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Pull kvm updates from Paolo Bonzini:
"ARM64:
- Add support for 'slot' based PMU events, paired with new UAPI that
compels the user to select a specific PMU implementation
- Lazy save/restore of vCPU state for pKVM, along with various fixes
and cleanups to the management of vCPU state between the untrusted
host and pKVM hypervisor
- Disable traps of EL1 registers for nested hypervisors when
FEAT_NV2p1 is present, guaranteeing that EL2-specific register bits
are stateful in the EL1 counterpart
- Leverage FEAT_NV3 to avoid unnecessary ERET/TLBI traps when the
scope of those instructions remains 'in host' (i.e. L1
kernel/userspace)
- Pile of fixes for the management of the VNCR pseudo-TLB, such as
under-invalidations and races with concurrent TLBIs on other vCPUs
- Consolidate the non-protected and pKVM view of ICH_VTR_EL2 to a
runtime-patched constant, allowing the same data to be shared with
pKVM prior to dropping host privileges
- Considerable pile of LLM-assisted fixes around the shop but mostly
in the VGIC, our in-kernel generator of bugs (and sometimes
interrupts)
LoongArch:
- Advertise already-supported capabilities
- Some bug fixes about timer and MMIO
- Some hardening about interrupt injection
- Replace kvm_err() with kvm_pr_unimpl()
- Add FPU/LSX/LASX test cases for selftests
RISC-V:
- Svadu/Zicfiss/Zicfilp FWFT support for Guest
- Use try_cmpxchg for IMSIC MRIF RMW
- More arch-specific tracepoints in KVM RISC-V
- Eager page splitting when enabling dirty logging
- Optimize hfence request handling for SMP Guests
- Improve dirty log clearing by skipping zero bits in mask
- Guard HFENCE range loops against overflow
- CPU PM notifiers in KVM RISC-V for non-retentive idle states
- Fix kernel-mode vector context save/restore for Guest
s390:
- Fixes for vfio-ap
- Fixes for the gmap rework
- Fixes for vsie
- AI triggered fixes all over
- diag9c tracing
- code move preparation for the additional arm64 support
- enable CONTEXT_ANALYSIS
x86:
- Perform spring cleaning on x86.{c,h} and asm/kvm_host.h, by adding
regs.c (the kvm_cache_regs.h => regs.h is already applied) and
msrs.{c,h}, and moving relevant code out of x86.c
- Split kvm_mmu in three parts, respectively to describe the format
of page tables, walking the guest page tables and building the page
tables. Always use the same page table walker kvm->arch.gva_walk as
the entry point to convert a guest's virtual address, where the
previous code used two different kvm_mmu structs depending on
whether the walk included nested EPT/NPT or not. Make page fault
vmexits reuse the permission checking machinery that is used for
guest page faults. This is both a cleanup and a baby step towards
supporting XS/XU memory permissions
- Document some of the "fun" gotchas with the APIC base when creating
IRQCHIPs on x86
- Remove a defunct masterclock update from kvm_xen_shared_info_init().
It could result in incorrect kvmclock due to triggering an
unnecessary switch to/from masterclock mode
- Skip Xen runstate time updates if time has effectively gone
backwards, so that the guest doesn't report 100% steal time for
a very, very long time
- Drop KVM's runtime updates of the Xen PV timing CPUID leaf, as KVM
was updating the wrong sub-leaf, and upstream KVM will soon provide
all the information needed by userspace to populate the CPUID field
itself
- Fix a bug where KVM would walk a newly created rmap without holding
the rmap lock (or mmu_lock) during aging
- Fix a bug where aging TDP MMU SPTEs could clobber FROZEN SPTEs
- Fix a variety of #DB priority bugs
- Fix a class of races related to enabling Hyper-V emulation on a
vCPU after the vCPU is visible to the rest of KVM
- Use static calls for nested virtualization ops
- Move more KVM-internal code out of x86's kvm_host.h
- Enumerate support for a variety of Zhaoxin instructions that don't
require explicit virtualization
- Fix missing EFER validation bugs, including in the KVM_SET_SREGS*
path
- Harden kvm_vcpu_map() against double-mapping and thus leaking
references
- Misc fixes and cleanups, e.g. for largely benign syzkaller splats
x86 (Intel):
- Zero a vCPU's entry in VMX's Posted Interrupt Descriptor table used
for IPI virtualization when the vCPU is freed, to fix a
use-after-free where hardware will write to a freed vCPU's PID
- Service local TLB flushes on a failed nested VM-Enter to fix a bug
where KVM could miss a TLB on a future, successful VM-Enter with
the same L2 VPID
- Cap the maximum value shoved into the VMX Preemption Timer to
workaround an erratum that affects all existing Intel CPUs that
support CPUID 0x15
- Fix VPID virtualization bugs where KVM would fail to flush hardware
TLBs
- Harden the TDX "populate" ioctls against bad input, and to prepare
for supporting in-place private<=>shared conversion
x86 (AMD):
- Forcefully invalidate SNP VMSA pages if their backing guest_memfd
page is zapped/invalidated, e.g. due to a PUNCH_HOLE in response to
a Page-State Change request
- Remove a dying VM from the GA Log notifier list before the VM is
actually destroyed, to fix a potential use-after-free
- While FOLL_WRITE was needed in the past to trigger CoW unsharing,
nowadays FOLL_LONGTERM does that already even without FOLL_WRITE,
and in fact, get_user_pages() actually disallows FOLL_WRITE
together with FOLL_LONGTERM. So don't pass FOLL_WRITE when
registering encrypted memory regions, i.e. when pinning SEV/SEV-ES
guest memory, to fix a regression with file-backed memory
introduced by KVM's (correct) usage of long-term pins
(This was reviewed by mm maintainers; for more information, see
commit ee1a586dd1fa "KVM: SEV: Drop FOLL_WRITE for encrypted region
registration")
- Allocate full pages for SEV/SEV-ES {DE,EN}CRYPT ops on SNP-enabled
hosts to fix a data corruption issue due to the PSP driver
assigning to-be-written pages to firmware (as required by the SNP
specs)
- Unconditionally intercept ICBEP so that KVM generates the correct
guest RIP when handling an ICEBP-induced TASK_SWITCH #VMEXIT
- Harden the SNP "populate" ioctls against bad input, and to prepare
for supporting in-place private<=>shared conversion
Generic:
