From: Sascha Bischoff <Sascha.Bischoff@arm•com>
To: "linux-arm-kernel@lists•infradead.org"
<linux-arm-kernel@lists•infradead.org>,
"kvmarm@lists•linux.dev" <kvmarm@lists•linux.dev>,
"kvm@vger•kernel.org" <kvm@vger•kernel.org>
Cc: nd <nd@arm•com>, "maz@kernel•org" <maz@kernel•org>,
"oliver.upton@linux•dev" <oliver.upton@linux•dev>,
Joey Gouly <Joey.Gouly@arm•com>,
Suzuki Poulose <Suzuki.Poulose@arm•com>,
"yuzenghui@huawei•com" <yuzenghui@huawei•com>,
"peter.maydell@linaro•org" <peter.maydell@linaro•org>,
"lpieralisi@kernel•org" <lpieralisi@kernel•org>,
Timothy Hayes <Timothy.Hayes@arm•com>
Subject: [PATCH v2 37/39] Documentation: KVM: Add KVM_DEV_ARM_VGIC_GRP_IRS_REGS to VGICv5 docs
Date: Thu, 21 May 2026 15:01:53 +0000 [thread overview]
Message-ID: <20260521144846.1899475-38-sascha.bischoff@arm.com> (raw)
In-Reply-To: <20260521144846.1899475-1-sascha.bischoff@arm.com>
Document the KVM_DEV_ARM_VGIC_GRP_IRS_REGS attribute group used to
read and write the virtual IRS's MMIO register state. This provides a
GICv5-specific interface for state that is conceptually similar to the
VGICv3 ITS register interface, but uses IRS terminology instead of ITS.
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm•com>
---
.../virt/kvm/devices/arm-vgic-v5.rst | 36 +++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/Documentation/virt/kvm/devices/arm-vgic-v5.rst b/Documentation/virt/kvm/devices/arm-vgic-v5.rst
index e2045b09f27d0..217a1ecfbdc5f 100644
--- a/Documentation/virt/kvm/devices/arm-vgic-v5.rst
+++ b/Documentation/virt/kvm/devices/arm-vgic-v5.rst
@@ -141,3 +141,39 @@ Groups:
ICC_CR0_EL1
ICC_PCR_EL1
======================= ===================================================
+
+ KVM_DEV_ARM_VGIC_GRP_IRS_REGS
+ Attributes:
+ The attr field of kvm_device_attr encodes the offset of the IRS register,
+ relative to the IRS CONFIG_FRAME base address. This is the address that
+ was provided via KVM_VGIC_V5_ADDR_TYPE_IRS when creating VGICv5 in the
+ first place.
+
+ kvm_device_attr.addr points to a __u64 value whatever the width
+ of the addressed register (32/64 bits). 64 bit registers can only
+ be accessed with full length.
+
+ Writes to read-only registers are ignored by the kernel except for:
+
+ - IRS_IDR0 - IRS_IDR2 and IRS_IDR5 - IRS_IDR7: These are sanity checked to
+ ensure that they match a sane config.
+ - IRS_IDR3 and IRS_IDR4: These are RAZ/WI as nested virtualization is not
+ supported.
+
+ For registers without dedicated userspace accessors, getting or setting a
+ register uses the same emulated MMIO handlers as guest reads/writes.
+ Dedicated userspace accessors may instead save or restore migration state
+ without triggering guest-visible side effects. For example, restoring
+ IRS_IST_BASER only restores the emulated register state; any host LPI IST
+ allocation based on the restored IRS_IST_CFGR and IRS_IST_BASER state
+ happens when KVM_DEV_ARM_VGIC_GRP_IST is restored.
+
+ Errors:
+
+ ======= =================================================================
+ -ENXIO Offset does not correspond to any supported register
+ -EFAULT Invalid user pointer for attr->addr
+ -EINVAL Offset is not 32-bit aligned for 32-bit MMIO registers, or not
+ 64-bit aligned for 64-bit registers
+ -EBUSY VGIC is not initialized, or one or more VCPUs are running
+ ======= =================================================================
--
2.34.1
next prev parent reply other threads:[~2026-05-21 15:03 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-21 14:49 [PATCH v2 00/39] KVM: arm64: Add GICv5 IRS support Sascha Bischoff
2026-05-21 14:49 ` [PATCH v2 01/39] irqchip/gic-v5: Allow KVM setup without a maintenance IRQ Sascha Bischoff
2026-05-21 14:49 ` [PATCH v2 02/39] irqchip/gic-v5: Provide OF IRS config frame attrs to KVM Sascha Bischoff
2026-05-21 14:50 ` [PATCH v2 03/39] irqchip/gic-v5: Setup gic_kvm_info on ACPI hosts Sascha Bischoff
2026-05-27 10:51 ` Marc Zyngier
2026-05-29 14:33 ` Sascha Bischoff
2026-05-28 7:14 ` Lorenzo Pieralisi
2026-05-29 14:41 ` Sascha Bischoff
