Commit Graph

1825 Commits

Author SHA1 Message Date
Jérôme Glisse dfcd66604c mm/mmu_notifier: convert user range->blockable to helper function
Use the mmu_notifier_range_blockable() helper function instead of directly
dereferencing the range->blockable field.  This is done to make it easier
to change the mmu_notifier range field.

This patch is the outcome of the following coccinelle patch:

%<-------------------------------------------------------------------
@@
identifier I1, FN;
@@
FN(..., struct mmu_notifier_range *I1, ...) {
<...
-I1->blockable
+mmu_notifier_range_blockable(I1)
...>
}
------------------------------------------------------------------->%

spatch --in-place --sp-file blockable.spatch --dir .

Link: http://lkml.kernel.org/r/20190326164747.24405-3-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Jason Gunthorpe <jgg@mellanox.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: John Hubbard <jhubbard@nvidia.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 09:47:49 -07:00
Linus Torvalds c620f7bd0b arm64 updates for 5.2
Mostly just incremental improvements here:
 
 - Introduce AT_HWCAP2 for advertising CPU features to userspace
 
 - Expose SVE2 availability to userspace
 
 - Support for "data cache clean to point of deep persistence" (DC PODP)
 
 - Honour "mitigations=off" on the cmdline and advertise status via sysfs
 
 - CPU timer erratum workaround (Neoverse-N1 #1188873)
 
 - Introduce perf PMU driver for the SMMUv3 performance counters
 
 - Add config option to disable the kuser helpers page for AArch32 tasks
 
 - Futex modifications to ensure liveness under contention
 
 - Rework debug exception handling to seperate kernel and user handlers
 
 - Non-critical fixes and cleanup
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "Mostly just incremental improvements here:

   - Introduce AT_HWCAP2 for advertising CPU features to userspace

   - Expose SVE2 availability to userspace

   - Support for "data cache clean to point of deep persistence" (DC PODP)

   - Honour "mitigations=off" on the cmdline and advertise status via
     sysfs

   - CPU timer erratum workaround (Neoverse-N1 #1188873)

   - Introduce perf PMU driver for the SMMUv3 performance counters

   - Add config option to disable the kuser helpers page for AArch32 tasks

   - Futex modifications to ensure liveness under contention

   - Rework debug exception handling to seperate kernel and user
     handlers

   - Non-critical fixes and cleanup"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits)
  Documentation: Add ARM64 to kernel-parameters.rst
  arm64/speculation: Support 'mitigations=' cmdline option
  arm64: ssbs: Don't treat CPUs with SSBS as unaffected by SSB
  arm64: enable generic CPU vulnerabilites support
  arm64: add sysfs vulnerability show for speculative store bypass
  arm64: Fix size of __early_cpu_boot_status
  clocksource/arm_arch_timer: Use arch_timer_read_counter to access stable counters
  clocksource/arm_arch_timer: Remove use of workaround static key
  clocksource/arm_arch_timer: Drop use of static key in arch_timer_reg_read_stable
  clocksource/arm_arch_timer: Direcly assign set_next_event workaround
  arm64: Use arch_timer_read_counter instead of arch_counter_get_cntvct
  watchdog/sbsa: Use arch_timer_read_counter instead of arch_counter_get_cntvct
  ARM: vdso: Remove dependency with the arch_timer driver internals
  arm64: Apply ARM64_ERRATUM_1188873 to Neoverse-N1
  arm64: Add part number for Neoverse N1
  arm64: Make ARM64_ERRATUM_1188873 depend on COMPAT
  arm64: Restrict ARM64_ERRATUM_1188873 mitigation to AArch32
  arm64: mm: Remove pte_unmap_nested()
  arm64: Fix compiler warning from pte_unmap() with -Wunused-but-set-variable
  arm64: compat: Reduce address limit for 64K pages
  ...
2019-05-06 17:54:22 -07:00
Paolo Bonzini 6245242d91 KVM/ARM fixes for 5.1, take #2:
- Don't try to emulate timers on userspace access
 - Fix unaligned huge mappings, again
 - Properly reset a vcpu that fails to reset(!)
 - Properly retire pending LPIs on reset
 - Fix computation of emulated CNTP_TVAL
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Merge tag 'kvmarm-fixes-for-5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

KVM/ARM fixes for 5.1, take #2:

- Don't try to emulate timers on userspace access
- Fix unaligned huge mappings, again
- Properly reset a vcpu that fails to reset(!)
- Properly retire pending LPIs on reset
- Fix computation of emulated CNTP_TVAL
2019-04-30 21:23:06 +02:00
Paolo Bonzini 76d58e0f07 KVM: fix KVM_CLEAR_DIRTY_LOG for memory slots of unaligned size
If a memory slot's size is not a multiple of 64 pages (256K), then
the KVM_CLEAR_DIRTY_LOG API is unusable: clearing the final 64 pages
either requires the requested page range to go beyond memslot->npages,
or requires log->num_pages to be unaligned, and kvm_clear_dirty_log_protect
requires log->num_pages to be both in range and aligned.

To allow this case, allow log->num_pages not to be a multiple of 64 if
it ends exactly on the last page of the slot.

Reported-by: Peter Xu <peterx@redhat.com>
Fixes: 98938aa8ed ("KVM: validate userspace input in kvm_clear_dirty_log_protect()", 2019-01-02)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-04-30 21:22:15 +02:00
Christoffer Dall 6bc210003d KVM: arm/arm64: Don't emulate virtual timers on userspace ioctls
When a VCPU never runs before a guest exists, but we set timer registers
up via ioctls, the associated hrtimer might never get cancelled.

Since we moved vcpu_load/put into the arch-specific implementations and
only have load/put for KVM_RUN, we won't ever have a scheduled hrtimer
for emulating a timer when modifying the timer state via an ioctl from
user space.  All we need to do is make sure that we pick up the right
state when we load the timer state next time userspace calls KVM_RUN
again.

We also do not need to worry about this interacting with the bg_timer,
because if we were in WFI from the guest, and somehow ended up in a
kvm_arm_timer_set_reg, it means that:

 1. the VCPU thread has received a signal,
 2. we have called vcpu_load when being scheduled in again,
 3. we have called vcpu_put when we returned to userspace for it to issue
    another ioctl

And therefore will not have a bg_timer programmed and the event is
treated as a spurious wakeup from WFI if userspace decides to run the
vcpu again even if there are not virtual interrupts.

