EDIT: Did some analysis myself about the GCVM_L2_PROTECTION_FAULT errors...

In the errors last time contained this:

src_id:0 ring:40 vmid:7 pasid:32769
GCVM_L2_PROTECTION_FAULT_STATUS:0x00741A51 (only on first error)

Whereas in the errors this time contained this:

src_id:0 ring:40 vmid:1 pasid:32769
GCVM_L2_PROTECTION_FAULT_STATUS:0x00141A51 (only on first error)

vmid became 1 and GCVM_L2_PROTECTION_FAULT_STATUS changed from 0x00741A51 to
0x00141A51. The rest of the first error remained the same.

MORE_FAULTS: 0x1
WALKER_ERROR: 0x0
PERMISSION_FAULTS: 0x5
MAPPING_ERROR: 0x0
RW: 0x1

In subsequent errors those values were all 0.

Both times the first error has a starting address of 0x00000318c00e7000.

Not sure if these could be of any help, though.