Commit Graph

10 Commits

Author SHA1 Message Date
Cédric Le Goater
6520ca64cd KVM: PPC: Book3S HV: XIVE: Add a mapping for the source ESB pages
Each source is associated with an Event State Buffer (ESB) with a
even/odd pair of pages which provides commands to manage the source:
to trigger, to EOI, to turn off the source for instance.

The custom VM fault handler will deduce the guest IRQ number from the
offset of the fault, and the ESB page of the associated XIVE interrupt
will be inserted into the VMA using the internal structure caching
information on the interrupts.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Cédric Le Goater
39e9af3de5 KVM: PPC: Book3S HV: XIVE: Add a TIMA mapping
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.

A custom VM fault handler will populate the VMA with the appropriate
pages, which should only be the OS page for now.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Cédric Le Goater
e4945b9da5 KVM: PPC: Book3S HV: XIVE: Add get/set accessors for the VP XIVE state
The state of the thread interrupt management registers needs to be
collected for migration. These registers are cached under the
'xive_saved_state.w01' field of the VCPU when the VPCU context is
pulled from the HW thread. An OPAL call retrieves the backup of the
IPB register in the underlying XIVE NVT structure and merges it in the
KVM state.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Cédric Le Goater
e6714bd167 KVM: PPC: Book3S HV: XIVE: Add a control to dirty the XIVE EQ pages
When migration of a VM is initiated, a first copy of the RAM is
transferred to the destination before the VM is stopped, but there is
no guarantee that the EQ pages in which the event notifications are
queued have not been modified.

To make sure migration will capture a consistent memory state, the
XIVE device should perform a XIVE quiesce sequence to stop the flow of
event notifications and stabilize the EQs. This is the purpose of the
KVM_DEV_XIVE_EQ_SYNC control which will also marks the EQ pages dirty
to force their transfer.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Cédric Le Goater
7b46b6169a KVM: PPC: Book3S HV: XIVE: Add a control to sync the sources
This control will be used by the H_INT_SYNC hcall from QEMU to flush
event notifications on the XIVE IC owning the source.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Cédric Le Goater
5ca8064748 KVM: PPC: Book3S HV: XIVE: Add a global reset control
This control is to be used by the H_INT_RESET hcall from QEMU. Its
purpose is to clear all configuration of the sources and EQs. This is
necessary in case of a kexec (for a kdump kernel for instance) to make
sure that no remaining configuration is left from the previous boot
setup so that the new kernel can start safely from a clean state.

The queue 7 is ignored when the XIVE device is configured to run in
single escalation mode. Prio 7 is used by escalations.

The XIVE VP is kept enabled as the vCPU is still active and connected
to the XIVE device.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Cédric Le Goater
13ce3297c5 KVM: PPC: Book3S HV: XIVE: Add controls for the EQ configuration
These controls will be used by the H_INT_SET_QUEUE_CONFIG and
H_INT_GET_QUEUE_CONFIG hcalls from QEMU to configure the underlying
Event Queue in the XIVE IC. They will also be used to restore the
configuration of the XIVE EQs and to capture the internal run-time
state of the EQs. Both 'get' and 'set' rely on an OPAL call to access
the EQ toggle bit and EQ index which are updated by the XIVE IC when
event notifications are enqueued in the EQ.

The value of the guest physical address of the event queue is saved in
the XIVE internal xive_q structure for later use. That is when
migration needs to mark the EQ pages dirty to capture a consistent
memory state of the VM.

To be noted that H_INT_SET_QUEUE_CONFIG does not require the extra
OPAL call setting the EQ toggle bit and EQ index to configure the EQ,
but restoring the EQ state will.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Cédric Le Goater
e8676ce50e KVM: PPC: Book3S HV: XIVE: Add a control to configure a source
This control will be used by the H_INT_SET_SOURCE_CONFIG hcall from
QEMU to configure the target of a source and also to restore the
configuration of a source when migrating the VM.

The XIVE source interrupt structure is extended with the value of the
Effective Interrupt Source Number. The EISN is the interrupt number
pushed in the event queue that the guest OS will use to dispatch
events internally. Caching the EISN value in KVM eases the test when
checking if a reconfiguration is indeed needed.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Cédric Le Goater
4131f83c3d KVM: PPC: Book3S HV: XIVE: add a control to initialize a source
The XIVE KVM device maintains a list of interrupt sources for the VM
which are allocated in the pool of generic interrupts (IPIs) of the
main XIVE IC controller. These are used for the CPU IPIs as well as
for virtual device interrupts. The IRQ number space is defined by
QEMU.

The XIVE device reuses the source structures of the XICS-on-XIVE
device for the source blocks (2-level tree) and for the source
interrupts. Under XIVE native, the source interrupt caches mostly
configuration information and is less used than under the XICS-on-XIVE
device in which hcalls are still necessary at run-time.

When a source is initialized in KVM, an IPI interrupt source is simply
allocated at the OPAL level and then MASKED. KVM only needs to know
about its type: LSI or MSI.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Cédric Le Goater
90c73795af KVM: PPC: Book3S HV: Add a new KVM device for the XIVE native exploitation mode
This is the basic framework for the new KVM device supporting the XIVE
native exploitation mode. The user interface exposes a new KVM device
to be created by QEMU, only available when running on a L0 hypervisor.
Support for nested guests is not available yet.

The XIVE device reuses the device structure of the XICS-on-XIVE device
as they have a lot in common. That could possibly change in the future
if the need arise.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00