diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-07-30 17:14:01 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2025-07-30 17:14:01 -0700 |
| commit | 63eb28bb1402891b1ad2be02a530f29a9dd7f1cd (patch) | |
| tree | 982d9fa36c6e4f3e437c6fca10c151d165f7ddde /Documentation | |
| parent | 7d767a9528f6d203bca5e83faf1b8f2f6af3fc07 (diff) | |
| parent | 196d9e72c4b0bd68b74a4ec7f52d248f37d0f030 (diff) | |
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
"ARM:
- Host driver for GICv5, the next generation interrupt controller for
arm64, including support for interrupt routing, MSIs, interrupt
translation and wired interrupts
- Use FEAT_GCIE_LEGACY on GICv5 systems to virtualize GICv3 VMs on
GICv5 hardware, leveraging the legacy VGIC interface
- Userspace control of the 'nASSGIcap' GICv3 feature, allowing
userspace to disable support for SGIs w/o an active state on
hardware that previously advertised it unconditionally
- Map supporting endpoints with cacheable memory attributes on
systems with FEAT_S2FWB and DIC where KVM no longer needs to
perform cache maintenance on the address range
- Nested support for FEAT_RAS and FEAT_DoubleFault2, allowing the
guest hypervisor to inject external aborts into an L2 VM and take
traps of masked external aborts to the hypervisor
- Convert more system register sanitization to the config-driven
implementation
- Fixes to the visibility of EL2 registers, namely making VGICv3
system registers accessible through the VGIC device instead of the
ONE_REG vCPU ioctls
- Various cleanups and minor fixes
LoongArch:
- Add stat information for in-kernel irqchip
- Add tracepoints for CPUCFG and CSR emulation exits
- Enhance in-kernel irqchip emulation
- Various cleanups
RISC-V:
- Enable ring-based dirty memory tracking
- Improve perf kvm stat to report interrupt events
- Delegate illegal instruction trap to VS-mode
- MMU improvements related to upcoming nested virtualization
s390x
- Fixes
x86:
- Add CONFIG_KVM_IOAPIC for x86 to allow disabling support for I/O
APIC, PIC, and PIT emulation at compile time
- Share device posted IRQ code between SVM and VMX and harden it
against bugs and runtime errors
- Use vcpu_idx, not vcpu_id, for GA log tag/metadata, to make lookups
O(1) instead of O(n)
- For MMIO stale data mitigation, track whether or not a vCPU has
access to (host) MMIO based on whether the page tables have MMIO
pfns mapped; using VFIO is prone to false negatives
- Rework the MSR interception code so that the SVM and VMX APIs are
more or less identical
- Recalculate all MSR intercepts from scratch on MSR filter changes,
instead of maintaining shadow bitmaps
- Advertise support for LKGS (Load Kernel GS base), a new instruction
that's loosely related to FRED, but is supported and enumerated
independently
- Fix a user-triggerable WARN that syzkaller found by setting the
vCPU in INIT_RECEIVED state (aka wait-for-SIPI), and then putting
the vCPU into VMX Root Mode (post-VMXON). Trying to detect every
possible path leading to architecturally forbidden states is hard
and even risks breaking userspace (if it goes from valid to valid
state but passes through invalid states), so just wait until
KVM_RUN to detect that the vCPU state isn't allowed
- Add KVM_X86_DISABLE_EXITS_APERFMPERF to allow disabling
interception of APERF/MPERF reads, so that a "properly" configured
VM can access APERF/MPERF. This has many caveats (APERF/MPERF
cannot be zeroed on vCPU creation or saved/restored on suspend and
resume, or preserved over thread migration let alone VM migration)
but can be useful whenever you're interested in letting Linux
guests see the effective physical CPU frequency in /proc/cpuinfo
- Reject KVM_SET_TSC_KHZ for vm file descriptors if vCPUs have been
created, as there's no known use case for changing the default
frequency for other VM types and it goes counter to the very reason
why the ioctl was added to the vm file descriptor. And also, there
would be no way to make it work for confidential VMs with a
"secure" TSC, so kill two birds with one stone
- Dynamically allocation the shadow MMU's hashed page list, and defer
allocating the hashed list until it's actually needed (the TDP MMU
doesn't use the list)
- Extract many of KVM's helpers for accessing architectural local
APIC state to common x86 so that they can be shared by guest-side
code for Secure AVIC
- Various cleanups and fixes
x86 (Intel):
- Preserve the host's DEBUGCTL.FREEZE_IN_SMM when running the guest.
