Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 127 insertions, 0 deletions

diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt
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+ARM Virtual Generic Interrupt Controller v2 (VGIC)
+==================================================
+
+Device types supported:
+  KVM_DEV_TYPE_ARM_VGIC_V2     ARM Generic Interrupt Controller v2.0
+
+Only one VGIC instance may be instantiated through either this API or the
+legacy KVM_CREATE_IRQCHIP API.  The created VGIC will act as the VM interrupt
+controller, requiring emulated user-space devices to inject interrupts to the
+VGIC instead of directly to CPUs.
+
+GICv3 implementations with hardware compatibility support allow creating a
+guest GICv2 through this interface.  For information on creating a guest GICv3
+device and guest ITS devices, see arm-vgic-v3.txt.  It is not possible to
+create both a GICv3 and GICv2 device on the same VM.
+
+
+Groups:
+  KVM_DEV_ARM_VGIC_GRP_ADDR
+  Attributes:
+    KVM_VGIC_V2_ADDR_TYPE_DIST (rw, 64-bit)
+      Base address in the guest physical address space of the GIC distributor
+      register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V2.
+      This address needs to be 4K aligned and the region covers 4 KByte.
+
+    KVM_VGIC_V2_ADDR_TYPE_CPU (rw, 64-bit)
+      Base address in the guest physical address space of the GIC virtual cpu
+      interface register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V2.
+      This address needs to be 4K aligned and the region covers 4 KByte.
+  Errors:
+    -E2BIG:  Address outside of addressable IPA range
+    -EINVAL: Incorrectly aligned address
+    -EEXIST: Address already configured
+    -ENXIO:  The group or attribute is unknown/unsupported for this device
+             or hardware support is missing.
+    -EFAULT: Invalid user pointer for attr->addr.
+
+  KVM_DEV_ARM_VGIC_GRP_DIST_REGS
+  Attributes:
+    The attr field of kvm_device_attr encodes two values:
+    bits:     | 63   ....  40 | 39 ..  32  |  31   ....    0 |
+    values:   |    reserved   | vcpu_index |      offset     |
+
+    All distributor regs are (rw, 32-bit)
+
+    The offset is relative to the "Distributor base address" as defined in the
+    GICv2 specs.  Getting or setting such a register has the same effect as
+    reading or writing the register on the actual hardware from the cpu whose
+    index is specified with the vcpu_index field.  Note that most distributor
+    fields are not banked, but return the same value regardless of the
+    vcpu_index used to access the register.
+
+    GICD_IIDR.Revision is updated when the KVM implementation of an emulated
+    GICv2 is changed in a way directly observable by the guest or userspace.
+    Userspace should read GICD_IIDR from KVM and write back the read value to
+    confirm its expected behavior is aligned with the KVM implementation.
+    Userspace should set GICD_IIDR before setting any other registers (both
+    KVM_DEV_ARM_VGIC_GRP_DIST_REGS and KVM_DEV_ARM_VGIC_GRP_CPU_REGS) to ensure
+    the expected behavior. Unless GICD_IIDR has been set from userspace, writes
+    to the interrupt group registers (GICD_IGROUPR) are ignored.
+  Errors:
+    -ENXIO: Getting or setting this register is not yet supported
+    -EBUSY: One or more VCPUs are running
+    -EINVAL: Invalid vcpu_index supplied
+
+  KVM_DEV_ARM_VGIC_GRP_CPU_REGS
+  Attributes:
+    The attr field of kvm_device_attr encodes two values:
+    bits:     | 63   ....  40 | 39 ..  32  |  31   ....    0 |
+    values:   |    reserved   | vcpu_index |      offset     |
+
+    All CPU interface regs are (rw, 32-bit)
+
+    The offset specifies the offset from the "CPU interface base address" as
+    defined in the GICv2 specs.  Getting or setting such a register has the
+    same effect as reading or writing the register on the actual hardware.
+
+    The Active Priorities Registers APRn are implementation defined, so we set a
+    fixed format for our implementation that fits with the model of a "GICv2
+    implementation without the security extensions" which we present to the
+    guest.  This interface always exposes four register APR[0-3] describing the
+    maximum possible 128 preemption levels.  The semantics of the register
+    indicate if any interrupts in a given preemption level are in the active
+    state by setting the corresponding bit.
+
+    Thus, preemption level X has one or more active interrupts if and only if:
+
+      APRn[X mod 32] == 0b1,  where n = X / 32
+
+    Bits for undefined preemption levels are RAZ/WI.
+
+    Note that this differs from a CPU's view of the APRs on hardware in which
+    a GIC without the security extensions expose group 0 and group 1 active
+    priorities in separate register groups, whereas we show a combined view
+    similar to GICv2's GICH_APR.
+
+    For historical reasons and to provide ABI compatibility with userspace we
+    export the GICC_PMR register in the format of the GICH_VMCR.VMPriMask
+    field in the lower 5 bits of a word, meaning that userspace must always
+    use the lower 5 bits to communicate with the KVM device and must shift the
+    value left by 3 places to obtain the actual priority mask level.
+
+  Errors:
+    -ENXIO: Getting or setting this register is not yet supported
+    -EBUSY: One or more VCPUs are running
+    -EINVAL: Invalid vcpu_index supplied
+
+  KVM_DEV_ARM_VGIC_GRP_NR_IRQS
+  Attributes:
+    A value describing the number of interrupts (SGI, PPI and SPI) for
+    this GIC instance, ranging from 64 to 1024, in increments of 32.
+
+  Errors:
+    -EINVAL: Value set is out of the expected range
+    -EBUSY: Value has already be set, or GIC has already been initialized
+            with default values.
+
+  KVM_DEV_ARM_VGIC_GRP_CTRL
+  Attributes:
+    KVM_DEV_ARM_VGIC_CTRL_INIT
+      request the initialization of the VGIC or ITS, no additional parameter
+      in kvm_device_attr.addr.
+  Errors:
+    -ENXIO: VGIC not properly configured as required prior to calling
+     this attribute
+    -ENODEV: no online VCPU
+    -ENOMEM: memory shortage when allocating vgic internal data