This fixes stray virtual timer interrupts triggered by an expiring
hrtimer, which happens after a failed live migration, for instance.

Fixes: bee038a674 ("KVM: arm/arm64: Rework the timer code to use a timer_map")
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Reported-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-25 14:13:31 +01:00
Suzuki K Poulose 2e8010bb71 kvm: arm: Skip stage2 huge mappings for unaligned ipa backed by THP
With commit a80868f398, we no longer ensure that the
THP page is properly aligned in the guest IPA. Skip the stage2
huge mapping for unaligned IPA backed by transparent hugepages.

Fixes: a80868f398 ("KVM: arm/arm64: Enforce PTE mappings at stage2 when needed")
Reported-by: Eric Auger <eric.auger@redhat.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Chirstoffer Dall <christoffer.dall@arm.com>
Cc: Zenghui Yu <yuzenghui@huawei.com>
Cc: Zheng Xiang <zhengxiang9@huawei.com>
Cc: Andrew Murray <andrew.murray@arm.com>
Cc: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-25 11:50:31 +01:00
Andrew Jones 811328fc32 KVM: arm/arm64: Ensure vcpu target is unset on reset failure
A failed KVM_ARM_VCPU_INIT should not set the vcpu target,
as the vcpu target is used by kvm_vcpu_initialized() to
determine if other vcpu ioctls may proceed. We need to set
the target before calling kvm_reset_vcpu(), but if that call
fails, we should then unset it and clear the feature bitmap
while we're at it.

Signed-off-by: Andrew Jones <drjones@redhat.com>
[maz: Simplified patch, completed commit message]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-25 11:50:31 +01:00
Paolo Bonzini 1d487e9bf8 KVM: fix spectrev1 gadgets
These were found with smatch, and then generalized when applicable.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-04-16 15:38:07 +02:00
Anshuman Khandual 14b94d0757 KVM: ARM: Remove pgtable page standard functions from stage-2 page tables
ARM64 standard pgtable functions are going to use pgtable_page_[ctor|dtor]
or pgtable_pmd_page_[ctor|dtor] constructs. At present KVM guest stage-2
PUD|PMD|PTE level page tabe pages are allocated with __get_free_page()
via mmu_memory_cache_alloc() but released with standard pud|pmd_free() or
pte_free_kernel(). These will fail once they start calling into pgtable_
[pmd]_page_dtor() for pages which never originally went through respective
constructor functions. Hence convert all stage-2 page table page release
functions to call buddy directly while freeing pages.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Yu Zhao <yuzhao@google.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-09 11:21:50 +01:00
Marc Zyngier 96085b9496 KVM: arm/arm64: vgic-v3: Retire pending interrupts on disabling LPIs
When disabling LPIs (for example on reset) at the redistributor
level, it is expected that LPIs that was pending in the CPU
interface are eventually retired.

Currently, this is not what is happening, and these LPIs will
stay in the ap_list, eventually being acknowledged by the vcpu
(which didn't quite expect this behaviour).

The fix is thus to retire these LPIs from the list of pending
interrupts as we disable LPIs.

Reported-by: Heyi Guo <guoheyi@huawei.com>
Tested-by: Heyi Guo <guoheyi@huawei.com>
Fixes: 0e4e82f154 ("KVM: arm64: vgic-its: Enable ITS emulation as a virtual MSI controller")
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-03 02:18:43 +01:00
Wei Huang 8fa7616248 KVM: arm/arm64: arch_timer: Fix CNTP_TVAL calculation
Recently the generic timer test of kvm-unit-tests failed to complete
(stalled) when a physical timer is being used. This issue is caused
by incorrect update of CNTP_CVAL when CNTP_TVAL is being accessed,
introduced by 'Commit 84135d3d18 ("KVM: arm/arm64: consolidate arch
timer trap handlers")'. According to Arm ARM, the read/write behavior
of accesses to the TVAL registers is expected to be:

  * READ: TimerValue = (CompareValue – (Counter - Offset)
  * WRITE: CompareValue = ((Counter - Offset) + Sign(TimerValue)

This patch fixes the TVAL read/write code path according to the
specification.

Fixes: 84135d3d18 ("KVM: arm/arm64: consolidate arch timer trap handlers")
Signed-off-by: Wei Huang <wei@redhat.com>
[maz: commit message tidy-up]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-03-30 10:06:00 +00:00
Paolo Bonzini 690edec54c KVM/ARM fixes for 5.1
- Fix THP handling in the presence of pre-existing PTEs
 - Honor request for PTE mappings even when THPs are available
 - GICv4 performance improvement
 - Take the srcu lock when writing to guest-controlled ITS data structures
 - Reset the virtual PMU in preemptible context
 - Various cleanups
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Merge tag 'kvmarm-fixes-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

KVM/ARM fixes for 5.1

- Fix THP handling in the presence of pre-existing PTEs
- Honor request for PTE mappings even when THPs are available
- GICv4 performance improvement
- Take the srcu lock when writing to guest-controlled ITS data structures
- Reset the virtual PMU in preemptible context
- Various cleanups
2019-03-28 19:07:30 +01:00
Sebastian Andrzej Siewior ca0488aadd kvm: don't redefine flags as something else
The function irqfd_wakeup() has flags defined as __poll_t and then it
has additional flags which is used for irqflags.

Redefine the inner flags variable as iflags so it does not shadow the
outer flags.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-28 17:28:59 +01:00
Sean Christopherson ddba91801a KVM: Reject device ioctls from processes other than the VM's creator
KVM's API requires thats ioctls must be issued from the same process
that created the VM.  In other words, userspace can play games with a
VM's file descriptors, e.g. fork(), SCM_RIGHTS, etc..., but only the
creator can do anything useful.  Explicitly reject device ioctls that
are issued by a process other than the VM's creator, and update KVM's
API documentation to extend its requirements to device ioctls.