Failure to honor FREEZE_IN_SMM can leak host state into guests
- Explicitly check vmcs12.GUEST_DEBUGCTL on nested VM-Enter to
prevent L1 from running L2 with features that KVM doesn't support,
e.g. BTF
x86 (AMD):
- WARN and reject loading kvm-amd.ko instead of panicking the kernel
if the nested SVM MSRPM offsets tracker can't handle an MSR (which
is pretty much a static condition and therefore should never
happen, but still)
- Fix a variety of flaws and bugs in the AVIC device posted IRQ code
- Inhibit AVIC if a vCPU's ID is too big (relative to what hardware
supports) instead of rejecting vCPU creation
- Extend enable_ipiv module param support to SVM, by simply leaving
IsRunning clear in the vCPU's physical ID table entry
- Disable IPI virtualization, via enable_ipiv, if the CPU is affected
by erratum #1235, to allow (safely) enabling AVIC on such CPUs
- Request GA Log interrupts if and only if the target vCPU is
blocking, i.e. only if KVM needs a notification in order to wake
the vCPU
- Intercept SPEC_CTRL on AMD if the MSR shouldn't exist according to
the vCPU's CPUID model
- Accept any SNP policy that is accepted by the firmware with respect
to SMT and single-socket restrictions. An incompatible policy
doesn't put the kernel at risk in any way, so there's no reason for
KVM to care
- Drop a superfluous WBINVD (on all CPUs!) when destroying a VM and
use WBNOINVD instead of WBINVD when possible for SEV cache
maintenance
- When reclaiming memory from an SEV guest, only do cache flushes on
CPUs that have ever run a vCPU for the guest, i.e. don't flush the
caches for CPUs that can't possibly have cache lines with dirty,
encrypted data
Generic:
- Rework irqbypass to track/match producers and consumers via an
xarray instead of a linked list. Using a linked list leads to
O(n^2) insertion times, which is hugely problematic for use cases
that create large numbers of VMs. Such use cases typically don't
actually use irqbypass, but eliminating the pointless registration
is a future problem to solve as it likely requires new uAPI
- Track irqbypass's "token" as "struct eventfd_ctx *" instead of a
"void *", to avoid making a simple concept unnecessarily difficult
to understand
- Decouple device posted IRQs from VFIO device assignment, as binding
a VM to a VFIO group is not a requirement for enabling device
posted IRQs
- Clean up and document/comment the irqfd assignment code
- Disallow binding multiple irqfds to an eventfd with a priority
waiter, i.e. ensure an eventfd is bound to at most one irqfd
through the entire host, and add a selftest to verify eventfd:irqfd
bindings are globally unique
- Add a tracepoint for KVM_SET_MEMORY_ATTRIBUTES to help debug issues
related to private <=> shared memory conversions
- Drop guest_memfd's .getattr() implementation as the VFS layer will
call generic_fillattr() if inode_operations.getattr is NULL
- Fix issues with dirty ring harvesting where KVM doesn't bound the
processing of entries in any way, which allows userspace to keep
KVM in a tight loop indefinitely
- Kill off kvm_arch_{start,end}_assignment() and x86's associated
tracking, now that KVM no longer uses assigned_device_count as a
heuristic for either irqbypass usage or MDS mitigation
Selftests:
- Fix a comment typo
- Verify KVM is loaded when getting any KVM module param so that
attempting to run a selftest without kvm.ko loaded results in a
