postcopy: postcopy_notify_shared_wake

Add a hook to allow a client userfaultfd to be 'woken'
when a page arrives, and a walker that calls that
hook for relevant clients given a RAMBlock and offset.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Dr. David Alan Gilbert 2018-03-12 17:21:15 +00:00 committed by Michael S. Tsirkin
parent 5efc356403
commit d488b349a3
2 changed files with 26 additions and 0 deletions

View File

@ -827,6 +827,22 @@ static int qemu_ufd_copy_ioctl(int userfault_fd, void *host_addr,
return ret;
}
int postcopy_notify_shared_wake(RAMBlock *rb, uint64_t offset)
{
int i;
MigrationIncomingState *mis = migration_incoming_get_current();
GArray *pcrfds = mis->postcopy_remote_fds;
for (i = 0; i < pcrfds->len; i++) {
struct PostCopyFD *cur = &g_array_index(pcrfds, struct PostCopyFD, i);
int ret = cur->waker(cur, rb, offset);
if (ret) {
return ret;
}
}
return 0;
}
/*
* Place a host page (from) at (host) atomically
* returns 0 on success

View File

@ -148,6 +148,10 @@ struct PostCopyFD;
/* ufd is a pointer to the struct uffd_msg *TODO: more Portable! */
typedef int (*pcfdhandler)(struct PostCopyFD *pcfd, void *ufd);
/* Notification to wake, either on place or on reception of
* a fault on something that's already arrived (race)
*/
typedef int (*pcfdwake)(struct PostCopyFD *pcfd, RAMBlock *rb, uint64_t offset);
struct PostCopyFD {
int fd;
@ -155,6 +159,8 @@ struct PostCopyFD {
void *data;
/* Handler to be called whenever we get a poll event */
pcfdhandler handler;
/* Notification to wake shared client */
pcfdwake waker;
/* A string to use in error messages */
const char *idstr;
};
@ -164,6 +170,10 @@ struct PostCopyFD {
*/
void postcopy_register_shared_ufd(struct PostCopyFD *pcfd);
void postcopy_unregister_shared_ufd(struct PostCopyFD *pcfd);
/* Call each of the shared 'waker's registerd telling them of
* availability of a block.
*/
int postcopy_notify_shared_wake(RAMBlock *rb, uint64_t offset);
/* postcopy_wake_shared: Notify a client ufd that a page is available
*
* Returns 0 on success