CSR Bit Fields

RISC-V vstopei CSR Register

Address 0x25CPrivilege Hypervisor direct / VS aliasAccess HRW / VSXLENHypervisor and virtualization CSRs

vstopei is a VS top external interrupt claim/complete CSR.

Field Map

Understand vstopei By Bit Fields

1 key fields
VSXLEN-1:0

VSTOPEI

RW

vstopei fields for VS top external interrupt; detailed encoding follows the AIA specification.

VSTOPEI (bits VSXLEN-1:0) — vstopei fields for VS top external interrupt; detailed encoding follows the AIA specification.

What This Field Controls

  • - vstopei fields for VS top external interrupt; detailed encoding follows the AIA specification.

Common Values

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

Open Official Manual
Official Basis & Search Notes

vstopei is an AIA virtual-interrupt 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.

vstopei address, access class, and width are checked against the official CSR tables: 0x25C, HRW, VSXLEN.
AIA defines hypervisor virtual-interrupt CSRs that augment hvip for injecting interrupts into VS level.
vstopei corresponds to the VS-level top external interrupt and exists only with an IMSIC.
When writing, modify only officially defined fields; handle WARL, WLRL, WPRI, and reserved fields according to the official specification and implementation behavior.

What To Check First When Reading This CSR

  • - vstopei'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 vstopei, modify only officially defined target fields and preserve WPRI, reserved, and unchanged fields.

Put It Back Into A Real Flow

1

Confirm AIA is implemented and whether an IMSIC or relevant guest interrupt file exists.

2

Interpret fields according to AIA definitions for top interrupt, enable, pending, priority, or delivery control.

3

Check mstateen0/hstateen0 access control for the related AIA state.

FAQ

What AIA state does vstopei represent?

vstopei belongs to AIA Hypervisor/VS virtual-interrupt state and is used for VS top external interrupt.

Can state-enable CSRs control access to vstopei?

When Smstateen and AIA are implemented, AIA, IMSIC, or CSRIND bits in mstateen0/hstateen0 may control lower-privilege or VM access to related AIA state.