SKIP message about KVM not being loaded/enabled (versus some random
parameter not existing)
- Skip tests that hit EACCES when attempting to access a file, and
print a "Root required?" help message. In most cases, the test just
needs to be run with elevated permissions"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (340 commits)
Documentation: KVM: Use unordered list for pre-init VGIC registers
RISC-V: KVM: Avoid re-acquiring memslot in kvm_riscv_gstage_map()
RISC-V: KVM: Use find_vma_intersection() to search for intersecting VMAs
RISC-V: perf/kvm: Add reporting of interrupt events
RISC-V: KVM: Enable ring-based dirty memory tracking
RISC-V: KVM: Fix inclusion of Smnpm in the guest ISA bitmap
RISC-V: KVM: Delegate illegal instruction fault to VS mode
RISC-V: KVM: Pass VMID as parameter to kvm_riscv_hfence_xyz() APIs
RISC-V: KVM: Factor-out g-stage page table management
RISC-V: KVM: Add vmid field to struct kvm_riscv_hfence
RISC-V: KVM: Introduce struct kvm_gstage_mapping
RISC-V: KVM: Factor-out MMU related declarations into separate headers
RISC-V: KVM: Use ncsr_xyz() in kvm_riscv_vcpu_trap_redirect()
RISC-V: KVM: Implement kvm_arch_flush_remote_tlbs_range()
RISC-V: KVM: Don't flush TLB when PTE is unchanged
RISC-V: KVM: Replace KVM_REQ_HFENCE_GVMA_VMID_ALL with KVM_REQ_TLB_FLUSH
RISC-V: KVM: Rename and move kvm_riscv_local_tlb_sanitize()
RISC-V: KVM: Drop the return value of kvm_riscv_vcpu_aia_init()
RISC-V: KVM: Check kvm_riscv_vcpu_alloc_vector_context() return value
KVM: arm64: selftests: Add FEAT_RAS EL2 registers to get-reg-list
...
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/arch/arm64/booting.rst | 41 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/interrupt-controller/arm,gic-v5-iwb.yaml | 78 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/interrupt-controller/arm,gic-v5.yaml | 267 | ||||
| -rw-r--r-- | Documentation/virt/kvm/api.rst | 40 | ||||
| -rw-r--r-- | Documentation/virt/kvm/devices/arm-vgic-v3.rst | 77 |
5 files changed, 495 insertions, 8 deletions
diff --git a/Documentation/arch/arm64/booting.rst b/Documentation/arch/arm64/booting.rst index 12bac2ea141c..2f666a7c303c 100644 --- a/Documentation/arch/arm64/booting.rst +++ b/Documentation/arch/arm64/booting.rst @@ -223,6 +223,47 @@ Before jumping into the kernel, the following conditions must be met: - SCR_EL3.HCE (bit 8) must be initialised to 0b1. + For systems with a GICv5 interrupt controller to be used in v5 mode: + + - If the kernel is entered at EL1 and EL2 is present: + + - ICH_HFGRTR_EL2.ICC_PPI_ACTIVERn_EL1 (bit 20) must be initialised to 0b1. + - ICH_HFGRTR_EL2.ICC_PPI_PRIORITYRn_EL1 (bit 19) must be initialised to 0b1. + - ICH_HFGRTR_EL2.ICC_PPI_PENDRn_EL1 (bit 18) must be initialised to 0b1. + - ICH_HFGRTR_EL2.ICC_PPI_ENABLERn_EL1 (bit 17) must be initialised to 0b1. + - ICH_HFGRTR_EL2.ICC_PPI_HMRn_EL1 (bit 16) must be initialised to 0b1. + - ICH_HFGRTR_EL2.ICC_IAFFIDR_EL1 (bit 7) must be initialised to 0b1. + - ICH_HFGRTR_EL2.ICC_ICSR_EL1 (bit 6) must be initialised to 0b1. + - ICH_HFGRTR_EL2.ICC_PCR_EL1 (bit 5) must be initialised to 0b1. + - ICH_HFGRTR_EL2.ICC_HPPIR_EL1 (bit 4) must be initialised to 0b1. + - ICH_HFGRTR_EL2.ICC_HAPR_EL1 (bit 3) must be initialised to 0b1. + - ICH_HFGRTR_EL2.ICC_CR0_EL1 (bit 2) must be initialised to 0b1. + - ICH_HFGRTR_EL2.ICC_IDRn_EL1 (bit 1) must be initialised to 0b1. + - ICH_HFGRTR_EL2.ICC_APR_EL1 (bit 0) must be initialised to 0b1. + + - ICH_HFGWTR_EL2.ICC_PPI_ACTIVERn_EL1 (bit 20) must be initialised to 0b1. + - ICH_HFGWTR_EL2.ICC_PPI_PRIORITYRn_EL1 (bit 19) must be initialised to 0b1. + - ICH_HFGWTR_EL2.ICC_PPI_PENDRn_EL1 (bit 18) must be initialised to 0b1. + - ICH_HFGWTR_EL2.ICC_PPI_ENABLERn_EL1 (bit 17) must be initialised to 0b1. + - ICH_HFGWTR_EL2.ICC_ICSR_EL1 (bit 6) must be initialised to 0b1. + - ICH_HFGWTR_EL2.ICC_PCR_EL1 (bit 5) must be initialised to 0b1. + - ICH_HFGWTR_EL2.ICC_CR0_EL1 (bit 2) must be initialised to 0b1. + - ICH_HFGWTR_EL2.ICC_APR_EL1 (bit 0) must be initialised to 0b1. + + - ICH_HFGITR_EL2.GICRCDNMIA (bit 10) must be initialised to 0b1. + - ICH_HFGITR_EL2.GICRCDIA (bit 9) must be initialised to 0b1. + - ICH_HFGITR_EL2.GICCDDI (bit 8) must be initialised to 0b1. + - ICH_HFGITR_EL2.GICCDEOI (bit 7) must be initialised to 0b1. + - ICH_HFGITR_EL2.GICCDHM (bit 6) must be initialised to 0b1. + - ICH_HFGITR_EL2.GICCDRCFG (bit 5) must be initialised to 0b1. + - ICH_HFGITR_EL2.GICCDPEND (bit 4) must be initialised to 0b1. + - ICH_HFGITR_EL2.GICCDAFF (bit 3) must be initialised to 0b1. + - ICH_HFGITR_EL2.GICCDPRI (bit 2) must be initialised to 0b1. + - ICH_HFGITR_EL2.GICCDDIS (bit 1) must be initialised to 0b1. + - ICH_HFGITR_EL2.GICCDEN (bit 0) must be initialised to 0b1. + + - The DT or ACPI tables must describe a GICv5 interrupt controller. + For systems with a GICv3 interrupt controller to be used in v3 mode: - If EL3 is present: diff --git a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v5-iwb.yaml b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v5-iwb.yaml new file mode 100644 index 000000000000..99a266a62385 --- /dev/null +++ b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v5-iwb.yaml @@ -0,0 +1,78 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/interrupt-controller/arm,gic-v5-iwb.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: ARM Generic Interrupt Controller, version 5 Interrupt Wire Bridge (IWB) + +maintainers: + - Lorenzo Pieralisi <lpieralisi@kernel.org> + - Marc Zyngier <maz@kernel.org> + +description: | + The GICv5 architecture defines the guidelines to implement GICv5 + compliant interrupt controllers for AArch64 systems. + + The GICv5 specification can be found at + https://developer.arm.com/documentation/aes0070 + + GICv5 has zero or more Interrupt Wire Bridges (IWB) that are responsible + for translating wire signals into interrupt messages to the GICv5 ITS. + +allOf: + - $ref: /schemas/interrupt-controller.yaml# + +properties: + compatible: + const: arm,gic-v5-iwb + + reg: + items: + - description: IWB control frame + + "#address-cells": + const: 0 + + "#interrupt-cells": + description: | + The 1st cell corresponds to the IWB wire. + + The 2nd cell is the flags, encoded as follows: + bits[3:0] trigger type and level flags. + + 1 = low-to-high edge triggered + 2 = high-to-low edge triggered + 4 = active high level-sensitive + 8 = active low level-sensitive + + const: 2 + + interrupt-controller: true + + msi-parent: + maxItems: 1 + +required: + - compatible + - reg + - "#interrupt-cells" + - interrupt-controller + - msi-parent + +additionalProperties: false + +examples: + - | + interrupt-controller@2f000000 { + compatible = "arm,gic-v5-iwb"; + reg = <0x2f000000 0x10000>; + + #address-cells = <0>; + + #interrupt-cells = <2>; + interrupt-controller; + + msi-parent = <&its0 64>; + }; +... diff --git a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v5.yaml b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v5.yaml new file mode 100644 index 000000000000..86ca7f3ac281 --- /dev/null +++ b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v5.yaml @@ -0,0 +1,267 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/interrupt-controller/arm,gic-v5.