The CNTHVS_TVAL_EL2 characteristics are:
Holds the timer value for the Secure EL2 virtual timer.
AArch64 System register CNTHVS_TVAL_EL2 bits [31:0] are architecturally mapped to AArch32 System register CNTHVS_TVAL[31:0].
This register is present only when FEAT_SEL2 is implemented and FEAT_VHE is implemented. Otherwise, direct accesses to CNTHVS_TVAL_EL2 are UNDEFINED.
If EL2 is not implemented, this register is RES0 from EL3.
CNTHVS_TVAL_EL2 is a 64-bit register.
| 63 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 39 | 38 | 37 | 36 | 35 | 34 | 33 | 32 |
| 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 |
| RES0 | |||||||||||||||||||||||||||||||
| TimerValue | |||||||||||||||||||||||||||||||
Reserved, RES0.
The TimerValue view of the EL2 virtual timer.
On a read of this register:
On a write of this register, CNTHVS_CVAL_EL2 is set to (CNTVCT_EL0 + TimerValue), where TimerValue is treated as a signed 32-bit integer.
When CNTHVS_CTL_EL2.ENABLE is 1, the timer condition is met when ((CNTVCT_EL0 - CNTHVS_CVAL_EL2) is greater than or equal to zero. This means that TimerValue acts like a 32-bit downcounter timer. When the timer condition is met:
When CNTHVS_CTL_EL2.ENABLE is 0, the TimerValue cannot be read but continues to decrement. When the timer is enabled, the TimerValue represents the elapsed time whether that time was spent enabled or disabled.
The reset behavior of this field is:
Accesses to this register use the following encodings in the System register encoding space:
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b100 | 0b1110 | 0b0100 | 0b000 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if !IsCurrentSecurityState(SS_Secure) then UNDEFINED; elsif EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64.SystemAccessTrap(EL2, 0x18); else UNDEFINED; elsif PSTATE.EL == EL2 then if !IsCurrentSecurityState(SS_Secure) then UNDEFINED; else if CNTHVS_CTL_EL2.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTHVS_CVAL_EL2 - PhysicalCountInt(); elsif PSTATE.EL == EL3 then if SCR_EL3.EEL2 == '0' then UNDEFINED; else if CNTHVS_CTL_EL2.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTHVS_CVAL_EL2 - PhysicalCountInt();
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b100 | 0b1110 | 0b0100 | 0b000 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if !IsCurrentSecurityState(SS_Secure) then UNDEFINED; elsif EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64.SystemAccessTrap(EL2, 0x18); else UNDEFINED; elsif PSTATE.EL == EL2 then if !IsCurrentSecurityState(SS_Secure) then UNDEFINED; else CNTHVS_CVAL_EL2 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif PSTATE.EL == EL3 then if SCR_EL3.EEL2 == '0' then UNDEFINED; else CNTHVS_CVAL_EL2 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt();
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b011 | 0b1110 | 0b0011 | 0b000 |
if PSTATE.EL == EL0 then if !ELIsInHost(EL0) && CNTKCTL_EL1.EL0VTEN == '0' then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif ELIsInHost(EL0) && CNTHCTL_EL2.EL0VTEN == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && !ELIsInHost(EL0) && IsFeatureImplemented(FEAT_ECV) && CNTHCTL_EL2.EL1TVT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif ELIsInHost(EL0) && IsCurrentSecurityState(SS_Secure) && IsFeatureImplemented(FEAT_SEL2) then if CNTHVS_CTL_EL2.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTHVS_CVAL_EL2 - PhysicalCountInt(); elsif ELIsInHost(EL0) && !IsCurrentSecurityState(SS_Secure) then if CNTHV_CTL_EL2.