[PATCH v8] KVM: PPC: reserve a capability and ioctl numbers for realmode VFIO

This is to reserve a capablity number for upcoming support
of VFIO-IOMMU DMA operations in real mode.

The last ioctl in the group which KVM_CREATE_SPAPR_TCE_IOMMU is added to
is 0xac, the next two numbers are taken - 0xad for KVM_KVMCLOCK_CTRL and
0xae for KVM_ARM_VCPU_INIT. So the KVM_CREATE_SPAPR_TCE_IOMMU ioclt gets
0xaf.

Signed-off-by: Alexey Kardashevskiy <redacted>

---
Changes:
2013/08/15 v8:
* fixed comment again

2013/08/15:
* fixed mistype in comments
* fixed commit message which says what uses ioctls 0xad and 0xae

2013/07/16:
* changed the number

2013/07/11:
* changed order in a file, added comment about a gap in ioctl number
---
 include/uapi/linux/kvm.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 99c2533..bd94127 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h

@@ -668,6 +668,7 @@ struct kvm_ppc_smmu_info {
 #define KVM_CAP_IRQ_XICS 92
 #define KVM_CAP_ARM_EL1_32BIT 93
 #define KVM_CAP_SPAPR_MULTITCE 94
+#define KVM_CAP_SPAPR_TCE_IOMMU 95
 
 #ifdef KVM_CAP_IRQ_ROUTING
 

@@ -933,6 +934,11 @@ struct kvm_s390_ucas_mapping {
 #define KVM_ARM_SET_DEVICE_ADDR	  _IOW(KVMIO,  0xab, struct kvm_arm_device_addr)
 /* Available with KVM_CAP_PPC_RTAS */
 #define KVM_PPC_RTAS_DEFINE_TOKEN _IOW(KVMIO,  0xac, struct kvm_rtas_token_args)
+/* 0xad is taken by KVM_KVMCLOCK_CTRL */
+/* 0xae is taken by KVM_ARM_VCPU_INIT */
+/* Available with KVM_CAP_SPAPR_TCE_IOMMU */
+#define KVM_CREATE_SPAPR_TCE_IOMMU _IOW(KVMIO,  0xaf, \
+					struct kvm_create_spapr_tce_iommu)
 
 /* ioctl for vm fd */
 #define KVM_CREATE_DEVICE	  _IOWR(KVMIO,  0xe0, struct kvm_create_device)

-- 
1.8.3.2

On Thu, Aug 15, 2013 at 05:49:26PM +1000, Alexey Kardashevskiy wrote:

This is to reserve a capablity number for upcoming support
of VFIO-IOMMU DMA operations in real mode.

The last ioctl in the group which KVM_CREATE_SPAPR_TCE_IOMMU is added to
is 0xac, the next two numbers are taken - 0xad for KVM_KVMCLOCK_CTRL and

0xac was also taken by KVM_SET_ONE_REG :(

5 more quoted lines

Why not use KVM_CREATE_DEVICE API for that?

 /* ioctl for vm fd */
 #define KVM_CREATE_DEVICE	  _IOWR(KVMIO,  0xe0, struct kvm_create_device)
-- 
1.8.3.2

--
			Gleb.

On 08/27/2013 05:56 PM, Gleb Natapov wrote:

On Thu, Aug 15, 2013 at 05:49:26PM +1000, Alexey Kardashevskiy wrote:

quoted

This is to reserve a capablity number for upcoming support
of VFIO-IOMMU DMA operations in real mode.

The last ioctl in the group which KVM_CREATE_SPAPR_TCE_IOMMU is added to
is 0xac, the next two numbers are taken - 0xad for KVM_KVMCLOCK_CTRL and

0xac was also taken by KVM_SET_ONE_REG :(

quoted

0xae for KVM_ARM_VCPU_INIT. So the KVM_CREATE_SPAPR_TCE_IOMMU ioclt gets
0xaf.

Signed-off-by: Alexey Kardashevskiy <redacted>

---
Changes:
2013/08/15 v8:
* fixed comment again

2013/08/15:
* fixed mistype in comments
* fixed commit message which says what uses ioctls 0xad and 0xae

2013/07/16:
* changed the number

2013/07/11:
* changed order in a file, added comment about a gap in ioctl number
---
 include/uapi/linux/kvm.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 99c2533..bd94127 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h

@@ -668,6 +668,7 @@ struct kvm_ppc_smmu_info {
 #define KVM_CAP_IRQ_XICS 92
 #define KVM_CAP_ARM_EL1_32BIT 93
 #define KVM_CAP_SPAPR_MULTITCE 94
+#define KVM_CAP_SPAPR_TCE_IOMMU 95

14 more quoted lines

Because when I came up with my ioctl first time, it was not in upstream and
since then nobody pointed me to this new ioctl :)
So my stuff is not going to upstream again. Heh. Ok. I'll implement it.

quoted

 /* ioctl for vm fd */
 #define KVM_CREATE_DEVICE	  _IOWR(KVMIO,  0xe0, struct kvm_create_device)

-- 
Alexey

On Tue, Aug 27, 2013 at 06:42:18PM +1000, Alexey Kardashevskiy wrote:

On 08/27/2013 05:56 PM, Gleb Natapov wrote:

quoted

On Thu, Aug 15, 2013 at 05:49:26PM +1000, Alexey Kardashevskiy wrote:

quoted

This is to reserve a capablity number for upcoming support
of VFIO-IOMMU DMA operations in real mode.

The last ioctl in the group which KVM_CREATE_SPAPR_TCE_IOMMU is added to
is 0xac, the next two numbers are taken - 0xad for KVM_KVMCLOCK_CTRL and

0xac was also taken by KVM_SET_ONE_REG :(

quoted

0xae for KVM_ARM_VCPU_INIT. So the KVM_CREATE_SPAPR_TCE_IOMMU ioclt gets
0xaf.

