Commit 054b8839 authored by James Clark's avatar James Clark Committed by Marc Zyngier
Browse files

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: default avatarJames Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20250106142446.628923-7-james.clark@linaro.org


Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent a665e3bc

arch/arm64/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -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);

arch/arm64/kvm/debug.c

+18 −0
Original line number Diff line number Diff line
@@ -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);