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TRFCR_EL2: Trace Filter Control Register (EL2)

Purpose

Provides EL2 controls for Trace.

Configuration

AArch64 System register TRFCR_EL2 bits [31:0] are architecturally mapped to AArch32 System register HTRFCR[31:0].

This register is present only when FEAT_TRF is implemented. Otherwise, direct accesses to TRFCR_EL2 are UNDEFINED.

If EL2 is not implemented, this register is RES0 from EL3.

Attributes

TRFCR_EL2 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
RES0
RES0TSRES0CXRES0E2TREE0HTRE

Bits [63:7]

Reserved, RES0.

TS, bits [6:5]

Timestamp Control. Controls which timebase is used for trace timestamps.

TSMeaningApplies when
0b00

Timestamp controlled by TRFCR_EL1.TS or TRFCR.TS.

0b01

Virtual timestamp. The traced timestamp is the physical counter value minus the value of CNTVOFF_EL2.

0b10

Guest physical timestamp. The traced timestamp is the physical counter value minus a physical offset. If any of the following are true, the physical offset is zero, otherwise the physical offset is the value of CNTPOFF_EL2:

When FEAT_ECV is implemented
0b11

Physical timestamp. The traced timestamp is the physical counter value.

This field is ignored by the PE when SelfHostedTraceEnabled() == FALSE.

The reset behavior of this field is:

Bit [4]

Reserved, RES0.

CX, bit [3]

CONTEXTIDR_EL2 and VMID trace enable.

CXMeaning
0b0

CONTEXTIDR_EL2 and VMID trace prohibited.

0b1

CONTEXTIDR_EL2 and VMID trace allowed.

This field is ignored if SelfHostedTraceEnabled() == FALSE.

The reset behavior of this field is:

Bit [2]

Reserved, RES0.

E2TRE, bit [1]

EL2 Trace Enable.

E2TREMeaning
0b0

Trace is prohibited at EL2.

0b1

Trace is allowed at EL2.

This field is ignored if SelfHostedTraceEnabled() == FALSE.

The reset behavior of this field is:

E0HTRE, bit [0]

EL0 Trace Enable.

E0HTREMeaning
0b0

Trace is prohibited at EL0 when HCR_EL2.TGE == 1.

0b1

Trace is allowed at EL0 when HCR_EL2.TGE == 1.

This field is ignored if any of the following are true:

The reset behavior of this field is:

Accessing TRFCR_EL2

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

MRS <Xt>, TRFCR_EL2

op0op1CRnCRmop2
0b110b1000b00010b00100b001

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64.SystemAccessTrap(EL2, 0x18); else UNDEFINED; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.TTRF == '1' then UNDEFINED; elsif HaveEL(EL3) && MDCR_EL3.TTRF == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = TRFCR_EL2; elsif PSTATE.EL == EL3 then X[t, 64] = TRFCR_EL2;

MSR TRFCR_EL2, <Xt>

op0op1CRnCRmop2
0b110b1000b00010b00100b001

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EffectiveHCR_EL2_NVx() IN {'xx1'} then AArch64.SystemAccessTrap(EL2, 0x18); else UNDEFINED; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.TTRF == '1' then UNDEFINED; elsif HaveEL(EL3) && MDCR_EL3.TTRF == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else TRFCR_EL2 = X[t, 64]; elsif PSTATE.EL == EL3 then TRFCR_EL2 = X[t, 64];

When FEAT_VHE is implemented

MRS <Xt>, TRFCR_EL1

op0op1CRnCRmop2
0b110b0000b00010b00100b001

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.TTRF == '1' then UNDEFINED; elsif EL2Enabled() && MDCR_EL2.TTRF == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && MDCR_EL3.TTRF == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif EffectiveHCR_EL2_NVx() == '111' then X[t, 64] = NVMem[0x880]; else X[t, 64] = TRFCR_EL1; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.TTRF == '1' then UNDEFINED; elsif HaveEL(EL3) && MDCR_EL3.TTRF == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif ELIsInHost(EL2) then X[t, 64] = TRFCR_EL2; else X[t, 64] = TRFCR_EL1; elsif PSTATE.EL == EL3 then X[t, 64] = TRFCR_EL1;

When FEAT_VHE is implemented

MSR TRFCR_EL1, <Xt>

op0op1CRnCRmop2
0b110b0000b00010b00100b001

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.TTRF == '1' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HDFGWTR_EL2.TRFCR_EL1 == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && MDCR_EL2.TTRF == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && MDCR_EL3.TTRF == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif EffectiveHCR_EL2_NVx() == '111' then NVMem[0x880] = X[t, 64]; else TRFCR_EL1 = X[t, 64]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.TTRF == '1' then UNDEFINED; elsif HaveEL(EL3) && MDCR_EL3.TTRF == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif ELIsInHost(EL2) then TRFCR_EL2 = X[t, 64]; else TRFCR_EL1 = X[t, 64]; elsif PSTATE.EL == EL3 then TRFCR_EL1 = X[t, 64];