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: ARM Generic Interrupt Controller, version 5 + +maintainers: + - Lorenzo Pieralisi <lpieralisi@kernel.org> + - Marc Zyngier <maz@kernel.org> + +description: | + The GICv5 architecture defines the guidelines to implement GICv5 + compliant interrupt controllers for AArch64 systems. + + The GICv5 specification can be found at + https://developer.arm.com/documentation/aes0070 + + The GICv5 architecture is composed of multiple components: + - one or more IRS (Interrupt Routing Service) + - zero or more ITS (Interrupt Translation Service) + + The architecture defines: + - PE-Private Peripheral Interrupts (PPI) + - Shared Peripheral Interrupts (SPI) + - Logical Peripheral Interrupts (LPI) + +allOf: + - $ref: /schemas/interrupt-controller.yaml# + +properties: + compatible: + const: arm,gic-v5 + + "#address-cells": + enum: [ 1, 2 ] + + "#size-cells": + enum: [ 1, 2 ] + + ranges: true + + "#interrupt-cells": + description: | + The 1st cell corresponds to the INTID.Type field in the INTID; 1 for PPI, + 3 for SPI. LPI interrupts must not be described in the bindings since + they are allocated dynamically by the software component managing them. + + The 2nd cell contains the interrupt INTID.ID field. + + The 3rd cell is the flags, encoded as follows: + bits[3:0] trigger type and level flags. + + 1 = low-to-high edge triggered + 2 = high-to-low edge triggered + 4 = active high level-sensitive + 8 = active low level-sensitive + + const: 3 + + interrupt-controller: true + + interrupts: + description: + The VGIC maintenance interrupt. + maxItems: 1 + +required: + - compatible + - "#address-cells" + - "#size-cells" + - ranges + - "#interrupt-cells" + - interrupt-controller + +patternProperties: + "^irs@[0-9a-f]+$": + type: object + description: + GICv5 has one or more Interrupt Routing Services (IRS) that are + responsible for handling IRQ state and routing. + + additionalProperties: false + + properties: + compatible: + const: arm,gic-v5-irs + + reg: + minItems: 1 + items: + - description: IRS config frames + - description: IRS setlpi frames + + reg-names: + description: + Describe config and setlpi frames that are present. + "ns-" stands for non-secure, "s-" for secure, "realm-" for realm + and "el3-" for EL3. + minItems: 1 + maxItems: 8 + items: + enum: [ ns-config, s-config, realm-config, el3-config, ns-setlpi, + s-setlpi, realm-setlpi, el3-setlpi ] + + "#address-cells": + enum: [ 1, 2 ] + + "#size-cells": + enum: [ 1, 2 ] + + ranges: true + + dma-noncoherent: + description: + Present if the GIC IRS permits programming shareability and + cacheability attributes but is connected to a non-coherent + downstream interconnect. + + cpus: + description: + CPUs managed by the IRS. + + arm,iaffids: + $ref: /schemas/types.yaml#/definitions/uint16-array + description: + Interrupt AFFinity ID (IAFFID) associated with the CPU whose + CPU node phandle is at the same index in the cpus