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path: root/include/hw/ppc/xive_regs.h
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2019-05-29spapr/xive: fix EQ page addresses above 64GBCédric Le Goater
The high order bits of the address of the OS event queue is stored in bits [4-31] of word2 of the XIVE END internal structures and the low order bits in word3. This structure is using Big Endian ordering and computing the value requires some simple arithmetic which happens to be wrong. The mask removing bits [0-3] of word2 is applied to the wrong value and the resulting address is bogus when above 64GB. Guests with more than 64GB of RAM will allocate pages for the OS event queues which will reside above the 64GB limit. In this case, the XIVE device model will wake up the CPUs in case of a notification, such as IPIs, but the update of the event queue will be written at the wrong place in memory. The result is uncertain as the guest memory is trashed and IPI are not delivered. Introduce a helper xive_end_qaddr() to compute this value correctly in all places where it is used. Signed-off-by: Cédric Le Goater <clg@kaod.org> Message-Id: <20190508171946.657-3-clg@kaod.org> Reviewed-by: Greg Kurz <groug@kaod.org> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21ppc/xive: introduce a simplified XIVE presenterCédric Le Goater
The last sub-engine of the XIVE architecture is the Interrupt Virtualization Presentation Engine (IVPE). On HW, the IVRE and the IVPE share elements, the Power Bus interface (CQ), the routing table descriptors, and they can be combined in the same HW logic. We do the same in QEMU and combine both engines in the XiveRouter for simplicity. When the IVRE has completed its job of matching an event source with a Notification Virtual Target (NVT) to notify, it forwards the event notification to the IVPE sub-engine. The IVPE scans the thread interrupt contexts of the Notification Virtual Targets (NVT) dispatched on the HW processor threads and if a match is found, it signals the thread. If not, the IVPE escalates the notification to some other targets and records the notification in a backlog queue. The IVPE maintains the thread interrupt context state for each of its NVTs not dispatched on HW processor threads in the Notification Virtual Target table (NVTT). The model currently only supports single NVT notifications. Signed-off-by: Cédric Le Goater <clg@kaod.org> [dwg: Folded in fix for field accessors] Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21ppc/xive: introduce the XIVE interrupt thread contextCédric Le Goater
Each POWER9 processor chip has a XIVE presenter that can generate four different exceptions to its threads: - hypervisor exception, - O/S exception - Event-Based Branch (EBB) - msgsnd (doorbell). Each exception has a state independent from the others called a Thread Interrupt Management context. This context is a set of registers which lets the thread handle priority management and interrupt acknowledgment among other things. The most important ones being : - Interrupt Priority Register (PIPR) - Interrupt Pending Buffer (IPB) - Current Processor Priority (CPPR) - Notification Source Register (NSR) These registers are accessible through a specific MMIO region, called the Thread Interrupt Management Area (TIMA), four aligned pages, each exposing a different view of the registers. First page (page address ending in 0b00) gives access to the entire context and is reserved for the ring 0 view for the physical thread context. The second (page address ending in 0b01) is for the hypervisor, ring 1 view. The third (page address ending in 0b10) is for the operating system, ring 2 view. The fourth (page address ending in 0b11) is for user level, ring 3 view. The thread interrupt context is modeled with a XiveTCTX object containing the values of the different exception registers. The TIMA region is mapped at the same address for each CPU. Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21ppc/xive: introduce the XIVE Event Notification DescriptorsCédric Le Goater
To complete the event routing, the IVRE sub-engine uses a second table containing Event Notification Descriptor (END) structures. An END specifies on which Event Queue (EQ) the event notification data, defined in the associated EAS, should be posted when an exception occurs. It also defines which Notification Virtual Target (NVT) should be notified. The Event Queue is a memory page provided by the O/S defining a circular buffer, one per server and priority couple, containing Event Queue entries. These are 4 bytes long, the first bit being a 'generation' bit and the 31 following bits the END Data field. They are pulled by the O/S when the exception occurs. The END Data field is a way to set an invariant logical event source number for an IRQ. On sPAPR machines, it is set with the H_INT_SET_SOURCE_CONFIG hcall when the EISN flag is used. Signed-off-by: Cédric Le Goater <clg@kaod.org> [dwg: Fold in a later fix from Cédric fixing field accessors] Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21ppc/xive: introduce the XiveRouter modelCédric Le Goater
The XiveRouter models the second sub-engine of the XIVE architecture : the Interrupt Virtualization Routing Engine (IVRE). The IVRE handles event notifications of the IVSE and performs the interrupt routing process. For this purpose, it uses a set of tables stored in system memory, the first of which being the Event Assignment Structure (EAS) table. The EAT associates an interrupt source number with an Event Notification Descriptor (END) which will be used in a second phase of the routing process to identify a Notification Virtual Target. The XiveRouter is an abstract class which needs to be inherited from to define a storage for the EAT, and other upcoming tables. Signed-off-by: Cédric Le Goater <clg@kaod.org> [dwg: Folded in parts of a later fix by Cédric fixing field access] [dwg: Fix style nits] Signed-off-by: David Gibson <david@gibson.dropbear.id.au>