[PATCH v3 0/3] amd_iommu: Support Generation of IOMMU XT interrupts

[Sairaj Kodilkar <sarunkod@amd.com>]

AMD IOMMU uses MMIO registers 0x170-0x180 to generate the interrupts when guest
has enabled xt support through control register. The guest programs these
registers with appropriate vector and destination ID instead of writing to PCI
MSI capability.

Until now enabling the xt support through command line "xtsup=on" provided
support for 128 bit IRTE. But it has few limitations:

1. It does not consider if guest has actually enabled xt support through MMIO
   control register (0x18). This may cause problems for the guests which do
   not enable this support.
2. The vIOMMU is not capable of generating interrupts using vector and
   destinatio ID in IOMMU x2APIC Control Registers (not supporting event log
   interrupts).

To overcome above limitations, this patch series introduces new internal flag 
"intcapxten" which is set when guest writes "1" to MMIO control register (0x18)
bit 51 (IntCapXTEn) and adds support to generate event log interrupt using
vector and 32 bit destination ID in XT MMIO register 0x170.

-------------------------------------------------------------------------------

Changes since v2:
https://lore.kernel.org/qemu-devel/20260129102814.4488-1-sarunkod@amd.com/
Patch 1:
    - Delete  amdvi_mmio_trace_{read,write} and AMDVI_MMIO_REGS_{LOW,HIGH}
      definitions [AJ]
    - Move MMIO_REG_TO_STRING definition inside amdvi_mmio_get_name() [CM]
Patch 2: Improve commit message [AJ]
Patch 3: Improve commit message and comment [AJ]


Changes since v1:
https://lore.kernel.org/qemu-devel/20251118082403.3455-1-sarunkod@amd.com/
Patch 1: Return string literals directly instead of copying [AJ]
Patch 2: 
    - Update commit message [AJ]
    - Introduce new subsection for migration compatibility [AJ]
    - Update comment [AJ]
Patch 3: Use ga_enabled flag while setting xten flag [AJ]


-------------------------------------------------------------------------------

The patches are based on top of upstream qemu master 07f97d5da04a

-------------------------------------------------------------------------------

Sairaj Kodilkar (3):
  amd_iommu: Use switch case to determine mmio register name
  amd_iommu: Turn on XT support only when guest has enabled it
  amd_iommu: Generate XT interrupts when xt support is enabled

 hw/i386/amd_iommu.c  | 144 ++++++++++++++++++++++++++-----------------
 hw/i386/amd_iommu.h  |  25 ++++++--
 hw/i386/trace-events |   1 +
 3 files changed, 108 insertions(+), 62 deletions(-)

-- 
2.34.1