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Diffstat (limited to 'Documentation/virt/kvm/devices/arm-vgic-its.txt')
| -rw-r--r-- | Documentation/virt/kvm/devices/arm-vgic-its.txt | 181 |
1 files changed, 0 insertions, 181 deletions
diff --git a/Documentation/virt/kvm/devices/arm-vgic-its.txt b/Documentation/virt/kvm/devices/arm-vgic-its.txt deleted file mode 100644 index eeaa95b893a8..000000000000 --- a/Documentation/virt/kvm/devices/arm-vgic-its.txt +++ /dev/null @@ -1,181 +0,0 @@ -ARM Virtual Interrupt Translation Service (ITS) -=============================================== - -Device types supported: - KVM_DEV_TYPE_ARM_VGIC_ITS ARM Interrupt Translation Service Controller - -The ITS allows MSI(-X) interrupts to be injected into guests. This extension is -optional. Creating a virtual ITS controller also requires a host GICv3 (see -arm-vgic-v3.txt), but does not depend on having physical ITS controllers. - -There can be multiple ITS controllers per guest, each of them has to have -a separate, non-overlapping MMIO region. - - -Groups: - KVM_DEV_ARM_VGIC_GRP_ADDR - Attributes: - KVM_VGIC_ITS_ADDR_TYPE (rw, 64-bit) - Base address in the guest physical address space of the GICv3 ITS - control register frame. - This address needs to be 64K aligned and the region covers 128K. - Errors: - -E2BIG: Address outside of addressable IPA range - -EINVAL: Incorrectly aligned address - -EEXIST: Address already configured - -EFAULT: Invalid user pointer for attr->addr. - -ENODEV: Incorrect attribute or the ITS is not supported. - - - KVM_DEV_ARM_VGIC_GRP_CTRL - Attributes: - KVM_DEV_ARM_VGIC_CTRL_INIT - request the initialization of the ITS, no additional parameter in - kvm_device_attr.addr. - - KVM_DEV_ARM_ITS_CTRL_RESET - reset the ITS, no additional parameter in kvm_device_attr.addr. - See "ITS Reset State" section. - - KVM_DEV_ARM_ITS_SAVE_TABLES - save the ITS table data into guest RAM, at the location provisioned - by the guest in corresponding registers/table entries. - - The layout of the tables in guest memory defines an ABI. The entries - are laid out in little endian format as described in the last paragraph. - - KVM_DEV_ARM_ITS_RESTORE_TABLES - restore the ITS tables from guest RAM to ITS internal structures. - - The GICV3 must be restored before the ITS and all ITS registers but - the GITS_CTLR must be restored before restoring the ITS tables. - - The GITS_IIDR read-only register must also be restored before - calling KVM_DEV_ARM_ITS_RESTORE_TABLES as the IIDR revision field - encodes the ABI revision. - - The expected ordering when restoring the GICv3/ITS is described in section - "ITS Restore Sequence". - - Errors: - -ENXIO: ITS not properly configured as required prior to setting - this attribute - -ENOMEM: Memory shortage when allocating ITS internal data - -EINVAL: Inconsistent restored data - -EFAULT: Invalid guest ram access - -EBUSY: One or more VCPUS are running - -EACCES: The virtual ITS is backed by a physical GICv4 ITS, and the - state is not available - - KVM_DEV_ARM_VGIC_GRP_ITS_REGS - Attributes: - The attr field of kvm_device_attr encodes the offset of the - ITS register, relative to the ITS control frame base address - (ITS_base). - - kvm_device_attr.addr points to a __u64 value whatever the width - of the addressed register (32/64 bits). 64 bit registers can only - be accessed with full length. - - Writes to read-only registers are ignored by the kernel except for: - - GITS_CREADR. It must be restored otherwise commands in the queue - will be re-executed after restoring CWRITER. GITS_CREADR must be - restored before restoring the GITS_CTLR which is likely to enable the - ITS. Also it must be restored after GITS_CBASER since a write to - GITS_CBASER resets GITS_CREADR. - - GITS_IIDR. The Revision field encodes the table layout ABI revision. - In the future we might implement direct injection of virtual LPIs. - This will require an upgrade of the table layout and an evolution of - the ABI. GITS_IIDR must be restored before calling - KVM_DEV_ARM_ITS_RESTORE_TABLES. - - For other registers, getting or setting a register has the same - effect as reading/writing the register on real hardware. - Errors: - -ENXIO: Offset does not correspond to any supported register - -EFAULT: Invalid user pointer for attr->addr - -EINVAL: Offset is not 64-bit aligned - -EBUSY: one or more VCPUS are running - - ITS Restore Sequence: - ------------------------- - -The following ordering must be followed when restoring the GIC and the ITS: -a) restore all guest memory and create vcpus -b) restore all redistributors -c) provide the ITS base address - (KVM_DEV_ARM_VGIC_GRP_ADDR) -d) restore the ITS in the following order: - 1. Restore GITS_CBASER - 2. Restore all other GITS_ registers, except GITS_CTLR! - 3. Load the ITS table data (KVM_DEV_ARM_ITS_RESTORE_TABLES) - 4. Restore GITS_CTLR - -Then vcpus can be started. - - ITS Table ABI REV0: - ------------------- - - Revision 0 of the ABI only supports the features of a virtual GICv3, and does - not support a virtual GICv4 with support for direct injection of virtual - interrupts for nested hypervisors. - - The device table and ITT are indexed by the DeviceID and EventID, - respectively. The collection table is not indexed by CollectionID, and the - entries in the collection are listed in no particular order. - All entries are 8 bytes. - - Device Table Entry (DTE): - - bits: | 63| 62 ... 49 | 48 ... 5 | 4 ... 0 | - values: | V | next | ITT_addr | Size | - - where; - - V indicates whether the entry is valid. If not, other fields - are not meaningful. - - next: equals to 0 if this entry is the last one; otherwise it - corresponds to the DeviceID offset to the next DTE, capped by - 2^14 -1. - - ITT_addr matches bits [51:8] of the ITT address (256 Byte aligned). - - Size specifies the supported number of bits for the EventID, - minus one - - Collection Table Entry (CTE): - - bits: | 63| 62 .. 52 | 51 ... 16 | 15 ... 0 | - values: | V | RES0 | RDBase | ICID | - - where: - - V indicates whether the entry is valid. If not, other fields are - not meaningful. - - RES0: reserved field with Should-Be-Zero-or-Preserved behavior. - - RDBase is the PE number (GICR_TYPER.Processor_Number semantic), - - ICID is the collection ID - - Interrupt Translation Entry (ITE): - - bits: | 63 ... 48 | 47 ... 16 | 15 ... 0 | - values: | next | pINTID | ICID | - - where: - - next: equals to 0 if this entry is the last one; otherwise it corresponds - to the EventID offset to the next ITE capped by 2^16 -1. - - pINTID is the physical LPI ID; if zero, it means the entry is not valid - and other fields are not meaningful. - - ICID is the collection ID - - ITS Reset State: - ---------------- - -RESET returns the ITS to the same state that it was when first created and -initialized. When the RESET command returns, the following things are -guaranteed: - -- The ITS is not enabled and quiescent - GITS_CTLR.Enabled = 0 .Quiescent=1 -- There is no internally cached state -- No collection or device table are used - GITS_BASER<n>.Valid = 0 -- GITS_CBASER = 0, GITS_CREADR = 0, GITS_CWRITER = 0 -- The ABI version is unchanged and remains the one set when the ITS - device was first created. |