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CSR Bit Fields

RISC-V vsepc CSR Register

Address 0x241Privilege Hypervisor direct / VS aliasAccess HRW / VSXLENHypervisor and virtualization CSRs

vsepc holds VS exception program counter as the VS copy of the corresponding supervisor CSR.

Related Search Terms
vsepc CSRvsepc 0x241vsepc VS copydirect HRW accessguest supervisor state
Bit Overview
bit 3 = only bit 3; bits 12..11 = bits 12 down to 11
MSBLSB
EPC63:0RW
Field Map

Understand vsepc By Bit Fields

1 key fields
VSXLEN-1:0

EPC

RW

vsepc VS exception program counter; exact fields follow the corresponding supervisor CSR semantics for the VS copy.

EPC (bits VSXLEN-1:0) — vsepc VS exception program counter; exact fields follow the corresponding supervisor CSR semantics for the VS copy.

What This Field Controls

  • - vsepc VS exception program counter; exact fields follow the corresponding supervisor CSR semantics for the VS copy.

Common Values

This field is better understood together with surrounding context than as a fixed memorized enumeration.

↗Open Official Manual
Official Basis & Search Notes

vsepc is a VS supervisor state or trap CSR. The separate CSR address is for M/HS-side management; when V=1, guest access to the corresponding supervisor CSR is substituted with VS state unless an extension specifies otherwise.

vsepc address, access class, and width are checked against the official CSR tables: 0x241, HRW, VSXLEN.
The H extension specifies that, when V=1, access to the corresponding supervisor CSR is substituted with the VS CSR.
When writing, modify only officially defined fields; handle WARL, WLRL, WPRI, and reserved fields according to the official specification and implementation behavior.
RISC-V Privileged Architecture Manual - CSR tableRISC-V Privileged Architecture Manual - Hypervisor extension

What To Check First When Reading This CSR

  • - vsepc's separate CSR address is in the official HRW access class; a VS/VU guest normally reaches VS state through the corresponding supervisor CSR alias.
  • - Before reading it, confirm that the defining extension such as H, AIA, Sstc, Smstateen, or Smcsrind is implemented.

Risk Checks Before Writing

  • - When writing vsepc, modify only officially defined target fields and preserve WPRI, reserved, and unchanged fields.

Put It Back Into A Real Flow

1

M/HS software may access the VS copy through the separate CSR address.

2

When V=1, guest access to the corresponding supervisor CSR aliases to VS state; direct access to the separate VS CSR address raises a virtual-instruction exception.

3

Update only official fields and do not treat VS state as ordinary HS supervisor state.

FAQ

Can VS-mode directly access vsepc's separate CSR address?

No. The H extension substitutes VS state for the corresponding supervisor CSR when V=1; direct access to the separate VS CSR address raises a virtual-instruction exception.

What does vsepc mainly hold?

vsepc holds VS exception program counter, allowing the hypervisor to manage guest-supervisor trap, status, or execution context.