Re: [PATCH 2/4] KVM: PPC: BOOK3S: PR: Doorbell support
On 05.06.14 14:08, Aneesh Kumar K.V wrote:
We don't have SMT support yet, hence we should not find a doorbell
message generated
Signed-off-by: Aneesh Kumar K.V
---
arch/powerpc/kvm/book3s_emulate.c | 18 ++
1 file changed, 18 insertions(+)
diff --git a/arch/powerpc/kvm/book3s_emulate.c
b/arch/powerpc/kvm/book3s_emulate.c
index 1bb16a59dcbc..d6c87d085182 100644
--- a/arch/powerpc/kvm/book3s_emulate.c
+++ b/arch/powerpc/kvm/book3s_emulate.c
@@ -28,7 +28,9 @@
#define OP_19_XOP_RFI 50
#define OP_31_XOP_MFMSR 83
+#define OP_31_XOP_MSGSNDP 142
#define OP_31_XOP_MTMSR 146
+#define OP_31_XOP_MSGCLRP 174
#define OP_31_XOP_MTMSRD 178
#define OP_31_XOP_MTSR210
#define OP_31_XOP_MTSRIN 242
@@ -303,6 +305,22 @@ int kvmppc_core_emulate_op_pr(struct kvm_run *run, struct
kvm_vcpu *vcpu,
break;
}
+ case OP_31_XOP_MSGSNDP:
+ {
+ /*
+* PR KVM still don't support SMT mode. So we should
still?
+* not see a MSGSNDP/MSGCLRP used with PR KVM
+*/
+ pr_info("KVM: MSGSNDP used in non SMT case\n");
+ emulated = EMULATE_FAIL;
What would happen on an HV guest with only 1 thread that MSGSNDs to
thread 0? Would the guest get an illegal instruction trap, a
self-interrupt or would this be a simple nop?
Alex
+ break;
+ }
+ case OP_31_XOP_MSGCLRP:
+ {
+ pr_info("KVM: MSGCLRP used in non SMT case\n");
+ emulated = EMULATE_FAIL;
+ break;
+ }
default:
emulated = EMULATE_FAIL;
}
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Re: [PATCH 2/4] KVM: PPC: BOOK3S: PR: Doorbell support
On 05.06.14 14:21, Alexander Graf wrote:
On 05.06.14 14:08, Aneesh Kumar K.V wrote:
We don't have SMT support yet, hence we should not find a doorbell
message generated
Signed-off-by: Aneesh Kumar K.V
---
arch/powerpc/kvm/book3s_emulate.c | 18 ++
1 file changed, 18 insertions(+)
diff --git a/arch/powerpc/kvm/book3s_emulate.c
b/arch/powerpc/kvm/book3s_emulate.c
index 1bb16a59dcbc..d6c87d085182 100644
--- a/arch/powerpc/kvm/book3s_emulate.c
+++ b/arch/powerpc/kvm/book3s_emulate.c
@@ -28,7 +28,9 @@
#define OP_19_XOP_RFI50
#define OP_31_XOP_MFMSR83
+#define OP_31_XOP_MSGSNDP142
#define OP_31_XOP_MTMSR146
+#define OP_31_XOP_MSGCLRP174
#define OP_31_XOP_MTMSRD178
#define OP_31_XOP_MTSR210
#define OP_31_XOP_MTSRIN242
@@ -303,6 +305,22 @@ int kvmppc_core_emulate_op_pr(struct kvm_run
*run, struct kvm_vcpu *vcpu,
break;
}
+case OP_31_XOP_MSGSNDP:
+{
+/*
+ * PR KVM still don't support SMT mode. So we should
still?
+ * not see a MSGSNDP/MSGCLRP used with PR KVM
+ */
+pr_info("KVM: MSGSNDP used in non SMT case\n");
+emulated = EMULATE_FAIL;
What would happen on an HV guest with only 1 thread that MSGSNDs to
thread 0? Would the guest get an illegal instruction trap, a
self-interrupt or would this be a simple nop?
What I'm trying to say here is that it's ok to treat it as illegal
instructions, but then we don't need this patch :).
