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Diffstat (limited to 'Documentation/virtual')
| -rw-r--r-- | Documentation/virtual/kvm/api.txt | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index aca994a90355..64f217af0416 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -3266,6 +3266,101 @@ The ap_encodings gives the supported page sizes and their AP field encodings, encoded with the AP value in the top 3 bits and the log base 2 of the page size in the bottom 6 bits. +4.102 KVM_PPC_RESIZE_HPT_PREPARE + +Capability: KVM_CAP_SPAPR_RESIZE_HPT +Architectures: powerpc +Type: vm ioctl +Parameters: struct kvm_ppc_resize_hpt (in) +Returns: 0 on successful completion, + >0 if a new HPT is being prepared, the value is an estimated + number of milliseconds until preparation is complete + -EFAULT if struct kvm_reinject_control cannot be read, + -EINVAL if the supplied shift or flags are invalid + -ENOMEM if unable to allocate the new HPT + -ENOSPC if there was a hash collision when moving existing + HPT entries to the new HPT + -EIO on other error conditions + +Used to implement the PAPR extension for runtime resizing of a guest's +Hashed Page Table (HPT). Specifically this starts, stops or monitors +the preparation of a new potential HPT for the guest, essentially +implementing the H_RESIZE_HPT_PREPARE hypercall. + +If called with shift > 0 when there is no pending HPT for the guest, +this begins preparation of a new pending HPT of size 2^(shift) bytes. +It then returns a positive integer with the estimated number of +milliseconds until preparation is complete. + +If called when there is a pending HPT whose size does not match that +requested in the parameters, discards the existing pending HPT and +creates a new one as above. + +If called when there is a pending HPT of the size requested, will: + * If preparation of the pending HPT is already complete, return 0 + * If preparation of the pending HPT has failed, return an error + code, then discard the pending HPT. + * If preparation of the pending HPT is still in progress, return an + estimated number of milliseconds until preparation is complete. + +If called with shift == 0, discards any currently pending HPT and +returns 0 (i.e. cancels any in-progress preparation). + +flags is reserved for future expansion, currently setting any bits in +flags will result in an -EINVAL. + +Normally this will be called repeatedly with the same parameters until +it returns <= 0. The first call will initiate preparation, subsequent +ones will monitor preparation until it completes or fails. + +struct kvm_ppc_resize_hpt { + __u64 flags; + __u32 shift; + __u32 pad; +}; + +4.103 KVM_PPC_RESIZE_HPT_COMMIT + +Capability: KVM_CAP_SPAPR_RESIZE_HPT +Architectures: powerpc +Type: vm ioctl +Parameters: struct kvm_ppc_resize_hpt (in) +Returns: 0 on successful completion, + -EFAULT if struct kvm_reinject_control cannot be read, + -EINVAL if the supplied shift or flags are invalid + -ENXIO is there is no pending HPT, or the pending HPT doesn't + have the requested size + -EBUSY if the pending HPT is not fully prepared + -ENOSPC if there was a hash collision when moving existing + HPT entries to the new HPT + -EIO on other error conditions + +Used to implement the PAPR extension for runtime resizing of a guest's +Hashed Page Table (HPT). Specifically this requests that the guest be +transferred to working with the new HPT, essentially implementing the +H_RESIZE_HPT_COMMIT hypercall. + +This should only be called after KVM_PPC_RESIZE_HPT_PREPARE has +returned 0 with the same parameters. In other cases +KVM_PPC_RESIZE_HPT_COMMIT will return an error (usually -ENXIO or +-EBUSY, though others may be possible if the preparation was started, +but failed). + +This will have undefined effects on the guest if it has not already +placed itself in a quiescent state where no vcpu will make MMU enabled +memory accesses. + +On succsful completion, the pending HPT will become the guest's active +HPT and the previous HPT will be discarded. + +On failure, the guest will still be operating on its previous HPT. + +struct kvm_ppc_resize_hpt { + __u64 flags; + __u32 shift; + __u32 pad; +}; + 5. The kvm_run structure ------------------------ |