hedeleg
Hypervisor Exception Delegation
Controls exception delegation from HS-mode to VS-mode.
By default, all traps at any privilege level are handled in M-mode, though M-mode usually uses
the medeleg and mideleg CSRs to delegate some traps to HS-mode. The hedeleg and hideleg
CSRs allow these traps to be further delegated to a VS-mode guest; their layout is the same as
medeleg and mideleg.
A synchronous trap that has been delegated to HS-mode (using medeleg) is further delegated to VS-mode if V=1 before the trap and the corresponding hedeleg bit is set. Each bit of hedeleg shall be either writable or read-only zero. Many bits of hedeleg are required specifically to be writable or zero. Bit 0, corresponding to instruction address misaligned exceptions, must be writable if IALIGN=32.
Requiring that certain bits of hedeleg be writable reduces some of the burden on a hypervisor to handle variations of implementation. |
Field Summary
Name | Location | Type | Reset Value |
---|---|---|---|
0 |
RW |
UNDEFINED_LEGAL |
|
1 |
RW |
UNDEFINED_LEGAL |
|
2 |
RW |
UNDEFINED_LEGAL |
|
3 |
RW |
UNDEFINED_LEGAL |
|
4 |
RW |
UNDEFINED_LEGAL |
|
5 |
RW |
UNDEFINED_LEGAL |
|
6 |
RW |
UNDEFINED_LEGAL |
|
7 |
RW |
UNDEFINED_LEGAL |
|
8 |
RW |
UNDEFINED_LEGAL |
|
9 |
RO |
0 |
|
10 |
RO |
0 |
|
11 |
RO |
0 |
|
12 |
RW |
UNDEFINED_LEGAL |
|
13 |
RW |
UNDEFINED_LEGAL |
|
15 |
RW |
UNDEFINED_LEGAL |
|
20 |
RO |
0 |
|
21 |
RO |
0 |
|
22 |
RO |
0 |
|
23 |
RO |
0 |