From e2788c4a41cb5fa68096f5a58bccacec1a700295 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 28 Mar 2019 17:22:31 +0100 Subject: [PATCH] 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 Signed-off-by: Paolo Bonzini --- Documentation/virtual/kvm/api.txt | 18 ++++++++++-------- 1 file 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 -- GitLab