Fixes: 852b6d57dc ("kvm: add device control API")
Cc: <stable@vger.kernel.org>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-28 17:27:06 +01:00
Zenghui Yu 8324c3d518 KVM: arm/arm64: Comments cleanup in mmu.c
Some comments in virt/kvm/arm/mmu.c are outdated. Update them to
reflect the current state of the code.

Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[maz: commit message tidy-up]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-03-28 13:17:17 +00:00
YueHaibing d9ea27a330 KVM: arm/arm64: vgic-its: Make attribute accessors static
Fix sparse warnings:

arch/arm64/kvm/../../../virt/kvm/arm/vgic/vgic-its.c:1732:5: warning:
 symbol 'vgic_its_has_attr_regs' was not declared. Should it be static?
arch/arm64/kvm/../../../virt/kvm/arm/vgic/vgic-its.c:1753:5: warning:
 symbol 'vgic_its_attr_regs_access' was not declared. Should it be static?

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
[maz: fixed subject]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-03-20 17:33:41 +00:00
Suzuki K Poulose 3c3736cd32 KVM: arm/arm64: Fix handling of stage2 huge mappings
We rely on the mmu_notifier call backs to handle the split/merge
of huge pages and thus we are guaranteed that, while creating a
block mapping, either the entire block is unmapped at stage2 or it
is missing permission.

However, we miss a case where the block mapping is split for dirty
logging case and then could later be made block mapping, if we cancel the
dirty logging. This not only creates inconsistent TLB entries for
the pages in the the block, but also leakes the table pages for
PMD level.

Handle this corner case for the huge mappings at stage2 by
unmapping the non-huge mapping for the block. This could potentially
release the upper level table. So we need to restart the table walk
once we unmap the range.

Fixes : ad361f093c ("KVM: ARM: Support hugetlbfs backed huge pages")
Reported-by: Zheng Xiang <zhengxiang9@huawei.com>
Cc: Zheng Xiang <zhengxiang9@huawei.com>
Cc: Zenghui Yu <yuzenghui@huawei.com>
Cc: 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>
2019-03-20 17:29:55 +00:00
Suzuki K Poulose a80868f398 KVM: arm/arm64: Enforce PTE mappings at stage2 when needed
commit 6794ad5443 ("KVM: arm/arm64: Fix unintended stage 2 PMD mappings")
made the checks to skip huge mappings, stricter. However it introduced
a bug where we still use huge mappings, ignoring the flag to
use PTE mappings, by not reseting the vma_pagesize to PAGE_SIZE.

Also, the checks do not cover the PUD huge pages, that was
under review during the same period. This patch fixes both
the issues.

Fixes : 6794ad5443 ("KVM: arm/arm64: Fix unintended stage 2 PMD mappings")
Reported-by: Zenghui Yu <yuzenghui@huawei.com>
Cc: Zenghui Yu <yuzenghui@huawei.com>
Cc: 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>
2019-03-19 18:01:57 +00:00
Marc Zyngier 7494cec6cb KVM: arm/arm64: vgic-its: Take the srcu lock when parsing the memslots
Calling kvm_is_visible_gfn() implies that we're parsing the memslots,
and doing this without the srcu lock is frown upon:

[12704.164532] =============================
[12704.164544] WARNING: suspicious RCU usage
[12704.164560] 5.1.0-rc1-00008-g600025238f51-dirty #16 Tainted: G        W
[12704.164573] -----------------------------
[12704.164589] ./include/linux/kvm_host.h:605 suspicious rcu_dereference_check() usage!
[12704.164602] other info that might help us debug this:
[12704.164616] rcu_scheduler_active = 2, debug_locks = 1
[12704.164631] 6 locks held by qemu-system-aar/13968:
[12704.164644]  #0: 000000007ebdae4f (&kvm->lock){+.+.}, at: vgic_its_set_attr+0x244/0x3a0
[12704.164691]  #1: 000000007d751022 (&its->its_lock){+.+.}, at: vgic_its_set_attr+0x250/0x3a0
[12704.164726]  #2: 00000000219d2706 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[12704.164761]  #3: 00000000a760aecd (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[12704.164794]  #4: 000000000ef8e31d (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[12704.164827]  #5: 000000007a872093 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[12704.164861] stack backtrace:
[12704.164878] CPU: 2 PID: 13968 Comm: qemu-system-aar Tainted: G        W         5.1.0-rc1-00008-g600025238f51-dirty #16
[12704.164887] Hardware name: rockchip evb_rk3399/evb_rk3399, BIOS 2019.04-rc3-00124-g2feec69fb1 03/15/2019
[12704.164896] Call trace:
[12704.164910]  dump_backtrace+0x0/0x138
[12704.164920]  show_stack+0x24/0x30
[12704.164934]  dump_stack+0xbc/0x104
[12704.164946]  lockdep_rcu_suspicious+0xcc/0x110
[12704.164958]  gfn_to_memslot+0x174/0x190
[12704.164969]  kvm_is_visible_gfn+0x28/0x70
[12704.164980]  vgic_its_check_id.isra.0+0xec/0x1e8
[12704.164991]  vgic_its_save_tables_v0+0x1ac/0x330
[12704.165001]  vgic_its_set_attr+0x298/0x3a0
[12704.165012]  kvm_device_ioctl_attr+0x9c/0xd8
[12704.165022]  kvm_device_ioctl+0x8c/0xf8
[12704.165035]  do_vfs_ioctl+0xc8/0x960
[12704.165045]  ksys_ioctl+0x8c/0xa0
[12704.165055]  __arm64_sys_ioctl+0x28/0x38
[12704.165067]  el0_svc_common+0xd8/0x138
[12704.165078]  el0_svc_handler+0x38/0x78
[12704.165089]  el0_svc+0x8/0xc

Make sure the lock is taken when doing this.

Fixes: bf308242ab ("KVM: arm/arm64: VGIC/ITS: protect kvm_read_guest() calls with SRCU lock")
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-03-19 17:56:56 +00:00
Marc Zyngier a6ecfb11bf KVM: arm/arm64: vgic-its: Take the srcu lock when writing to guest memory
When halting a guest, QEMU flushes the virtual ITS caches, which
amounts to writing to the various tables that the guest has allocated.

