Commit 67961344 authored by Marcelo Tosatti's avatar Marcelo Tosatti Committed by Avi Kivity
Browse files

KVM: add doc note about PIO/MMIO completion API 



Document that partially emulated instructions leave the guest state
inconsistent, and that the kernel will complete operations before
checking for pending signals.

Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 1ef6ce7a

Documentation/kvm/api.txt

+7 −0
Original line number Diff line number Diff line
@@ -820,6 +820,13 @@ executed a memory-mapped I/O instruction which could not be satisfied 
by kvm.  The 'data' member contains the written data if 'is_write' is

true, and should be filled by application code otherwise.



NOTE: For KVM_EXIT_IO and KVM_EXIT_MMIO, the corresponding operations

are complete (and guest state is consistent) only after userspace has

re-entered the kernel with KVM_RUN.  The kernel side will first finish

incomplete operations and then check for pending signals.  Userspace

can re-enter the guest with an unmasked signal pending to complete

pending operations.



		/* KVM_EXIT_HYPERCALL */

		struct {

			__u64 nr;