- Remove kvm_debugfs_dir if kvm_init() fails after creating KVM's
debugfs
- Add a per-VM bitmap to track which vCPU IDs have been "claimed" but
for which the vCPU isn't yet online, and use the bitmap to reject
duplicate IDs before calling into arch code. This allows arch code
to consume vcpu_id without having to worry about cross-vCPU
clobbering (at least s390 and x86 have had related bugs)
- Rework the so called "prepare" and "invalidate" guest_memfd hooks
to prepare for in-place private<=>shared conversion, and clean up a
few warts along the way
Selftests:
- Automatically allocate a full page for L2 guest stacks on x86
instead of requiring test-specific L1 guest code to carve out a
portion of the L1 stack for L2 usage, and to ensure the L2 stack
also adheres to the x86-64 calling convention ABI
- Add a selftest to verify {Guest,Host}-Only behavior in x86's
mediated PMU
- Clean up nested SVM's handling of GPRs on L2<=>L1 transitions,
reuse the functionality for nested VMX, and drop the ucall hack
that was fudging around the lack of GPR switching on nVMX
- Add a stress test to verify KVM doesn't clobber/drop #PF state,
e.g. CR2, across save/restore, including when L2 is active
- Add a test to verify KVM_CREATE_VM accepts exactly what is reported
by KVM_CAP_VM_TYPES
- Misc selftests fixes and cleanups
- Fix several issues with seeding the pRNG, and rework the pRNG APIs
to that the pRNG can be sanely used in host code, not just guest
code
- Add an IRQ test to validate virtual IRQ deliverty for IRQs wired up
via KVM_IRQFD + KVM_SET_GSI_ROUTING, with optional support for
triggering IRQs via writes to an assigned VFIO device
- Add syscall wrappers to assert success on a variety of pthreads and
CPU affinity APIs
- Set vCPU pthread affinity as early as possible to reduce contention
issues that were surfaced by PREEMPT_LAZY, which result in runtimes
of over a minute on large hosts, versus the expected ~5 seconds
- Rework the PMU counters test to run each testcase using a single VM
with many vCPUs for each sub-testcase, instead of using a unique VM
for each sub-testcase. This cuts the runtime by ~20x
Miscellaneous:
- MAINTAINERS updates for vfio-ap, guest_memfd, kvm-x86. Mostly
representing the status quo more accurately, but also... welcome
David Hildenbrand as guest_memfd reviewer!"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (413 commits)
KVM: arm64: Validate GICv5 timer PPIs before claiming ownership
KVM: arm64: vgic: Reject out-of-range GICv5 PPI IDs
KVM: arm64: vgic: Prevent speculative SPI array underflow
KVM: arm64: vgic: Free gic_kvm_info on initialization failure
KVM: arm64: Avoid mismatched accesses to 'struct kvm_nvhe_init_params'
s390/vfio-ap: Fix NULL deref in status_show() during queue probe
s390/vfio-ap: Fix hot-unplug skipped when last AP adapter or domain removed
s390/vfio-ap: fix potential use of uninitialized apm_filtered bitmap
s390/vfio-ap: Fix control domain removal in vfio_ap_mdev_cfg_remove
s390/vfio-ap: Fix required lock not held during update of ap_matrix_mdev object
s390/vfio-ap: Fix missing lock required to access list of ap_matrix_mdev objects
s390/vfio-ap: Fix dereference matrix_mdev->kvm without checking for NULL
s390/vfio-ap: Fix stale do_remove flag across iterations in vfio_ap_mdev_cfg_remove
RISC-V: KVM: fix vcpu vector context handling for kernel-mode vector
riscv: vector: allow non-preemptible kernel-mode vector with IRQs off
riscv: vector: refactor riscv_v_start_kernel_context
KVM: s390: gmap: Make prefix handling optional
KVM: s390: gmap: Make CMMA optional
KVM: s390: gmap: Make storage keys optional
KVM: s390: Prepare gmap for a second KVM implementation
...
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https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 changes for 7.3
- Add support for 'slot' based PMU events, paired with new UAPI that
compels the user to select a specific PMU implementation
- Lazy save/restore of vCPU state for pKVM, along with various fixes
and cleanups to the management of vCPU state between the untrusted
host and pKVM hypervisor
- Disable traps of EL1 registers for nested hypervisors when FEAT_NV2p1
is present, guaranteeing that EL2-specific register bits are stateful
in the EL1 counterpart
- Leverage FEAT_NV3 to avoid unnecessary ERET/TLBI traps when the scope
of those instructions remains 'in host' (i.e. L1 kernel/userspace)
- Pile of fixes for the management of the VNCR pseudo-TLB, such as
under-invalidations and races with concurrent TLBIs on other vCPUs
- Consolidate the non-protected and pKVM view of ICH_VTR_EL2 to a
runtime-patched constant, allowing the same data to be shared with
pKVM prior to dropping host privileges
- Considerable pile of LLM-assisted fixes around the shop but mostly in
the VGIC, our in-kernel generator of bugs (and sometimes interrupts)
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Madhavan Srinivasan:
- Enable Rust for ppc64le
- ppc4xx gpio driver updates
- Add power12 base enablement support
- Validate arch_compat against host compatibility mode
- Simplify bootx_scan_dt_build_struct() in powermac platform
- Implement get_direction() in cpm2
- Use cpu_relax() in ps3_create_spu()
- Add NULL guard for cause_ipi in smp_muxed_ipi_message_pass
- Fixes to handle pseries watchdogs in kdump path
- Fix missing r2 clobber in PCREL inline assembly
- Set GPIO chip parent on ppc44x
- KVM: Introduce KVM_CAP_PPC_COMPAT_CAPS and wire up ioctl
- KVM: Use generic xfer to guest work function
- Enable to run posix cpu timers in task context
- Misc fixes and cleanups
Thanks to Aditya Gupta, Alice Ryhl, Amit Machhiwal, Andrew Morton,
Anushree Mathur, Athira Rajeev, Bartosz Golaszewski, Cédric Le Goater,
Christian König, Christophe Leroy (CS GROUP), Gary Guo, Gaurav Batra,
Gautam Menghani, Gou Hao, Hari Bathini, Harsh Prateek Bora, jiazhenyuan,
Jinjie Ruan, Link Mauve, Linus Walleij, Mahesh Kumar G Mahesh
Salgaonkar, Michael Walle, Michal Suchánek, Mukesh Kumar Chaurasiya
(IBM), Nicholas Piggin, Nikhil Kumar Singh, Praveen K Pandey, Ritesh
Harjani (IBM), Rosen Penev, Saket Kumar Bhaskar, Shrikanth Hegde,
Sourabh Jain, Thorsten Blum, Vaibhav Jain, Venkat Rao Bagalkote, Vishal
Chourasia, Wentao Guan, and Yanfei Xu.