When doing this, we fail to take the srcu lock, and the kernel
shouts loudly if running a lockdep kernel:

[   69.680416] =============================
[   69.680819] WARNING: suspicious RCU usage
[   69.681526] 5.1.0-rc1-00008-g600025238f51-dirty #18 Not tainted
[   69.682096] -----------------------------
[   69.682501] ./include/linux/kvm_host.h:605 suspicious rcu_dereference_check() usage!
[   69.683225]
[   69.683225] other info that might help us debug this:
[   69.683225]
[   69.683975]
[   69.683975] rcu_scheduler_active = 2, debug_locks = 1
[   69.684598] 6 locks held by qemu-system-aar/4097:
[   69.685059]  #0: 0000000034196013 (&kvm->lock){+.+.}, at: vgic_its_set_attr+0x244/0x3a0
[   69.686087]  #1: 00000000f2ed935e (&its->its_lock){+.+.}, at: vgic_its_set_attr+0x250/0x3a0
[   69.686919]  #2: 000000005e71ea54 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.687698]  #3: 00000000c17e548d (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.688475]  #4: 00000000ba386017 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.689978]  #5: 00000000c2c3c335 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.690729]
[   69.690729] stack backtrace:
[   69.691151] CPU: 2 PID: 4097 Comm: qemu-system-aar Not tainted 5.1.0-rc1-00008-g600025238f51-dirty #18
[   69.691984] Hardware name: rockchip evb_rk3399/evb_rk3399, BIOS 2019.04-rc3-00124-g2feec69fb1 03/15/2019
[   69.692831] Call trace:
[   69.694072]  lockdep_rcu_suspicious+0xcc/0x110
[   69.694490]  gfn_to_memslot+0x174/0x190
[   69.694853]  kvm_write_guest+0x50/0xb0
[   69.695209]  vgic_its_save_tables_v0+0x248/0x330
[   69.695639]  vgic_its_set_attr+0x298/0x3a0
[   69.696024]  kvm_device_ioctl_attr+0x9c/0xd8
[   69.696424]  kvm_device_ioctl+0x8c/0xf8
[   69.696788]  do_vfs_ioctl+0xc8/0x960
[   69.697128]  ksys_ioctl+0x8c/0xa0
[   69.697445]  __arm64_sys_ioctl+0x28/0x38
[   69.697817]  el0_svc_common+0xd8/0x138
[   69.698173]  el0_svc_handler+0x38/0x78
[   69.698528]  el0_svc+0x8/0xc

The fix is to obviously take the srcu lock, just like we do on the
read side of things since bf308242ab. One wonders why this wasn't
fixed at the same time, but hey...

Fixes: bf308242ab ("KVM: arm/arm64: VGIC/ITS: protect kvm_read_guest() calls with SRCU lock")
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-03-19 17:56:56 +00:00
Marc Zyngier ca71228b42 arm64: KVM: Always set ICH_HCR_EL2.EN if GICv4 is enabled
The normal interrupt flow is not to enable the vgic when no virtual
interrupt is to be injected (i.e. the LRs are empty). But when a guest
is likely to use GICv4 for LPIs, we absolutely need to switch it on
at all times. Otherwise, VLPIs only get delivered when there is something
in the LRs, which doesn't happen very often.

Reported-by: Nianyao Tang <tangnianyao@huawei.com>
Tested-by: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-03-19 17:56:34 +00:00
Linus Torvalds 636deed6c0 ARM: some cleanups, direct physical timer assignment, cache sanitization
for 32-bit guests
 
 s390: interrupt cleanup, introduction of the Guest Information Block,
 preparation for processor subfunctions in cpu models
 
 PPC: bug fixes and improvements, especially related to machine checks
 and protection keys
 
 x86: many, many cleanups, including removing a bunch of MMU code for
 unnecessary optimizations; plus AVIC fixes.
 
 Generic: memcg accounting
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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:
   - some cleanups
   - direct physical timer assignment
   - cache sanitization for 32-bit guests

  s390:
   - interrupt cleanup
   - introduction of the Guest Information Block
   - preparation for processor subfunctions in cpu models

  PPC:
   - bug fixes and improvements, especially related to machine checks
     and protection keys

  x86:
   - many, many cleanups, including removing a bunch of MMU code for
     unnecessary optimizations
   - AVIC fixes

  Generic:
   - memcg accounting"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (147 commits)
  kvm: vmx: fix formatting of a comment
  KVM: doc: Document the life cycle of a VM and its resources
  MAINTAINERS: Add KVM selftests to existing KVM entry
  Revert "KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range()"
  KVM: PPC: Book3S: Add count cache flush parameters to kvmppc_get_cpu_char()
  KVM: PPC: Fix compilation when KVM is not enabled
  KVM: Minor cleanups for kvm_main.c
  KVM: s390: add debug logging for cpu model subfunctions
  KVM: s390: implement subfunction processor calls
  arm64: KVM: Fix architecturally invalid reset value for FPEXC32_EL2
  KVM: arm/arm64: Remove unused timer variable
  KVM: PPC: Book3S: Improve KVM reference counting
  KVM: PPC: Book3S HV: Fix build failure without IOMMU support
  Revert "KVM: Eliminate extra function calls in kvm_get_dirty_log_protect()"
  x86: kvmguest: use TSC clocksource if invariant TSC is exposed
  KVM: Never start grow vCPU halt_poll_ns from value below halt_poll_ns_grow_start
  KVM: Expose the initial start value in grow_halt_poll_ns() as a module parameter
  KVM: grow_halt_poll_ns() should never shrink vCPU halt_poll_ns
  KVM: x86/mmu: Consolidate kvm_mmu_zap_all() and kvm_mmu_zap_mmio_sptes()
  KVM: x86/mmu: WARN if zapping a MMIO spte results in zapping children
  ...
2019-03-15 15:00:28 -07:00
Linus Torvalds d276709ce6 ACPI updates for 5.1-rc1
- Update the ACPICA code in the kernel to upstream revision 20190215
    including ACPI 6.3 support and more:
    * New predefined methods: _NBS, _NCH, _NIC, _NIH, and _NIG (Erik
      Schmauss).
    * Update of the PCC Identifier structure in PDTT (Erik Schmauss).
    * Support for new Generic Affinity Structure subtable in SRAT
      (Erik Schmauss).
    * New PCC operation region support (Erik Schmauss).
    * Support for GICC statistical profiling for MADT (Erik Schmauss).
    * New Error Disconnect Recover notification support (Erik Schmauss).
    * New PPTT Processor Structure Flags fields support (Erik Schmauss).
    * ACPI 6.3 HMAT updates (Erik Schmauss).
    * GTDT Revision 3 support (Erik Schmauss).
    * Legacy module-level code (MLC) support removal (Erik Schmauss).
    * Update/clarification of messages for control method failures
      (Bob Moore).
    * Warning on creation of a zero-length opregion (Bob Moore).
    * acpiexec option to dump extra info for memory leaks (Bob Moore).
    * More ACPI error to firmware error conversions (Bob Moore).
    * Debugger fix (Bob Moore).
    * Copyrights update (Bob Moore).
 
