From: Sairaj Kodilkar <sarunkod@amd.com>
To: <qemu-devel@nongnu.org>
Cc: <alejandro.j.jimenez@oracle.com>, <pbonzini@redhat.com>,
<richard.henderson@linaro.org>, <eduardo@habkost.net>,
<mst@redhat.com>, <marcel.apfelbaum@gmail.com>,
Sairaj Kodilkar <sarunkod@amd.com>
Subject: [PATCH 0/3] amd_iommu: Support Generation of IOMMU XT interrupts
Date: Tue, 18 Nov 2025 13:54:00 +0530 [thread overview]
Message-ID: <20251118082403.3455-1-sarunkod@amd.com> (raw)
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.
-------------------------------------------------------------------------------
The patches are based on top of upstream qemu master (e88510fcdc13)
-------------------------------------------------------------------------------
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 | 130 ++++++++++++++++++++++++++++---------------
hw/i386/amd_iommu.h | 7 ++-
hw/i386/trace-events | 1 +
3 files changed, 93 insertions(+), 45 deletions(-)
--
2.34.1
next reply other threads:[~2025-11-18 8:29 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-18 8:24 Sairaj Kodilkar [this message]
2025-11-18 8:24 ` [PATCH 1/3] amd_iommu: Use switch case to determine mmio register name Sairaj Kodilkar
2025-11-20 1:36 ` Alejandro Jimenez
2025-11-20 4:43 ` Sairaj Kodilkar
2025-11-20 13:31 ` Alejandro Jimenez
2025-11-21 5:20 ` Sairaj Kodilkar
2025-11-21 16:36 ` Alejandro Jimenez
2025-11-18 8:24 ` [PATCH 2/3] amd_iommu: Turn on XT support only when guest has enabled it Sairaj Kodilkar
2025-11-18 8:24 ` [PATCH 3/3] amd_iommu: Generate XT interrupts when xt support is enabled Sairaj Kodilkar
2025-11-19 10:38 ` [PATCH 0/3] amd_iommu: Support Generation of IOMMU XT interrupts Vasant Hegde
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