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* kvm-arm64/nv-sve:
: CPTR_EL2, FPSIMD/SVE support for nested
:
: This series brings support for honoring the guest hypervisor's CPTR_EL2
: trap configuration when running a nested guest, along with support for
: FPSIMD/SVE usage at L1 and L2.
KVM: arm64: Allow the use of SVE+NV
KVM: arm64: nv: Add additional trap setup for CPTR_EL2
KVM: arm64: nv: Add trap description for CPTR_EL2
KVM: arm64: nv: Add TCPAC/TTA to CPTR->CPACR conversion helper
KVM: arm64: nv: Honor guest hypervisor's FP/SVE traps in CPTR_EL2
KVM: arm64: nv: Load guest FP state for ZCR_EL2 trap
KVM: arm64: nv: Handle CPACR_EL1 traps
KVM: arm64: Spin off helper for programming CPTR traps
KVM: arm64: nv: Ensure correct VL is loaded before saving SVE state
KVM: arm64: nv: Use guest hypervisor's max VL when running nested guest
KVM: arm64: nv: Save guest's ZCR_EL2 when in hyp context
KVM: arm64: nv: Load guest hyp's ZCR into EL1 state
KVM: arm64: nv: Handle ZCR_EL2 traps
KVM: arm64: nv: Forward SVE traps to guest hypervisor
KVM: arm64: nv: Forward FP/ASIMD traps to guest hypervisor
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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* kvm-arm64/ctr-el0:
: Support for user changes to CTR_EL0, courtesy of Sebastian Ott
:
: Allow userspace to change the guest-visible value of CTR_EL0 for a VM,
: so long as the requested value represents a subset of features supported
: by hardware. In other words, prevent the VMM from over-promising the
: capabilities of hardware.
:
: Make this happen by fitting CTR_EL0 into the existing infrastructure for
: feature ID registers.
KVM: selftests: Assert that MPIDR_EL1 is unchanged across vCPU reset
KVM: arm64: nv: Unfudge ID_AA64PFR0_EL1 masking
KVM: selftests: arm64: Test writes to CTR_EL0
KVM: arm64: rename functions for invariant sys regs
KVM: arm64: show writable masks for feature registers
KVM: arm64: Treat CTR_EL0 as a VM feature ID register
KVM: arm64: unify code to prepare traps
KVM: arm64: nv: Use accessors for modifying ID registers
KVM: arm64: Add helper for writing ID regs
KVM: arm64: Use read-only helper for reading VM ID registers
KVM: arm64: Make idregs debugfs iterator search sysreg table directly
KVM: arm64: Get sys_reg encoding from descriptor in idregs_debug_show()
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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Unlike other SVE-related registers, ZCR_EL2 takes a sysreg trap to EL2
when HCR_EL2.NV = 1. KVM still needs to honor the guest hypervisor's
trap configuration, which expects an SVE trap (i.e. ESR_EL2.EC = 0x19)
when CPTR traps are enabled for the vCPU's current context.
Otherwise, if the guest hypervisor has traps disabled, emulate the
access by mapping the requested VL into ZCR_EL1.
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240620164653.1130714-4-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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Similar to FPSIMD traps, don't load SVE state if the guest hypervisor
has SVE traps enabled and forward the trap instead. Note that ZCR_EL2
will require some special handling, as it takes a sysreg trap to EL2
when HCR_EL2.NV = 1.
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240620164653.1130714-3-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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Give precedence to the guest hypervisor's trap configuration when
routing an FP/ASIMD trap taken to EL2. Take advantage of the
infrastructure for translating CPTR_EL2 into the VHE (i.e. EL1) format
and base the trap decision solely on the VHE view of the register. The
in-memory value of CPTR_EL2 will always be up to date for the guest
hypervisor (more on that later), so just read it directly from memory.
Bury all of this behind a macro keyed off of the CPTR bitfield in
anticipation of supporting other traps (e.g. SVE).
[maz: account for HCR_EL2.E2H when testing for TFP/FPEN, with
all the hard work actually being done by Chase Conklin]
[ oliver: translate nVHE->VHE format for testing traps; macro for reuse
in other CPTR_EL2.xEN fields ]
Signed-off-by: Jintack Lim <jintack.lim@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240620164653.1130714-2-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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There are 2 functions to calculate traps via HCR_EL2:
* kvm_init_sysreg() called via KVM_RUN (before the 1st run or when
the pid changes)
* vcpu_reset_hcr() called via KVM_ARM_VCPU_INIT
To unify these 2 and to support traps that are dependent on the
ID register configuration, move the code from vcpu_reset_hcr()
to sys_regs.c and call it via kvm_init_sysreg().
