diff options
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/include/asm/el2_setup.h | |
parent | d2602bb4f5a450642b96d467e27e6d5d3ef7fa54 (diff) |
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/include/asm/el2_setup.h')
-rw-r--r-- | arch/arm64/include/asm/el2_setup.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h index d77d358f9395..bda918948471 100644 --- a/arch/arm64/include/asm/el2_setup.h +++ b/arch/arm64/include/asm/el2_setup.h @@ -65,6 +65,19 @@ // use EL1&0 translation. .Lskip_spe_\@: + /* Trace buffer */ + ubfx x0, x1, #ID_AA64DFR0_TRBE_SHIFT, #4 + cbz x0, .Lskip_trace_\@ // Skip if TraceBuffer is not present + + mrs_s x0, SYS_TRBIDR_EL1 + and x0, x0, TRBIDR_PROG + cbnz x0, .Lskip_trace_\@ // If TRBE is available at EL2 + + mov x0, #(MDCR_EL2_E2TB_MASK << MDCR_EL2_E2TB_SHIFT) + orr x2, x2, x0 // allow the EL1&0 translation + // to own it. + +.Lskip_trace_\@: msr mdcr_el2, x2 // Configure debug traps .endm |