Re: [RFC v8 6/7] KVM: arm/arm64: Enable MSI routing

[Auger Eric]

On 22/07/2016 16:14, Radim Krčmář wrote:
> 2016-07-22 13:46+, Eric Auger:
>> Up to now, only irqchip routing entries could be set. This patch
>> adds the capability to insert MSI routing entries.
>>
>> For ARM64, let's also increase KVM_MAX_IRQ_ROUTES to 4096: this
>> include SPI irqchip routes plus MSI routes. In the future this
>> might be extended.
>>
>> Signed-off-by: Eric Auger 
>> Reviewed-by: Andre Przywara 
>>
>> ---
>> v7 -> v8:
>> - adapt to changes in kvm_kernel_irq_routing_entry and check the
>>   user entry flags according to the user entry type
>>
>> v6 -> v7:
>> - added Andre's R-b
>>
>> v2 -> v3:
>> - remove any reference to KVM_IRQ_ROUTING_EXTENDED_MSI type
>> - unconditionnaly uapi flags and devid downto the kernel
>>   routing entry struct
>> - handle KVM_MSI_VALID_DEVID flag in kvm_set_irq_routing
>> - note about KVM_CAP_MSI_DEVID moved in the first patch file
>>   of the series
>>
>> v1 -> v2:
>> - adapt to new routing entry types
>>
>> RFC -> PATCH:
>> - move api MSI routing updates into that patch file
>> - use new devid field of user api struct
>> ---
>> diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c
>> @@ -201,23 +202,25 @@ int kvm_set_irq_routing(struct kvm *kvm,
>>  new->chip[i][j] = -1;
>>  
>>  for (i = 0; i < nr; ++i) {
>> -struct kvm_kernel_irq_routing_entry *e;
>> -
>>  r = -ENOMEM;
>>  e = kzalloc(sizeof(*e), GFP_KERNEL);
>>  if (!e)
>>  goto out;
>>  
>>  r = -EINVAL;
>> -if (ue->flags) {
>> -kfree(e);
>> -goto out;
>> +switch (ue->type) {
>> +case KVM_IRQ_ROUTING_IRQCHIP:
>> +if (ue->flags)
>> +goto free_entry;
>> +break;
>> +case KVM_IRQ_ROUTING_MSI:
>> +if (ue->flags & ~KVM_MSI_VALID_DEVID)
>> +goto free_entry;
>> +break;
> 
> The function is common for all arches and there are currently two other
> routing types (S390_ADAPTER and HV_SINT) that ought to be checked as
> well, so "default" instead of "KVM_IRQ_ROUTING_IRQCHIP" would be better.
Sure

Thanks

Eric
> 
>>  }
>>  r = setup_routing_entry(new, e, ue);
>> -if (r) {
>> -kfree(e);
>> -goto out;
>> -}
>> +if (r)
>> +goto free_entry;
>>  ++ue;
>>  }
>>  
___
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[RFC v8 6/7] KVM: arm/arm64: Enable MSI routing

[Eric Auger]

Up to now, only irqchip routing entries could be set. This patch
adds the capability to insert MSI routing entries.

For ARM64, let's also increase KVM_MAX_IRQ_ROUTES to 4096: this
include SPI irqchip routes plus MSI routes. In the future this
might be extended.

Signed-off-by: Eric Auger 
Reviewed-by: Andre Przywara 

---
v7 -> v8:
- adapt to changes in kvm_kernel_irq_routing_entry and check the
  user entry flags according to the user entry type

v6 -> v7:
- added Andre's R-b

v2 -> v3:
- remove any reference to KVM_IRQ_ROUTING_EXTENDED_MSI type
- unconditionnaly uapi flags and devid downto the kernel
  routing entry struct
- handle KVM_MSI_VALID_DEVID flag in kvm_set_irq_routing
- note about KVM_CAP_MSI_DEVID moved in the first patch file
  of the series