  - Clean up sleep states support code in ACPICA (Christoph Hellwig).
 
  - Rework in_nmi() handling in the APEI code and add suppor for the
    ARM Software Delegated Exception Interface (SDEI) to it (James
    Morse).
 
  - Fix possible out-of-bounds accesses in BERT-related core (Ross
    Lagerwall).
 
  - Fix the APEI code parsing HEST that includes a Deferred Machine
    Check subtable (Yazen Ghannam).
 
  - Use DEFINE_DEBUGFS_ATTRIBUTE for APEI-related debugfs files
    (YueHaibing).
 
  - Switch the APEI ERST code to the new generic UUID API (Andy
    Shevchenko).
 
  - Update the MAINTAINERS entry for APEI (Borislav Petkov).
 
  - Fix and clean up the ACPI EC driver (Rafael Wysocki, Zhang Rui).
 
  - Fix DMI checks handling in the ACPI backlight driver and add the
    "Lunch Box" chassis-type check to it (Hans de Goede).
 
  - Add support for using ACPI table overrides included in built-in
    initrd images (Shunyong Yang).
 
  - Update ACPI device enumeration to treat the PWM2 device as "always
    present" on Lenovo Yoga Book (Yauhen Kharuzhy).
 
  - Fix up the enumeration of device objects with the PRP0001 device
    ID (Andy Shevchenko).
 
  - Clean up PPTT parsing error messages (John Garry).
 
  - Clean up debugfs files creation handling (Greg Kroah-Hartman,
    Rafael Wysocki).
 
  - Clean up the ACPI DPTF Makefile (Masahiro Yamada).
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Merge tag 'acpi-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI updates from Rafael Wysocki:
 "These are ACPICA updates including ACPI 6.3 support among other
  things, APEI updates including the ARM Software Delegated Exception
  Interface (SDEI) support, ACPI EC driver fixes and cleanups and other
  assorted improvements.

  Specifics:

   - Update the ACPICA code in the kernel to upstream revision 20190215
     including ACPI 6.3 support and more:
      * New predefined methods: _NBS, _NCH, _NIC, _NIH, and _NIG (Erik
        Schmauss).
      * Update of the PCC Identifier structure in PDTT (Erik Schmauss).
      * Support for new Generic Affinity Structure subtable in SRAT
        (Erik Schmauss).
      * New PCC operation region support (Erik Schmauss).
      * Support for GICC statistical profiling for MADT (Erik Schmauss).
      * New Error Disconnect Recover notification support (Erik
        Schmauss).
      * New PPTT Processor Structure Flags fields support (Erik
        Schmauss).
      * ACPI 6.3 HMAT updates (Erik Schmauss).
      * GTDT Revision 3 support (Erik Schmauss).
      * Legacy module-level code (MLC) support removal (Erik Schmauss).
      * Update/clarification of messages for control method failures
        (Bob Moore).
      * Warning on creation of a zero-length opregion (Bob Moore).
      * acpiexec option to dump extra info for memory leaks (Bob Moore).
      * More ACPI error to firmware error conversions (Bob Moore).
      * Debugger fix (Bob Moore).
      * Copyrights update (Bob Moore)

   - Clean up sleep states support code in ACPICA (Christoph Hellwig)

   - Rework in_nmi() handling in the APEI code and add suppor for the
     ARM Software Delegated Exception Interface (SDEI) to it (James
     Morse)

   - Fix possible out-of-bounds accesses in BERT-related core (Ross
     Lagerwall)

   - Fix the APEI code parsing HEST that includes a Deferred Machine
     Check subtable (Yazen Ghannam)

   - Use DEFINE_DEBUGFS_ATTRIBUTE for APEI-related debugfs files
     (YueHaibing)

   - Switch the APEI ERST code to the new generic UUID API (Andy
     Shevchenko)

   - Update the MAINTAINERS entry for APEI (Borislav Petkov)

   - Fix and clean up the ACPI EC driver (Rafael Wysocki, Zhang Rui)

   - Fix DMI checks handling in the ACPI backlight driver and add the
     "Lunch Box" chassis-type check to it (Hans de Goede)

   - Add support for using ACPI table overrides included in built-in
     initrd images (Shunyong Yang)

   - Update ACPI device enumeration to treat the PWM2 device as "always
     present" on Lenovo Yoga Book (Yauhen Kharuzhy)

   - Fix up the enumeration of device objects with the PRP0001 device ID
     (Andy Shevchenko)

   - Clean up PPTT parsing error messages (John Garry)

   - Clean up debugfs files creation handling (Greg Kroah-Hartman,
     Rafael Wysocki)

   - Clean up the ACPI DPTF Makefile (Masahiro Yamada)"

