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| author | Suzuki K Poulose <suzuki.poulose@arm.com> | 2021-04-05 17:42:54 +0100 |
|---|---|---|
| committer | Mathieu Poirier <mathieu.poirier@linaro.org> | 2021-04-06 16:05:28 -0600 |
| commit | a1319260bf62951e279ea228f682bf4b8834a3c2 (patch) | |
| tree | 856ce34e19e6189e4e931e6f58ec2df84dec1f13 /arch/arm64/kernel/hyp-stub.S | |
| parent | d2602bb4f5a450642b96d467e27e6d5d3ef7fa54 (diff) | |
| download | linux-a1319260bf62951e279ea228f682bf4b8834a3c2.tar.bz2 | |
arm64: KVM: Enable access to TRBE support for host
For a nvhe host, the EL2 must allow the EL1&0 translation
regime for TraceBuffer (MDCR_EL2.E2TB == 0b11). This must
be saved/restored over a trip to the guest. Also, before
entering the guest, we must flush any trace data if the
TRBE was enabled. And we must prohibit the generation
of trace while we are in EL1 by clearing the TRFCR_EL1.
For vhe, the EL2 must prevent the EL1 access to the Trace
Buffer.
The MDCR_EL2 bit definitions for TRBE are available here :
https://developer.arm.com/documentation/ddi0601/2020-12/AArch64-Registers/
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210405164307.1720226-8-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Diffstat (limited to 'arch/arm64/kernel/hyp-stub.S')
| -rw-r--r-- | arch/arm64/kernel/hyp-stub.S | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index 5eccbd62fec8..05d25e645b46 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -115,9 +115,10 @@ SYM_CODE_START_LOCAL(mutate_to_vhe) mrs_s x0, SYS_VBAR_EL12 msr vbar_el1, x0 - // Use EL2 translations for SPE and disable access from EL1 + // Use EL2 translations for SPE & TRBE and disable access from EL1 mrs x0, mdcr_el2 bic x0, x0, #(MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT) + bic x0, x0, #(MDCR_EL2_E2TB_MASK << MDCR_EL2_E2TB_SHIFT) msr mdcr_el2, x0 // Transfer the MM state from EL1 to EL2 |