The XIVE interrupt controller on P10 can automatically save and
restore the state of the interrupt registers under the internal NVP
structure representing the VCPU. This saves a costly store/load in
guest entries and exits.
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The thread interrupt management area (TIMA) is a set of pages mapped
in the Hypervisor and in the guest OS address space giving access to
the interrupt thread context registers for interrupt management, ACK,
EOI, CPPR, etc.
XIVE2 changes slightly the TIMA layout with extra bits for the new
features, larger CAM lines and the controller provides configuration
switches for backward compatibility. This is called the XIVE2
P9-compat mode, of Gen1 TIMA. It impacts the layout of the TIMA and
the availability of the internal features associated with it,
Automatic Save & Restore for instance. Using a P9 layout also means
setting the controller in such a mode at init time.
As the OPAL driver initializes the XIVE2 controller with a XIVE2/P10
TIMA directly, the XIVE2 model only has a simple support for the
compat mode in the OS TIMA.
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
These bits control the availability of interrupt features : StoreEOI,
PHB PQ_disable, PHB Address-Based Trigger and the overall XIVE
exploitation mode. These bits can be set at early boot time of the
system to activate/deactivate a feature for testing purposes. The
default value should be '1'.
The 'XIVE exploitation mode' bit is a software bit that skiboot could
use to disable the XIVE OS interface and propose a P8 style XICS
interface instead. There are no plans for that for the moment.
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The XIVE2 interrupt controller of the POWER10 processor follows the
same logic than on POWER9 but the HW interface has been largely
reviewed. It has a new register interface, different BARs, extra
VSDs, new layout for the XIVE2 structures, and a set of new features
which are described below.
This is a model of the POWER10 XIVE2 interrupt controller for the
PowerNV machine. It focuses primarily on the needs of the skiboot
firmware but some initial hypervisor support is implemented for KVM
use (escalation).
Support for new features will be implemented in time and will require
new support from the OS.
* XIVE2 BARS
The interrupt controller BARs have a different layout outlined below.
Each sub-engine has now own its range and the indirect TIMA access was
replaced with a set of pages, one per CPU, under the IC BAR:
- IC BAR (Interrupt Controller)
. 4 pages, one per sub-engine
. 128 indirect TIMA pages
- TM BAR (Thread Interrupt Management Area)
. 4 pages
- ESB BAR (ESB pages for IPIs)
. up to 1TB
- END BAR (ESB pages for ENDs)
. up to 2TB
- NVC BAR (Notification Virtual Crowd)
. up to 128
- NVPG BAR (Notification Virtual Process and Group)
. up to 1TB
- Direct mapped Thread Context Area (reads & writes)
OPAL does not use the grouping and crowd capability.
* Virtual Structure Tables
XIVE2 adds new tables types and also changes the field layout of the END
and NVP Virtualization Structure Descriptors.
- EAS
- END new layout
- NVT was splitted in :
. NVP (Processor), 32B
. NVG (Group), 32B
. NVC (Crowd == P9 block group) 32B
- IC for remote configuration
- SYNC for cache injection
- ERQ for event input queue
The setup is slighly different on XIVE2 because the indexing has changed
for some of the tables, block ID or the chip topology ID can be used.
* XIVE2 features
SCOM and MMIO registers have a new layout and XIVE2 adds a new global
capability and configuration registers.
The lowlevel hardware offers a set of new features among which :
- a configurable number of priorities : 1 - 8
- StoreEOI with load-after-store ordering is activated by default
- Gen2 TIMA layout
- A P9-compat mode, or Gen1, TIMA toggle bit for SW compatibility
- increase to 24bit for VP number
Other features will have some impact on the Hypervisor and guest OS
when activated, but this is not required for initial support of the
controller.
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Cédric Le Goater