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Introduce a paravirtualization interface for KVM/arm64 based on the "Arm Paravirtualized Time for Arm-Base Systems" specification DEN 0057A. This only adds the details about "Stolen Time" as the details of "Live Physical Time" have not been fully agreed. User space can specify a reserved area of memory for the guest and inform KVM to populate the memory with information on time that the host kernel has stolen from the guest. A hypercall interface is provided for the guest to interrogate the hypervisor's support for this interface and the location of the shared memory structures. Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
77 lines
3.3 KiB
Plaintext
77 lines
3.3 KiB
Plaintext
Generic vcpu interface
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====================================
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The virtual cpu "device" also accepts the ioctls KVM_SET_DEVICE_ATTR,
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KVM_GET_DEVICE_ATTR, and KVM_HAS_DEVICE_ATTR. The interface uses the same struct
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kvm_device_attr as other devices, but targets VCPU-wide settings and controls.
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The groups and attributes per virtual cpu, if any, are architecture specific.
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1. GROUP: KVM_ARM_VCPU_PMU_V3_CTRL
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Architectures: ARM64
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1.1. ATTRIBUTE: KVM_ARM_VCPU_PMU_V3_IRQ
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Parameters: in kvm_device_attr.addr the address for PMU overflow interrupt is a
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pointer to an int
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Returns: -EBUSY: The PMU overflow interrupt is already set
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-ENXIO: The overflow interrupt not set when attempting to get it
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-ENODEV: PMUv3 not supported
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-EINVAL: Invalid PMU overflow interrupt number supplied or
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trying to set the IRQ number without using an in-kernel
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irqchip.
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A value describing the PMUv3 (Performance Monitor Unit v3) overflow interrupt
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number for this vcpu. This interrupt could be a PPI or SPI, but the interrupt
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type must be same for each vcpu. As a PPI, the interrupt number is the same for
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all vcpus, while as an SPI it must be a separate number per vcpu.
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1.2 ATTRIBUTE: KVM_ARM_VCPU_PMU_V3_INIT
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Parameters: no additional parameter in kvm_device_attr.addr
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Returns: -ENODEV: PMUv3 not supported or GIC not initialized
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-ENXIO: PMUv3 not properly configured or in-kernel irqchip not
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configured as required prior to calling this attribute
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-EBUSY: PMUv3 already initialized
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Request the initialization of the PMUv3. If using the PMUv3 with an in-kernel
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virtual GIC implementation, this must be done after initializing the in-kernel
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irqchip.
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2. GROUP: KVM_ARM_VCPU_TIMER_CTRL
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Architectures: ARM,ARM64
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2.1. ATTRIBUTE: KVM_ARM_VCPU_TIMER_IRQ_VTIMER
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2.2. ATTRIBUTE: KVM_ARM_VCPU_TIMER_IRQ_PTIMER
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Parameters: in kvm_device_attr.addr the address for the timer interrupt is a
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pointer to an int
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Returns: -EINVAL: Invalid timer interrupt number
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-EBUSY: One or more VCPUs has already run
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A value describing the architected timer interrupt number when connected to an
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in-kernel virtual GIC. These must be a PPI (16 <= intid < 32). Setting the
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attribute overrides the default values (see below).
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KVM_ARM_VCPU_TIMER_IRQ_VTIMER: The EL1 virtual timer intid (default: 27)
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KVM_ARM_VCPU_TIMER_IRQ_PTIMER: The EL1 physical timer intid (default: 30)
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Setting the same PPI for different timers will prevent the VCPUs from running.
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Setting the interrupt number on a VCPU configures all VCPUs created at that
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time to use the number provided for a given timer, overwriting any previously
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configured values on other VCPUs. Userspace should configure the interrupt
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numbers on at least one VCPU after creating all VCPUs and before running any
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VCPUs.
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3. GROUP: KVM_ARM_VCPU_PVTIME_CTRL
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Architectures: ARM64
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3.1 ATTRIBUTE: KVM_ARM_VCPU_PVTIME_IPA
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Parameters: 64-bit base address
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Returns: -ENXIO: Stolen time not implemented
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-EEXIST: Base address already set for this VCPU
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-EINVAL: Base address not 64 byte aligned
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Specifies the base address of the stolen time structure for this VCPU. The
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base address must be 64 byte aligned and exist within a valid guest memory
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region. See Documentation/virt/kvm/arm/pvtime.txt for more information
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including the layout of the stolen time structure.
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