array. + + patternProperties: + "^its@[0-9a-f]+$": + type: object + description: + GICv5 has zero or more Interrupt Translation Services (ITS) that are + used to route Message Signalled Interrupts (MSI) to the CPUs. Each + ITS is connected to an IRS. + additionalProperties: false + + properties: + compatible: + const: arm,gic-v5-its + + reg: + items: + - description: ITS config frames + + reg-names: + description: + Describe config frames that are present. + "ns-" stands for non-secure, "s-" for secure, "realm-" for realm + and "el3-" for EL3. + minItems: 1 + maxItems: 4 + items: + enum: [ ns-config, s-config, realm-config, el3-config ] + + "#address-cells": + enum: [ 1, 2 ] + + "#size-cells": + enum: [ 1, 2 ] + + ranges: true + + dma-noncoherent: + description: + Present if the GIC ITS permits programming shareability and + cacheability attributes but is connected to a non-coherent + downstream interconnect. + + patternProperties: + "^msi-controller@[0-9a-f]+$": + type: object + description: + GICv5 ITS has one or more translate register frames. + additionalProperties: false + + properties: + reg: + items: + - description: ITS translate frames + + reg-names: + description: + Describe translate frames that are present. + "ns-" stands for non-secure, "s-" for secure, "realm-" for realm + and "el3-" for EL3. + minItems: 1 + maxItems: 4 + items: + enum: [ ns-translate, s-translate, realm-translate, el3-translate ] + + "#msi-cells": + description: + The single msi-cell is the DeviceID of the device which will + generate the MSI. + const: 1 + + msi-controller: true + + required: + - reg + - reg-names + - "#msi-cells" + - msi-controller + + required: + - compatible + - reg + - reg-names + + required: + - compatible + - reg + - reg-names + - cpus + - arm,iaffids + +additionalProperties: false + +examples: + - | + interrupt-controller { + compatible = "arm,gic-v5"; + + #interrupt-cells = <3>; + interrupt-controller; + + #address-cells = <1>; + #size-cells = <1>; + ranges; + + interrupts = <1 25 4>; + + irs@2f1a0000 { + compatible = "arm,gic-v5-irs"; + reg = <0x2f1a0000 0x10000>; // IRS_CONFIG_FRAME + reg-names = "ns-config"; + + #address-cells = <1>; + #size-cells = <1>; + ranges; + + cpus = <&cpu0>, <&cpu1>, <&cpu2>, <&cpu3>, <&cpu4>, <&cpu5>, <&cpu6>, <&cpu7>; + arm,iaffids = /bits/ 16 <0 1 2 3 4 5 6 7>; + + its@2f120000 { + compatible = "arm,gic-v5-its"; + reg = <0x2f120000 0x10000>; // ITS_CONFIG_FRAME + reg-names = "ns-config"; + + #address-cells = <1>; + #size-cells = <1>; + ranges; + + msi-controller@2f130000 { + reg = <0x2f130000 0x10000>; // ITS_TRANSLATE_FRAME + reg-names = "ns-translate"; + + #msi-cells = <1>; + msi-controller; + }; + }; + }; + }; +... diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 544fb11351d9..6aa40ee05a4a 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -2006,7 +2006,7 @@ frequency is KHz. If the KVM_CAP_VM_TSC_CONTROL capability is advertised, this can also be used as a vm ioctl to set the initial tsc frequency of subsequently -created vCPUs. +created vCPUs. Note, the vm ioctl is only allowed prior to creating vCPUs. For TSC protected Confidential Computing (CoCo) VMs where TSC frequency is configured once at VM scope and remains unchanged during VM's @@ -7851,6 +7851,7 @@ Valid bits in args[0] are:: #define KVM_X86_DISABLE_EXITS_HLT (1 << 1) #define KVM_X86_DISABLE_EXITS_PAUSE (1 << 2) #define