* tag 'powerpc-7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (62 commits)
powerpc/pseries/iommu: switch to Default DMA window during kdump
powerpc/configs: enable CONFIG_RAS to fix EDAC support
KVM: PPC: Document KVM_PPC_GET_COMPAT_CAPS ioctl
KVM: PPC: Book3S HV: Add support for compat CPU capabilities for KVM on PowerNV
KVM: PPC: Book3S HV: Implement compat CPU capability retrieval for KVM on PowerVM
KVM: PPC: Introduce KVM_CAP_PPC_COMPAT_CAPS and wire up ioctl
gpio: ppc44x: use dev_name() for chip label
gpio: ppc44x: fix undefined behavior in GPIO_MASK2 macro
gpio: ppc44x: drop PPC-specific IO helpers
gpio: ppc44x: Convert GPIO to generic MMIO
gpio: ppc44x: Use platform resource helper for GPIO MMIO
gpio: ppc44x: Use module platform driver helper for GPIO
gpio: ppc44x: update all 4xx to 44x
gpio: move ppc4xx gpio driver from arch/powerpc to drivers/gpio
KVM: PPC: Use min() in kvm_vm_ioctl_check_extension()
KVM: PPC: booke: Use min() in watchdog_next_timeout()
powerpc/perf: Add power12 Base Performance Monitoring support
powerpc: Add Power12 architected mode
powerpc: Add Power12 raw mode
powerpc/pseries: Limit PVR list to 16 entries for CAS negotiation
...
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KVM arch-neutral and documentation changes for 7.3
- Remove kvm_debugfs_dir if kvm_init() fails after creating KVM's debugfs.
- Document some of the "fun" gotchas with the APIC base when creating IRQCHIPs
on x86.
- Add a per-VM bitmap to track which vCPU IDs have been "claimed" but for
which the vCPU isn't yet online, and use the bitmap to reject duplicate IDs
before calling into arch code. This allows arch code to consume vcpu_id
without having to worry about cross-vCPU clobbering (at least s390 and x86
have had related bugs).
- Zero a vCPU's entry in VMX's Posted Interrupt Descriptor table used for IPI
virtualization when the vCPU is freed to fix a use-after-free where hardware
will write to a freed vCPU's PID.
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Add documentation for the KVM_PPC_GET_COMPAT_CAPS ioctl to the KVM API
documentation.
The ioctl exposes host processor compatibility modes supported for
nested KVM guests on PowerPC systems. The documentation covers error
code descriptions including E2BIG for forward compatibility,
KVM_PPC_COMPAT_CAPS_SIZE_VER0 as the minimum size floor, the rationale
for rejecting non-zero reserved fields to prevent ABI ambiguity, bit
numbering clarification for IBM MSB-0 convention, and KVM-specific
capability bit constants.
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Reviewed-by: Gautam Menghani <gautam@linux.ibm.com>
Tested-by: Anushree Mathur <anushree.mathur@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260808161148.66673-5-amachhiw@linux.ibm.com
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When virtual APIC access acceleration is enabled (APICv on Intel, AVIC
on AMD), vcpu creation installs a private memory slot at the default
APIC base address (0xfee00000). If a user memory region overlaps this
address, vcpu creation fails with EEXIST. The same error occurs when
installing an overlapping user memory region after vcpu creation.
This also applies when using KVM_CAP_SPLIT_IRQCHIP.
This constraint is not documented anywhere. Add a note to the
KVM_CREATE_IRQCHIP and KVM_CAP_SPLIT_IRQCHIP documentation.
Signed-off-by: Tim Wiederhake <twiederh@redhat.com>
Link: https://patch.msgid.link/20260708133856.302151-3-twiederh@redhat.com
[sean: call out "subsequent vcpu creation"]
Signed-off-by: Sean Christopherson <seanjc@google.com>
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The kernel rejects KVM_CREATE_IRQCHIP with -EINVAL if any vCPUs have
already been created, but the API documentation does not mention this
constraint. Add a note.
Signed-off-by: Tim Wiederhake <twiederh@redhat.com>
Link: https://patch.msgid.link/20260708133856.302151-2-twiederh@redhat.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Introduce a new vCPU feature KVM_ARM_VCPU_PMU_V3_STRICT. When set, KVM
does not create a default PMU when initializing the vCPU, and userspace
must select one explicitly via KVM_ARM_VCPU_PMU_V3_SET_PMU before the
first KVM_RUN.
The flag forces the VMM to be aware of the PMU implementation of the
guest to be created, so that certain information about the PMU becomes
deterministic (if on a heterogeneous system) and becomes safe to be
exposed to the guest. It can be used as an umbrella flag to gate future
PMUv3 UAPI changes.
When no default PMU is created, kvm->arch.arm_pmu stays NULL until SET_PMU
runs, so kvm_arm_pmu_v3_init() now refuses to run if kvm->arch.arm_pmu
is NULL.
Signed-off-by: Congkai Tan <congkai@amazon.com>
Reviewed-by: Geoff Blake <blakgeof@amazon.com>
Reviewed-by: Haris Okanovic <harisokn@amazon.com>
Reviewed-by: Stanislav Spassov <stanspas@amazon.de>
Co-developed-by: Oliver Upton <oupton@kernel.org>
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
Tested-by: Fuad Tabba <fuad.tabba@linux.dev>
Link: https://patch.msgid.link/20260722202702.4165917-5-congkai@amazon.com
Signed-off-by: Oliver Upton <oupton@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 fixes for 7.2, take #3
- Fix a tiny buglet when propagating the deactivation of an interrupt
from a nested guest, which happened to trigger a gold plated CPU bug
on a particular implementation
- Fix a race between LPI unmapping and mapping, resulting in leaked
LPIs
- Make LPI mapping more robust on memory allocation failure
- Fix the handling of the EL2 tracing clock being disabled
- A couple of Sashiko-driven fixes for corner cases in the EL2 tracing
code
- Add missing sysreg tracepoint for the EL2 code
- Tidy-up the mutual exclusion of guest-memfd and MTE
- Update Fuad's email address to point to @linux.dev
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FOLL_LONGTERM pinning fails for some memory types, such as file-backed
guest memory. As a result, kvm_s390_adapter_map() returns -EINVAL and
irqfd adapter registration fails even though interrupt delivery could
still work via the existing non-atomic path.
