Page tag-based memory trap-and-emulate operations

A system, comprising:

• a processor of a host, wherein the processor includes a memory management unit (MMU);
• a memory of the host, wherein the memory stores instructions that when executed on the processor:
• launch a hypervisor, wherein the hypervisor comprises a plurality of emulation routines, wherein individual ones of the emulation routines are used to perform respective tasks on behalf of one or more guest virtual machines running at the host, and wherein the respective tasks require a privilege level granted to the hypervisor and not granted to the one or more guest virtual machines;
• initiate, by a particular guest virtual machine which was launched at the host, an operation which requires access to a particular virtual address;
• and
• subsequent to a determination by the MMU that a virtual-to-physical address translation mapping for the particular virtual address which permits the operation initiated by the guest virtual machine is not available, perform a task using a particular emulation routine of the plurality of emulation routines, wherein the particular emulation routine is identified using a page tag associated within the particular virtual address, and wherein the task is performed without using, by the hypervisor, the particular virtual address to select the particular emulation routine from the plurality of emulation routines.

One or more non-transitory computer-accessible storage media storing program instructions that when executed on or across one or more processors:

• launch a hypervisor at a virtualization host, wherein the hypervisor comprises a plurality of emulation routines, wherein individual ones of the emulation routines are used to perform respective tasks on behalf of one or more guest virtual machines launched at the virtualization host by the hypervisor, and wherein the respective tasks require a privilege level granted to the hypervisor and not granted to the one or more guest virtual machines;
• initiate, by a particular guest virtual machine which was launched at the virtualization host, an operation which requires access to a particular virtual address;
• and
• subsequent to a determination by a memory management unit (MMU) of a processor of the one or more processors that a virtual-to-physical address translation mapping for the particular virtual address which permits the operation initiated by the particular guest virtual machine is not available, select, using a page tag associated within the particular virtual address, a particular emulation routine of the plurality of emulation routines;
• and
• perform a task using the particular emulation routine of the plurality of emulation routines, wherein the task is performed without initiating an analysis using the particular virtual address to select the particular emulation routine from among the plurality of emulation routines.