On 05/10/2023 17:58, Suzuki K Poulose wrote:
On 05/10/2023 13:57, James Clark wrote:
Add an interface for the Coresight driver to use to set the value of the TRFCR register for the guest. This register controls the exclude
settings for trace at different exception levels, and is used to honor the exclude_host and exclude_guest parameters from the Perf session. This will be used to later write TRFCR_EL1 on nVHE at guest switch. For VHE, TRFCR_EL1 is written immediately. Because guest writes
minor nit: May be it would be clearer to say:
For VHE, the host trace is controlled by TRFCR_EL2 and thus we can write to the TRFCR_EL1 immediately. Because, ...
to the register are trapped, the value will persist and can't be modified.
The settings must be copied to the vCPU before each run in the same way that PMU events are because the per-cpu struct isn't accessible in
super minor nit:
way that PMU events are, because ...
protected mode.
Now that both guest and host values are saved, rename trfcr_el1 to host_trfcr_el1 to make it clear that's the value that should be restored
This seems obsolete ? I couldn't find any reference to host_trfcr_el1 anywhere ?
Yep it was from an old version. I remove it and fixed all of the above too.
Otherwise looks good to me.
Suzuki
on return to the host.
Signed-off-by: James Clark james.clark@arm.com
arch/arm64/include/asm/kvm_host.h | 3 +++ arch/arm64/kvm/arm.c | 1 + arch/arm64/kvm/debug.c | 26 ++++++++++++++++++++++++++ 3 files changed, 30 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index b5200f199692..8f2b4ec8ea61 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1123,6 +1123,8 @@ void kvm_arch_vcpu_put_debug_state_flags(struct kvm_vcpu *vcpu); void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr); void kvm_clr_pmu_events(u32 clr); bool kvm_set_pmuserenr(u64 val); +void kvm_etm_set_guest_trfcr(u64 trfcr_guest); +void kvm_etm_update_vcpu_events(struct kvm_vcpu *vcpu); #else static inline void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr) {} static inline void kvm_clr_pmu_events(u32 clr) {} @@ -1130,6 +1132,7 @@ static inline bool kvm_set_pmuserenr(u64 val) { return false; } +static inline void kvm_etm_set_guest_trfcr(u64 trfcr_guest) {} #endif void kvm_vcpu_load_sysregs_vhe(struct kvm_vcpu *vcpu); diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 78b0970eb8e6..22fab356b88f 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1012,6 +1012,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) kvm_vgic_flush_hwstate(vcpu); kvm_pmu_update_vcpu_events(vcpu); + kvm_etm_update_vcpu_events(vcpu); /* * Ensure we set mode to IN_GUEST_MODE after we disable diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c index 6a1bad1a921b..19e722359154 100644 --- a/arch/arm64/kvm/debug.c +++ b/arch/arm64/kvm/debug.c @@ -23,6 +23,12 @@ static DEFINE_PER_CPU(u64, mdcr_el2); +/*
- Per CPU value for TRFCR that should be applied to any guest vcpu
that may
- run on that core in the future.
- */
+static DEFINE_PER_CPU(u64, guest_trfcr);
/** * save/restore_guest_debug_regs * @@ -342,3 +348,23 @@ void kvm_arch_vcpu_put_debug_state_flags(struct kvm_vcpu *vcpu) vcpu_clear_flag(vcpu, DEBUG_STATE_SAVE_SPE); vcpu_clear_flag(vcpu, DEBUG_STATE_SAVE_TRFCR); }
+void kvm_etm_set_guest_trfcr(u64 trfcr_guest) +{ + if (has_vhe()) + write_sysreg_s(trfcr_guest, SYS_TRFCR_EL12); + else + *this_cpu_ptr(&guest_trfcr) = trfcr_guest; +} +EXPORT_SYMBOL_GPL(kvm_etm_set_guest_trfcr);
+/*
- Updates the vcpu's view of the etm events for this cpu. Must be
- called before every vcpu run after disabling interrupts, to ensure
- that an interrupt cannot fire and update the structure.
- */
+void kvm_etm_update_vcpu_events(struct kvm_vcpu *vcpu) +{ + if (!has_vhe() && vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRFCR)) + ctxt_sys_reg(&vcpu->arch.ctxt, TRFCR_EL1) = *this_cpu_ptr(&guest_trfcr); +}