When FOLL_LONGTERM pinning fails, verify that the page is accessible
using a short-term pin instead. If the short-term pin succeeds, unpin
the page and add a map entry with pinned=false to preserve MAP/UNMAP
symmetry. The non-atomic irqfd path already performs short-term pinning
for interrupt delivery, so this restores the previous behavior for
memory that cannot be pinned long-term.
get_map_info() is updated to return NULL for unpinned entries so that
the atomic irqfd fast path falls back to the non-atomic path.
kvm_s390_adapter_unmap() and kvm_s390_unmap_all_adapters() skip dirty
marking and unpin for unpinned entries.
Update Documentation/virt/kvm/devices/s390_flic.rst to reflect the
new MAP/UNMAP behavior.
Fixes: c9a568838086 ("KVM: s390: Add map/unmap ioctl and clean mappings post-guest")
Signed-off-by: Jaehoon Kim <jhkim@linux.ibm.com>
Reviewed-by: Douglas Freimuth <freimuth@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
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The user cannot use MTE on VMAs created by mapping a guest_memfd file,
as arch_calc_vm_flag_bits() does not set VM_MTE_ALLOWED.
When creating a guest_memfd backed memslot,
kvm_arch_prepare_memory_region() rejects the memslot if MTE is enabled for
the VM and if guest_memfd has been mapped in a VMA that intersects the
memslot.
However, the documentation for KVM_SET_USER_MEMORY_REGION2 explicitly
states that the only condition for userspace_addr is for it to be a legal
userspace address, but the mapping is not required to be valid nor
populated at memslot creation.
If userspace sets userspace_addr to an address that hasn't been mapped, or
if userspace_addr belongs to a VMA that isn't backed by the guest_memfd
file, or if the VMA doesn't intersect the memslot, memslot creation is
successful and KVM ends up with a VM with MTE and guest_memfd-backed
memslots.
The same happens if the order is reversed: when userspace enables MTE, KVM
does not check if memslots backed by guest_memfd are already present.
Fix both issues by rejecting guest_memfd-backed memslots when MTE is
enabled, and by rejecting MTE when guest_memfd-backed memslots are already
present.
Fixes: 32e200bd6e44 ("KVM: arm64: Enable support for guest_memfd backed memory")
Tested-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://patch.msgid.link/20260722090354.94245-1-alexandru.elisei@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
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https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
* Fix S390_USER_OPEREXEC so it can now be enabled regardless of other
unrelated capabilities
* Fix handling of the _PAGE_UNUSED pte bit that could lead to guest
memory corruption in some scenarios
* A bunch of misc gmap fixes (locking, behaviour under memory pressure)
* Fix CMMA dirty tracking
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Small typo noticed while writing the USER_OPEREXEC selftest.
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20260507200836.3500368-4-farman@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
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https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
KVM: s390: New features for 7.2
New features for 7.2 for KVM/s390:
* KVM_PRE_FAULT_MEMORY support
* Support for 2G hugepages
* Support for the ASTFLEIE 2 facility
* kvm_arch_set_irq_inatomic Fast Inject
* Fix potential leak of uninitialized bytes
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git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for 7.2
* New features:
- None. Zilch. Nada. Que dalle.
* Fixes and other improvements:
- Significant cleanup of the vgic-v5 PPI support which was merged in
7.1. This makes the code more maintainable, and squashes a couple
of bugs in the meantime.
- Set of fixes for the handling of the MMU in an NV context,
particularly VNCR-triggered faults. S1POE support is fixed
as well.
- Large set of pKVM fixes, mostly addressing recurring issues
around hypervisor tracking of donated pages in obscure cases
where the donation could fail and leave things in a bizarre
state.
- Fixes for the so-called "lazy vgic init", which resulted in
sleeping operations in non-preemptible sections. This turned
out to be far more invasive than initially expected...
- Reduce the overhead of L1/L2 context switch by not touching
the FP registers.
- Fix the way non-implemented page sizes are dealt with when
a guest insist on using them for S2 translation.
- The usual set of low-impact fixes and cleanups all over the map.
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KVM SVM changes for 7.2
- Add support for virtualizing gPAT (KVM previously just used L1's PAT when
running L2).
- Fix goofs where KVM mishandles side effects (e.g. single-step and PMC
updates) when emulating VMRUN.
- Fix a variety of bugs in AVIC's handling of x2APIC MSR interception, most
notably where KVM didn't disable interception of IRR, ISR, and TMR regs.
- Add support for virtualizing Host-Only/Guest-Only bits in the mediated PMU.
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KVM misc x86 changes for 7.2
- Handle EXIT_FASTPATH_EXIT_USERSPACE in vendor code to ensure vendor code
gets a chance to handle things like reaping the PML buffer.
- Ensure KVM's copy of CR0 and CR3 are up-to-date on SVM prior to invoking
fastpath handlers.
- Update KVM's view of PV async enabling if and only if the MSR write fully
succeeds.
- Fix a variety of issues where the emulator doesn't honor guest-debug state,
and clean up related code along the way.
- Synthesize EPT Violation and #NPF "error code" bits when injecting faults
into L1 that didn't originate in hardware (in which case the VMCS/VMCB
doesn't hold relevant information).
- Add support for virtualizing (well, emulating) AMD's flavor of CPL>0 CPUID
faulting.
- Clean up the GPR APIs so that KVM's use of "raw" is consistent, and fix a
variety of minor bugs along the way.
- Fix an OOB memory access due to not checking the VP ID when handling a
Hyper-V PV TLB flush for L2.
- Fix a bug in the mediated PMU's handling of fixed counters that allowed the
guest to bypass the PMU event filter.
- Allow userspace to return EAGAIN when handling SNP and TDX hypercalls, so
the KVM can forward a "retry" status code to the guest, and reserve all
unused error codes for future usage.
- Misc fixes and cleanups.
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* kvm-arm64/vgic-v5-PPI-fixes:
: .
: Substantial cleanup of the vgic-v5 PPI support. From the original
: cover letter:
:
: "With the GICv5 PPi support merged in, it has become obvious that a few
: things could be improved, both from the correctness and maintainability
: angles."
: .
