US 9,852,100 B2 · Guest-programmable location of advanced configuration and power interface (ACPI) tables in virtualized systems

Abstract

A system and method are disclosed for guest-programmable relocation of system tables in a virtualized computer system. In accordance with one embodiment, a hypervisor that is executed by a computer system obtains a first base address of a first portion of memory, where the first base address is in an address space of a guest of a virtual machine, and where the first base address is for a set of one or more system tables that is currently exposed by the hypervisor at a second portion of memory having a second base address in the address space of the guest. The hypervisor then generates a new version of the set of one or more system tables that is exposed to the guest at the first base address.

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Drawings

Claims19

Dependent claims

A method comprising:

detecting, by a processing device executing a hypervisor, that a hardware register protected by the hypervisor has been written to by a guest of a virtual machine;
reading, by the hypervisor, in response to the detecting, a value stored in the hardware register by the guest, wherein the value is a first base address of a first portion of memory in an address space of the guest, the first base address for exposing a second system table to the guest, the second system table to be a new version of a first system table exposed by the hypervisor to the guest at a second portion of memory, and wherein the second portion of memory has a second base address in the address space of the guest;
generating, by the hypervisor, after the reading of the hardware register, the second system table;
and
populating, by the processing device, an entry of the second system table in view of an entry of the first system table, wherein the populating comprises:
in response to determining that the entry of the first system table is not a pointer to a first address in the address space of the guest corresponding to another entry in the first system table, setting the entry of the second system table to the entry of the first system table;
and
in response to determining that the entry of the first system table is a pointer to a second address in the address space of the guest that corresponds to another entry in the first system table, setting the entry of the second system table to a pointer that points to a third address in the address space of the guest that is different than the second address.

5 more elements

A computer system comprising:

a memory to store a virtual machine;
and
a processing device, operatively coupled to the memory, to:
execute a hypervisor;
receive, from a guest of a virtual machine, via the hypervisor, a message that specifies a first base address of a first portion of memory in an address space of the guest, the first base address for exposing a second system table to the guest, the second system table to be a new version of a first system table that is exposed by the hypervisor to the guest at a second portion of memory, and wherein the second portion of memory has a second base address in the address space of the guest;
generate, via the hypervisor, after the receiving of the message, the second system table;
and
populate, via the hypervisor, an entry of the second system table in view of an entry of the first system table, wherein to populate the entry of the second system table comprises:
in response to determining that the entry of the first system table is not a pointer to a first address in the address space of the guest corresponding to another entry in the first system table, setting the entry of the second system table to the entry of the first system table;
and
in response to determining that the entry of the first system table is a pointer to a second address in the address space of the guest that corresponds to another entry in the first system table, setting the entry of the second system table to a pointer that points to a third address in the address space of the guest that is different than the second address.

8 more elements

A non-transitory computer readable storage medium, having instructions stored therein, which when executed, cause a processing device to execute a hypervisor to:

detect, by the hypervisor, that a hardware register protected by the hypervisor has been written to by a guest of a virtual machine;
read by the hypervisor, in response to the detection, a value stored in the hardware register by the guest, wherein the value is a first base address of a first portion of memory in an address space of the guest, the first base address for exposing a second system table to the guest, the second system table to be a new version of a first system table exposed by the hypervisor to the guest at a second portion of memory, and wherein the second portion of memory has a second base address in the address space of the guest
generate by the hypervisor, after the reading of the hardware register, the second system table;
and
populate, by the hypervisor, an entry of the second system table in view of an entry of the first system table, wherein to populate the entry of the second table comprises:
in response to determining that the entry of the first system table is not a pointer to a first address in the address space of the guest corresponding to another entry in the first system table, setting the entry of the second system table to the entry of the first system table;
and
in response to a determination that the entry of the first system table is a pointer to a second address in the address space of the guest that corresponds to another entry in the first system table, set the entry of the second system table to a pointer that points to a third address in the address space of the guest that is different than the second address.

5 more elements

Dependencies are inferred from the claim text.

Description3,779 words

Summary189 words

#This disclosure relates to computer systems, and more particularly, to virtualized computer systems.

#An operating system (OS) is a set of programs that manage computer hardware resources and provide common services for application software. For hardware functions such as input and output and memory allocation, the operating system typically acts as an intermediary between application programs and hardware. Operating systems may be found on a variety of devices, including desktop computers, servers, smartphones, video game consoles, and so forth.

