Paul Mackerras
0d4ee88d92
KVM: PPC: Book3S HV: Use new mutex to synchronize MMU setup
Currently the HV KVM code uses kvm->lock in conjunction with a flag, kvm->arch.mmu_ready, to synchronize MMU setup and hold off vcpu execution until the MMU-related data structures are ready. However, this means that kvm->lock is being taken inside vcpu->mutex, which is contrary to Documentation/virtual/kvm/locking.txt and results in lockdep warnings. To fix this, we add a new mutex, kvm->arch.mmu_setup_lock, which nests inside the vcpu mutexes, and is taken in the places where kvm->lock was taken that are related to MMU setup. Additionally we take the new mutex in the vcpu creation code at the point where we are creating a new vcore, in order to provide mutual exclusion with kvmppc_update_lpcr() and ensure that an update to kvm->arch.lpcr doesn't get missed, which could otherwise lead to a stale vcore->lpcr value. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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