PTAB

IPR2025-00853

Microsoft Corp v. VirtaMove Corp

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: System for Executing Software Applications
  • Brief Description: The ’058 patent discloses a computing system architecture for improving performance and flexibility by replicating critical operating system services. The system places functional replicas of kernel-level "OS critical system elements" (OSCSEs) into a user-mode "shared library" as "shared library critical system elements" (SLCSEs), allowing multiple software applications to access these services without invoking the resource-intensive kernel mode.

3. Grounds for Unpatentability

Ground 1: Obviousness over Callender - Claims 1-18 are obvious over Callender

  • Prior Art Relied Upon: Callender (Patent 7,024,672).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Callender, which was not considered during prosecution, discloses every limitation of the challenged claims. Callender teaches a hardware driver model that provides a "single implementation of operations that are common to both kernel mode processing and user mode processing." Petitioner mapped Callender’s disclosures to the key limitations of independent claim 1 as follows:
      • Operating System with Kernel & OSCSEs: Callender’s system was described as having a conventional operating system with a kernel that performs kernel-mode operations, such as sending and receiving network data via a hardware adapter. Petitioner contended these kernel-mode networking operations are the claimed OSCSEs.
      • Shared Library with SLCSEs: Callender was alleged to disclose a "user mode library" that is implemented as a "dynamic link library" (DLL), which Petitioner asserted is a quintessential "shared library." This library contains user-mode implementations of the same networking operations found in the kernel, which provide applications with "kernel-bypass" access to the hardware adapter. Petitioner argued these user-mode functions are the claimed SLCSEs stored in the shared library.
      • Functional Replicas: Callender was cited for its teaching that "the same source code may be written for a kernel mode communication operation and a user mode communication operation." Petitioner argued this disclosure means Callender’s user-mode SLCSEs are direct copies or, at minimum, "functional replicas" of the kernel-mode OSCSEs, as they perform the identical function.
      • Application Use: Callender’s user-mode library (the shared library) was shown to be for use by a plurality of software applications. Petitioner argued that the standard operation of a DLL, as known to a person of ordinary skill in the art (POSITA) and described in Callender, involves linking to an application, thereby providing each application with a unique, unshared "instance" of the library function that runs in the context of that application.
    • Motivation to Combine (for §103 grounds): As a single-reference ground, the motivation was presented as inherent to Callender's own teachings. Petitioner argued that Callender's express purpose was to create a unified driver model with parallel user-mode and kernel-mode functionalities. Any minor implementation details not explicitly stated, such as implementing library operations as functions, would have been obvious to a POSITA as it was a "well-known and customary software technique."
    • Expectation of Success (for §103 grounds): Petitioner asserted a POSITA would have a high expectation of success in implementing Callender’s system as claimed, because the underlying techniques (e.g., using DLLs, creating kernel drivers, managing processor modes) were all conventional and well-understood in the art at the time.
    • Key Aspects: Petitioner contended that its analysis demonstrates obviousness regardless of which competing claim construction from a parallel district court case is adopted, presenting alternative mappings where necessary.

4. Key Claim Construction Positions

  • Petitioner presented its unpatentability arguments under the competing proposed claim constructions from a parallel district court litigation involving the ’058 patent.
  • For key terms like "shared library" and "functional replicas," Petitioner argued that Callender's disclosures meet the claim limitations under either its own proposed construction or the broader construction proposed by the Patent Owner, thereby demonstrating unpatentability irrespective of the outcome of the claim construction dispute.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial is unwarranted.
  • The petition was filed concurrently with a Motion for Joinder with a previously-filed IPR petition by another party (IPR2025-00489). Petitioner stated that if joined, it would assume an "understudy role," which would conserve the Board’s resources and not impact the proceeding’s schedule. Petitioner also noted it would address any other discretionary denial arguments raised by the Patent Owner in a separate brief, consistent with the Director’s interim guidance.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-18 of Patent 7,784,058 as unpatentable.