Index
HVC
Hypervisor Call causes an exception to EL2. Software executing at EL1 can use this instruction to call the hypervisor to request a service.
The HVC instruction is UNDEFINED:
- When EL3 is implemented and SCR_EL3.HCE is set to 0.
- When EL3 is not implemented and HCR_EL2.HCD is set to 1.
- When EL2 is not implemented.
- At EL1 if EL2 is not enabled in the current Security state.
- At EL0.
On executing an HVC instruction, the PE records the exception as a Hypervisor Call exception in ESR_ELx, using the EC value 0x16, and the value of the immediate argument.
| 31 |
30 |
29 |
28 |
27 |
26 |
25 |
24 |
23 |
22 |
21 |
20 |
19 |
18 |
17 |
16 |
15 |
14 |
13 |
12 |
11 |
10 |
9 |
8 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| 1 |
1 |
0 |
1 |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
imm16 |
0 |
0 |
0 |
1 |
0 |
// Empty.
Assembler Symbols
| <imm> |
Is a 16-bit unsigned immediate, in the range 0 to 65535, encoded in the "imm16" field. |
Operation
if !HaveEL(EL2) || PSTATE.EL == EL0 || (PSTATE.EL == EL1 && !EL2Enabled()) then
UNDEFINED;
bits(1) hvc_enable = if HaveEL(EL3) then SCR_EL3.HCE else NOT(HCR_EL2.HCD);
if hvc_enable == '0' then
UNDEFINED;
else
AArch64.CallHypervisor(imm16);