Change Details

Previously bhyve obtained a "read lock" on the memory map for ioctls needing to read the map by locking the last vCPU. This is now replaced by a new per-VM sx lock. Modifying the map requires exclusively locking the sx lock as well as locking all existing vCPUs. Reading the map requires either locking one vCPU or the sx lock. This permits safely modififying or querying the memory map while some vCPUs do not exist which will be true in a future commit.

Previously bhyve obtained a "read lock" on the memory map for ioctls needing to read the map by locking the last vCPU. This is now replaced by a new per-VM sx lock. Modifying the map requires exclusively locking the sx lock as well as locking all existing vCPUs. Reading the map requires either locking one vCPU or the sx lock. This permits safely modifying or querying the memory map while some vCPUs do not exist which will be true in a future commit.

Previously bhyve obtained a "read lock" on the memory map for ioctls needing to read the map by locking the last vCPU. This is now replaced by a new per-VM sx lock. Modifying the map requires exclusively locking the sx lock as well as locking all existing vCPUs. Reading the map requires either locking one vCPU or the sx lock. This permits safely modififying or querying the memory map while some vCPUs do not exist which will be true in a future commit.