the code that performs the bounds checks to ensure negative
  signal numbers are handled"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (80 commits)
  signal: Guard against negative signal numbers in copy_siginfo_from_user32
  signal: Guard against negative signal numbers in copy_siginfo_from_user
  signal: In sigqueueinfo prefer sig not si_signo
  signal: Use a smaller struct siginfo in the kernel
  signal: Distinguish between kernel_siginfo and siginfo
  signal: Introduce copy_siginfo_from_user and use it's return value
  signal: Remove the need for __ARCH_SI_PREABLE_SIZE and SI_PAD_SIZE
  signal: Fail sigqueueinfo if si_signo != sig
  signal/sparc: Move EMT_TAGOVF into the generic siginfo.h
  signal/unicore32: Use force_sig_fault where appropriate
  signal/unicore32: Generate siginfo in ucs32_notify_die
  signal/unicore32: Use send_sig_fault where appropriate
  signal/arc: Use force_sig_fault where appropriate
  signal/arc: Push siginfo generation into unhandled_exception
  signal/ia64: Use force_sig_fault where appropriate
  signal/ia64: Use the force_sig(SIGSEGV,...) in ia64_rt_sigreturn
  signal/ia64: Use the generic force_sigsegv in setup_frame
  signal/arm/kvm: Use send_sig_mceerr
  signal/arm: Use send_sig_fault where appropriate
  signal/arm: Use force_sig_fault where appropriate
  ...
2018-10-24 11:22:39 +01:00