Hi,
On 11/01/15 18:42, Christoffer Dall wrote:
> On Thu, Jan 08, 2015 at 01:33:35PM -0600, Wei Huang wrote:
>> 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).
>>
>
> it really should all be _wfx, not wfi, and we should identify if it's a
> wfi or wfe we're seeing, now when we're at it. (It could be good for
> counting stats too).
I have a patch for this in my queue. I will rebase it on top of Wei's
patch and send it out ASAP.
Cheers,
Andre.
>>> +);
>>> +
>>> +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>
>>>
>
> This looks like it's going to conflict with Mark Rutland's series:
> http://www.spinics.net/lists/arm-kernel/msg388934.html
>
> But it should be relatively easy to fixup the conflicts.
>
> -Christoffer
>
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