diff options
| author | James Clark <james.clark@linaro.org> | 2025-01-06 14:24:40 +0000 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2025-01-12 12:50:11 +0000 |
| commit | a665e3bc88081dd65642d83fc22a1abdb6a901bc (patch) | |
| tree | af3275ecb9f2ea20b75ea809fefd2e534c4893c4 /drivers/hwtracing | |
| parent | a2b579c41fe9c295804abd167751f9fdc73c7006 (diff) | |
KVM: arm64: coresight: Give TRBE enabled state to KVM
Currently in nVHE, KVM has to check if TRBE is enabled on every guest
switch even if it was never used. Because it's a debug feature and is
more likely to not be used than used, give KVM the TRBE buffer status to
allow a much simpler and faster do-nothing path in the hyp.
Protected mode now disables trace regardless of TRBE (because
trfcr_while_in_guest is always 0), which was not previously done.
However, it continues to flush whenever the buffer is enabled
regardless of the filter status. This avoids the hypothetical case of a
host that had disabled the filter but not flushed which would arise if
only doing the flush when the filter was enabled.
Signed-off-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20250106142446.628923-6-james.clark@linaro.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'drivers/hwtracing')
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-trbe.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index 03d3695ba5aa..a728802d2206 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -17,6 +17,7 @@ #include <asm/barrier.h> #include <asm/cpufeature.h> +#include <linux/kvm_host.h> #include <linux/vmalloc.h> #include "coresight-self-hosted-trace.h" @@ -221,6 +222,7 @@ static inline void set_trbe_enabled(struct trbe_cpudata *cpudata, u64 trblimitr) */ trblimitr |= TRBLIMITR_EL1_E; write_sysreg_s(trblimitr, SYS_TRBLIMITR_EL1); + kvm_enable_trbe(); /* Synchronize the TRBE enable event */ isb(); @@ -239,6 +241,7 @@ static inline void set_trbe_disabled(struct trbe_cpudata *cpudata) */ trblimitr &= ~TRBLIMITR_EL1_E; write_sysreg_s(trblimitr, SYS_TRBLIMITR_EL1); + kvm_disable_trbe(); if (trbe_needs_drain_after_disable(cpudata)) trbe_drain_buffer(); |