KVM: arm64: Fix arch timer interrupts for GICv3-on-GICv5 guests
irqchip/gic-v5: Immediately exec priority drop following activate
Documentation: KVM: Clarify that PMU_V3_IRQ IntID requirements for GICv5
Documentation: KVM: Fix typos in VGICv5 documentation
KVM: arm64: selftests: Improve error handling for GICv5 PPI selftest
KVM: arm64: selftests: Cleanup unused vars in GICv5 PPI selftest
KVM: arm64: selftests: Add missing GIC CDEN to no-vgic-v5 selftest
KVM: arm64: vgic-v5: Atomically assign bits to PPI DVI bitmap
KVM: arm64: vgic-v5: Add missing trap handing for NV triage
KVM: arm64: vgic-v5: Limit support to 64 PPIs
KVM: arm64: vgic: Rationalise per-CPU irq accessor
KVM: arm64: vgic-v5: Drop defensive checks from vgic_v5_ppi_queue_irq_unlock()
KVM: arm64: vgic: Consolidate vgic_allocate_private_irqs_locked()
KVM: arm64: vgic: Constify struct irq_ops usage
KVM: arm64: vgic-v5: Drop pointless ARM64_HAS_GICV5_CPUIF check
KVM: arm64: vgic-v5: Remove use of __assign_bit() with a constant
KVM: arm64: vgic-v5: Move PPI caps into kvm_vgic_global_state
KVM: arm64: vgic-v5: Add for_each_visible_v5_ppi() iterator
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
Document the KVM_CAP_S390_HPAGE_2G capability, which behaves very
similarly to the existing KVM_CAP_S390_HPAGE_1M.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20260609150930.665370-5-imbrenda@linux.ibm.com>
|
|
KVM has reflected KVM_X86_SNP_VM to userspace since 1dfe571c12cf
("KVM: SEV: Add initial SEV-SNP support"), and KVM_X86_TDX_VM since
161d34609f9b ("KVM: TDX: Make TDX VM type supported"). Update the
documentation to reflect this fact.
Fixes: 1dfe571c12cf ("KVM: SEV: Add initial SEV-SNP support")
Fixes: 161d34609f9b ("KVM: TDX: Make TDX VM type supported")
Signed-off-by: Carlos López <clopez@suse.de>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Link: https://patch.msgid.link/20260603114504.814647-2-clopez@suse.de
[sean: use one tab instead of two]
Signed-off-by: Sean Christopherson <seanjc@google.com>
|
|
Merge the final part of the GHCB 7.2 fixes at
https://lore.kernel.org/kvm/20260529183549.1104619-1-pbonzini@redhat.com/.
Patches 1-17 have already been included in Linux 7.1; these are minor
cleanups, and fixes for behaviors that are suboptimal or contradicting
the specification.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Update the API documentation for KVM_PRE_FAULT_MEMORY to account for
its s390 implementation.
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20260527144358.186359-4-imbrenda@linux.ibm.com>
|
|
MAPGPA request from TDX VMs gets split into chunks by KVM using a loop
of userspace exits until the complete range is handled.
In some cases userspace VMM might decide to break the MAPGPA operation
and continue it later. For example: in the case of intrahost migration
userspace might decide to continue the MAPGPA operation after the
migration is completed.
Allow userspace to signal to TDX guests that the MAPGPA operation should
be retried the next time the guest is scheduled.
This is potentially a breaking change since if userspace sets
hypercall.ret to a value other than EBUSY or EINVAL an EINVAL error code
will be returned to userspace. As of now QEMU never sets hypercall.ret
to a non-zero value after handling KVM_EXIT_HYPERCALL so this change
should be safe.
Reviewed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Vishal Annapurve <vannapurve@google.com>
Co-developed-by: Sagi Shahar <sagis@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
Link: https://patch.msgid.link/20260305222627.4193305-2-sagis@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
|
|
When running a GICv5-based guest, the PMU must use PPI 23. This,
however, must be communicated via the
KVM_ARM_VCPU_PMU_V3_CTRL->KVM_ARM_VCPU_PMU_V3_IRQ ioctl as a full
GICv5-style Interrupt ID. That is, 0x20000017. Optionally, the whole
ioctl can be skipped for GICv5.
This was previously not clearly documented, so bump the documentation
accordingly.
Fixes: 7c31c06e2d2d ("KVM: arm64: gic-v5: Mandate architected PPI for PMU emulation on GICv5")
Link: https://sashiko.dev/#/patchset/20260319154937.3619520-1-sascha.bischoff%40arm.com
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Link: https://lore.kernel.org/r/20260520091949.542365-17-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
Fix two typos in the VGICv5 documentation.
Fixes: d51c978b7d3e ("KVM: arm64: gic-v5: Communicate userspace-driveable PPIs via a UAPI")
Fixes: eb3c4d2c9a4d ("Documentation: KVM: Introduce documentation for VGICv5")
Link: https://sashiko.dev/#/patchset/20260319154937.3619520-1-sascha.bischoff%40arm.com
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Link: https://lore.kernel.org/r/20260520091949.542365-16-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
Add a 'gpat' field to kvm_svm_nested_state_hdr to carry L2's guest PAT
value across save and restore.
When KVM_X86_QUIRK_NESTED_SVM_SHARED_PAT is disabled and the vCPU is in
guest mode with nested NPT enabled, save vmcb02's g_pat into the header on
KVM_GET_NESTED_STATE, and restore it on KVM_SET_NESTED_STATE.
Host-initiated accesses to IA32_PAT (via KVM_GET/SET_MSRS) always target
L1's hPAT, so they cannot be used to save or restore gPAT. The separate
header field ensures that KVM_GET/SET_MSRS and KVM_GET/SET_NESTED_STATE are
independent and can be ordered arbitrarily during save and restore.
Note that struct kvm_svm_nested_state_hdr is included in a union padded to
120 bytes, so there is room to add the gpat field without changing any
offsets.
Fixes: cc440cdad5b7 ("KVM: nSVM: implement KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE")
Signed-off-by: Jim Mattson <jmattson@google.com>
Link: https://patch.msgid.link/20260407190343.325299-9-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
|
|
Document the nested state constants and structures for SVM that were added
by commit cc440cdad5b7 ("KVM: nSVM: implement KVM_GET_NESTED_STATE and
KVM_SET_NESTED_STATE").