We still have to keep the non-FWB handling stuff in vcpu_reset_hcr().
Also the initialization with HCR_GUEST_FLAGS is kept there but guarded
by !vcpu_has_run_once() to ensure that previous calculated values
don't get overwritten.
While at it rename kvm_init_sysreg() to kvm_calculate_traps() to
better reflect what it's doing.
Signed-off-by: Sebastian Ott <sebott@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240619174036.483943-7-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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When setting/clearing CPACR bits for EL0 and EL1, use the ELx
format of the bits, which covers both. This makes the code
clearer, and reduces the chances of accidentally missing a bit.
No functional change intended.
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20240603122852.3923848-9-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
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The same traps controlled by CPTR_EL2 or CPACR_EL1 need to be
toggled in different parts of the code, but the exact bits and
their polarity differ between these two formats and the mode
(vhe/nvhe/hvhe).
To reduce the amount of duplicated code and the chance of getting
the wrong bit/polarity or missing a field, abstract the set/clear
of CPTR_EL2 bits behind a helper.
Since (h)VHE is the way of the future, use the CPACR_EL1 format,
which is a subset of the VHE CPTR_EL2, as a reference.
No functional change intended.
Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20240603122852.3923848-4-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
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* kvm-arm64/pkvm-6.10: (25 commits)
: .
: At last, a bunch of pKVM patches, courtesy of Fuad Tabba.
: From the cover letter:
:
: "This series is a bit of a bombay-mix of patches we've been
: carrying. There's no one overarching theme, but they do improve
: the code by fixing existing bugs in pKVM, refactoring code to
: make it more readable and easier to re-use for pKVM, or adding
: functionality to the existing pKVM code upstream."
: .
KVM: arm64: Force injection of a data abort on NISV MMIO exit
KVM: arm64: Restrict supported capabilities for protected VMs
KVM: arm64: Refactor setting the return value in kvm_vm_ioctl_enable_cap()
KVM: arm64: Document the KVM/arm64-specific calls in hypercalls.rst
KVM: arm64: Rename firmware pseudo-register documentation file
KVM: arm64: Reformat/beautify PTP hypercall documentation
KVM: arm64: Clarify rationale for ZCR_EL1 value restored on guest exit
KVM: arm64: Introduce and use predicates that check for protected VMs
KVM: arm64: Add is_pkvm_initialized() helper
KVM: arm64: Simplify vgic-v3 hypercalls
KVM: arm64: Move setting the page as dirty out of the critical section
KVM: arm64: Change kvm_handle_mmio_return() return polarity
KVM: arm64: Fix comment for __pkvm_vcpu_init_traps()
KVM: arm64: Prevent kmemleak from accessing .hyp.data
KVM: arm64: Do not map the host fpsimd state to hyp in pKVM
KVM: arm64: Rename __tlb_switch_to_{guest,host}() in VHE
KVM: arm64: Support TLB invalidation in guest context
KVM: arm64: Avoid BBM when changing only s/w bits in Stage-2 PTE
KVM: arm64: Check for PTE validity when checking for executable/cacheable
KVM: arm64: Avoid BUG-ing from the host abort path
...
Signed-off-by: Marc Zyngier <maz@kernel.org>
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* kvm-arm64/nv-eret-pauth:
: .
: Add NV support for the ERETAA/ERETAB instructions. From the cover letter:
:
: "Although the current upstream NV support has *some* support for
: correctly emulating ERET, that support is only partial as it doesn't
: support the ERETAA and ERETAB variants.
:
: Supporting these instructions was cast aside for a long time as it
: involves implementing some form of PAuth emulation, something I wasn't
: overly keen on. But I have reached a point where enough of the
: infrastructure is there that it actually makes sense. So here it is!"
: .
