Documentation: kvm: clarify KVM_SET_USER_MEMORY_REGION

The documentation does not mention how to delete a slot, add the
information.

Reported-by: Nathaniel McCallum <npmccallum@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2019-03-28 17:22:31 +01:00
parent 919f6cd8bb
commit e2788c4a41
1 changed files with 10 additions and 8 deletions

View File

@ -1114,14 +1114,12 @@ struct kvm_userspace_memory_region {
#define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0)
#define KVM_MEM_READONLY (1UL << 1)
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.
Bits 0-15 of "slot" specifies the slot id and this value should be
less than the maximum number of user memory slots supported per VM.
The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS,
if this capability is supported by the architecture.
This ioctl allows the user to create, modify or delete a guest physical
memory slot. Bits 0-15 of "slot" specify the slot id and this value
should be less than the maximum number of user memory slots supported per
VM. The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS,
if this capability is supported by the architecture. Slots may not
overlap in guest physical address space.
If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of "slot"
specifies the address space which is being modified. They must be
@ -1130,6 +1128,10 @@ KVM_CAP_MULTI_ADDRESS_SPACE capability. Slots in separate address spaces
are unrelated; the restriction on overlapping slots only applies within
each address space.
Deleting a slot is done by passing zero for memory_size. When changing
an existing slot, it may be moved in the guest physical memory space,
or its flags may be modified, but it may not be resized.
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