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author | Christoffer Dall <c.dall@virtualopensystems.com> | 2013-01-23 18:18:04 (GMT) |
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committer | Marc Zyngier <marc.zyngier@arm.com> | 2013-02-11 18:58:39 (GMT) |
commit | 3401d54696f992edf036f00f46c8c399d1b75c2a (patch) | |
tree | bbb3bb02050b3b513e4b55839b553d793c1e63b9 /Documentation/virtual/kvm | |
parent | a96ab03917dcf4c9477d03b31e8d74779bca1074 (diff) | |
download | linux-fsl-qoriq-3401d54696f992edf036f00f46c8c399d1b75c2a.tar.xz |
KVM: ARM: Introduce KVM_ARM_SET_DEVICE_ADDR ioctl
On ARM some bits are specific to the model being emulated for the guest and
user space needs a way to tell the kernel about those bits. An example is mmio
device base addresses, where KVM must know the base address for a given device
to properly emulate mmio accesses within a certain address range or directly
map a device with virtualiation extensions into the guest address space.
We make this API ARM-specific as we haven't yet reached a consensus for a
generic API for all KVM architectures that will allow us to do something like
this.
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'Documentation/virtual/kvm')
-rw-r--r-- | Documentation/virtual/kvm/api.txt | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index c25439a..4505f86 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2210,6 +2210,43 @@ This ioctl returns the guest registers that are supported for the 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 +Type: vm ioctl +Parameters: struct kvm_arm_device_address (in) +Returns: 0 on success, -1 on error +Errors: + ENODEV: The device id is unknown + ENXIO: Device not supported on current system + EEXIST: Address already set + E2BIG: Address outside guest physical address space + +struct kvm_arm_device_addr { + __u64 id; + __u64 addr; +}; + +Specify a device address in the guest's physical address space where guests +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. + + 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. + + 5. The kvm_run structure ------------------------ |