Signed-off-by: Alexey Kardashevskiy <redacted>

---
Changes:
2013/08/15 v8:
* fixed comment again

2013/08/15:
* fixed mistype in comments
* fixed commit message which says what uses ioctls 0xad and 0xae

2013/07/16:
* changed the number

2013/07/11:
* changed order in a file, added comment about a gap in ioctl number
---
 include/uapi/linux/kvm.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 99c2533..bd94127 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h

@@ -668,6 +668,7 @@ struct kvm_ppc_smmu_info {
 #define KVM_CAP_IRQ_XICS 92
 #define KVM_CAP_ARM_EL1_32BIT 93
 #define KVM_CAP_SPAPR_MULTITCE 94

19 more quoted lines

Sorry about that :(. The ioctl exists for a while now, but with v8 patch I
imaging your patch series predates it.

So my stuff is not going to upstream again. Heh. Ok. I'll implement it.

Thanks! Should I keep KVM_CAP_SPAPR_MULTITCE capability patch or can I
drop it for now?

--
			Gleb.

On 08/27/2013 08:58 PM, Gleb Natapov wrote:

On Tue, Aug 27, 2013 at 06:42:18PM +1000, Alexey Kardashevskiy wrote:

quoted

On 08/27/2013 05:56 PM, Gleb Natapov wrote:

quoted

On Thu, Aug 15, 2013 at 05:49:26PM +1000, Alexey Kardashevskiy wrote:

quoted

This is to reserve a capablity number for upcoming support
of VFIO-IOMMU DMA operations in real mode.

The last ioctl in the group which KVM_CREATE_SPAPR_TCE_IOMMU is added to
is 0xac, the next two numbers are taken - 0xad for KVM_KVMCLOCK_CTRL and

0xac was also taken by KVM_SET_ONE_REG :(

quoted

0xae for KVM_ARM_VCPU_INIT. So the KVM_CREATE_SPAPR_TCE_IOMMU ioclt gets
0xaf.

Signed-off-by: Alexey Kardashevskiy <redacted>

---
Changes:
2013/08/15 v8:
* fixed comment again

2013/08/15:
* fixed mistype in comments
* fixed commit message which says what uses ioctls 0xad and 0xae

2013/07/16:
* changed the number

2013/07/11:
* changed order in a file, added comment about a gap in ioctl number
---
 include/uapi/linux/kvm.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 99c2533..bd94127 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h

@@ -668,6 +668,7 @@ struct kvm_ppc_smmu_info {
 #define KVM_CAP_IRQ_XICS 92
 #define KVM_CAP_ARM_EL1_32BIT 93

22 more quoted lines

The ioctl I made up is basically a copy of KVM_CREATE_SPAPR_TCE which does
the same thing for emulated devices and it is there for quite a while but
it is not really extensible. And these two ioctls share some bits of code.
Now we will have 2 pieces of code which do almost the same thing but in a
different way. Kinda sucks :(

quoted

So my stuff is not going to upstream again. Heh. Ok. I'll implement it.

Thanks! Should I keep KVM_CAP_SPAPR_MULTITCE capability patch or can I
drop it for now?

Please keep it, it is unrelated to the IOMMU-VFIO thing.



-- 
Alexey

On Wed, 2013-08-28 at 10:51 +1000, Alexey Kardashevskiy wrote:

The ioctl I made up is basically a copy of KVM_CREATE_SPAPR_TCE which does
the same thing for emulated devices and it is there for quite a while but
it is not really extensible. And these two ioctls share some bits of code.
Now we will have 2 pieces of code which do almost the same thing but in a
different way. Kinda sucks :(

Right. Thus the question, Gleb, we can either:

 - Keep Alexey patch as-is allowing us to *finally* merge that stuff
that's been around for monthes

 - Convert *both* existing TCE objects to the new 
KVM_CREATE_DEVICE, and have some backward compat code for the old one.

I don't think it makes sense to have the "emulated TCE" and "IOMMU TCE"
objects use a fundamentally different API and infrastructure.

quoted

quoted

So my stuff is not going to upstream again. Heh. Ok. I'll implement it.

Thanks! Should I keep KVM_CAP_SPAPR_MULTITCE capability patch or can I
drop it for now?

Please keep it, it is unrelated to the IOMMU-VFIO thing.

On Wed, Aug 28, 2013 at 11:26:31AM +1000, Benjamin Herrenschmidt wrote:

On Wed, 2013-08-28 at 10:51 +1000, Alexey Kardashevskiy wrote:

quoted

The ioctl I made up is basically a copy of KVM_CREATE_SPAPR_TCE which does
the same thing for emulated devices and it is there for quite a while but
it is not really extensible. And these two ioctls share some bits of code.
Now we will have 2 pieces of code which do almost the same thing but in a
different way. Kinda sucks :(

Right. Thus the question, Gleb, we can either:

 - Keep Alexey patch as-is allowing us to *finally* merge that stuff
that's been around for monthes

 - Convert *both* existing TCE objects to the new 
KVM_CREATE_DEVICE, and have some backward compat code for the old one.

I don't think it makes sense to have the "emulated TCE" and "IOMMU TCE"
objects use a fundamentally different API and infrastructure.

As a general rule we are not going to mandate converting old devices to
new API, but if it make sense to do here I would much prefer that over
adding another special ioctl

quoted

quoted

quoted

So my stuff is not going to upstream again. Heh. Ok. I'll implement it.

Thanks! Should I keep KVM_CAP_SPAPR_MULTITCE capability patch or can I
drop it for now?

Please keep it, it is unrelated to the IOMMU-VFIO thing.

--
			Gleb.