Fixes: cc440cdad5b7 ("KVM: nSVM: implement KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE")
Signed-off-by: Jim Mattson <jmattson@google.com>
Link: https://patch.msgid.link/20260407190343.325299-8-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
|
|
Define a quirk to control whether nested SVM shares L1's PAT with L2
(legacy behavior) or gives L2 its own independent gPAT (correct behavior
per the APM).
When the quirk is enabled (default), L2 shares L1's PAT, preserving the
legacy KVM behavior. When userspace disables the quirk, KVM correctly
virtualizes the PAT for nested SVM guests, giving L2 a separate gPAT as
specified in the AMD architecture.
Signed-off-by: Jim Mattson <jmattson@google.com>
Link: https://patch.msgid.link/20260407190343.325299-2-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
|
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Encryption
Replace non-working links in the reference section with the working ones.
Signed-off-by: Ninad Naik <ninadnaik07@gmail.com>
Link: https://patch.msgid.link/20260511174302.811918-1-ninadnaik07@gmail.com/
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Guest page tables can be reused independent of the value of CR4.SMEP
(at least if WP=1). However, this is not true of EPT MBEC pages,
because presence of EPT entries is signaled by bits 0-2 when MBEC
is off, and bits 0-2 + bit 10 when MBEC is on.
In preparation for enabling MBEC, move cr4_smep to the base role.
This makes the smep_andnot_wp bit redundant, so remove it.
Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
- ESA nesting support
- 4k memslots
- LPSW/E fix
|
|
* kvm-arm64/pkvm-protected-guest: (41 commits)
: .
: pKVM support for protected guests, implementing the very long
: awaited support for anonymous memory, as the elusive guestmem
: has failed to deliver on its promises despite a multi-year
: effort. Patches courtesy of Will Deacon. From the initial cover
: letter:
:
: "[...] this patch series implements support for protected guest
: memory with pKVM, where pages are unmapped from the host as they are
: faulted into the guest and can be shared back from the guest using pKVM
: hypercalls. Protected guests are created using a new machine type
: identifier and can be booted to a shell using the kvmtool patches
: available at [2], which finally means that we are able to test the pVM
: logic in pKVM. Since this is an incremental step towards full isolation
: from the host (for example, the CPU register state and DMA accesses are
: not yet isolated), creating a pVM requires a developer Kconfig option to
: be enabled in addition to booting with 'kvm-arm.mode=protected' and
: results in a kernel taint."
: .
KVM: arm64: Don't hold 'vm_table_lock' across guest page reclaim
KVM: arm64: Allow get_pkvm_hyp_vm() to take a reference to a dying VM
KVM: arm64: Prevent teardown finalisation of referenced 'hyp_vm'
drivers/virt: pkvm: Add Kconfig dependency on DMA_RESTRICTED_POOL
KVM: arm64: Rename PKVM_PAGE_STATE_MASK
KVM: arm64: Extend pKVM page ownership selftests to cover guest hvcs
KVM: arm64: Extend pKVM page ownership selftests to cover forced reclaim
KVM: arm64: Register 'selftest_vm' in the VM table
KVM: arm64: Extend pKVM page ownership selftests to cover guest donation
KVM: arm64: Add some initial documentation for pKVM
KVM: arm64: Allow userspace to create protected VMs when pKVM is enabled
KVM: arm64: Implement the MEM_UNSHARE hypercall for protected VMs
KVM: arm64: Implement the MEM_SHARE hypercall for protected VMs
KVM: arm64: Add hvc handler at EL2 for hypercalls from protected VMs
KVM: arm64: Return -EFAULT from VCPU_RUN on access to a poisoned pte
KVM: arm64: Reclaim faulting page from pKVM in spurious fault handler
KVM: arm64: Introduce hypercall to force reclaim of a protected page
KVM: arm64: Annotate guest donations with handle and gfn in host stage-2
KVM: arm64: Change 'pkvm_handle_t' to u16
KVM: arm64: Introduce host_stage2_set_owner_metadata_locked()
...
Signed-off-by: Marc Zyngier <maz@kernel.org>
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|
Now that all the bits are properly addressed, provide a mechanism
for testing ESA mode guests in nested configurations.
Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com>
[farman@us.ibm.com: Updated commit message]
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
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Add some initial documentation for pKVM to help people understand what
is supported, the limitations of protected VMs when compared to
non-protected VMs and also what is left to do.
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-33-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
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GICv5 systems will likely not support the full set of PPIs. The
presence of any virtual PPI is tied to the presence of the physical
PPI. Therefore, the available PPIs will be limited by the physical
host. Userspace cannot drive any PPIs that are not implemented.
Moreover, it is not desirable to expose all PPIs to the guest in the
first place, even if they are supported in hardware. Some devices,
such as the arch timer, are implemented in KVM, and hence those PPIs
shouldn't be driven by userspace, either.
Provided a new UAPI:
KVM_DEV_ARM_VGIC_GRP_CTRL => KVM_DEV_ARM_VGIC_USERPSPACE_PPIs
This allows userspace to query which PPIs it is able to drive via
KVM_IRQ_LINE.
Additionally, introduce a check in kvm_vm_ioctl_irq_line() to reject
any PPIs not in the userspace mask.
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20260319154937.3619520-40-sascha.bischoff@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
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|
Now that it is possible to create a VGICv5 device, provide initial
documentation for it. At this stage, there is little to document.
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20260319154937.3619520-39-sascha.bischoff@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
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Make it mandatory to use the architected PPI when running a GICv5
guest. Attempts to set anything other than the architected PPI (23)
are rejected.
Additionally, KVM_ARM_VCPU_PMU_V3_INIT is relaxed to no longer require
KVM_ARM_VCPU_PMU_V3_IRQ to be called for GICv5-based guests. In this
case, the architectued PPI is automatically used.
Documentation is bumped accordingly.
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://patch.msgid.link/20260319154937.3619520-33-sascha.bischoff@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
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Interrupts under GICv5 look quite different to those from older Arm
GICs. Specifically, the type is encoded in the top bits of the
interrupt ID.
Extend KVM_IRQ_LINE to cope with GICv5 PPIs and SPIs. The requires
subtly changing the KVM_IRQ_LINE API for GICv5 guests. For older Arm
GICs, PPIs had to be in the range of 16-31, and SPIs had to be
32-1019, but this no longer holds true for GICv5. Instead, for a GICv5
guest support PPIs in the range of 0-127, and SPIs in the range
0-65535. The documentation is updated accordingly.