KVM: arm64: nv: Work around lack of pauth support in old toolchains
KVM: arm64: Drop trapping of PAuth instructions/keys
KVM: arm64: nv: Advertise support for PAuth
KVM: arm64: nv: Handle ERETA[AB] instructions
KVM: arm64: nv: Add emulation for ERETAx instructions
KVM: arm64: nv: Add kvm_has_pauth() helper
KVM: arm64: nv: Reinject PAC exceptions caused by HCR_EL2.API==0
KVM: arm64: nv: Handle HCR_EL2.{API,APK} independently
KVM: arm64: nv: Honor HFGITR_EL2.ERET being set
KVM: arm64: nv: Fast-track 'InHost' exception returns
KVM: arm64: nv: Add trap forwarding for ERET and SMC
KVM: arm64: nv: Configure HCR_EL2 for FEAT_NV2
KVM: arm64: nv: Drop VCPU_HYP_CONTEXT flag
KVM: arm64: Constraint PAuth support to consistent implementations
KVM: arm64: Add helpers for ESR_ELx_ERET_ISS_ERET*
KVM: arm64: Harden __ctxt_sys_reg() against out-of-range values
Signed-off-by: Marc Zyngier <maz@kernel.org>
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To avoid direct comparison against the fp_owner enum, add a new
function that performs the check, host_owns_fp_regs(), to
complement the existing guest_owns_fp_regs().
To check for fpsimd state ownership, use the helpers instead of
directly using the enums.
No functional change intended.
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240423150538.2103045-4-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
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We currently insist on disabling PAuth on vcpu_load(), and get to
enable it on first guest use of an instruction or a key (ignoring
the NV case for now).
It isn't clear at all what this is trying to achieve: guests tend
to use PAuth when available, and nothing forces you to expose it
to the guest if you don't want to. This also isn't totally free:
we take a full GPR save/restore between host and guest, only to
write ten 64bit registers. The "value proposition" escapes me.
So let's forget this stuff and enable PAuth eagerly if exposed to
the guest. This results in much simpler code. Performance wise,
that's not bad either (tested on M2 Pro running a fully automated
Debian installer as the workload):
- On a non-NV guest, I can see reduction of 0.24% in the number
of cycles (measured with perf over 10 consecutive runs)
- On a NV guest (L2), I see a 2% reduction in wall-clock time
(measured with 'time', as M2 doesn't have a PMUv3 and NV
doesn't support it either)
So overall, a much reduced complexity and a (small) performance
improvement.
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240419102935.1935571-16-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
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Although KVM couples API and APK for simplicity, the architecture
makes no such requirement, and the two can be independently set or
cleared.
Check for which of the two possible reasons we have trapped here,
and if the corresponding L1 control bit isn't set, delegate the
handling for forwarding.
Otherwise, set this exact bit in HCR_EL2 and resume the guest.
Of course, in the non-NV case, we keep setting both bits and
be done with it. Note that the entry core already saves/restores
the keys should any of the two control bits be set.
This results in a bit of rework, and the removal of the (trivial)
vcpu_ptrauth_enable() helper.
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240419102935.1935571-10-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
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In retrospect, it is fairly obvious that the FP state ownership
is only meaningful for a given CPU, and that locating this
information in the vcpu was just a mistake.
Move the ownership tracking into the host data structure, and
rename it from fp_state to fp_owner, which is a better description
(name suggested by Mark Brown).
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
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Pull kvm updates from Paolo Bonzini:
"S390:
- Changes to FPU handling came in via the main s390 pull request
- Only deliver to the guest the SCLP events that userspace has
requested
- More virtual vs physical address fixes (only a cleanup since
virtual and physical address spaces are currently the same)
- Fix selftests undefined behavior
x86:
- Fix a restriction that the guest can't program a PMU event whose
encoding matches an architectural event that isn't included in the
guest CPUID. The enumeration of an architectural event only says
that if a CPU supports an architectural event, then the event can
be programmed *using the architectural encoding*. The enumeration
does NOT say anything about the encoding when the CPU doesn't
report support the event *in general*. It might support it, and it
might support it using the same encoding that made it into the
architectural PMU spec
- Fix a variety of bugs in KVM's emulation of RDPMC (more details on
individual commits) and add a selftest to verify KVM correctly
emulates RDMPC, counter availability, and a variety of other
PMC-related behaviors that depend on guest CPUID and therefore are
easier to validate with selftests than with custom guests (aka
kvm-unit-tests)
- Zero out PMU state on AMD if the virtual PMU is disabled, it does
not cause any bug but it wastes time in various cases where KVM
would check if a PMC event needs to be synthesized
- Optimize triggering of emulated events, with a nice ~10%
performance improvement in VM-Exit microbenchmarks when a vPMU is
exposed to the guest
- Tighten the check for "PMI in guest" to reduce false positives if
an NMI arrives in the host while KVM is handling an IRQ VM-Exit
- Fix a bug where KVM would report stale/bogus exit qualification
information when exiting to userspace with an internal error exit