KVM_X86_DISABLE_EXITS_CSTATE (1 << 3) + #define KVM_X86_DISABLE_EXITS_APERFMPERF (1 << 4) Enabling this capability on a VM provides userspace with a way to no longer intercept some instructions for improved latency in some @@ -7861,6 +7862,28 @@ all such vmexits. Do not enable KVM_FEATURE_PV_UNHALT if you disable HLT exits. +Virtualizing the ``IA32_APERF`` and ``IA32_MPERF`` MSRs requires more +than just disabling APERF/MPERF exits. While both Intel and AMD +document strict usage conditions for these MSRs--emphasizing that only +the ratio of their deltas over a time interval (T0 to T1) is +architecturally defined--simply passing through the MSRs can still +produce an incorrect ratio. + +This erroneous ratio can occur if, between T0 and T1: + +1. The vCPU thread migrates between logical processors. +2. Live migration or suspend/resume operations take place. +3. Another task shares the vCPU's logical processor. +4. C-states lower than C0 are emulated (e.g., via HLT interception). +5. The guest TSC frequency doesn't match the host TSC frequency. + +Due to these complexities, KVM does not automatically associate this +passthrough capability with the guest CPUID bit, +``CPUID.6:ECX.APERFMPERF[bit 0]``. Userspace VMMs that deem this +mechanism adequate for virtualizing the ``IA32_APERF`` and +``IA32_MPERF`` MSRs must set the guest CPUID bit explicitly. + + 7.14 KVM_CAP_S390_HPAGE_1M -------------------------- @@ -8387,7 +8410,7 @@ core crystal clock frequency, if a non-zero CPUID 0x15 is exposed to the guest. 7.36 KVM_CAP_DIRTY_LOG_RING/KVM_CAP_DIRTY_LOG_RING_ACQ_REL ---------------------------------------------------------- -:Architectures: x86, arm64 +:Architectures: x86, arm64, riscv :Type: vm :Parameters: args[0] - size of the dirty log ring @@ -8599,7 +8622,7 @@ ENOSYS for the others. When enabled, KVM will exit to userspace with KVM_EXIT_SYSTEM_EVENT of type KVM_SYSTEM_EVENT_SUSPEND to process the guest suspend request. -7.37 KVM_CAP_ARM_WRITABLE_IMP_ID_REGS +7.42 KVM_CAP_ARM_WRITABLE_IMP_ID_REGS ------------------------------------- :Architectures: arm64 @@ -8628,6 +8651,17 @@ given VM. When this capability is enabled, KVM resets the VCPU when setting MP_STATE_INIT_RECEIVED through IOCTL. The original MP_STATE is preserved. +7.43 KVM_CAP_ARM_CACHEABLE_PFNMAP_SUPPORTED +------------------------------------------- + +:Architectures: arm64 +:Target: VM +:Parameters: None + +This capability indicate to the userspace whether a PFNMAP memory region +can be safely mapped as cacheable. This relies on the presence of +force write back (FWB) feature support on the hardware. + 8. Other capabilities. ====================== diff --git a/Documentation/virt/kvm/devices/arm-vgic-v3.rst b/Documentation/virt/kvm/devices/arm-vgic-v3.rst index e860498b1e35..ff02102f7141 100644 --- a/Documentation/virt/kvm/devices/arm-vgic-v3.rst +++ b/Documentation/virt/kvm/devices/arm-vgic-v3.rst @@ -78,6 +78,8 @@ Groups: -ENXIO The group or attribute is unknown/unsupported for this device or hardware support is missing. -EFAULT Invalid user pointer for attr->addr. + -EBUSY Attempt to write a register that is read-only after + initialization ======= ============================================================= @@ -120,6 +122,12 @@ Groups: Note that distributor fields are not banked, but return the same value regardless of the mpidr used to access the