* tag 'acpi-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (65 commits)
  ACPI / bus: Respect PRP0001 when retrieving device match data
  ACPICA: Update version to 20190215
  ACPI/ACPICA: Trivial: fix spelling mistakes and fix whitespace formatting
  ACPICA: ACPI 6.3: add GTDT Revision 3 support
  ACPICA: ACPI 6.3: HMAT updates
  ACPICA: ACPI 6.3: PPTT add additional fields in Processor Structure Flags
  ACPICA: ACPI 6.3: add Error Disconnect Recover Notification value
  ACPICA: ACPI 6.3: MADT: add support for statistical profiling in GICC
  ACPICA: ACPI 6.3: add PCC operation region support for AML interpreter
  efi: cper: Fix possible out-of-bounds access
  ACPI: APEI: Fix possible out-of-bounds access to BERT region
  ACPICA: ACPI 6.3: SRAT: add Generic Affinity Structure subtable
  ACPICA: ACPI 6.3: Add Trigger order to PCC Identifier structure in PDTT
  ACPICA: ACPI 6.3: Adding predefined methods _NBS, _NCH, _NIC, _NIH, and _NIG
  ACPICA: Update/clarify messages for control method failures
  ACPICA: Debugger: Fix possible fault with the "test objects" command
  ACPICA: Interpreter: Emit warning for creation of a zero-length op region
  ACPICA: Remove legacy module-level code support
  ACPI / x86: Make PWM2 device always present at Lenovo Yoga Book
  ACPI / video: Extend chassis-type detection with a "Lunch Box" check
  ..
2019-03-06 13:33:11 -08:00
Linus Torvalds 3717f613f4 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 main RCU related changes in this cycle were:

   - Additional cleanups after RCU flavor consolidation

   - Grace-period forward-progress cleanups and improvements

   - Documentation updates

   - Miscellaneous fixes

   - spin_is_locked() conversions to lockdep

   - SPDX changes to RCU source and header files

   - SRCU updates

   - Torture-test updates, including nolibc updates and moving nolibc to
     tools/include"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
  locking/locktorture: Convert to SPDX license identifier
  linux/torture: Convert to SPDX license identifier
  torture: Convert to SPDX license identifier
  linux/srcu: Convert to SPDX license identifier
  linux/rcutree: Convert to SPDX license identifier
  linux/rcutiny: Convert to SPDX license identifier
  linux/rcu_sync: Convert to SPDX license identifier
  linux/rcu_segcblist: Convert to SPDX license identifier
  linux/rcupdate: Convert to SPDX license identifier
  linux/rcu_node_tree: Convert to SPDX license identifier
  rcu/update: Convert to SPDX license identifier
  rcu/tree: Convert to SPDX license identifier
  rcu/tiny: Convert to SPDX license identifier
  rcu/sync: Convert to SPDX license identifier
  rcu/srcu: Convert to SPDX license identifier
  rcu/rcutorture: Convert to SPDX license identifier
  rcu/rcu_segcblist: Convert to SPDX license identifier
  rcu/rcuperf: Convert to SPDX license identifier
  rcu/rcu.h: Convert to SPDX license identifier
  RCU/torture.txt: Remove section MODULE PARAMETERS
  ...
2019-03-05 14:49:11 -08:00
Rafael J. Wysocki dcaed592b2 Merge branch 'acpi-apei'
* acpi-apei: (29 commits)
  efi: cper: Fix possible out-of-bounds access
  ACPI: APEI: Fix possible out-of-bounds access to BERT region
  MAINTAINERS: Add James Morse to the list of APEI reviewers
  ACPI / APEI: Add support for the SDEI GHES Notification type
  firmware: arm_sdei: Add ACPI GHES registration helper
  ACPI / APEI: Use separate fixmap pages for arm64 NMI-like notifications
  ACPI / APEI: Only use queued estatus entry during in_nmi_queue_one_entry()
  ACPI / APEI: Split ghes_read_estatus() to allow a peek at the CPER length
  ACPI / APEI: Make GHES estatus header validation more user friendly
  ACPI / APEI: Pass ghes and estatus separately to avoid a later copy
  ACPI / APEI: Let the notification helper specify the fixmap slot
  ACPI / APEI: Move locking to the notification helper
  arm64: KVM/mm: Move SEA handling behind a single 'claim' interface
  KVM: arm/arm64: Add kvm_ras.h to collect kvm specific RAS plumbing
  ACPI / APEI: Switch NOTIFY_SEA to use the estatus queue
  ACPI / APEI: Move NOTIFY_SEA between the estatus-queue and NOTIFY_NMI
  ACPI / APEI: Don't allow ghes_ack_error() to mask earlier errors
  ACPI / APEI: Generalise the estatus queue's notify code
  ACPI / APEI: Don't update struct ghes' flags in read/clear estatus
  ACPI / APEI: Remove spurious GHES_TO_CLEAR check
  ...
2019-03-04 11:16:35 +01:00
Greg Kroah-Hartman 8ed0579c12 kvm: properly check debugfs dentry before using it
debugfs can now report an error code if something went wrong instead of
just NULL.  So if the return value is to be used as a "real" dentry, it
needs to be checked if it is an error before dereferencing it.

This is now happening because of ff9fb72bc0 ("debugfs: return error
values, not NULL").  syzbot has found a way to trigger multiple debugfs
files attempting to be created, which fails, and then the error code
gets passed to dentry_path_raw() which obviously does not like it.

Reported-by: Eric Biggers <ebiggers@kernel.org>
Reported-and-tested-by: syzbot+7857962b4d45e602b8ad@syzkaller.appspotmail.com
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-28 08:57:32 -08:00
Paolo Bonzini 71783e09b4 KVM/arm updates for Linux v5.1
- A number of pre-nested code rework
 - Direct physical timer assignment on VHE systems
 - kvm_call_hyp type safety enforcement
 - Set/Way cache sanitisation for 32bit guests
 - Build system cleanups
 - A bunch of janitorial fixes
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Merge tag 'kvmarm-for-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-next

KVM/arm updates for Linux v5.1

- A number of pre-nested code rework
- Direct physical timer assignment on VHE systems
- kvm_call_hyp type safety enforcement
- Set/Way cache sanitisation for 32bit guests
- Build system cleanups
- A bunch of janitorial fixes
2019-02-22 17:45:05 +01:00
Leo Yan a242010776 KVM: Minor cleanups for kvm_main.c
This patch contains two minor cleanups: firstly it puts exported symbol
for kvm_io_bus_write() by following the function definition; secondly it
removes a redundant blank line.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-22 17:43:57 +01:00
Shaokun Zhang 7f5d9c1bc0 KVM: arm/arm64: Remove unused timer variable
The 'timer' local variable became unused after commit bee038a674
("KVM: arm/arm64: Rework the timer code to use a timer_map").
Remove it to avoid [-Wunused-but-set-variable] warning.

Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Pouloze <suzuki.poulose@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-22 09:41:52 +00:00
Lan Tianyu a67794cafb Revert "KVM: Eliminate extra function calls in kvm_get_dirty_log_protect()"
The value of "dirty_bitmap[i]" is already check before setting its value
to mask. The following check of "mask" is redundant. The check of "mask" was
introduced by commit 58d2930f4e ("KVM: Eliminate extra function calls in
kvm_get_dirty_log_protect()"), revert it.

Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-20 22:48:52 +01:00
Nir Weiner dee339b5c1 KVM: Never start grow vCPU halt_poll_ns from value below halt_poll_ns_grow_start
grow_halt_poll_ns() have a strange behaviour in case
(vcpu->halt_poll_ns != 0) &&
(vcpu->halt_poll_ns < halt_poll_ns_grow_start).

In this case, vcpu->halt_poll_ns will be multiplied by grow factor
(halt_poll_ns_grow) which will require several grow iteration in order
to reach a value bigger than halt_poll_ns_grow_start.
This means that growing vcpu->halt_poll_ns from value of 0 is slower
than growing it from a positive value less than halt_poll_ns_grow_start.
Which is misleading and inaccurate.

Fix issue by changing grow_halt_poll_ns() to set vcpu->halt_poll_ns
to halt_poll_ns_grow_start in any case that
(vcpu->halt_poll_ns < halt_poll_ns_grow_start).
Regardless if vcpu->halt_poll_ns is 0.

use READ_ONCE to get a consistent number for all cases.

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Nir Weiner <nir.weiner@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-20 22:48:51 +01:00
Nir Weiner 49113d360b KVM: Expose the initial start value in grow_halt_poll_ns() as a module parameter
The hard-coded value 10000 in grow_halt_poll_ns() stands for the initial
start value when raising up vcpu->halt_poll_ns.
It actually sets the first timeout to the first polling session.
This value has significant effect on how tolerant we are to outliers.
On the standard case, higher value is better - we will spend more time
in the polling busyloop, handle events/interrupts faster and result
in better performance.
But on outliers it puts us in a busy loop that does nothing.
Even if the shrink factor is zero, we will still waste time on the first
iteration.
The optimal value changes between different workloads. It depends on
outliers rate and polling sessions length.
As this value has significant effect on the dynamic halt-polling
algorithm, it should be configurable and exposed.

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Nir Weiner <nir.weiner@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-20 22:48:50 +01:00
Nir Weiner 7fa08e71b4 KVM: grow_halt_poll_ns() should never shrink vCPU halt_poll_ns
grow_halt_poll_ns() have a strange behavior in case
(halt_poll_ns_grow == 0) && (vcpu->halt_poll_ns != 0).

In this case, vcpu->halt_pol_ns will be set to zero.
That results in shrinking instead of growing.

Fix issue by changing grow_halt_poll_ns() to not modify
vcpu->halt_poll_ns in case halt_poll_ns_grow is zero

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Nir Weiner <nir.weiner@oracle.com>
Suggested-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-20 22:48:50 +01:00
Sean Christopherson 164bf7e56c KVM: Move the memslot update in-progress flag to bit 63
...now that KVM won't explode by moving it out of bit 0.  Using bit 63
eliminates the need to jump over bit 0, e.g. when calculating a new
memslots generation or when propagating the memslots generation to an
MMIO spte.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-20 22:48:37 +01:00
Sean Christopherson 0e32958ec4 KVM: Remove the hack to trigger memslot generation wraparound
x86 captures a subset of the memslot generation (19 bits) in its MMIO
sptes so that it can expedite emulated MMIO handling by checking only
the releveant spte, i.e. doesn't need to do a full page fault walk.

Because the MMIO sptes capture only 19 bits (due to limited space in
the sptes), there is a non-zero probability that the MMIO generation
could wrap, e.g. after 500k memslot updates.  Since normal usage is
extremely unlikely to result in 500k memslot updates, a hack was added
by commit 69c9ea93ea ("KVM: MMU: init kvm generation close to mmio
wrap-around value") to offset the MMIO generation in order to trigger
a wraparound, e.g. after 150 memslot updates.

When separate memslot generation sequences were assigned to each
address space, commit 00f034a12f ("KVM: do not bias the generation
number in kvm_current_mmio_generation") moved the offset logic into the
initialization of the memslot generation itself so that the per-address
space bit(s) were not dropped/corrupted by the MMIO shenanigans.

Remove the offset hack for three reasons:

  - While it does exercise x86's kvm_mmu_invalidate_mmio_sptes(), simply
    wrapping the generation doesn't actually test the interesting case
    of having stale MMIO sptes with the new generation number, e.g. old
    sptes with a generation number of 0.

  - Triggering kvm_mmu_invalidate_mmio_sptes() prematurely makes its
    performance rather important since the probability of invalidating
    MMIO sptes jumps from "effectively never" to "fairly likely".  This
    limits what can be done in future patches, e.g. to simplify the
    invalidation code, as doing so without proper caution could lead to
    a noticeable performance regression.

  - Forcing the memslots generation, which is a 64-bit number, to wrap
    prevents KVM from assuming the memslots generation will never wrap.
    This in turn prevents KVM from using an arbitrary bit for the
    "update in-progress" flag, e.g. using bit 63 would immediately
    collide with using a large value as the starting generation number.
    The "update in-progress" flag is effectively forced into bit 0 so
    that it's (subtly) taken into account when incrementing the
    generation.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-20 22:48:36 +01:00
Sean Christopherson 361209e054 KVM: Explicitly define the "memslot update in-progress" bit
KVM uses bit 0 of the memslots generation as an "update in-progress"
flag, which is used by x86 to prevent caching MMIO access while the
memslots are changing.  Although the intended behavior is flag-like,
e.g. MMIO sptes intentionally drop the in-progress bit so as to avoid
caching data from in-flux memslots, the implementation oftentimes treats
the bit as part of the generation number itself, e.g. incrementing the
generation increments twice, once to set the flag and once to clear it.

Prior to commit 4bd518f159 ("KVM: use separate generations for
each address space"), incorporating the "update in-progress" bit into
the generation number largely made sense, e.g. "real" generations are
even, "bogus" generations are odd, most code doesn't need to be aware of
the bit, etc...

