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author | Avi Kivity <avi@redhat.com> | 2010-03-25 10:16:48 (GMT) |
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committer | Avi Kivity <avi@redhat.com> | 2010-05-17 09:16:46 (GMT) |
commit | 0f2d8f4dd0663defff8c1738d33478c1fb65a4f5 (patch) | |
tree | c013f378ae0dc27192bd6349f690ed507b7f6b04 /Documentation/kvm | |
parent | 84b0c8c6a6f87b62bca93727dee12ec59e32e597 (diff) | |
download | linux-0f2d8f4dd0663defff8c1738d33478c1fb65a4f5.tar.xz |
KVM: Document KVM_SET_USER_MEMORY_REGION
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'Documentation/kvm')
-rw-r--r-- | Documentation/kvm/api.txt | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt index d170cb4..9d6e647 100644 --- a/Documentation/kvm/api.txt +++ b/Documentation/kvm/api.txt @@ -749,6 +749,51 @@ Writes debug registers into the vcpu. See KVM_GET_DEBUGREGS for the data structure. The flags field is unused yet and must be cleared on entry. +4.34 KVM_SET_USER_MEMORY_REGION + +Capability: KVM_CAP_USER_MEM +Architectures: all +Type: vm ioctl +Parameters: struct kvm_userspace_memory_region (in) +Returns: 0 on success, -1 on error + +struct kvm_userspace_memory_region { + __u32 slot; + __u32 flags; + __u64 guest_phys_addr; + __u64 memory_size; /* bytes */ + __u64 userspace_addr; /* start of the userspace allocated memory */ +}; + +/* for kvm_memory_region::flags */ +#define KVM_MEM_LOG_DIRTY_PAGES 1UL + +This ioctl allows the user to create or modify a guest physical memory +slot. When changing an existing slot, it may be moved in the guest +physical memory space, or its flags may be modified. It may not be +resized. Slots may not overlap in guest physical address space. + +Memory for the region is taken starting at the address denoted by the +field userspace_addr, which must point at user addressable memory for +the entire memory slot size. Any object may back this memory, including +anonymous memory, ordinary files, and hugetlbfs. + +It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr +be identical. This allows large pages in the guest to be backed by large +pages in the host. + +The flags field supports just one flag, KVM_MEM_LOG_DIRTY_PAGES, which +instructs kvm to keep track of writes to memory within the slot. See +the KVM_GET_DIRTY_LOG ioctl. + +When the KVM_CAP_SYNC_MMU capability, changes in the backing of the memory +region are automatically reflected into the guest. For example, an mmap() +that affects the region will be made visible immediately. Another example +is madvise(MADV_DROP). + +It is recommended to use this API instead of the KVM_SET_MEMORY_REGION ioctl. +The KVM_SET_MEMORY_REGION does not allow fine grained control over memory +allocation and is deprecated. 5. The kvm_run structure |