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTHV_CVAL_EL2 - PhysicalCountInt(); elsif HaveEL(EL2) && (!EL2Enabled() || !ELIsInHost(EL0)) then if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTV_CVAL_EL0 - (PhysicalCountInt() - CNTVOFF_EL2); else if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTV_CVAL_EL0 - PhysicalCountInt(); elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_ECV) && CNTHCTL_EL2.EL1TVT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL2) then if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTV_CVAL_EL0 - (PhysicalCountInt() - CNTVOFF_EL2); else if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTV_CVAL_EL0 - PhysicalCountInt(); elsif PSTATE.EL == EL2 then if ELIsInHost(EL2) && IsCurrentSecurityState(SS_Secure) && IsFeatureImplemented(FEAT_SEL2) then if CNTHVS_CTL_EL2.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTHVS_CVAL_EL2 - PhysicalCountInt(); elsif ELIsInHost(EL2) && !IsCurrentSecurityState(SS_Secure) then if CNTHV_CTL_EL2.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTHV_CVAL_EL2 - PhysicalCountInt(); elsif !ELIsInHost(EL2) then if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTV_CVAL_EL0 - (PhysicalCountInt() - CNTVOFF_EL2); else if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTV_CVAL_EL0 - PhysicalCountInt(); elsif PSTATE.EL == EL3 then if CNTV_CTL_EL0.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; elsif HaveEL(EL2) && !ELUsingAArch32(EL2) then X[t, 64] = CNTV_CVAL_EL0 - (PhysicalCountInt() - CNTVOFF_EL2); elsif HaveEL(EL2) && ELUsingAArch32(EL2) then X[t, 64] = CNTV_CVAL_EL0 - (PhysicalCountInt() - CNTVOFF); else X[t, 64] = CNTV_CVAL_EL0 - PhysicalCountInt();
| op0 | op1 | CRn | CRm | op2 |
|---|---|---|---|---|
| 0b11 | 0b011 | 0b1110 | 0b0011 | 0b000 |
if PSTATE.EL == EL0 then if !ELIsInHost(EL0) && CNTKCTL_EL1.EL0VTEN == '0' then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif ELIsInHost(EL0) && CNTHCTL_EL2.EL0VTEN == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && !ELIsInHost(EL0) && IsFeatureImplemented(FEAT_ECV) && CNTHCTL_EL2.EL1TVT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif ELIsInHost(EL0) && IsCurrentSecurityState(SS_Secure) && IsFeatureImplemented(FEAT_SEL2) then CNTHVS_CVAL_EL2 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif ELIsInHost(EL0) && !IsCurrentSecurityState(SS_Secure) then CNTHV_CVAL_EL2 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif HaveEL(EL2) && (!EL2Enabled() || !ELIsInHost(EL0)) then CNTV_CVAL_EL0 = (SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt()) - CNTVOFF_EL2; else CNTV_CVAL_EL0 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_ECV) && CNTHCTL_EL2.EL1TVT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL2) then CNTV_CVAL_EL0 = (SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt()) - CNTVOFF_EL2; else CNTV_CVAL_EL0 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif PSTATE.EL == EL2 then if ELIsInHost(EL2) && IsCurrentSecurityState(SS_Secure) && IsFeatureImplemented(FEAT_SEL2) then CNTHVS_CVAL_EL2 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif ELIsInHost(EL2) && !IsCurrentSecurityState(SS_Secure) then CNTHV_CVAL_EL2 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif !ELIsInHost(EL2) then CNTV_CVAL_EL0 = (SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt()) - CNTVOFF_EL2; else CNTV_CVAL_EL0 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif PSTATE.EL == EL3 then if HaveEL(EL2) && !ELUsingAArch32(EL2) then CNTV_CVAL_EL0 = (SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt()) - CNTVOFF_EL2; elsif HaveEL(EL2) && ELUsingAArch32(EL2) then CNTV_CVAL_EL0 = (SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt()) - CNTVOFF; else CNTV_CVAL_EL0 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt();
26/03/2024 09:49; 67c0ae5282a7629ba0ea0ba7267b43cd4f7939f6
Copyright © 2010-2024 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.