Re: [PATCH] Revert "KVM: doc: Document the life cycle of a VM and its resources"

From: Paolo Bonzini
Date: Tue Apr 30 2019 - 15:31:29 EST


On 29/04/19 15:25, Radim KrÄmÃÅ wrote:
> This reverts commit 919f6cd8bb2fe7151f8aecebc3b3d1ca2567396e.
>
> The patch was applied twice.
> The first commit is eca6be566d47029f945a5f8e1c94d374e31df2ca.
>
> Reported-by: Cornelia Huck <cohuck@xxxxxxxxxx>
> Signed-off-by: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
> ---
> Documentation/virtual/kvm/api.txt | 17 -----------------
> 1 file changed, 17 deletions(-)
>
> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
> index b62ad0d94234..26dc1280b49b 100644
> --- a/Documentation/virtual/kvm/api.txt
> +++ b/Documentation/virtual/kvm/api.txt
> @@ -69,23 +69,6 @@ by and on behalf of the VM's process may not be freed/unaccounted when
> the VM is shut down.
>
>
> -It is important to note that althought VM ioctls may only be issued from
> -the process that created the VM, a VM's lifecycle is associated with its
> -file descriptor, not its creator (process). In other words, the VM and
> -its resources, *including the associated address space*, are not freed
> -until the last reference to the VM's file descriptor has been released.
> -For example, if fork() is issued after ioctl(KVM_CREATE_VM), the VM will
> -not be freed until both the parent (original) process and its child have
> -put their references to the VM's file descriptor.
> -
> -Because a VM's resources are not freed until the last reference to its
> -file descriptor is released, creating additional references to a VM via
> -via fork(), dup(), etc... without careful consideration is strongly
> -discouraged and may have unwanted side effects, e.g. memory allocated
> -by and on behalf of the VM's process may not be freed/unaccounted when
> -the VM is shut down.
> -
> -
> 3. Extensions
> -------------
>
>

Applied, thanks.

Paolo