The SPI range doesn't cover the full SPI range that a GICv5 system can
potentially cope with (GICv5 provides up to 24-bits of SPI ID space,
and we only have 16 bits to work with in KVM_IRQ_LINE). However, 65k
SPIs is more than would be reasonably expected on systems for years to
come.
In order to use vgic_is_v5(), the kvm/arm_vgic.h header is added to
kvm/arm.c.
Note: As the GICv5 KVM implementation currently doesn't support
injecting SPIs attempts to do so will fail. This restriction will by
lifted as the GICv5 KVM support evolves.
Co-authored-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20260319154937.3619520-28-sascha.bischoff@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
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A recently added quirk does not fit in the left column of the table,
so it all has to be reformatted and realigned.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Add KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM to allow L1 to set
FREEZE_IN_SMM in vmcs12's GUEST_IA32_DEBUGCTL field, as permitted
prior to commit 6b1dd26544d0 ("KVM: VMX: Preserve host's
DEBUGCTLMSR_FREEZE_IN_SMM while running the guest"). Enable the quirk
by default for backwards compatibility (like all quirks); userspace
can disable it via KVM_CAP_DISABLE_QUIRKS2 for consistency with the
constraints on WRMSR(IA32_DEBUGCTL).
Note that the quirk only bypasses the consistency check. The vmcs02 bit is
still owned by the host, and PMCs are not frozen during virtualized SMM.
In particular, if a host administrator decides that PMCs should not be
frozen during physical SMM, then L1 has no say in the matter.
Fixes: 095686e6fcb4 ("KVM: nVMX: Check vmcs12->guest_ia32_debugctl on nested VM-Enter")
Cc: stable@vger.kernel.org
Signed-off-by: Jim Mattson <jmattson@google.com>
Link: https://patch.msgid.link/20260205231537.1278753-1-jmattson@google.com
[sean: tag for stable@, clean-up and fix goofs in the comment and docs]
Signed-off-by: Sean Christopherson <seanjc@google.com>
[Rename quirk. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
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HEAD
KVM generic changes for 7.0
- Remove a subtle pseudo-overlay of kvm_stats_desc, which, aside from being
unnecessary and confusing, triggered compiler warnings due to
-Wflex-array-member-not-at-end.
- Document that vcpu->mutex is take outside of kvm->slots_lock and
kvm->slots_arch_lock, which is intentional and desirable despite being
rather unintuitive.
|
|
Explicitly document the ordering of vcpu->mutex being taken *outside* of
kvm->slots_lock. While somewhat unintuitive since vCPUs conceptually have
narrower scope than VMs, the scope of the owning object (vCPU versus VM)
doesn't automatically carry over to the lock. In this case, vcpu->mutex
has far broader scope than kvm->slots_lock. As Paolo put it, it's a
"don't worry about multiple ioctls at the same time" mutex that's intended
to be taken at the outer edges of KVM.
More importantly, arm64 and x86 have gained flows that take kvm->slots_lock
inside of vcpu->mutex. x86's kvm_inhibit_apic_access_page() is particularly
nasty, as slots_lock is taken quite deep within KVM_RUN, i.e. simply
swapping the ordering isn't an option.
Commit to the vcpu->mutex => kvm->slots_lock ordering, as vcpu->mutex
really is intended to be a "top-level" lock, whereas kvm->slots_lock is
"just" a helper lock.
Opportunistically document that vcpu->mutex is also taken outside of
slots_arch_lock, e.g. when allocating shadow roots on x86 (which is the
entire reason slots_arch_lock exists, as shadow roots must be allocated
while holding kvm->srcu)
kvm_mmu_new_pgd()
|
-> kvm_mmu_reload()
|
-> kvm_mmu_load()
|
-> mmu_alloc_shadow_roots()
|
-> mmu_first_shadow_root_alloc()
but also when manipulating memslots in vCPU context, e.g. when inhibiting
the APIC-access page via the aforementioned kvm_inhibit_apic_access_page()
kvm_inhibit_apic_access_page()
|
-> __x86_set_memory_region()
|
-> kvm_set_internal_memslot()
|
-> kvm_set_memory_region()
|
-> kvm_set_memslot()
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Marc Zyngier <maz@kernel.org>
Link: https://patch.msgid.link/20260302170239.596810-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
|
|
KVM_CAP_SYNC_MMU is provided by KVM's MMU notifiers, which are now always
available. Move the definition from individual architectures to common
code.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
- gmap rewrite: completely new memory management for kvm/s390
- vSIE improvement
- maintainership change for s390 vfio-pci
- small quality of life improvement for protected guests
|
|
KVM guest_memfd changes for 6.20
- Remove kvm_gmem_populate()'s preparation tracking and half-baked hugepage
handling, and instead rely on SNP (the only user of the tracking) to do its
own tracking via the RMP.
- Retroactively document and enforce (for SNP) that KVM_SEV_SNP_LAUNCH_UPDATE
and KVM_TDX_INIT_MEM_REGION require the source page to be 4KiB aligned, to
avoid non-trivial complexity for a non-existent usecase (and because
in-place conversion simply can't support unaligned sources).
- When populating guest_memfd memory, GUP the source page in common code and
pass the refcounted page to the vendor callback, instead of letting vendor
code do the heavy lifting. Doing so avoids a looming deadlock bug with
in-place due an AB-BA conflict betwee mmap_lock and guest_memfd's filemap
invalidate lock.
|
|
KVM x86 misc changes for 6.20
- Disallow changing the virtual CPU model if L2 is active, for all the same
reasons KVM disallows change the model after the first KVM_RUN.
- Fix a bug where KVM would incorrectly reject host accesses to PV MSRs that
were advertised as supported to userspace when running with
KVM_CAP_ENFORCE_PV_FEATURE_CPUID enabled.
- Fix a bug where KVM would attempt to read protect guest state (CR3) when
configuring an async #PF entry.
- Fail the build if EXPORT_SYMBOL_GPL or EXPORT_SYMBOL is used in KVM (for x86
only) to enforce usage of EXPORT_SYMBOL_FOR_KVM_INTERNAL. Explicitly allow
the few exports that are intended for external usage.
- Ignore -EBUSY when checking nested events after a vCPU exits blocking as
the WARN is user-triggerable, and because exiting to userspace on -EBUSY
does more harm than good in pretty much every situation.
- Throw in the towel and drop the WARN on INIT/SIPI being blocked when vCPU is
in Wait-For-SIPI, as playing whack-a-mole with syzkaller turned out to be an
unwinnable game.
