Method for patching virtually aliased pages by a virtual-machine monitor
First Claim
1. A method for patching and aliasing a virtual-memory page by a virtual-machine monitor, the method comprising:
- when the virtual-memory page is aliased and needs to be patched, physically aliasing each alias of the virtual-memory page and separately patching each physical alias;
when the virtual-memory page is patched and needs to be aliased, aliasing the virtual-memory page by creating a virtual-address alias, physically aliasing the created alias of the virtual-memory page, and separately patching each physical alias; and
detecting access to patched, aliased pages and resolving the access.
1 Assignment
0 Petitions
Accused Products
Abstract
Various embodiments of the present invention are directed to methods by which a virtual-machine monitor can introduce branch instructions, in order to emulate privileged and other instructions on behalf of a guest operating system, into guest-operating-system code residing on virtually aliased virtual-memory pages. In a described embodiment of the present invention, the virtual-machine monitor physically aliases each virtual alias for a particular physical memory page by allocating a physical page for the virtual alias, copying the original contents of the physical memory page to the allocated physical page, or physical alias page, and subsequently patching each physical alias page appropriate to the physical address of the physical alias page.
61 Citations
8 Claims
-
1. A method for patching and aliasing a virtual-memory page by a virtual-machine monitor, the method comprising:
-
when the virtual-memory page is aliased and needs to be patched, physically aliasing each alias of the virtual-memory page and separately patching each physical alias;
when the virtual-memory page is patched and needs to be aliased, aliasing the virtual-memory page by creating a virtual-address alias, physically aliasing the created alias of the virtual-memory page, and separately patching each physical alias; and
detecting access to patched, aliased pages and resolving the access. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
Specification