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authorChristoffer Dall <cdall@linaro.org>2017-05-02 14:41:02 +0300
committerChristoffer Dall <cdall@linaro.org>2017-06-08 17:59:44 +0300
commita2befacf50940017e0de8461c4b924a929c4edc5 (patch)
treeaa53d740e25468b943b0d89d0b51cd3a35d9ca75 /Documentation/virtual
parent1b6502e5bc5ef16179bcd812dfa43d8bbb5689d4 (diff)
downloadlinux-a2befacf50940017e0de8461c4b924a929c4edc5.tar.xz
KVM: arm64: Allow creating the PMU without the in-kernel GIC
Since we got support for devices in userspace which allows reporting the PMU overflow output status to userspace, we should actually allow creating the PMU on systems without an in-kernel irqchip, which in turn requires us to slightly clarify error codes for the ABI and move things around for the initialization phase. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'Documentation/virtual')
-rw-r--r--Documentation/virtual/kvm/devices/vcpu.txt16
1 files changed, 9 insertions, 7 deletions
diff --git a/Documentation/virtual/kvm/devices/vcpu.txt b/Documentation/virtual/kvm/devices/vcpu.txt
index 02f50686c418..d7236a3e01dc 100644
--- a/Documentation/virtual/kvm/devices/vcpu.txt
+++ b/Documentation/virtual/kvm/devices/vcpu.txt
@@ -16,7 +16,9 @@ Parameters: in kvm_device_attr.addr the address for PMU overflow interrupt is a
Returns: -EBUSY: The PMU overflow interrupt is already set
-ENXIO: The overflow interrupt not set when attempting to get it
-ENODEV: PMUv3 not supported
- -EINVAL: Invalid PMU overflow interrupt number supplied
+ -EINVAL: Invalid PMU overflow interrupt number supplied or
+ trying to set the IRQ number without using an in-kernel
+ irqchip.
A value describing the PMUv3 (Performance Monitor Unit v3) overflow interrupt
number for this vcpu. This interrupt could be a PPI or SPI, but the interrupt
@@ -25,11 +27,11 @@ all vcpus, while as an SPI it must be a separate number per vcpu.
1.2 ATTRIBUTE: KVM_ARM_VCPU_PMU_V3_INIT
Parameters: no additional parameter in kvm_device_attr.addr
-Returns: -ENODEV: PMUv3 not supported
- -ENXIO: PMUv3 not properly configured as required prior to calling this
- attribute
+Returns: -ENODEV: PMUv3 not supported or GIC not initialized
+ -ENXIO: PMUv3 not properly configured or in-kernel irqchip not
+ configured as required prior to calling this attribute
-EBUSY: PMUv3 already initialized
-Request the initialization of the PMUv3. This must be done after creating the
-in-kernel irqchip. Creating a PMU with a userspace irqchip is currently not
-supported.
+Request the initialization of the PMUv3. If using the PMUv3 with an in-kernel
+virtual GIC implementation, this must be done after initializing the in-kernel
+irqchip.