code
- Add a VMX flag in /proc/cpuinfo to report 5-level EPT support
- Rework TDP MMU root unload, free, and alloc to run with mmu_lock
held for read, e.g. to avoid serializing vCPUs when userspace
deletes a memslot
- Tear down TDP MMU page tables at 4KiB granularity (used to be
1GiB). KVM doesn't support yielding in the middle of processing a
zap, and 1GiB granularity resulted in multi-millisecond lags that
are quite impolite for CONFIG_PREEMPT kernels
- Allocate write-tracking metadata on-demand to avoid the memory
overhead when a kernel is built with i915 virtualization support
but the workloads use neither shadow paging nor i915 virtualization
- Explicitly initialize a variety of on-stack variables in the
emulator that triggered KMSAN false positives
- Fix the debugregs ABI for 32-bit KVM
- Rework the "force immediate exit" code so that vendor code
ultimately decides how and when to force the exit, which allowed
some optimization for both Intel and AMD
- Fix a long-standing bug where kvm_has_noapic_vcpu could be left
elevated if vCPU creation ultimately failed, causing extra
unnecessary work
- Cleanup the logic for checking if the currently loaded vCPU is
in-kernel
- Harden against underflowing the active mmu_notifier invalidation
count, so that "bad" invalidations (usually due to bugs elsehwere
in the kernel) are detected earlier and are less likely to hang the
kernel
x86 Xen emulation:
- Overlay pages can now be cached based on host virtual address,
instead of guest physical addresses. This removes the need to
reconfigure and invalidate the cache if the guest changes the gpa
but the underlying host virtual address remains the same
- When possible, use a single host TSC value when computing the
deadline for Xen timers in order to improve the accuracy of the
timer emulation
- Inject pending upcall events when the vCPU software-enables its
APIC to fix a bug where an upcall can be lost (and to follow Xen's
behavior)
- Fall back to the slow path instead of warning if "fast" IRQ
delivery of Xen events fails, e.g. if the guest has aliased xAPIC
IDs
RISC-V:
- Support exception and interrupt handling in selftests
- New self test for RISC-V architectural timer (Sstc extension)
- New extension support (Ztso, Zacas)
- Support userspace emulation of random number seed CSRs
ARM:
- Infrastructure for building KVM's trap configuration based on the
architectural features (or lack thereof) advertised in the VM's ID
registers
- Support for mapping vfio-pci BARs as Normal-NC (vaguely similar to
x86's WC) at stage-2, improving the performance of interacting with
assigned devices that can tolerate it
- Conversion of KVM's representation of LPIs to an xarray, utilized
to address serialization some of the serialization on the LPI
injection path
- Support for _architectural_ VHE-only systems, advertised through
the absence of FEAT_E2H0 in the CPU's ID register
- Miscellaneous cleanups, fixes, and spelling corrections to KVM and
selftests
LoongArch:
- Set reserved bits as zero in CPUCFG
- Start SW timer only when vcpu is blocking
- Do not restart SW timer when it is expired
- Remove unnecessary CSR register saving during enter guest
- Misc cleanups and fixes as usual
Generic:
- Clean up Kconfig by removing CONFIG_HAVE_KVM, which was basically
always true on all architectures except MIPS (where Kconfig
determines the available depending on CPU capabilities). It is
replaced either by an architecture-dependent symbol for MIPS, and
IS_ENABLED(CONFIG_KVM) everywhere else
- Factor common "select" statements in common code instead of
requiring each architecture to specify it
- Remove thoroughly obsolete APIs from the uapi headers
- Move architecture-dependent stuff to uapi/asm/kvm.h
- Always flush the async page fault workqueue when a work item is
being removed, especially during vCPU destruction, to ensure that
there are no workers running in KVM code when all references to
KVM-the-module are gone, i.e. to prevent a very unlikely
use-after-free if kvm.ko is unloaded
- Grab a reference to the VM's mm_struct in the async #PF worker
itself instead of gifting the worker a reference, so that there's
no need to remember to *conditionally* clean up after the worker
Selftests:
- Reduce boilerplate especially when utilize selftest TAP
infrastructure
- Add basic smoke tests for SEV and SEV-ES, along with a pile of
library support for handling private/encrypted/protected memory
- Fix benign bugs where tests neglect to close() guest_memfd files"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (246 commits)
selftests: kvm: remove meaningless assignments in Makefiles
KVM: riscv: selftests: Add Zacas extension to get-reg-list test
RISC-V: KVM: Allow Zacas extension for Guest/VM
KVM: riscv: selftests: Add Ztso extension to get-reg-list test
RISC-V: KVM: Allow Ztso extension for Guest/VM
RISC-V: KVM: Forward SEED CSR access to user space
KVM: riscv: selftests: Add sstc timer test
KVM: riscv: selftests: Change vcpu_has_ext to a common function
KVM: riscv: selftests: Add guest helper to get vcpu id
KVM: riscv: selftests: Add exception handling support
LoongArch: KVM: Remove unnecessary CSR register saving during enter guest
LoongArch: KVM: Do not restart SW timer when it is expired
LoongArch: KVM: Start SW timer only when vcpu is blocking
LoongArch: KVM: Set reserved bits as zero in CPUCFG
KVM: selftests: Explicitly close guest_memfd files in some gmem tests
KVM: x86/xen: fix recursive deadlock in timer injection
KVM: pfncache: simplify locking and make more self-contained
KVM: x86/xen: remove WARN_ON_ONCE() with false positives in evtchn delivery
KVM: x86/xen: inject vCPU upcall vector when local APIC is enabled
KVM: x86/xen: improve accuracy of Xen timers
...
