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Diffstat (limited to 'Documentation/virtual/kvm/devices/xive.txt')
| -rw-r--r-- | Documentation/virtual/kvm/devices/xive.txt | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/devices/xive.txt b/Documentation/virtual/kvm/devices/xive.txt index 525d1eebcf34..0cd7847ec38a 100644 --- a/Documentation/virtual/kvm/devices/xive.txt +++ b/Documentation/virtual/kvm/devices/xive.txt @@ -13,6 +13,29 @@ requires a POWER9 host and the guest OS should have support for the XIVE native exploitation interrupt mode. If not, it should run using the legacy interrupt mode, referred as XICS (POWER7/8). +* Device Mappings + + The KVM device exposes different MMIO ranges of the XIVE HW which + are required for interrupt management. These are exposed to the + guest in VMAs populated with a custom VM fault handler. + + 1. Thread Interrupt Management Area (TIMA) + + Each thread has an associated Thread Interrupt Management context + composed of a set of registers. These registers let the thread + handle priority management and interrupt acknowledgment. The most + important are : + + - Interrupt Pending Buffer (IPB) + - Current Processor Priority (CPPR) + - Notification Source Register (NSR) + + They are exposed to software in four different pages each proposing + a view with a different privilege. The first page is for the + physical thread context and the second for the hypervisor. Only the + third (operating system) and the fourth (user level) are exposed the + guest. + * Groups: 1. KVM_DEV_XIVE_GRP_CTRL |