2026-05-21 14:50 ` [PATCH v2 04/39] KVM: arm64: gic-v5: Define remaining IRS MMIO registers Sascha Bischoff
2026-05-21 14:50 ` [PATCH v2 05/39] arm64/sysreg: Add GICv5 GIC VDPEND and VDRCFG encodings Sascha Bischoff
2026-05-21 14:51 ` [PATCH v2 06/39] arm64/sysreg: Update ICC_CR0_EL1 with LINK and LINK_IDLE fields Sascha Bischoff
2026-05-21 14:51 ` [PATCH v2 07/39] KVM: arm64: gic-v5: Extract host IRS caps from IRS config frame Sascha Bischoff
2026-05-21 14:51 ` [PATCH v2 08/39] KVM: arm64: gic-v5: Add VPE doorbell domain Sascha Bischoff
2026-05-21 14:52 ` [PATCH v2 09/39] KVM: arm64: gic-v5: Create & manage VM and VPE tables Sascha Bischoff
2026-05-21 14:52 ` [PATCH v2 10/39] KVM: arm64: gic-v5: Introduce guest IST alloc and management Sascha Bischoff
2026-05-21 14:52 ` [PATCH v2 11/39] KVM: arm64: gic-v5: Implement VMT/vIST IRS MMIO Ops Sascha Bischoff
2026-05-21 14:53 ` [PATCH v2 12/39] KVM: arm64: gic-v5: Keep GICv5 vCPU limit model-specific Sascha Bischoff
2026-05-21 14:53 ` [PATCH v2 13/39] KVM: arm64: gic-v5: Implement VPE IRS MMIO Ops Sascha Bischoff
2026-05-21 14:53 ` [PATCH v2 14/39] KVM: arm64: gic-v5: Set up VMTEs and VPE doorbells Sascha Bischoff
2026-05-21 14:54 ` [PATCH v2 15/39] KVM: arm64: gic-v5: Add resident/non-resident hyp calls Sascha Bischoff
2026-05-21 14:54 ` [PATCH v2 16/39] KVM: arm64: gic-v5: Request doorbells when VPEs enter WFI Sascha Bischoff
2026-05-21 14:54 ` [PATCH v2 17/39] KVM: arm64: gic-v5: Introduce struct vgic_v5_irs and IRS base address Sascha Bischoff
2026-05-21 14:55 ` [PATCH v2 18/39] KVM: arm64: gic-v5: Add IRS IODEV support to MMIO handlers Sascha Bischoff
2026-05-21 14:55 ` [PATCH v2 19/39] KVM: arm64: gic-v5: Add KVM_VGIC_V5_ADDR_TYPE_IRS to UAPI Sascha Bischoff
2026-05-21 14:55 ` [PATCH v2 20/39] KVM: arm64: gic-v5: Add GICv5 IRS IODEV and MMIO emulation Sascha Bischoff
2026-05-21 14:56 ` [PATCH v2 21/39] KVM: arm64: gic-v5: Initialise per-VM IRS state Sascha Bischoff
2026-05-21 14:56 ` [PATCH v2 22/39] KVM: arm64: gic-v5: Register the IRS IODEV Sascha Bischoff
2026-05-21 14:57 ` [PATCH v2 23/39] KVM: arm64: gic-v5: Set IRICHPPIDIS based on IRS enable state Sascha Bischoff
2026-05-21 14:57 ` [PATCH v2 24/39] KVM: arm64: selftests: Update vGICv5 selftest to set IRS address Sascha Bischoff
2026-05-21 14:57 ` [PATCH v2 25/39] KVM: arm64: gic-v5: Introduce SPI AP list Sascha Bischoff
2026-05-21 14:58 ` [PATCH v2 26/39] KVM: arm64: gic-v5: Add GIC VDPEND and GIC VDRCFG hyp calls Sascha Bischoff
2026-05-21 14:58 ` [PATCH v2 27/39] KVM: arm64: gic-v5: Track SPI state for in-flight SPIs Sascha Bischoff
2026-05-21 14:58 ` [PATCH v2 28/39] KVM: arm64: gic: Introduce set_pending_state() to irq_op Sascha Bischoff
2026-05-21 14:59 ` [PATCH v2 29/39] KVM: arm64: gic-v5: Support SPI injection Sascha Bischoff
2026-05-26 13:41 ` Vladimir Murzin
2026-05-28 14:59 ` Sascha Bischoff
2026-05-21 14:59 ` [PATCH v2 30/39] Documentation: KVM: Extend VGICv5 docs for KVM_VGIC_V5_ADDR_TYPE_IRS Sascha Bischoff
2026-05-21 14:59 ` [PATCH v2 31/39] KVM: arm64: gic-v5: Add GICv5 SPI injection to irqfd Sascha Bischoff
2026-06-04 10:51 ` Vladimir Murzin
2026-05-21 15:00 ` [PATCH v2 32/39] KVM: arm64: gic-v5: Mask per-vcpu PPI state in vgic_v5_finalize_ppi_state() Sascha Bischoff
2026-05-21 15:00 ` [PATCH v2 33/39] KVM: arm64: gic-v5: Add GICv5 EL1 sysreg userspace accessors Sascha Bischoff
2026-05-21 15:00 ` [PATCH v2 34/39] KVM: arm64: gic-v5: Handle userspace accesses to IRS MMIO region Sascha Bischoff
2026-05-21 15:01 ` [PATCH v2 35/39] KVM: arm64: gic-v5: Implement save/restore mechanisms for ISTs Sascha Bischoff
2026-05-21 15:01 ` [PATCH v2 36/39] Documentation: KVM: Document KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS for VGICv5 Sascha Bischoff
2026-05-21 15:01 ` Sascha Bischoff [this message]
2026-05-21 15:02 ` [PATCH v2 38/39] Documentation: KVM: Add docs for KVM_DEV_ARM_VGIC_GRP_IST Sascha Bischoff
2026-05-21 15:02 ` [PATCH v2 39/39] Documentation: KVM: Add the VGICv5 IRS save/restore sequences Sascha Bischoff
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