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Diffstat (limited to 'Documentation/virtual/kvm/api.txt')
-rw-r--r-- | Documentation/virtual/kvm/api.txt | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 9301266..310fe50 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1930,6 +1930,42 @@ The "pte_enc" field provides a value that can OR'ed into the hash PTE's RPN field (ie, it needs to be shifted left by 12 to OR it into the hash PTE second double word). + +4.75 KVM_PPC_ALLOCATE_HTAB + +Capability: KVM_CAP_PPC_ALLOC_HTAB +Architectures: powerpc +Type: vm ioctl +Parameters: Pointer to u32 containing hash table order (in/out) +Returns: 0 on success, -1 on error + +This requests the host kernel to allocate an MMU hash table for a +guest using the PAPR paravirtualization interface. This only does +anything if the kernel is configured to use the Book 3S HV style of +virtualization. Otherwise the capability doesn't exist and the ioctl +returns an ENOTTY error. The rest of this description assumes Book 3S +HV. + +There must be no vcpus running when this ioctl is called; if there +are, it will do nothing and return an EBUSY error. + +The parameter is a pointer to a 32-bit unsigned integer variable +containing the order (log base 2) of the desired size of the hash +table, which must be between 18 and 46. On successful return from the +ioctl, it will have been updated with the order of the hash table that +was allocated. + +If no hash table has been allocated when any vcpu is asked to run +(with the KVM_RUN ioctl), the host kernel will allocate a +default-sized hash table (16 MB). + +If this ioctl is called when a hash table has already been allocated, +the kernel will clear out the existing hash table (zero all HPTEs) and +return the hash table order in the parameter. (If the guest is using +the virtualized real-mode area (VRMA) facility, the kernel will +re-create the VMRA HPTEs on the next KVM_RUN of any vcpu.) + + 5. The kvm_run structure ------------------------ |