| Message ID | 1459759657-7402-2-git-send-email-eric.auger@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Mon, Apr 04, 2016 at 10:47:31AM +0200, Eric Auger wrote: > On ARM, the MSI msg (address and data) comes along with > out-of-band device ID information. The device ID encodes the > device that writes the MSI msg. Let's convey the device id in > kvm_irq_routing_msi and use KVM_MSI_VALID_DEVID flag value in > kvm_irq_routing_entry to indicate the msi devid is populated. > > Signed-off-by: Eric Auger <eric.auger@linaro.org> > > --- > v2 -> v3: > - replace usage of KVM_IRQ_ROUTING_EXTENDED_MSI type by > usage of KVM_MSI_VALID_DEVID flag > - add note about KVM_CAP_MSI_DEVID capability > > v1 -> v2: > - devid id passed in kvm_irq_routing_msi instead of in > kvm_irq_routing_entry > > RFC -> PATCH > - remove kvm_irq_routing_extended_msi and use union instead > --- > Documentation/virtual/kvm/api.txt | 18 ++++++++++++++++-- > include/uapi/linux/kvm.h | 5 ++++- > 2 files changed, 20 insertions(+), 3 deletions(-) > > diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > index 536f19b..c436bb6 100644 > --- a/Documentation/virtual/kvm/api.txt > +++ b/Documentation/virtual/kvm/api.txt > @@ -1462,7 +1462,10 @@ struct kvm_irq_routing_entry { > #define KVM_IRQ_ROUTING_S390_ADAPTER 3 > #define KVM_IRQ_ROUTING_HV_SINT 4 > > -No flags are specified so far, the corresponding field must be set to zero. > +flags: > +- KVM_MSI_VALID_DEVID: used along with KVM_IRQ_ROUTING_MSI > + routing entry type, it tells the msi devid contains a valid value. s/it tells the msi devid/specifies that the devid field/ > +- zero otherwise > > struct kvm_irq_routing_irqchip { > __u32 irqchip; > @@ -1473,9 +1476,20 @@ struct kvm_irq_routing_msi { > __u32 address_lo; > __u32 address_hi; > __u32 data; > - __u32 pad; > + union { > + __u32 pad; > + __u32 devid; > + }; > }; > > +devid: If KVM_MSI_VALID_DEVID is set, contains a unique device identifier > + for the device that wrote the MSI message. > + For PCI, this is usually a BFD identifier in the lower 16 bits. > + > +The per-VM KVM_CAP_MSI_DEVID capability advertises the need to provide "the need to" or "the possibility to"? Is there ever a situation where KVM_CAP_MSI_DEVID is set but you don't need to provide a device ID and set the flag? > +the device ID. If this capability is not set, userland cannot rely on > +the kernel to allow the KVM_MSI_VALID_DEVID flag being set. > + > struct kvm_irq_routing_s390_adapter { > __u64 ind_addr; > __u64 summary_addr; > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 6a02871..52a973f 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -865,7 +865,10 @@ struct kvm_irq_routing_msi { > __u32 address_lo; > __u32 address_hi; > __u32 data; > - __u32 pad; > + union { > + __u32 pad; > + __u32 devid; > + }; > }; > > struct kvm_irq_routing_s390_adapter { > -- > 1.9.1 >
Christoffer, On 04/14/2016 02:04 PM, Christoffer Dall wrote: > On Mon, Apr 04, 2016 at 10:47:31AM +0200, Eric Auger wrote: >> On ARM, the MSI msg (address and data) comes along with >> out-of-band device ID information. The device ID encodes the >> device that writes the MSI msg. Let's convey the device id in >> kvm_irq_routing_msi and use KVM_MSI_VALID_DEVID flag value in >> kvm_irq_routing_entry to indicate the msi devid is populated. >> >> Signed-off-by: Eric Auger <eric.auger@linaro.org> >> >> --- >> v2 -> v3: >> - replace usage of KVM_IRQ_ROUTING_EXTENDED_MSI type by >> usage of KVM_MSI_VALID_DEVID flag >> - add note about KVM_CAP_MSI_DEVID capability >> >> v1 -> v2: >> - devid id passed in kvm_irq_routing_msi instead of in >> kvm_irq_routing_entry >> >> RFC -> PATCH >> - remove kvm_irq_routing_extended_msi and use union instead >> --- >> Documentation/virtual/kvm/api.txt | 18 ++++++++++++++++-- >> include/uapi/linux/kvm.h | 5 ++++- >> 2 files changed, 20 insertions(+), 3 deletions(-) >> >> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt >> index 536f19b..c436bb6 100644 >> --- a/Documentation/virtual/kvm/api.txt >> +++ b/Documentation/virtual/kvm/api.txt >> @@ -1462,7 +1462,10 @@ struct kvm_irq_routing_entry { >> #define KVM_IRQ_ROUTING_S390_ADAPTER 3 >> #define