2020-09-04 11:28:47

by Haiwei Li

Subject: [PATCH] KVM: SVM: Add tracepoint for cr_interception

From: Haiwei Li <[email protected]>

Add trace_kvm_cr_write and trace_kvm_cr_read for svm.

Signed-off-by: Haiwei Li <[email protected]>
---
arch/x86/kvm/svm/svm.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 03dd7bac8034..2c6dea48ba62 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2261,6 +2261,7 @@ static int cr_interception(struct vcpu_svm *svm)
if (cr >= 16) { /* mov to cr */
cr -= 16;
val = kvm_register_read(&svm->vcpu, reg);
+ trace_kvm_cr_write(cr, val);
switch (cr) {
case 0:
if (!check_selective_cr0_intercepted(svm, val))
@@ -2306,6 +2307,7 @@ static int cr_interception(struct vcpu_svm *svm)
return 1;
}
kvm_register_write(&svm->vcpu, reg, val);
+ trace_kvm_cr_read(cr, val);
}
return kvm_complete_insn_gp(&svm->vcpu, err);
}
--
2.18.4

2020-09-04 12:03:14

by Vitaly Kuznetsov

Subject: Re: [PATCH] KVM: SVM: Add tracepoint for cr_interception

Haiwei Li <[email protected]> writes:

> From: Haiwei Li <[email protected]>
>
> Add trace_kvm_cr_write and trace_kvm_cr_read for svm.
>
> Signed-off-by: Haiwei Li <[email protected]>
> ---
> arch/x86/kvm/svm/svm.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 03dd7bac8034..2c6dea48ba62 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -2261,6 +2261,7 @@ static int cr_interception(struct vcpu_svm *svm)

There are two special cases when we go to emulate_on_interception() and
these won't be logged but I don't think this is a must.

> if (cr >= 16) { /* mov to cr */
> cr -= 16;
> val = kvm_register_read(&svm->vcpu, reg);
> + trace_kvm_cr_write(cr, val);
> switch (cr) {
> case 0:
> if (!check_selective_cr0_intercepted(svm, val))
> @@ -2306,6 +2307,7 @@ static int cr_interception(struct vcpu_svm *svm)
> return 1;
> }
> kvm_register_write(&svm->vcpu, reg, val);
> + trace_kvm_cr_read(cr, val);

The 'default:' case above does 'return 1;' so we won't get the trace but
I understand you put trace_kvm_cr_read() here so you can log the
returned 'val', #UD should be clearly visible.

> }
> return kvm_complete_insn_gp(&svm->vcpu, err);
> }
> --
> 2.18.4
>

Reviewed-by: Vitaly Kuznetsov <[email protected]>

--
Vitaly

2020-09-04 12:46:42

by Haiwei Li

Subject: Re: [PATCH] KVM: SVM: Add tracepoint for cr_interception

On 20/9/4 20:01, Vitaly Kuznetsov wrote:
> Haiwei Li <[email protected]> writes:
>
>> From: Haiwei Li <[email protected]>
>>
>> Add trace_kvm_cr_write and trace_kvm_cr_read for svm.
>>
>> Signed-off-by: Haiwei Li <[email protected]>
>> ---
>> arch/x86/kvm/svm/svm.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
>> index 03dd7bac8034..2c6dea48ba62 100644
>> --- a/arch/x86/kvm/svm/svm.c
>> +++ b/arch/x86/kvm/svm/svm.c
>> @@ -2261,6 +2261,7 @@ static int cr_interception(struct vcpu_svm *svm)
>
> There are two special cases when we go to emulate_on_interception() and
> these won't be logged but I don't think this is a must.
>
>> if (cr >= 16) { /* mov to cr */
>> cr -= 16;
>> val = kvm_register_read(&svm->vcpu, reg);
>> + trace_kvm_cr_write(cr, val);
>> switch (cr) {
>> case 0:
>> if (!check_selective_cr0_intercepted(svm, val))
>> @@ -2306,6 +2307,7 @@ static int cr_interception(struct vcpu_svm *svm)
>> return 1;
>> }
>> kvm_register_write(&svm->vcpu, reg, val);
>> + trace_kvm_cr_read(cr, val);
>
> The 'default:' case above does 'return 1;' so we won't get the trace but
> I understand you put trace_kvm_cr_read() here so you can log the
> returned 'val', #UD should be clearly visible.
>
>> }
>> return kvm_complete_insn_gp(&svm->vcpu, err);
>> }
>> --
>> 2.18.4
>>
>
> Reviewed-by: Vitaly Kuznetsov <[email protected]>

Thanks a lot.

>

2020-09-23 06:25:56

by Haiwei Li

Subject: Re: [PATCH] KVM: SVM: Add tracepoint for cr_interception

Kindly ping. :)
On 20/9/4 19:25, Haiwei Li wrote:
> From: Haiwei Li <[email protected]>
>
> Add trace_kvm_cr_write and trace_kvm_cr_read for svm.
>
> Signed-off-by: Haiwei Li <[email protected]>
> ---
>  arch/x86/kvm/svm/svm.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 03dd7bac8034..2c6dea48ba62 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -2261,6 +2261,7 @@ static int cr_interception(struct vcpu_svm *svm)
>      if (cr >= 16) { /* mov to cr */
>          cr -= 16;
>          val = kvm_register_read(&svm->vcpu, reg);
> +        trace_kvm_cr_write(cr, val);
>          switch (cr) {
>          case 0:
>              if (!check_selective_cr0_intercepted(svm, val))
> @@ -2306,6 +2307,7 @@ static int cr_interception(struct vcpu_svm *svm)
>              return 1;
>          }
>          kvm_register_write(&svm->vcpu, reg, val);
> +        trace_kvm_cr_read(cr, val);
>      }
>      return kvm_complete_insn_gp(&svm->vcpu, err);
>  }
> --
> 2.18.4

2020-09-24 00:46:35

by Wanpeng Li

Subject: Re: [PATCH] KVM: SVM: Add tracepoint for cr_interception

On Fri, 4 Sep 2020 at 19:29, Haiwei Li <[email protected]> wrote:
>
> From: Haiwei Li <[email protected]>
>
> Add trace_kvm_cr_write and trace_kvm_cr_read for svm.
>
> Signed-off-by: Haiwei Li <[email protected]>

Reviewed-by: Wanpeng Li <[email protected]>