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authorPaolo Bonzini <pbonzini@redhat.com>2019-03-28 17:22:31 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2019-03-28 17:30:11 +0100
commite2788c4a41cb5fa68096f5a58bccacec1a700295 (patch)
treed345144ddc4a893cc42134c1986e82173a7be008 /Documentation
parent919f6cd8bb2fe7151f8aecebc3b3d1ca2567396e (diff)
downloadlinux-e2788c4a41cb5fa68096f5a58bccacec1a700295.tar.bz2
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>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/virtual/kvm/api.txt18
1 files changed, 10 insertions, 8 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index f39969d0121e..67068c47c591 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -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