On 01/07/2015 02:27 PM, Wei Huang wrote:
> arm64 uses its own copy of exit handler (arm64/kvm/handle_exit.c).
> Currently this file doesn't hook up with any trace points. As a result
> users might not see certain events (e.g. HVC & WFI) while using ftrace
> with arm64 KVM. This patch fixes this issue by adding a new trace file
> for arm64 and linking new trace points with related functions.
>
> Signed-off-by: Wei Huang <wei@xxxxxxxxxx>
> ---
> arch/arm64/include/asm/kvm_arm.h | 2 ++
> arch/arm64/include/asm/kvm_emulate.h | 5 ++++
> arch/arm64/kvm/handle_exit.c | 8 ++++++
> arch/arm64/kvm/trace.h | 52 ++++++++++++++++++++++++++++++++++++
> 4 files changed, 67 insertions(+)
> create mode 100644 arch/arm64/kvm/trace.h
>
> diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
> index 7fd3e27..e3e2350 100644
> --- a/arch/arm64/include/asm/kvm_arm.h
> +++ b/arch/arm64/include/asm/kvm_arm.h
> @@ -256,4 +256,6 @@
>
> #define ESR_EL2_EC_WFI_ISS_WFE (1 << 0)
>
> +#define ESR_EL2_HVC_IMM_MASK ((1UL << 16) - 1)
> +
> #endif /* __ARM64_KVM_ARM_H__ */
> diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
> index 8127e45..a6fa2d2 100644
> --- a/arch/arm64/include/asm/kvm_emulate.h
> +++ b/arch/arm64/include/asm/kvm_emulate.h
> @@ -126,6 +126,11 @@ static inline phys_addr_t kvm_vcpu_get_fault_ipa(const struct kvm_vcpu *vcpu)
> return ((phys_addr_t)vcpu->arch.fault.hpfar_el2 & HPFAR_MASK) << 8;
> }
>
> +static inline u32 kvm_vcpu_hvc_get_imm(const struct kvm_vcpu *vcpu)
> +{
> + return kvm_vcpu_get_hsr(vcpu) & ESR_EL2_HVC_IMM_MASK;
> +}
> +
> static inline bool kvm_vcpu_dabt_isvalid(const struct kvm_vcpu *vcpu)
> {
> return !!(kvm_vcpu_get_hsr(vcpu) & ESR_EL2_ISV);
> diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
> index 34b8bd0..4fdb907 100644
> --- a/arch/arm64/kvm/handle_exit.c
> +++ b/arch/arm64/kvm/handle_exit.c
> @@ -26,12 +26,18 @@
> #include <asm/kvm_mmu.h>
> #include <asm/kvm_psci.h>
>
> +#define CREATE_TRACE_POINTS
> +#include "trace.h"
> +
> typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);
>
> static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
> {
> int ret;
>
> + trace_kvm_hvc_arm64(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),
> + kvm_vcpu_hvc_get_imm(vcpu));
> +
> ret = kvm_psci_call(vcpu);
> if (ret < 0) {
> kvm_inject_undefined(vcpu);
> @@ -61,6 +67,8 @@ static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
> */
> static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
> {
> + trace_kvm_wfi_arm64(*vcpu_pc(vcpu));
> +
> if (kvm_vcpu_get_hsr(vcpu) & ESR_EL2_EC_WFI_ISS_WFE)
> kvm_vcpu_on_spin(vcpu);
> else
> diff --git a/arch/arm64/kvm/trace.h b/arch/arm64/kvm/trace.h
> new file mode 100644
> index 0000000..96c7de0
> --- /dev/null
> +++ b/arch/arm64/kvm/trace.h
> @@ -0,0 +1,52 @@
> +#if !defined(_TRACE_ARM64_KVM_H) || defined(TRACE_HEADER_MULTI_READ)
> +#define _TRACE_ARM64_KVM_H
> +
> +#include <linux/tracepoint.h>
> +
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM kvm
> +
> +TRACE_EVENT(kvm_wfi_arm64,
> + TP_PROTO(unsigned long vcpu_pc),
> + TP_ARGS(vcpu_pc),
> +
> + TP_STRUCT__entry(
> + __field(unsigned long, vcpu_pc)
> + ),
> +
> + TP_fast_assign(
> + __entry->vcpu_pc = vcpu_pc;
> + ),
> +
> + TP_printk("guest executed wfxx at: 0x%08lx", __entry->vcpu_pc)
I realized that there is a typo in TP_printk. "guest executed wfxx" is
supposed to be "guest executed wfi". Sorry. That is a debug string
accidentally left behind. Please correct it (or I can send another patch
if requested).
-Wei
> +);
> +
> +TRACE_EVENT(kvm_hvc_arm64,
> + TP_PROTO(unsigned long vcpu_pc, unsigned long r0, unsigned long imm),
> + TP_ARGS(vcpu_pc, r0, imm),
> +
> + TP_STRUCT__entry(
> + __field(unsigned long, vcpu_pc)
> + __field(unsigned long, r0)
> + __field(unsigned long, imm)
> + ),
> +
> + TP_fast_assign(
> + __entry->vcpu_pc = vcpu_pc;
> + __entry->r0 = r0;
> + __entry->imm = imm;
> + ),
> +
> + TP_printk("HVC at 0x%08lx (r0: 0x%08lx, imm: 0x%lx)",
> + __entry->vcpu_pc, __entry->r0, __entry->imm)
> +);
> +
> +#endif /* _TRACE_ARM64_KVM_H */
> +
> +#undef TRACE_INCLUDE_PATH
> +#define TRACE_INCLUDE_PATH .
> +#undef TRACE_INCLUDE_FILE
> +#define TRACE_INCLUDE_FILE trace
> +
> +/* This part must be outside protection */
> +#include <trace/define_trace.h>
>
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