KVM_IRQ_ROUTING_HV_SINT 4 >> >> -No flags are specified so far, the corresponding field must be set to zero. >> +flags: >> +- KVM_MSI_VALID_DEVID: used along with KVM_IRQ_ROUTING_MSI >> + routing entry type, it tells the msi devid contains a valid value. > > s/it tells the msi devid/specifies that the devid field/ ok > >> +- zero otherwise >> >> struct kvm_irq_routing_irqchip { >> __u32 irqchip; >> @@ -1473,9 +1476,20 @@ struct kvm_irq_routing_msi { >> __u32 address_lo; >> __u32 address_hi; >> __u32 data; >> - __u32 pad; >> + union { >> + __u32 pad; >> + __u32 devid; >> + }; >> }; >> >> +devid: If KVM_MSI_VALID_DEVID is set, contains a unique device identifier >> + for the device that wrote the MSI message. >> + For PCI, this is usually a BFD identifier in the lower 16 bits. >> + >> +The per-VM KVM_CAP_MSI_DEVID capability advertises the need to provide > > "the need to" or "the possibility to"? Is there ever a situation where > KVM_CAP_MSI_DEVID is set but you don't need to provide a device ID and > set the flag? I could replace by "requirement": if it is not requested to pass a devid, we don't set the flag. If it is we pass it. if the user fails passing the devid and this ends up in the in-kernel ITS emul, injection will fail. Thanks Eric > >> +the device ID. If this capability is not set, userland cannot rely on >> +the kernel to allow the KVM_MSI_VALID_DEVID flag being set. >> + >> struct kvm_irq_routing_s390_adapter { >> __u64 ind_addr; >> __u64 summary_addr; >> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h >> index 6a02871..52a973f 100644 >> --- a/include/uapi/linux/kvm.h >> +++ b/include/uapi/linux/kvm.h >> @@ -865,7 +865,10 @@ struct kvm_irq_routing_msi { >> __u32 address_lo; >> __u32 address_hi; >> __u32 data; >> - __u32 pad; >> + union { >> + __u32 pad; >> + __u32 devid; >> + }; >> }; >> >> struct kvm_irq_routing_s390_adapter { >> -- >> 1.9.1 >>
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 536f19b..c436bb6 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1462,7 +1462,10 @@ struct kvm_irq_routing_entry { #define KVM_IRQ_ROUTING_S390_ADAPTER 3 #define KVM_IRQ_ROUTING_HV_SINT 4 -No flags are specified so far, the corresponding field must be set to zero. +flags: +- KVM_MSI_VALID_DEVID: used along with KVM_IRQ_ROUTING_MSI + routing entry type, it tells the msi devid contains a valid value. +- zero otherwise struct kvm_irq_routing_irqchip { __u32 irqchip; @@ -1473,9 +1476,20 @@ struct kvm_irq_routing_msi { __u32 address_lo; __u32 address_hi; __u32 data; - __u32 pad; + union { + __u32 pad; + __u32 devid; + }; }; +devid: If KVM_MSI_VALID_DEVID is set, contains a unique device identifier + for the device that wrote the MSI message. + For PCI, this is usually a BFD identifier in the lower 16 bits. + +The per-VM KVM_CAP_MSI_DEVID capability advertises the need to provide +the device ID. If this capability is not set, userland cannot rely on +the kernel to allow the KVM_MSI_VALID_DEVID flag being set. + struct kvm_irq_routing_s390_adapter { __u64 ind_addr; __u64 summary_addr; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 6a02871..52a973f 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -865,7 +865,10 @@ struct kvm_irq_routing_msi { __u32 address_lo; __u32 address_hi; __u32 data; - __u32 pad; + union { + __u32 pad; + __u32 devid; + }; }; struct kvm_irq_routing_s390_adapter {
On ARM, the MSI msg (address and data) comes along with out-of-band device ID information. The device ID encodes the device that writes the MSI msg. Let's convey the device id in kvm_irq_routing_msi and use KVM_MSI_VALID_DEVID flag value in kvm_irq_routing_entry to indicate the msi devid is populated. Signed-off-by: Eric Auger <eric.auger@linaro.org> --- v2 -> v3: - replace usage of KVM_IRQ_ROUTING_EXTENDED_MSI type by usage of KVM_MSI_VALID_DEVID flag - add note about KVM_CAP_MSI_DEVID capability v1 -> v2: - devid id passed in kvm_irq_routing_msi instead of in kvm_irq_routing_entry RFC -> PATCH - remove kvm_irq_routing_extended_msi and use union instead --- Documentation/virtual/kvm/api.txt | 18 ++++++++++++++++-- include/uapi/linux/kvm.h | 5 ++++- 2 files changed, 20 insertions(+), 3 deletions(-) -- 1.9.1