- Add support for new Intel instructions that don't require anything beyond
enumerating feature flags to userspace.
- Grab SRCU when reading PDPTRs in KVM_GET_SREGS2.
- Add WARNs to guard against modifying KVM's CPU caps outside of the intended
setup flow, as nested VMX in particular is sensitive to unexpected changes
in KVM's golden configuration.
- Add a quirk to allow userspace to opt-in to actually suppress EOI broadcasts
when the suppression feature is enabled by the guest (currently limited to
split IRQCHIP, i.e. userspace I/O APIC). Sadly, simply fixing KVM to honor
Suppress EOI Broadcasts isn't an option as some userspaces have come to rely
on KVM's buggy behavior (KVM advertises Supress EOI Broadcast irrespective
of whether or not userspace I/O APIC supports Directed EOIs).
- Minor cleanups.
|
|
KVM SVM changes for 6.20
- Drop a user-triggerable WARN on nested_svm_load_cr3() failure.
- Add support for virtualizing ERAPS. Note, correct virtualization of ERAPS
relies on an upcoming, publicly announced change in the APM to reduce the
set of conditions where hardware (i.e. KVM) *must* flush the RAP.
- Ignore nSVM intercepts for instructions that are not supported according to
L1's virtual CPU model.
- Add support for expedited writes to the fast MMIO bus, a la VMX's fastpath
for EPT Misconfig.
- Don't set GIF when clearing EFER.SVME, as GIF exists independently of SVM,
and allow userspace to restore nested state with GIF=0.
- Treat exit_code as an unsigned 64-bit value through all of KVM.
- Add support for fetching SNP certificates from userspace.
- Fix a bug where KVM would use vmcb02 instead of vmcb01 when emulating VMLOAD
or VMSAVE on behalf of L2.
- Misc fixes and cleanups.
|
|
Add a new IOCTL to allow userspace to manipulate storage keys directly.
This will make it easier to write selftests related to storage keys.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
|
|
Add two flags for KVM_CAP_X2APIC_API to allow userspace to control support
for Suppress EOI Broadcasts when using a split IRQCHIP (I/O APIC emulated
by userspace), which KVM completely mishandles. When x2APIC support was
first added, KVM incorrectly advertised and "enabled" Suppress EOI
Broadcast, without fully supporting the I/O APIC side of the equation,
i.e. without adding directed EOI to KVM's in-kernel I/O APIC.
That flaw was carried over to split IRQCHIP support, i.e. KVM advertised
support for Suppress EOI Broadcasts irrespective of whether or not the
userspace I/O APIC implementation supported directed EOIs. Even worse,
KVM didn't actually suppress EOI broadcasts, i.e. userspace VMMs without
support for directed EOI came to rely on the "spurious" broadcasts.
KVM "fixed" the in-kernel I/O APIC implementation by completely disabling
support for Suppress EOI Broadcasts in commit 0bcc3fb95b97 ("KVM: lapic:
stop advertising DIRECTED_EOI when in-kernel IOAPIC is in use"), but
didn't do anything to remedy userspace I/O APIC implementations.
KVM's bogus handling of Suppress EOI Broadcast is problematic when the
guest relies on interrupts being masked in the I/O APIC until well after
the initial local APIC EOI. E.g. Windows with Credential Guard enabled
handles interrupts in the following order:
1. Interrupt for L2 arrives.
2. L1 APIC EOIs the interrupt.
3. L1 resumes L2 and injects the interrupt.
4. L2 EOIs after servicing.
5. L1 performs the I/O APIC EOI.
Because KVM EOIs the I/O APIC at step #2, the guest can get an interrupt
storm, e.g. if the IRQ line is still asserted and userspace reacts to the
EOI by re-injecting the IRQ, because the guest doesn't de-assert the line
until step #4, and doesn't expect the interrupt to be re-enabled until
step #5.
Unfortunately, simply "fixing" the bug isn't an option, as KVM has no way
of knowing if the userspace I/O APIC supports directed EOIs, i.e.
suppressing EOI broadcasts would result in interrupts being stuck masked
in the userspace I/O APIC due to step #5 being ignored by userspace. And
fully disabling support for Suppress EOI Broadcast is also undesirable, as
picking up the fix would require a guest reboot, *and* more importantly
would change the virtual CPU model exposed to the guest without any buy-in
from userspace.
Add KVM_X2APIC_ENABLE_SUPPRESS_EOI_BROADCAST and
KVM_X2APIC_DISABLE_SUPPRESS_EOI_BROADCAST flags to allow userspace to
explicitly enable or disable support for Suppress EOI Broadcasts. This
gives userspace control over the virtual CPU model exposed to the guest,
as KVM should never have enabled support for Suppress EOI Broadcast without
userspace opt-in. Not setting either flag will result in legacy quirky
behavior for backward compatibility.
Disallow fully enabling SUPPRESS_EOI_BROADCAST when using an in-kernel
I/O APIC, as KVM's history/support is just as tragic. E.g. it's not clear
that commit c806a6ad35bf ("KVM: x86: call irq notifiers with directed EOI")
was entirely correct, i.e. it may have simply papered over the lack of
Directed EOI emulation in the I/O APIC.
Note, Suppress EOI Broadcasts is defined only in Intel's SDM, not in AMD's
APM. But the bit is writable on some AMD CPUs, e.g. Turin, and KVM's ABI
is to support Directed EOI (KVM's name) irrespective of guest CPU vendor.
Fixes: 7543a635aa09 ("KVM: x86: Add KVM exit for IOAPIC EOIs")
Closes: https://lore.kernel.org/kvm/7D497EF1-607D-4D37-98E7-DAF95F099342@nutanix.com
Cc: stable@vger.kernel.org
Suggested-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Khushit Shah <khushit.shah@nutanix.com>
Link: https://patch.msgid.link/20260123125657.3384063-1-khushit.shah@nutanix.com
[sean: clean up minor formatting goofs and fix a comment typo]
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Introduce a new command for KVM_MEMORY_ENCRYPT_OP ioctl that can be used
to enable fetching of endorsement key certificates from userspace via
the new KVM_EXIT_SNP_REQ_CERTS exit type. Also introduce a new
KVM_X86_SEV_SNP_REQ_CERTS KVM device attribute so that userspace can
query whether the kernel supports the new command/exit.
Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Tested-by: Liam Merwick <liam.merwick@oracle.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Link: https://patch.msgid.link/20260109231732.1160759-3-michael.roth@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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