Alex
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Re: [PATCH 2/4] KVM: PPC: BOOK3S: PR: Doorbell support
Alexander Graf writes:
> On 05.06.14 14:21, Alexander Graf wrote:
>>
>> On 05.06.14 14:08, Aneesh Kumar K.V wrote:
>>> We don't have SMT support yet, hence we should not find a doorbell
>>> message generated
>>>
>>> Signed-off-by: Aneesh Kumar K.V
>>> ---
>>> arch/powerpc/kvm/book3s_emulate.c | 18 ++
>>> 1 file changed, 18 insertions(+)
>>>
>>> diff --git a/arch/powerpc/kvm/book3s_emulate.c
>>> b/arch/powerpc/kvm/book3s_emulate.c
>>> index 1bb16a59dcbc..d6c87d085182 100644
>>> --- a/arch/powerpc/kvm/book3s_emulate.c
>>> +++ b/arch/powerpc/kvm/book3s_emulate.c
>>> @@ -28,7 +28,9 @@
>>> #define OP_19_XOP_RFI50
>>> #define OP_31_XOP_MFMSR83
>>> +#define OP_31_XOP_MSGSNDP142
>>> #define OP_31_XOP_MTMSR146
>>> +#define OP_31_XOP_MSGCLRP174
>>> #define OP_31_XOP_MTMSRD178
>>> #define OP_31_XOP_MTSR210
>>> #define OP_31_XOP_MTSRIN242
>>> @@ -303,6 +305,22 @@ int kvmppc_core_emulate_op_pr(struct kvm_run
>>> *run, struct kvm_vcpu *vcpu,
>>> break;
>>> }
>>> +case OP_31_XOP_MSGSNDP:
>>> +{
>>> +/*
>>> + * PR KVM still don't support SMT mode. So we should
>>
>> still?
>>
>>> + * not see a MSGSNDP/MSGCLRP used with PR KVM
>>> + */
>>> +pr_info("KVM: MSGSNDP used in non SMT case\n");
>>> +emulated = EMULATE_FAIL;
>>
>> What would happen on an HV guest with only 1 thread that MSGSNDs to
>> thread 0? Would the guest get an illegal instruction trap, a
>> self-interrupt or would this be a simple nop?
>
> What I'm trying to say here is that it's ok to treat it as illegal
> instructions, but then we don't need this patch :).
>
Agreed. I will verify whether it is treated as a nop. If so will send an
updated patch.
-aneesh
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Re: [PATCH 2/4] KVM: PPC: BOOK3S: PR: Doorbell support
Alexander Graf writes:
> On 05.06.14 14:08, Aneesh Kumar K.V wrote:
>> We don't have SMT support yet, hence we should not find a doorbell
>> message generated
>>
>> Signed-off-by: Aneesh Kumar K.V
>> ---
>> arch/powerpc/kvm/book3s_emulate.c | 18 ++
>> 1 file changed, 18 insertions(+)
>>
>> diff --git a/arch/powerpc/kvm/book3s_emulate.c
>> b/arch/powerpc/kvm/book3s_emulate.c
>> index 1bb16a59dcbc..d6c87d085182 100644
>> --- a/arch/powerpc/kvm/book3s_emulate.c
>> +++ b/arch/powerpc/kvm/book3s_emulate.c
>> @@ -28,7 +28,9 @@
>> #define OP_19_XOP_RFI 50
>>
>> #define OP_31_XOP_MFMSR83
>> +#define OP_31_XOP_MSGSNDP 142
>> #define OP_31_XOP_MTMSR146
>> +#define OP_31_XOP_MSGCLRP 174
>> #define OP_31_XOP_MTMSRD 178
>> #define OP_31_XOP_MTSR 210
>> #define OP_31_XOP_MTSRIN 242
>> @@ -303,6 +305,22 @@ int kvmppc_core_emulate_op_pr(struct kvm_run *run,
>> struct kvm_vcpu *vcpu,
>>
>> break;
>> }
>> +case OP_31_XOP_MSGSNDP:
>> +{
>> +/*
>> + * PR KVM still don't support SMT mode. So we should
>
> still?
>
>> + * not see a MSGSNDP/MSGCLRP used with PR KVM
>> + */
>> +pr_info("KVM: MSGSNDP used in non SMT case\n");
>> +emulated = EMULATE_FAIL;
>
> What would happen on an HV guest with only 1 thread that MSGSNDs to
> thread 0? Would the guest get an illegal instruction trap, a
> self-interrupt or would this be a simple nop?
>
We do get a self-interrupt. I tried the below
tag = mfspr(SPRN_TIR) & 0x7f;
ppc_msgsnd(5, 0, tag);
And that results in doorbell exception. That implies we will have to
have full implementation of doorbell. You can drop patch 2 and 3 from
this series. I will rework them.
NOTE: This is not an issue for Linux guest, because we don't send ipi
to self. But to complete the emulation of msgsndp we will need to
emulate it properly.
-aneesh
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