Unified extensible firmware interface system management mode initialization protections with system management interrupt transfer monitor sandboxing
View Patent ↗An information handling system includes a processor configured to trap system management interrupts (SMIs) via a system management mode transfer monitor (STM), a first system resource, a SMI handler configured to operate within the STM, launch a first system management mode (SMM) virtual machine, load first SMM code for a first driver into the first SMM virtual machine, and associate the first SMM virtual machine with the first system resource and not with the second system resource.
1. An information handling system comprising:
a processor configured to trap system management interrupts (SMIs) via a system management mode transfer monitor (STM);
a first system resource;
a second system resource; and
an SMI handler configured to:
operate within the STM;
launch a first system management mode (SMM) virtual machine;
load first SMM code for a first driver into the first SMM virtual machine;
associate the first SMM virtual machine with the first system resource and not with the second system resource;
receive a first SMI;
determine that the first SMI is a call to the first SMM code and is targeted to the first system resource;
forward the first SMI to the first SMM virtual machine;
receive a second SMI;
determine that the second SMI is a call to the first SMM code and is targeted to the second system resource; and
handle the second SMI without forwarding the second SMI to the first SMM virtual machine.
2. The information handling system of claim 1 , wherein the SMI handler is further configured to:
determine a resource policy for the first driver, the resource policy defining that the first SMM virtual machine should be associated with the first system resource and not with the second system resource;
wherein associating the first SMM virtual machine with the first system resource and not with the second system resource is based upon the resource policy.
3. The information handling system of claim 2 , wherein the resource policy is determined based upon the first driver.
4. The information handling system of claim 3 , wherein the resource policy is determined based upon a globally unique identifier of the first driver.
5. The information handling system of claim 1 , wherein the SMI handler is further configured to:
launch a second SMM virtual machine;
load second SMM code for a second driver into the second SMM virtual machine; and
associate the first SMM virtual machine with the second system resource and not with the first system resource.
6. The information handling system of claim 1 , wherein, in handling the second SMI, SMI handler is further configured to deny the second SMI access to the second system resource.
7. A method comprising:
launching, on an information handling system, a system management interrupt (SMI) handler within a system management mode transfer monitor (STM);
launching, by the SMI handler, a first system management mode (SMM) virtual machine in a memory of the information handling system;
loading first SMM code for a first driver into the first SMM virtual machine;
associating the first SMM virtual machine with a first system resource of the information handling system and not with a second system resource of the information handling system;
receiving, by the SMI handier, a first SMI;
determining that the first SMI is a call to the first SMM code and is targeted to the first system resource;
forwarding the first SMI to the first SMM virtual machine;
receiving, by the SMI handler, a second SMI;
determining that the second SMI is a call to the first SMM code and is targeted to the second system resource; and
handling, by the SMI handler, the second SMI without forwarding the second SMI to the first SMM virtual machine.
8. The method of claim 7 , further comprising:
determining, by the SMI handler, a resource policy for the first driver, the resource policy defining that the first SMM virtual machine should be associated with the first system resource and not with the second system resource;
wherein associating the first SMM virtual machine with the first system resource and not with the second system resource is based upon the resource policy.
9. The method of claim 8 , wherein the resource policy is determined based upon the first driver.
10. The method of claim 9 , wherein the resource policy is determined based upon a globally unique identifier of the first driver.
11. The method of claim 7 , further comprising:
launching, by the SMI handler, a second SMM virtual machine in the memory;
loading second SMM code for a second driver into the second SMM virtual machine; and
associating the second SMM virtual machine with the second system resource and not with the first system resource.
12. The method of claim 7 , wherein, in handling the second SMI, the method further comprises:
denying, by the SMI handler, the second SMI access to the second system resource.
13. A non-transitory computer-readable medium including code for performing a method, the method comprising:
launching, on an information handling system, a system management interrupt (SMI) handler within a system management mode transfer monitor (STM);
launching, by the SMI handler, a first system management mode (SMM) virtual machine in a memory of the information handling system;
loading first SMM code for a first driver into the first SMM virtual machine;
associating the first SMM virtual machine with a first system resource of the information handling system and not with a second system resource of the information handling system;
receiving, by the SMI handler, a first SMI;
determining that the first SMI is a call to the first SMM code and is targeted to the first system resource;
forwarding the first SMI to the first SMM virtual machine;
receiving, by the SMI handler, a second SMI;
determining that the second SMI is a call to the first SMM code and is targeted to the second system resource; and
handling, by the SMI handler, the second SMI without forwarding the second SMI to the first SMM virtual machine.
14. The computer-readable medium of claim 13 , the method further comprising:
determining, by the SMI handler, a resource policy for the first driver, the resource policy defining that the first SMM virtual machine should be associated with the first system resource and not with the second system resource;
wherein associating the first SMM virtual machine with the first system resource and not with the second system resource is based upon the resource policy.
15. The computer-readable medium of claim 14 , wherein the resource policy is determined based upon the first driver.
16. The computer-readable medium of claim 15 , wherein the resource policy is determined based upon a globally unique identifier of the first driver.
17. The computer-readable medium of claim 13 , wherein, in handling the second SMI, the method further comprises:
denying, by the SMI handler, the second SMI access to the second system resource.