From 3b7780945cc8494793040ab0a9805b77b7826abb Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Thu, 19 Dec 2024 14:41:06 -0800 Subject: [PATCH] KVM: arm64: Remove debug tracepoints The debug tracepoints are a useless firehose of information that track implementation detail rather than well-defined events. These are going to be rather difficult to uphold now that the implementation is getting redone, so throw them out instead of bending over backwards. Tested-by: James Clark Signed-off-by: Oliver Upton Link: https://lore.kernel.org/r/20241219224116.3941496-10-oliver.upton@linux.dev [maz: fixed compilation after trace-ectomy] Signed-off-by: Marc Zyngier --- arch/arm64/kvm/debug.c | 34 -------------- arch/arm64/kvm/sys_regs.c | 11 ----- arch/arm64/kvm/trace_handle_exit.h | 75 ------------------------------ 3 files changed, 120 deletions(-) diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c index 548016439acaa..9979fc1a20bd3 100644 --- a/arch/arm64/kvm/debug.c +++ b/arch/arm64/kvm/debug.c @@ -14,7 +14,6 @@ #include #include -#include "trace.h" /* * save/restore_guest_debug_regs @@ -35,10 +34,6 @@ static void save_guest_debug_regs(struct kvm_vcpu *vcpu) u64 val = vcpu_read_sys_reg(vcpu, MDSCR_EL1); vcpu->arch.guest_debug_preserved.mdscr_el1 = val; - - trace_kvm_arm_set_dreg32("Saved MDSCR_EL1", - vcpu->arch.guest_debug_preserved.mdscr_el1); - vcpu->arch.guest_debug_preserved.pstate_ss = (*vcpu_cpsr(vcpu) & DBG_SPSR_SS); } @@ -49,9 +44,6 @@ static void restore_guest_debug_regs(struct kvm_vcpu *vcpu) vcpu_write_sys_reg(vcpu, val, MDSCR_EL1); - trace_kvm_arm_set_dreg32("Restored MDSCR_EL1", - vcpu_read_sys_reg(vcpu, MDSCR_EL1)); - if (vcpu->arch.guest_debug_preserved.pstate_ss) *vcpu_cpsr(vcpu) |= DBG_SPSR_SS; else @@ -110,8 +102,6 @@ static void kvm_arm_setup_mdcr_el2(struct kvm_vcpu *vcpu) write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); preempt_enable(); - - trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.mdcr_el2); } /** @@ -158,8 +148,6 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) { unsigned long mdscr; - trace_kvm_arm_setup_debug(vcpu, vcpu->guest_debug); - kvm_arm_setup_mdcr_el2(vcpu); /* Check if we need to use the debug registers. */ @@ -209,8 +197,6 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) vcpu_write_sys_reg(vcpu, mdscr, MDSCR_EL1); } - trace_kvm_arm_set_dreg32("SPSR_EL2", *vcpu_cpsr(vcpu)); - /* * HW Breakpoints and watchpoints * @@ -228,14 +214,6 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) vcpu->arch.debug_ptr = &vcpu->arch.external_debug_state; vcpu_set_flag(vcpu, DEBUG_DIRTY); - trace_kvm_arm_set_regset("BKPTS", get_num_brps(), - &vcpu->arch.debug_ptr->dbg_bcr[0], - &vcpu->arch.debug_ptr->dbg_bvr[0]); - - trace_kvm_arm_set_regset("WAPTS", get_num_wrps(), - &vcpu->arch.debug_ptr->dbg_wcr[0], - &vcpu->arch.debug_ptr->dbg_wvr[0]); - /* * The OS Lock blocks debug exceptions in all ELs when it is * enabled. If the guest has enabled the OS Lock, constrain its @@ -257,14 +235,10 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) /* If KDE or MDE are set, perform a full save/restore cycle. */ if (vcpu_read_sys_reg(vcpu, MDSCR_EL1) & (DBG_MDSCR_KDE | DBG_MDSCR_MDE)) vcpu_set_flag(vcpu, DEBUG_DIRTY); - - trace_kvm_arm_set_dreg32("MDSCR_EL1", vcpu_read_sys_reg(vcpu, MDSCR_EL1)); } void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) { - trace_kvm_arm_clear_debug(vcpu->guest_debug); - /* * Restore the guest's debug registers if we were using them. */ @@ -286,14 +260,6 @@ void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) */ if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW) { kvm_arm_reset_debug_ptr(vcpu); - - trace_kvm_arm_set_regset("BKPTS", get_num_brps(), - &vcpu->arch.debug_ptr->dbg_bcr[0], - &vcpu->arch.debug_ptr->dbg_bvr[0]); - - trace_kvm_arm_set_regset("WAPTS", get_num_wrps(), - &vcpu->arch.debug_ptr->dbg_wcr[0], - &vcpu->arch.debug_ptr->dbg_wvr[0]); } } } diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index e45a096be6692..8c5771572133a 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -657,8 +657,6 @@ static bool trap_debug_regs(struct kvm_vcpu *vcpu, vcpu_set_flag(vcpu, DEBUG_DIRTY); kvm_debug_set_guest_ownership(vcpu); - trace_trap_reg(__func__, r->reg, p->is_write, p->regval); - return true; } @@ -711,8 +709,6 @@ static bool trap_bvr(struct kvm_vcpu *vcpu, else dbg_to_reg(vcpu, p, rd, dbg_reg); - trace_trap_reg(__func__, rd->CRm, p->is_write, *dbg_reg); - return true; } @@ -748,8 +744,6 @@ static bool trap_bcr(struct kvm_vcpu *vcpu, else dbg_to_reg(vcpu, p, rd, dbg_reg); - trace_trap_reg(__func__, rd->CRm, p->is_write, *dbg_reg); - return true; } @@ -785,9 +779,6 @@ static bool trap_wvr(struct kvm_vcpu *vcpu, else dbg_to_reg(vcpu, p, rd, dbg_reg); - trace_trap_reg(__func__, rd->CRm, p->is_write, - vcpu->arch.vcpu_debug_state.dbg_wvr[rd->CRm]); - return true; } @@ -823,8 +814,6 @@ static bool trap_wcr(struct kvm_vcpu *vcpu, else dbg_to_reg(vcpu, p, rd, dbg_reg); - trace_trap_reg(__func__, rd->CRm, p->is_write, *dbg_reg); - return true; } diff --git a/arch/arm64/kvm/trace_handle_exit.h b/arch/arm64/kvm/trace_handle_exit.h index 064a58c19f481..f85415db7713b 100644 --- a/arch/arm64/kvm/trace_handle_exit.h +++ b/arch/arm64/kvm/trace_handle_exit.h @@ -46,38 +46,6 @@ TRACE_EVENT(kvm_hvc_arm64, __entry->vcpu_pc, __entry->r0, __entry->imm) ); -TRACE_EVENT(kvm_arm_setup_debug, - TP_PROTO(struct kvm_vcpu *vcpu, __u32 guest_debug), - TP_ARGS(vcpu, guest_debug), - - TP_STRUCT__entry( - __field(struct kvm_vcpu *, vcpu) - __field(__u32, guest_debug) - ), - - TP_fast_assign( - __entry->vcpu = vcpu; - __entry->guest_debug = guest_debug; - ), - - TP_printk("vcpu: %p, flags: 0x%08x", __entry->vcpu, __entry->guest_debug) -); - -TRACE_EVENT(kvm_arm_clear_debug, - TP_PROTO(__u32 guest_debug), - TP_ARGS(guest_debug), - - TP_STRUCT__entry( - __field(__u32, guest_debug) - ), - - TP_fast_assign( - __entry->guest_debug = guest_debug; - ), - - TP_printk("flags: 0x%08x", __entry->guest_debug) -); - /* * The dreg32 name is a leftover from a distant past. This will really * output a 64bit value... @@ -99,49 +67,6 @@ TRACE_EVENT(kvm_arm_set_dreg32, TP_printk("%s: 0x%llx", __entry->name, __entry->value) ); -TRACE_DEFINE_SIZEOF(__u64); - -TRACE_EVENT(kvm_arm_set_regset, - TP_PROTO(const char *type, int len, __u64 *control, __u64 *value), - TP_ARGS(type, len, control, value), - TP_STRUCT__entry( - __field(const char *, name) - __field(int, len) - __array(u64, ctrls, 16) - __array(u64, values, 16) - ), - TP_fast_assign( - __entry->name = type; - __entry->len = len; - memcpy(__entry->ctrls, control, len << 3); - memcpy(__entry->values, value, len << 3); - ), - TP_printk("%d %s CTRL:%s VALUE:%s", __entry->len, __entry->name, - __print_array(__entry->ctrls, __entry->len, sizeof(__u64)), - __print_array(__entry->values, __entry->len, sizeof(__u64))) -); - -TRACE_EVENT(trap_reg, - TP_PROTO(const char *fn, int reg, bool is_write, u64 write_value), - TP_ARGS(fn, reg, is_write, write_value), - - TP_STRUCT__entry( - __field(const char *, fn) - __field(int, reg) - __field(bool, is_write) - __field(u64, write_value) - ), - - TP_fast_assign( - __entry->fn = fn; - __entry->reg = reg; - __entry->is_write = is_write; - __entry->write_value = write_value; - ), - - TP_printk("%s %s reg %d (0x%016llx)", __entry->fn, __entry->is_write?"write to":"read from", __entry->reg, __entry->write_value) -); - TRACE_EVENT(kvm_handle_sys_reg, TP_PROTO(unsigned long hsr), TP_ARGS(hsr),