From 054b88391bbe2e470c5484cb91622238314344fb Mon Sep 17 00:00:00 2001 From: James Clark Date: Mon, 6 Jan 2025 14:24:41 +0000 Subject: [PATCH] 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 Link: https://lore.kernel.org/r/20250106142446.628923-7-james.clark@linaro.org Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_host.h | 2 ++ arch/arm64/kvm/debug.c | 18 ++++++++++++++++++ 2 files changed, 20 insertions(+) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index fec53d84e990..05931a846e4e 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 92a24adadb0e..0e4c805e7e89 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); -- 2.50.1