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authorJames Clark <james.clark@linaro.org>2025-01-06 14:24:41 +0000
committerMarc Zyngier <maz@kernel.org>2025-01-12 12:50:11 +0000
commit054b88391bbe2e470c5484cb91622238314344fb (patch)
treee20bb0095b1bbcf44f165b403d5fcd972dc03e30
parenta665e3bc88081dd65642d83fc22a1abdb6a901bc (diff)
downloadnet-054b88391bbe2e470c5484cb91622238314344fb.tar.gz
KVM: arm64: Support trace filtering for guests
For nVHE, switch the filter value in and out if the Coresight driver asks for it. This will support filters for guests when sinks other than TRBE are used. For VHE, just write the filter directly to TRFCR_EL1 where trace can be used even with TRBE sinks. Signed-off-by: James Clark <james.clark@linaro.org> Link: https://lore.kernel.org/r/20250106142446.628923-7-james.clark@linaro.org Signed-off-by: Marc Zyngier <maz@kernel.org>
-rw-r--r--arch/arm64/include/asm/kvm_host.h2
-rw-r--r--arch/arm64/kvm/debug.c18
2 files changed, 20 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index fec53d84e99067..05931a846e4efd 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -1388,6 +1388,7 @@ void kvm_clr_pmu_events(u64 clr);
bool kvm_set_pmuserenr(u64 val);
void kvm_enable_trbe(void);
void kvm_disable_trbe(void);
+void kvm_tracing_set_el1_configuration(u64 trfcr_while_in_guest);
#else
static inline void kvm_set_pmu_events(u64 set, struct perf_event_attr *attr) {}
static inline void kvm_clr_pmu_events(u64 clr) {}
@@ -1397,6 +1398,7 @@ static inline bool kvm_set_pmuserenr(u64 val)
}
static inline void kvm_enable_trbe(void) {}
static inline void kvm_disable_trbe(void) {}
+static inline void kvm_tracing_set_el1_configuration(u64 trfcr_while_in_guest) {}
#endif
void kvm_vcpu_load_vhe(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
index 92a24adadb0eb1..0e4c805e7e8919 100644
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c
@@ -245,3 +245,21 @@ void kvm_disable_trbe(void)
host_data_clear_flag(TRBE_ENABLED);
}
EXPORT_SYMBOL_GPL(kvm_disable_trbe);
+
+void kvm_tracing_set_el1_configuration(u64 trfcr_while_in_guest)
+{
+ if (is_protected_kvm_enabled() || WARN_ON_ONCE(preemptible()))
+ return;
+
+ if (has_vhe()) {
+ write_sysreg_s(trfcr_while_in_guest, SYS_TRFCR_EL12);
+ return;
+ }
+
+ *host_data_ptr(trfcr_while_in_guest) = trfcr_while_in_guest;
+ if (read_sysreg_s(SYS_TRFCR_EL1) != trfcr_while_in_guest)
+ host_data_set_flag(EL1_TRACING_CONFIGURED);
+ else
+ host_data_clear_flag(EL1_TRACING_CONFIGURED);
+}
+EXPORT_SYMBOL_GPL(kvm_tracing_set_el1_configuration);