mshv: Fix infinite fault loop on permission-denied GPA intercepts

In the Linux kernel, the following vulnerability has been resolved: mshv: Fix infinite fault loop on permission-denied GPA intercepts Prevent infinite fault loops when guests access memory regions without proper permissions. Currently, mshv_handle_gpa_intercept() attempts to remap pages for all faults on movable memory regions, regardless of whether the access type is permitted. When a guest writes to a read-only region, the remap succeeds but the region remains read-only, causing immediate re-fault and spinning the vCPU indefinitely. Validate intercept access type against region permissions before attempting remaps. Reject writes to non-writable regions and executes to non-executable regions early, returning false to let the VMM handle the intercept appropriately. This also closes a potential DoS vector where malicious guests could intentionally trigger these fault loops to consume host resources.