Commit 379e04c7 authored by Marc Zyngier's avatar Marc Zyngier

arm64: KVM: userspace API documentation

Unsurprisingly, the arm64 userspace API is extremely similar to
the 32bit one, the only significant difference being the ONE_REG
register mapping.
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 0d854a60
......@@ -280,7 +280,7 @@ kvm_run' (see below).
4.11 KVM_GET_REGS
Capability: basic
Architectures: all except ARM
Architectures: all except ARM, arm64
Type: vcpu ioctl
Parameters: struct kvm_regs (out)
Returns: 0 on success, -1 on error
......@@ -301,7 +301,7 @@ struct kvm_regs {
4.12 KVM_SET_REGS
Capability: basic
Architectures: all except ARM
Architectures: all except ARM, arm64
Type: vcpu ioctl
Parameters: struct kvm_regs (in)
Returns: 0 on success, -1 on error
......@@ -587,7 +587,7 @@ struct kvm_fpu {
4.24 KVM_CREATE_IRQCHIP
Capability: KVM_CAP_IRQCHIP
Architectures: x86, ia64, ARM
Architectures: x86, ia64, ARM, arm64
Type: vm ioctl
Parameters: none
Returns: 0 on success, -1 on error
......@@ -595,14 +595,14 @@ Returns: 0 on success, -1 on error
Creates an interrupt controller model in the kernel. On x86, creates a virtual
ioapic, a virtual PIC (two PICs, nested), and sets up future vcpus to have a
local APIC. IRQ routing for GSIs 0-15 is set to both PIC and IOAPIC; GSI 16-23
only go to the IOAPIC. On ia64, a IOSAPIC is created. On ARM, a GIC is
only go to the IOAPIC. On ia64, a IOSAPIC is created. On ARM/arm64, a GIC is
created.
4.25 KVM_IRQ_LINE
Capability: KVM_CAP_IRQCHIP
Architectures: x86, ia64, arm
Architectures: x86, ia64, arm, arm64
Type: vm ioctl
Parameters: struct kvm_irq_level
Returns: 0 on success, -1 on error
......@@ -612,9 +612,10 @@ On some architectures it is required that an interrupt controller model has
been previously created with KVM_CREATE_IRQCHIP. Note that edge-triggered
interrupts require the level to be set to 1 and then back to 0.
ARM can signal an interrupt either at the CPU level, or at the in-kernel irqchip
(GIC), and for in-kernel irqchip can tell the GIC to use PPIs designated for
specific cpus. The irq field is interpreted like this:
ARM/arm64 can signal an interrupt either at the CPU level, or at the
in-kernel irqchip (GIC), and for in-kernel irqchip can tell the GIC to
use PPIs designated for specific cpus. The irq field is interpreted
like this:
 bits: | 31 ... 24 | 23 ... 16 | 15 ... 0 |
field: | irq_type | vcpu_index | irq_id |
......@@ -1831,6 +1832,22 @@ ARM 32-bit VFP control registers have the following id bit patterns:
ARM 64-bit FP registers have the following id bit patterns:
0x4030 0000 0012 0 <regno:12>
arm64 registers are mapped using the lower 32 bits. The upper 16 of
that is the register group type, or coprocessor number:
arm64 core/FP-SIMD registers have the following id bit patterns. Note
that the size of the access is variable, as the kvm_regs structure
contains elements ranging from 32 to 128 bits. The index is a 32bit
value in the kvm_regs structure seen as a 32bit array.
0x60x0 0000 0010 <index into the kvm_regs struct:16>
arm64 CCSIDR registers are demultiplexed by CSSELR value:
0x6020 0000 0011 00 <csselr:8>
arm64 system registers have the following id bit patterns:
0x6030 0000 0013 <op0:2> <op1:3> <crn:4> <crm:4> <op2:3>
4.69 KVM_GET_ONE_REG
Capability: KVM_CAP_ONE_REG
......@@ -2264,7 +2281,7 @@ current state. "addr" is ignored.
4.77 KVM_ARM_VCPU_INIT
Capability: basic
Architectures: arm
Architectures: arm, arm64
Type: vcpu ioctl
Parameters: struct struct kvm_vcpu_init (in)
Returns: 0 on success; -1 on error
......@@ -2283,12 +2300,14 @@ should be created before this ioctl is invoked.
Possible features:
- KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state.
Depends on KVM_CAP_ARM_PSCI.
- KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode.
Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only).
4.78 KVM_GET_REG_LIST
Capability: basic
Architectures: arm
Architectures: arm, arm64
Type: vcpu ioctl
Parameters: struct kvm_reg_list (in/out)
Returns: 0 on success; -1 on error
......@@ -2308,7 +2327,7 @@ KVM_GET_ONE_REG/KVM_SET_ONE_REG calls.
4.80 KVM_ARM_SET_DEVICE_ADDR
Capability: KVM_CAP_ARM_SET_DEVICE_ADDR
Architectures: arm
Architectures: arm, arm64
Type: vm ioctl
Parameters: struct kvm_arm_device_address (in)
Returns: 0 on success, -1 on error
......@@ -2329,18 +2348,19 @@ can access emulated or directly exposed devices, which the host kernel needs
to know about. The id field is an architecture specific identifier for a
specific device.
ARM divides the id field into two parts, a device id and an address type id
specific to the individual device.
ARM/arm64 divides the id field into two parts, a device id and an
address type id specific to the individual device.
 bits: | 63 ... 32 | 31 ... 16 | 15 ... 0 |
field: | 0x00000000 | device id | addr type id |
ARM currently only require this when using the in-kernel GIC support for the
hardware VGIC features, using KVM_ARM_DEVICE_VGIC_V2 as the device id. When
setting the base address for the guest's mapping of the VGIC virtual CPU
and distributor interface, the ioctl must be called after calling
KVM_CREATE_IRQCHIP, but before calling KVM_RUN on any of the VCPUs. Calling
this ioctl twice for any of the base addresses will return -EEXIST.
ARM/arm64 currently only require this when using the in-kernel GIC
support for the hardware VGIC features, using KVM_ARM_DEVICE_VGIC_V2
as the device id. When setting the base address for the guest's
mapping of the VGIC virtual CPU and distributor interface, the ioctl
must be called after calling KVM_CREATE_IRQCHIP, but before calling
KVM_RUN on any of the VCPUs. Calling this ioctl twice for any of the
base addresses will return -EEXIST.
4.82 KVM_PPC_RTAS_DEFINE_TOKEN
......
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