Hi,
I do understand the LSI SAS and mptscsi messages are coming inside the guests which are having a LSI controller. I can agree to a point that the LSI vmhba0 in the server might have nothing to do with the error messages inside the guests since you do not have the vms in the local datastore but from FC.
So, let us take a look at the usual suspects:
1. Like Memmad pointed out, from the vmkernel log, we can see if the FC lun is having any trouble and is being reported.
2. Does the ESX itself perform very slow while running any commands like esxcfg-scsidevs -m or esxcfg-rescan vmhbaX [X adapter of your FC]
3. Is the FC lun configured for multi path facing any issues, again this can be from vmkernel logs.?
4. I am sure that the swap file would be generated on the FC lun, but do have a check if the last updated swap file on the vm directory is having current time. This is to rule out any delay in the swap file writing from the guest due to FC issues.
5. There were earlier issues similar to yours like VM losing pings, slower performance, but they were in iscsi and in 4.1 kb here
It does seems that the guests are aborting or resetting their scsi commands which seems to be the issue here.