[PATCH 0/3] KVM: Make kvm_lock non-raw

[Paolo Bonzini <pbonzini@redhat.com>]

Paul Gortmaker reported a BUG on preempt-rt kernels, due to taking the
mmu_lock within the raw kvm_lock in mmu_shrink_scan.  He provided a
patch that shrunk the kvm_lock critical section so that the mmu_lock
critical section does not nest with it, but in the end there is no reason
for the vm_list to be protected by a raw spinlock.  Only manipulations
of kvm_usage_count and the consequent hardware_enable/disable operations
are not preemptable.

This small series thus splits the kvm_lock in the "raw" part and the
"non-raw" part.

Paul, could you please provide your Tested-by?

Thanks,

Paolo

Paolo Bonzini (3):
  KVM: cleanup (physical) CPU hotplug
  KVM: protect kvm_usage_count with its own spinlock
  KVM: Convert kvm_lock back to non-raw spinlock

 Documentation/virtual/kvm/locking.txt |  8 ++++--
 arch/x86/kvm/mmu.c                    |  4 +--
 arch/x86/kvm/x86.c                    |  8 +++---
 include/linux/kvm_host.h              |  2 +-
 virt/kvm/kvm_main.c                   | 51 ++++++++++++++++++-----------------
 5 files changed, 40 insertions(+), 33 deletions(-)

-- 
1.8.3.1