On 06/11/2015 12:17 PM, Dr. David Alan Gilbert (git) wrote:
From: "Dr. David Alan Gilbert" <address@hidden>
The 'offset' field in RDMACompress and 'current_addr' field
in RDMARegister are commented as being offsets within a particular
RAMBlock, however they appear to actually be offsets within the
ram_addr_t space.
The code currently assumes that the offsets on the source/destination
match, this change removes the need for the assumption for these
structures by translating the addresses into the ram_addr_t space of
the destination host.
Note: An alternative would be to change the fields to actually
take the data they're commented for; this would potentially be
simpler but would break stream compatibility for those cases
that currently work.
Signed-off-by: Dr. David Alan Gilbert <address@hidden>
---
migration/rdma.c | 31 ++++++++++++++++++++++++-------
1 file changed, 24 insertions(+), 7 deletions(-)
diff --git a/migration/rdma.c b/migration/rdma.c
index 9532461..cb66721 100644
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -411,7 +411,7 @@ static void network_to_control(RDMAControlHeader *control)
*/
typedef struct QEMU_PACKED {
union QEMU_PACKED {
- uint64_t current_addr; /* offset into the ramblock of the chunk */
+ uint64_t current_addr; /* offset into the ram_addr_t space */
uint64_t chunk; /* chunk to lookup if unregistering */
} key;
uint32_t current_index; /* which ramblock the chunk belongs to */
@@ -419,8 +419,19 @@ typedef struct QEMU_PACKED {
uint64_t chunks; /* how many sequential chunks to register */
} RDMARegister;
-static void register_to_network(RDMARegister *reg)
+static void register_to_network(RDMAContext *rdma, RDMARegister *reg)
{
+ RDMALocalBlock *local_block;
+ local_block = &rdma->local_ram_blocks.block[reg->current_index];
+
+ if (local_block->is_ram_block) {
+ /*
+ * current_addr as passed in is an address in the local ram_addr_t
+ * space, we need to translate this for the destination
+ */
+ reg->key.current_addr -= local_block->offset;
+ reg->key.current_addr += rdma->dest_blocks[reg->current_index].offset;
+ }
reg->key.current_addr = htonll(reg->key.current_addr);
reg->current_index = htonl(reg->current_index);
reg->chunks = htonll(reg->chunks);
@@ -436,13 +447,19 @@ static void network_to_register(RDMARegister *reg)
typedef struct QEMU_PACKED {
uint32_t value; /* if zero, we will madvise() */
uint32_t block_idx; /* which ram block index */
- uint64_t offset; /* where in the remote ramblock this chunk */
+ uint64_t offset; /* Address in remote ram_addr_t space */
uint64_t length; /* length of the chunk */
} RDMACompress;
-static void compress_to_network(RDMACompress *comp)
+static void compress_to_network(RDMAContext *rdma, RDMACompress *comp)
{
comp->value = htonl(comp->value);
+ /*
+ * comp->offset as passed in is an address in the local ram_addr_t
+ * space, we need to translate this for the destination
+ */
+ comp->offset -= rdma->local_ram_blocks.block[comp->block_idx].offset;
+ comp->offset += rdma->dest_blocks[comp->block_idx].offset;
comp->block_idx = htonl(comp->block_idx);
comp->offset = htonll(comp->offset);
comp->length = htonll(comp->length);
So, why add the destination block's offset on the source side
just for it to be re-adjusted again when it gets to the destination side?
Can you just stop at this:
+ reg->key.current_addr -= local_block->offset;
Without this:
+ reg->key.current_addr +=
rdma->dest_blocks[reg->current_index].offset;
... on the source, followed by this on the destionation:
+ comp->offset -= rdma->local_ram_blocks.block[comp->block_idx].offset;
Without this:
+ comp->offset += rdma->dest_blocks[comp->block_idx].offset;
Did I follow correctly?