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| author | Marcelo Tosatti <mtosatti@redhat.com> | 2010-02-13 21:10:26 +0300 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2010-04-25 13:26:32 +0400 |
| commit | 679613442f84702c06a80f2320cb8a50089200bc (patch) | |
| tree | 5dc5571f1b9a789c9e7d8082c3ffecea3dfe176d /Documentation/kvm | |
| parent | 1ef6ce7a340f9ed139a73147ff9cf7ad56889414 (diff) | |
| download | linux-679613442f84702c06a80f2320cb8a50089200bc.tar.xz | |
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: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'Documentation/kvm')
| -rw-r--r-- | Documentation/kvm/api.txt | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt index c6416a398163..beb444a95013 100644 --- a/Documentation/kvm/api.txt +++ b/Documentation/kvm/api.txt @@ -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; |