CNTHVS_TVAL_EL2, Counter-timer Secure Virtual Timer TimerValue Register (EL2)

The CNTHVS_TVAL_EL2 characteristics are:

Purpose

Holds the timer value for the Secure EL2 virtual timer.

Configuration

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.

Attributes

CNTHVS_TVAL_EL2 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
RES0
TimerValue

Bits [63:32]

Reserved, RES0.

TimerValue, bits [31:0]

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 timer condition is not met, but CNTVCT_EL0 continues to count, so the TimerValue view appears to continue to count down.

The reset behavior of this field is:

Accessing CNTHVS_TVAL_EL2

Accesses to this register use the following encodings in the System register encoding space:

MRS <Xt>, CNTHVS_TVAL_EL2

op0op1CRnCRmop2
0b110b1000b11100b01000b000

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if !IsCurrentSecurityState(SS_Secure) then UNDEFINED; elsif EL2Enabled() && HCR_EL2.NV == '1' 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();

MSR CNTHVS_TVAL_EL2, <Xt>

op0op1CRnCRmop2
0b110b1000b11100b01000b000

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if !IsCurrentSecurityState(SS_Secure) then UNDEFINED; elsif EL2Enabled() && HCR_EL2.NV == '1' 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();

MRS <Xt>, CNTV_TVAL_EL0

op0op1CRnCRmop2
0b110b0110b11100b00110b000

if PSTATE.EL == EL0 then if !(EL2Enabled() && HCR_EL2.<E2H,TGE> == '11') && CNTKCTL_EL1.EL0VTEN == '0' then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && CNTHCTL_EL2.EL0VTEN == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && HCR_EL2.<E2H,TGE> != '11' && CNTHCTL_EL2.EL1TVT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && SCR_EL3.NS == '0' && 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 EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && SCR_EL3.NS == '1' 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() || HCR_EL2.<E2H,TGE> != '11') 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() && 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 HCR_EL2.E2H == '1' && SCR_EL3.NS == '0' && 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 HCR_EL2.E2H == '1' && SCR_EL3.NS == '1' then if CNTHV_CTL_EL2.ENABLE == '0' then X[t, 64] = bits(64) UNKNOWN; else X[t, 64] = CNTHV_CVAL_EL2 - PhysicalCountInt(); elsif HCR_EL2.E2H == '0' 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();

MSR CNTV_TVAL_EL0, <Xt>

op0op1CRnCRmop2
0b110b0110b11100b00110b000

if PSTATE.EL == EL0 then if !(EL2Enabled() && HCR_EL2.<E2H,TGE> == '11') && CNTKCTL_EL1.EL0VTEN == '0' then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && CNTHCTL_EL2.EL0VTEN == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && HCR_EL2.<E2H,TGE> != '11' && CNTHCTL_EL2.EL1TVT == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && SCR_EL3.NS == '0' && IsFeatureImplemented(FEAT_SEL2) then CNTHVS_CVAL_EL2 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif EL2Enabled() && HCR_EL2.<E2H,TGE> == '11' && SCR_EL3.NS == '1' then CNTHV_CVAL_EL2 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif HaveEL(EL2) && (!EL2Enabled() || HCR_EL2.<E2H,TGE> != '11') 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() && 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 HCR_EL2.E2H == '1' && SCR_EL3.NS == '0' && IsFeatureImplemented(FEAT_SEL2) then CNTHVS_CVAL_EL2 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif HCR_EL2.E2H == '1' && SCR_EL3.NS == '1' then CNTHV_CVAL_EL2 = SignExtend(X[t, 64]<31:0>, 64) + PhysicalCountInt(); elsif HCR_EL2.E2H == '0' 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();


04/07/2023 11:25; 1b994cb0b8c6d1ae5a9a15edbc8bd6ce3b5c7d68

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