From c6ad5be7ae5b8c6bbbd0c592bbf18d4a78540516 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Thu, 22 Jul 2021 13:58:40 -0400 Subject: [PATCH] migration: Teach QEMUFile to be QIOChannel-aware migration uses QIOChannel typed qemufiles. In follow up patches, we'll need the capability to identify this fact, so that we can get the backing QIOChannel from a QEMUFile. We can also define types for QEMUFile but so far since we only need to be able to identify QIOChannel, introduce a boolean which is simpler. Introduce another helper qemu_file_get_ioc() to return the ioc backend of a qemufile if has_ioc is set. No functional change. Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Peter Xu Message-Id: <20210722175841.938739-5-peterx@redhat.com> Reviewed-by: Lukas Straub Signed-off-by: Dr. David Alan Gilbert --- migration/qemu-file-channel.c | 4 ++-- migration/qemu-file.c | 17 ++++++++++++++++- migration/qemu-file.h | 4 +++- migration/ram.c | 2 +- migration/savevm.c | 4 ++-- 5 files changed, 24 insertions(+), 7 deletions(-) diff --git a/migration/qemu-file-channel.c b/migration/qemu-file-channel.c index 867a5ed0c3..2f8b1fcd46 100644 --- a/migration/qemu-file-channel.c +++ b/migration/qemu-file-channel.c @@ -187,11 +187,11 @@ static const QEMUFileOps channel_output_ops = { QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc) { object_ref(OBJECT(ioc)); - return qemu_fopen_ops(ioc, &channel_input_ops); + return qemu_fopen_ops(ioc, &channel_input_ops, true); } QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc) { object_ref(OBJECT(ioc)); - return qemu_fopen_ops(ioc, &channel_output_ops); + return qemu_fopen_ops(ioc, &channel_output_ops, true); } diff --git a/migration/qemu-file.c b/migration/qemu-file.c index 1eacf9e831..6338d8e2ff 100644 --- a/migration/qemu-file.c +++ b/migration/qemu-file.c @@ -55,6 +55,8 @@ struct QEMUFile { Error *last_error_obj; /* has the file has been shutdown */ bool shutdown; + /* Whether opaque points to a QIOChannel */ + bool has_ioc; }; /* @@ -101,7 +103,7 @@ bool qemu_file_mode_is_not_valid(const char *mode) return false; } -QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops) +QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops, bool has_ioc) { QEMUFile *f; @@ -109,6 +111,7 @@ QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops) f->opaque = opaque; f->ops = ops; + f->has_ioc = has_ioc; return f; } @@ -851,3 +854,15 @@ void qemu_file_set_blocking(QEMUFile *f, bool block) f->ops->set_blocking(f->opaque, block, NULL); } } + +/* + * Return the ioc object if it's a migration channel. Note: it can return NULL + * for callers passing in a non-migration qemufile. E.g. see qemu_fopen_bdrv() + * and its usage in e.g. load_snapshot(). So we need to check against NULL + * before using it. If without the check, migration_incoming_state_destroy() + * could fail for load_snapshot(). + */ +QIOChannel *qemu_file_get_ioc(QEMUFile *file) +{ + return file->has_ioc ? QIO_CHANNEL(file->opaque) : NULL; +} diff --git a/migration/qemu-file.h b/migration/qemu-file.h index a9b6d6ccb7..3f36d4dc8c 100644 --- a/migration/qemu-file.h +++ b/migration/qemu-file.h @@ -27,6 +27,7 @@ #include #include "exec/cpu-common.h" +#include "io/channel.h" /* Read a chunk of data from a file at the given position. The pos argument * can be ignored if the file is only be used for streaming. The number of @@ -119,7 +120,7 @@ typedef struct QEMUFileHooks { QEMURamSaveFunc *save_page; } QEMUFileHooks; -QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops); +QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops, bool has_ioc); void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks); int qemu_get_fd(QEMUFile *f); int qemu_fclose(QEMUFile *f); @@ -179,5 +180,6 @@ void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data); size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset, ram_addr_t offset, size_t size, uint64_t *bytes_sent); +QIOChannel *qemu_file_get_ioc(QEMUFile *file); #endif diff --git a/migration/ram.c b/migration/ram.c index f728f5072f..08b3cb7a4a 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -550,7 +550,7 @@ static int compress_threads_save_setup(void) /* comp_param[i].file is just used as a dummy buffer to save data, * set its ops to empty. */ - comp_param[i].file = qemu_fopen_ops(NULL, &empty_ops); + comp_param[i].file = qemu_fopen_ops(NULL, &empty_ops, false); comp_param[i].done = true; comp_param[i].quit = false; qemu_mutex_init(&comp_param[i].mutex); diff --git a/migration/savevm.c b/migration/savevm.c index 72848b946c..96b5e5d639 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -168,9 +168,9 @@ static const QEMUFileOps bdrv_write_ops = { static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable) { if (is_writable) { - return qemu_fopen_ops(bs, &bdrv_write_ops); + return qemu_fopen_ops(bs, &bdrv_write_ops, false); } - return qemu_fopen_ops(bs, &bdrv_read_ops); + return qemu_fopen_ops(bs, &bdrv_read_ops, false); }