Now that unique memslots generation numbers are assigned to each address
space, stealthing the in-progress status into the generation number
results in a wide variety of subtle code, e.g. kvm_create_vm() jumps
over bit 0 when initializing the memslots generation without any hint as
to why.

Explicitly define the flag and convert as much code as possible (which
isn't much) to actually treat it like a flag.  This paves the way for
eventually using a different bit for "update in-progress" so that it can
be a flag in truth instead of a awkward extension to the generation
number.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-20 22:48:34 +01:00
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
Shaokun Zhang c2be79a0bc KVM: arm/arm64: Remove unused gpa_end variable
The 'gpa_end' local variable is never used and let's remove it.

Cc: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-20 11:00:27 +00:00
Colin Ian King a37f0c3c46 KVM: arm/arm64: fix spelling mistake: "auxilary" -> "auxiliary"
There is a spelling mistake in a kvm_err error message. Fix it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-19 21:05:54 +00:00
Masahiro Yamada 49dfe94fe5 KVM: arm/arm64: Fix TRACE_INCLUDE_PATH
As the comment block in include/trace/define_trace.h says,
TRACE_INCLUDE_PATH should be a relative path to the define_trace.h

../../virt/kvm/arm is the correct relative path.

../../../virt/kvm/arm is working by coincidence because the top
Makefile adds -I$(srctree)/arch/$(SRCARCH)/include as a header
search path, but we should not rely on it.

Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-19 21:05:51 +00:00
Marc Zyngier bae561c0cf KVM: arm/arm64: arch_timer: Mark physical interrupt active when a virtual interrupt is pending
When a guest gets scheduled, KVM performs a "load" operation,
which for the timer includes evaluating the virtual "active" state
of the interrupt, and replicating it on the physical side. This
ensures that the deactivation in the guest will also take place
in the physical GIC distributor.

If the interrupt is not yet active, we flag it as inactive on the
physical side.  This means that on restoring the timer registers,
if the timer has expired, we'll immediately take an interrupt.
That's absolutely fine, as the interrupt will then be flagged as
active on the physical side. What this assumes though is that we'll
enter the guest right after having taken the interrupt, and that
the guest will quickly ACK the interrupt, making it active at on
the virtual side.

It turns out that quite often, this assumption doesn't really hold.
The guest may be preempted on the back on this interrupt, either
from kernel space or whilst running at EL1 when a host interrupt
fires. When this happens, we repeat the whole sequence on the
next load (interrupt marked as inactive, timer registers restored,
interrupt fires). And if it takes a really long time for a guest
to activate the interrupt (as it does with nested virt), we end-up
with many such events in quick succession, leading to the guest only
making very slow progress.

This can also be seen with the number of virtual timer interrupt on the
host being far greater than the same number in the guest.

An easy way to fix this is to evaluate the timer state when performing
the "load" operation, just like we do when the interrupt actually fires.
If the timer has a pending virtual interrupt at this stage, then we
can safely flag the physical interrupt as being active, which prevents
spurious exits.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-19 21:05:50 +00:00
Christoffer Dall 64cf98fa55 KVM: arm/arm64: Move kvm_is_write_fault to header file
Move this little function to the header files for arm/arm64 so other
code can make use of it directly.

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-19 21:05:45 +00:00
Christoffer Dall bee038a674 KVM: arm/arm64: Rework the timer code to use a timer_map
We are currently emulating two timers in two different ways.  When we
add support for nested virtualization in the future, we are going to be
emulating either two timers in two diffferent ways, or four timers in a
single way.

We need a unified data structure to keep track of how we map virtual
state to physical state and we need to cleanup some of the timer code to
operate more independently on a struct arch_timer_context instead of
trying to consider the global state of the VCPU and recomputing all
state.

Co-written with Marc Zyngier <marc.zyngier@arm.com>

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2019-02-19 21:05:43 +00:00
Christoffer Dall 9e01dc76be KVM: arm/arm64: arch_timer: Assign the phys timer on VHE systems
VHE systems don't have to emulate the physical timer, we can simply
assign the EL1 physical timer directly to the VM as the host always
uses the EL2 timers.

In order to minimize the amount of cruft, AArch32 gets definitions for
the physical timer too, but is should be generally unused on this
architecture.

Co-written with Marc Zyngier <marc.zyngier@arm.com>

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2019-02-19 21:05:42 +00:00
Christoffer Dall e604dd5d45 KVM: arm/arm64: timer: Rework data structures for multiple timers
Prepare for having 4 timer data structures (2 for now).

Move loaded to the cpu data structure and not the individual timer
structure, in preparation for assigning the EL1 phys timer as well.

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-19 21:05:41 +00:00
Andre Przywara 84135d3d18 KVM: arm/arm64: consolidate arch timer trap handlers
At the moment we have separate system register emulation handlers for
each timer register. Actually they are quite similar, and we rely on
kvm_arm_timer_[gs]et_reg() for the actual emulation anyways, so let's
just merge all of those handlers into one function, which just marshalls
the arguments and then hands off to a set of common accessors.
This makes extending the emulation to include EL2 timers much easier.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
[Fixed 32-bit VM breakage and reduced to reworking existing code]
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
[Fixed 32bit host, general cleanup]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-19 21:05:40 +00:00
Marc Zyngier b98c079ba4 KVM: arm64: Fix ICH_ELRSR_EL2 sysreg naming
We previously incorrectly named the define for this system register.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2019-02-19 21:05:39 +00:00
Christoffer Dall accb99bcd0 KVM: arm/arm64: Simplify bg_timer programming
Instead of calling into kvm_timer_[un]schedule from the main kvm
blocking path, test if the VCPU is on the wait queue from the load/put
path and perform the background timer setup/cancel in this path.

This has the distinct advantage that we no longer race between load/put
and schedule/unschedule and programming and canceling of the bg_timer
always happens when the timer state is not loaded.

Note that we must now remove the checks in kvm_timer_blocking that do
not schedule a background timer if one of the timers can fire, because
we no longer have a guarantee that kvm_vcpu_check_block() will be called
before kvm_timer_blocking.

Reported-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-19 21:05:36 +00:00