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Diffstat (limited to 'Documentation/virtual/kvm/api.txt')
-rw-r--r-- | Documentation/virtual/kvm/api.txt | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 2c9948379469..bf33aaa4c59f 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt | |||
@@ -1946,6 +1946,40 @@ the guest using the specified gsi pin. The irqfd is removed using | |||
1946 | the KVM_IRQFD_FLAG_DEASSIGN flag, specifying both kvm_irqfd.fd | 1946 | the KVM_IRQFD_FLAG_DEASSIGN flag, specifying both kvm_irqfd.fd |
1947 | and kvm_irqfd.gsi. | 1947 | and kvm_irqfd.gsi. |
1948 | 1948 | ||
1949 | 4.76 KVM_PPC_ALLOCATE_HTAB | ||
1950 | |||
1951 | Capability: KVM_CAP_PPC_ALLOC_HTAB | ||
1952 | Architectures: powerpc | ||
1953 | Type: vm ioctl | ||
1954 | Parameters: Pointer to u32 containing hash table order (in/out) | ||
1955 | Returns: 0 on success, -1 on error | ||
1956 | |||
1957 | This requests the host kernel to allocate an MMU hash table for a | ||
1958 | guest using the PAPR paravirtualization interface. This only does | ||
1959 | anything if the kernel is configured to use the Book 3S HV style of | ||
1960 | virtualization. Otherwise the capability doesn't exist and the ioctl | ||
1961 | returns an ENOTTY error. The rest of this description assumes Book 3S | ||
1962 | HV. | ||
1963 | |||
1964 | There must be no vcpus running when this ioctl is called; if there | ||
1965 | are, it will do nothing and return an EBUSY error. | ||
1966 | |||
1967 | The parameter is a pointer to a 32-bit unsigned integer variable | ||
1968 | containing the order (log base 2) of the desired size of the hash | ||
1969 | table, which must be between 18 and 46. On successful return from the | ||
1970 | ioctl, it will have been updated with the order of the hash table that | ||
1971 | was allocated. | ||
1972 | |||
1973 | If no hash table has been allocated when any vcpu is asked to run | ||
1974 | (with the KVM_RUN ioctl), the host kernel will allocate a | ||
1975 | default-sized hash table (16 MB). | ||
1976 | |||
1977 | If this ioctl is called when a hash table has already been allocated, | ||
1978 | the kernel will clear out the existing hash table (zero all HPTEs) and | ||
1979 | return the hash table order in the parameter. (If the guest is using | ||
1980 | the virtualized real-mode area (VRMA) facility, the kernel will | ||
1981 | re-create the VMRA HPTEs on the next KVM_RUN of any vcpu.) | ||
1982 | |||
1949 | 1983 | ||
1950 | 5. The kvm_run structure | 1984 | 5. The kvm_run structure |
1951 | ------------------------ | 1985 | ------------------------ |