[PATCH v5 00/12] Introduce eSPI support

[Leonid Komarianskyi <Leonid_Komarianskyi@epam.com>]

Hello everyone!

This is V5 of the patch series to introduce eSPI support, which contains
fixes and improvements based on the comments received in V4.

The main changes in this version compared to V4 are related to removing
unnecessary #ifdefs that previously prevented the use of certain defines
and macros, leading to an overuse of #ifdefs. After refactoring, it is
now possible to reuse the existing code for vGIC eSPI emulation, which
improves readability and simplifies future changes. As some patches that
had already been reviewed were modified, I would ask Volodymyr and
Oleksandr to take a look at the updated versions of:

[4/12] xen/arm/irq: add handling for IRQs in the eSPI range
[5/12] xen/arm: gicv3: implement handling of GICv3.1 eSPI

The changes made in these patches allowed me to significantly simplify
the following patch:

[10/12] xen/arm: vgic-v3: add emulation of GICv3.1 eSPI registers

For the other patches, I have addressed comments and added reviewed-by
or acked-by tags accordingly, based on the received comments.

Summarized description:
This patch series adds support for the extended shared peripheral
interrupt (eSPI) range (INTIDs 4096-5119 [2](ranges of INTIDs)) for Xen
and guest domains. The implementation uses a generic approach to handle
eSPIs, similar to regular SPIs, while maintaining compatibility with the
existing SPI range. Functionality remains unchanged for setups that do
not require eSPIs.

The series includes:
1) General refactoring of common IRQ operations with GIC registers to
improve code readability, simplify further maintenance and prepare the
key functions for eSPI implementation.
2) Introducing a new Kconfig option (default n) to enable or disable
eSPI support. Disabling this option prevents unnecessary resource
allocation for setups that do not require eSPIs.
3) Adding additional resources to store required information and operate
with up to 1024 interrupts from eSPI range.
4) Adjusting assertions and checks to pass verification for INTIDs in
the eSPI range.
5) Configuration of eSPI-specific registers during GIC initialization
for systems with GICv3.1+ hardware.
6) Enables eSPI MMIO emulation for vGIC, allowing guest domains to
access and operate within the eSPI's INTIDs.
7) Updating documentation and CHANGELOG to reflect the changes made for eSPI
support.

Also, to simplify reviewing, please find below link to unsquashed patches, that
are on top of every patch, that is changed in the series, compared to V4:
https://github.com/LKomaryanskiy/xen/commits/espi-support-master-upstream-v5-unsquashed/


Changes in V5:
- individual changes in patches

Link on V4:
- https://lists.xenproject.org/archives/html/xen-devel/2025-08/msg01767.html

Changes in V4:
- added a patch for documentation
- individual changes in patches

Link on V3:
- https://lists.xenproject.org/archives/html/xen-devel/2025-08/msg01628.html

Changes in V3:
- added a patch to update CHANGELOG.md
- individual changes in patches

Link on V2:
- https://lists.xenproject.org/archives/html/xen-devel/2025-08/msg00372.html

Changes in V2:
- added 2 more patches to implement helper
  functions for gic/vgic:
  xen/arm: gic: implement helper functions for INTID checks
  xen/arm: vgic: implement helper functions for virq checks
- removed 2 patches:
  xen/arm/irq: allow assignment/releasing of eSPI interrupts
  xen/arm: gic/irq: permit routing of eSPI interrupts to Xen and domains
  since their functionality can be moved to appropriate patches after
  introducing patches with helper functions
- individual changes in patches

Link on V1:
- https://lists.xenproject.org/archives/html/xen-devel/2025-07/msg01809.html

Leonid Komarianskyi (12):
  xen/arm: gicv3: refactor obtaining GIC addresses for common operations
  xen/arm: gic: implement helper functions for INTID checks
  xen/arm: vgic: implement helper functions for virq checks
  xen/arm/irq: add handling for IRQs in the eSPI range
  xen/arm: gicv3: implement handling of GICv3.1 eSPI
  xen/arm/irq: allow eSPI processing in the gic_interrupt function
  xen/arm: gicv3: modify ICH_LR_PHYSICAL_MASK to allow eSPI processing
  xen/arm: vgic: add resource management for extended SPIs
  xen/arm: domain_build/dom0less-build: adjust domains config to support
    eSPIs
  xen/arm: vgic-v3: add emulation of GICv3.1 eSPI registers
  doc/man: update description for nr_spis with eSPI
  CHANGELOG.md: add mention of GICv3.1 eSPI support

 CHANGELOG.md                           |   2 +
 docs/man/xl.cfg.5.pod.in               |  13 +-
 xen/arch/arm/Kconfig                   |   8 +
 xen/arch/arm/dom0less-build.c          |   2 +-
 xen/arch/arm/domain_build.c            |   2 +-
 xen/arch/arm/gic-v3.c                  | 195 +++++++++++++++++----
 xen/arch/arm/gic.c                     |   8 +-
 xen/arch/arm/include/asm/gic.h         |  31 ++++
 xen/arch/arm/include/asm/gic_v3_defs.h |  40 ++++-
 xen/arch/arm/include/asm/irq.h         |  25 +++
 xen/arch/arm/include/asm/vgic.h        |  42 +++++
 xen/arch/arm/irq.c                     |  62 ++++++-
 xen/arch/arm/vgic-v3.c                 | 198 +++++++++++++++++----
 xen/arch/arm/vgic.c                    | 232 ++++++++++++++++++++++++-
 xen/arch/arm/vgic/vgic.c               |   5 +
 15 files changed, 778 insertions(+), 87 deletions(-)

-- 
2.34.1