From d488b349a3496184db408ffe4e16e644dcf323f4 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Mon, 12 Mar 2018 17:21:15 +0000 Subject: postcopy: postcopy_notify_shared_wake MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Peter Xu Reviewed-by: Marc-André Lureau Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- migration/postcopy-ram.c | 16 ++++++++++++++++ migration/postcopy-ram.h | 10 ++++++++++ 2 files changed, 26 insertions(+) diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index 868f77b34d..83c36d7cbd 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -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 diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h index fcd53b8295..2c73d77a5c 100644 --- a/migration/postcopy-ram.h +++ b/migration/postcopy-ram.h @@ -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 -- cgit v1.2.1