#The Advanced Configuration and Power Interface (ACPI) specification provides an open standard for device configuration and power management by the operating system. The ACPI specification defines four global “Gx” states G0 through G3, six sleep “Sx” states S0 through S5, four device states D0 through D3, four processor states C0 through C3, and up to 17 implementation-dependent power-performance states P0 through Pn, where n is an integer between 1 and 16 inclusive. In addition, ACPI defines several tables that provide an interface between an ACPI-compliant operating system and system firmware, including a Differentiated System Description Table (DSDT), a Secondary System Description Table (SSDT), and a System Resource Affinity Table (SRAT).

Brief description of the drawings4 figures

#The present disclosure is illustrated by way of example, and not by way of limitation, and can be more fully understood with reference to the following detailed description when considered in connection with the figures in which:

#FIG. 1 depicts an illustrative computer system architecture, in accordance with an embodiment of the present disclosure.

#FIG. 2 depicts a flow diagram of one embodiment of a method by which a hypervisor detects and processes a guest request to relocate ACPI tables.

Detailed description3,468 words

#Described herein is a system and method for guest-programmable relocation of Advanced Configuration and Power Interface (ACPI) tables in virtualized computer systems. In one embodiment, a hypervisor that is executed by a computer system obtains a new base address for the ACPI tables, where the new base address is in an address space of a guest of a virtual machine (e.g., a guest operating system [OS] of the virtual machine, a guest basic input/output system [BIOS] of the virtual machine, etc.), and where the ACPI tables are currently exposed to the guest by the hypervisor at an old base address in the address space of the guest. The hypervisor then generates a new version of the ACPI tables that is exposed to the guest at the new address.

#In one example, each entry of the new version of the ACPI tables is the same as the corresponding entry of the original ACPI tables when the corresponding entry is not a pointer to another entry of the ACPI tables. When the corresponding entry of the original ACPI tables is in fact a pointer to another entry of the original ACPI tables, the entry of the new version is set to the address of this pointer minus the old base address, plus the new base address. In this way, the entry is updated in the new version so that it continues pointing to the other entry, rather than to the old location at which this other entry was stored in the original ACPI tables. For example, suppose that the original set of ACPI tables has a base address of 1000, and that the new base address is 5000. Then if an entry of the original ACPI tables is a pointer to another entry of the original ACPI tables having, say, address 1035, then the corresponding entry of the new version will be a pointer to the table entry at address 5035.

#In accordance with one example, the guest determines that the ACPI tables are to be relocated to the new base address (e.g., as part of a re-organization of guest memory, etc.) and notifies the hypervisor by writing the new base address to a particular register that is protected by the hypervisor (e.g., a Peripheral Component Interconnect [PCI] base address register [BAR], a configuration register of a PCI device, etc.). In one such example, this register may be specified by the ACPI tables.

Facts

Application

14/191,226Filed 26 Feb 2014

Published

US 2015/0242330 A127 Aug 2015

Granted

26 Dec 2017

Term ends

2 Aug 2034

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 157 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification8 codes

G06F 13/4221
On a parallel bus: being an input/output bus, e.g. ISA bus, EISA bus, PCI bus, SCSI bus
G06F 9/45558
Hypervisors; Virtual machine monitors: hypervisor-specific management and integration aspects
G06F 9/50
Multiprogramming arrangements: allocation of resources, e.g. of the central processing unit [CPU]
G06F 12/0284
User address space allocation, e.g. contiguous or non contiguous base addressing: multiple user address space allocation, e.g. using different…

Timeline

26 Feb 2014Application filedUS 14/191,226
26 Feb 2014Assigned to Red Hat Israel, Ltd.assignment of assignor's interest
20 Aug 2014Assigned to Red Hat Israel, Ltdcorrective assignment to correct the assignor: gerd hoffman, gerd previously recorded on reel 032307 frame 0053. assignor(s) hereby confirms the assignor should read as: hoffman, gerd.
27 Aug 2015PublishedUS 2015/0242330 A1
26 Dec 2017GrantedUS 9,852,100 B2
12 Oct 2026TodayWithin its term
2 Aug 2034Term endsEstimated, includes 157 days of adjustment

Guest-programmable location of advanced configuration and power interface (ACPI) tables in virtualized systems

Life of this patent

Guest-programmable location of advanced configuration and power interface (ACPI) tables in virtualized systems

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims19

Description3,779 words

Drawings

Classification8 codes

Life of this patent

Description3,779 words