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author | David Hildenbrand <david@redhat.com> | 2020-06-26 09:22:35 +0200 |
---|---|---|
committer | Michael S. Tsirkin <mst@redhat.com> | 2020-07-02 05:54:59 -0400 |
commit | 5f1f1902f8e4020f27b4e35631a38c4e68d9be54 (patch) | |
tree | ba23f9fa54f4f49c0ac4629fdbadc1501279f9ef | |
parent | fee3f3baff12e78f544db51cc16ef028b8fe03a9 (diff) | |
download | qemu-5f1f1902f8e4020f27b4e35631a38c4e68d9be54.zip qemu-5f1f1902f8e4020f27b4e35631a38c4e68d9be54.tar.gz qemu-5f1f1902f8e4020f27b4e35631a38c4e68d9be54.tar.bz2 |
migration/rdma: Use ram_block_discard_disable()
RDMA will pin all guest memory (as documented in docs/rdma.txt). We want
to disable RAM block discards - however, to keep it simple use
ram_block_discard_is_required() instead of inhibiting.
Note: It is not sufficient to limit disabling to pin_all. Even when only
conditionally pinning 1 MB chunks, as soon as one page within such a
chunk was discarded and one page not, the discarded pages will be pinned
as well.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Juan Quintela <quintela@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200626072248.78761-9-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
-rw-r--r-- | migration/rdma.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/migration/rdma.c b/migration/rdma.c index ec45d33..bbe6f36 100644 --- a/migration/rdma.c +++ b/migration/rdma.c @@ -29,6 +29,7 @@ #include "qemu/sockets.h" #include "qemu/bitmap.h" #include "qemu/coroutine.h" +#include "exec/memory.h" #include <sys/socket.h> #include <netdb.h> #include <arpa/inet.h> @@ -4017,8 +4018,14 @@ void rdma_start_incoming_migration(const char *host_port, Error **errp) Error *local_err = NULL; trace_rdma_start_incoming_migration(); - rdma = qemu_rdma_data_init(host_port, &local_err); + /* Avoid ram_block_discard_disable(), cannot change during migration. */ + if (ram_block_discard_is_required()) { + error_setg(errp, "RDMA: cannot disable RAM discard"); + return; + } + + rdma = qemu_rdma_data_init(host_port, &local_err); if (rdma == NULL) { goto err; } @@ -4067,10 +4074,17 @@ void rdma_start_outgoing_migration(void *opaque, const char *host_port, Error **errp) { MigrationState *s = opaque; - RDMAContext *rdma = qemu_rdma_data_init(host_port, errp); RDMAContext *rdma_return_path = NULL; + RDMAContext *rdma; int ret = 0; + /* Avoid ram_block_discard_disable(), cannot change during migration. */ + if (ram_block_discard_is_required()) { + error_setg(errp, "RDMA: cannot disable RAM discard"); + return; + } + + rdma = qemu_rdma_data_init(host_port, errp); if (rdma == NULL) { goto err; } |