v1 -> v2:
- adapt to new routing entry types

RFC -> PATCH:
- move api MSI routing updates into that patch file
- use new devid field of user api struct
---
 Documentation/virtual/kvm/api.txt |  5 +
 include/linux/kvm_host.h  |  2 ++
 virt/kvm/arm/vgic/vgic-irqfd.c|  8 
 virt/kvm/irqchip.c| 24 +++-
 4 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/Documentation/virtual/kvm/api.txt 
b/Documentation/virtual/kvm/api.txt
index 3bb60d3..60d4999 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2375,6 +2375,11 @@ On arm/arm64, gsi routing being supported, the following 
can happen:
 - in case no routing entry is associated to this gsi, injection fails
 - in case the gsi is associated to an irqchip routing entry,
   irqchip.pin + 32 corresponds to the injected SPI ID.
+- in case the gsi is associated to an MSI routing entry,
+  * without GICv3 ITS in-kernel emulation, MSI data matches the SPI ID
+of the injected SPI
+  * with GICv3 ITS in-kernel emulation, the MSI message and device ID
+are translated into an LPI.
 
 4.76 KVM_PPC_ALLOCATE_HTAB
 
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 49e8152..9fa4bc2 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1040,6 +1040,8 @@ static inline int mmu_notifier_retry(struct kvm *kvm, 
unsigned long mmu_seq)
 
 #ifdef CONFIG_S390
 #define KVM_MAX_IRQ_ROUTES 4096 //FIXME: we can have more than that...
+#elif defined(CONFIG_ARM64)
+#define KVM_MAX_IRQ_ROUTES 4096
 #else
 #define KVM_MAX_IRQ_ROUTES 1024
 #endif
diff --git a/virt/kvm/arm/vgic/vgic-irqfd.c b/virt/kvm/arm/vgic/vgic-irqfd.c
index 77be112..04ce19f 100644
--- a/virt/kvm/arm/vgic/vgic-irqfd.c
+++ b/virt/kvm/arm/vgic/vgic-irqfd.c
@@ -60,6 +60,14 @@ int kvm_set_routing_entry(struct 
kvm_kernel_irq_routing_entry *e,
(e->irqchip.irqchip >= KVM_NR_IRQCHIPS))
goto out;
break;
+   case KVM_IRQ_ROUTING_MSI:
+   e->set = kvm_set_msi;
+   e->msi.address_lo = ue->u.msi.address_lo;
+   e->msi.address_hi = ue->u.msi.address_hi;
+   e->msi.data = ue->u.msi.data;
+   e->msi.flags = ue->flags;
+   e->msi.devid = ue->u.msi.devid;
+   break;
default:
goto out;
}
diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c
index 0c00054..349ea6d 100644
--- a/virt/kvm/irqchip.c
+++ b/virt/kvm/irqchip.c
@@ -178,6 +178,7 @@ int kvm_set_irq_routing(struct kvm *kvm,
unsigned flags)
 {
struct kvm_irq_routing_table *new, *old;
+   struct kvm_kernel_irq_routing_entry *e;
u32 i, j, nr_rt_entries = 0;
int r;
 
@@ -201,23 +202,25 @@ int kvm_set_irq_routing(struct kvm *kvm,
new->chip[i][j] = -1;
 
for (i = 0; i < nr; ++i) {
-   struct kvm_kernel_irq_routing_entry *e;
-
r = -ENOMEM;
e = kzalloc(sizeof(*e), GFP_KERNEL);
if (!e)
goto out;
 
r = -EINVAL;
-   if (ue->flags) {
-   kfree(e);
-   goto out;
+   switch (ue->type) {
+   case KVM_IRQ_ROUTING_IRQCHIP:
+   if (ue->flags)
+   goto free_entry;
+   break;
+   case KVM_IRQ_ROUTING_MSI:
+   if (ue->flags & ~KVM_MSI_VALID_DEVID)
+   goto free_entry;
+   break;
}
r = setup_routing_entry(new, e, ue);
-   if (r) {
-   kfree(e);
-   goto out;
-   }
+   if (r)
+   goto free_entry;
++ue;
}
 
@@ -234,7 +237,10 @@ int kvm_set_irq_routing(struct kvm *kvm,
 
new = old;
r = 0;
+   goto out;
 
+free_entry:
+   kfree(e);
 out:
free_irq_routing_table(new);
 
-- 
1.9.1