register. + Userspace is allowed to write the following register fields prior to + initialization of the VGIC: + + * GICD_IIDR.Revision + * GICD_TYPER2.nASSGIcap + GICD_IIDR.Revision is updated when the KVM implementation is changed in a way directly observable by the guest or userspace. Userspace should read GICD_IIDR from KVM and write back the read value to confirm its expected @@ -128,6 +136,12 @@ Groups: behavior. + GICD_TYPER2.nASSGIcap allows userspace to control the support of SGIs + without an active state. At VGIC creation the field resets to the + maximum capability of the system. Userspace is expected to read the field + to determine the supported value(s) before writing to the field. + + The GICD_STATUSR and GICR_STATUSR registers are architecturally defined such that a write of a clear bit has no effect, whereas a write with a set bit clears that value. To allow userspace to freely set the values of these two @@ -202,16 +216,69 @@ Groups: KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS accesses the CPU interface registers for the CPU specified by the mpidr field. - CPU interface registers access is not implemented for AArch32 mode. - Error -ENXIO is returned when accessed in AArch32 mode. + The available registers are: + + =============== ==================================================== + ICC_PMR_EL1 + ICC_BPR0_EL1 + ICC_AP0R0_EL1 + ICC_AP0R1_EL1 when the host implements at least 6 bits of priority + ICC_AP0R2_EL1 when the host implements 7 bits of priority + ICC_AP0R3_EL1 when the host implements 7 bits of priority + ICC_AP1R0_EL1 + ICC_AP1R1_EL1 when the host implements at least 6 bits of priority + ICC_AP1R2_EL1 when the host implements 7 bits of priority + ICC_AP1R3_EL1 when the host implements 7 bits of priority + ICC_BPR1_EL1 + ICC_CTLR_EL1 + ICC_SRE_EL1 + ICC_IGRPEN0_EL1 + ICC_IGRPEN1_EL1 + =============== ==================================================== + + When EL2 is available for the guest, these registers are also available: + + ============= ==================================================== + ICH_AP0R0_EL2 + ICH_AP0R1_EL2 when the host implements at least 6 bits of priority + ICH_AP0R2_EL2 when the host implements 7 bits of priority + ICH_AP0R3_EL2 when the host implements 7 bits of priority + ICH_AP1R0_EL2 + ICH_AP1R1_EL2 when the host implements at least 6 bits of priority + ICH_AP1R2_EL2 when the host implements 7 bits of priority + ICH_AP1R3_EL2 when the host implements 7 bits of priority + ICH_HCR_EL2 + ICC_SRE_EL2 + ICH_VTR_EL2 + ICH_VMCR_EL2 + ICH_LR0_EL2 + ICH_LR1_EL2 + ICH_LR2_EL2 + ICH_LR3_EL2 + ICH_LR4_EL2 + ICH_LR5_EL2 + ICH_LR6_EL2 + ICH_LR7_EL2 + ICH_LR8_EL2 + ICH_LR9_EL2 + ICH_LR10_EL2 + ICH_LR11_EL2 + ICH_LR12_EL2 + ICH_LR13_EL2 + ICH_LR14_EL2 + ICH_LR15_EL2 + ============= ==================================================== + + CPU interface registers are only described using the AArch64 + encoding. Errors: - ======= ===================================================== - -ENXIO Getting or setting this register is not yet supported + ======= ================================================= + -ENXIO Getting or setting this register is not supported -EBUSY VCPU is running -EINVAL Invalid mpidr or register value supplied - ======= ===================================================== + ======= ================================================= KVM_DEV_ARM_VGIC_GRP_NR_IRQS |