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The LPA2 feature introduces new FSC values to report abort exceptions
related to translation level -1. Define these and wire them up.
Reuse the new ESR FSC classification helpers that arrived via the KVM
arm64 tree, and update the one for translation faults to check
specifically for a translation fault at level -1. (Access flag or
permission faults cannot occur at level -1 because they alway involve a
descriptor at the superior level so changing those helpers is not
needed).
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240214122845.2033971-73-ardb+git@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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If NV1 isn't supported on a system, make sure we always evaluate
the guest's HCR_EL2.E2H as RES1, irrespective of what the guest
may have written there.
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240122181344.258974-10-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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* kvm-arm64/nv-6.8-prefix:
: .
: Nested Virtualization support update, focussing on the
: NV2 support (VNCR mapping and such).
: .
KVM: arm64: nv: Handle virtual EL2 registers in vcpu_read/write_sys_reg()
KVM: arm64: nv: Map VNCR-capable registers to a separate page
KVM: arm64: nv: Add EL2_REG_VNCR()/EL2_REG_REDIR() sysreg helpers
KVM: arm64: Introduce a bad_trap() primitive for unexpected trap handling
KVM: arm64: nv: Add include containing the VNCR_EL2 offsets
KVM: arm64: nv: Add non-VHE-EL2->EL1 translation helpers
KVM: arm64: nv: Drop EL12 register traps that are redirected to VNCR
KVM: arm64: nv: Compute NV view of idregs as a one-off
KVM: arm64: nv: Hoist vcpu_has_nv() into is_hyp_ctxt()
arm64: cpufeatures: Restrict NV support to FEAT_NV2
Signed-off-by: Marc Zyngier <maz@kernel.org>
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A rather common idiom when writing NV code as part of KVM is
to have things such has:
if (vcpu_has_nv(vcpu) && is_hyp_ctxt(vcpu)) {
[...]
}
to check that we are in a hyp-related context. The second part of
the conjunction would be enough, but the first one contains a
static key that allows the rest of the checkis to be elided when
in a non-NV environment.
Rewrite is_hyp_ctxt() to directly use vcpu_has_nv(). The result
is the same, and the code easier to read. The one occurence of
this that is already merged is rewritten in the process.
In order to avoid nasty cirtular dependencies between kvm_emulate.h
and kvm_nested.h, vcpu_has_feature() is itself hoisted into kvm_host.h,
at the cost of some #deferry...
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
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Currently, we rely on the fact that exceptions can be trivially
classified by applying a mask/value pair to the syndrome value reported
via the ESR register, but this will no longer be true once we enable
support for 5 level paging.
So introduce a couple of helpers that encapsulate this mask/value pair
matching, and wire them up in the code. No functional change intended,
the actual handling of translation level -1 will be added in a
subsequent patch.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
[maz: folded in changes suggested by Mark]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231128140400.3132145-2-ardb@google.com
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FEAT_LPA2 increases the maximum levels of translation from 4 to 5 for
the 4KB page case, when IA is >48 bits. While we can still use 4 levels
for stage2 translation in this case (due to stage2 allowing concatenated
page tables for first level lookup), the same kvm_pgtable library is
used for the hyp stage1 page tables and stage1 does not support
concatenation.
Therefore, modify the library to support up to 5 levels. Previous
patches already laid the groundwork for this by refactoring code to work
in terms of KVM_PGTABLE_FIRST_LEVEL and KVM_PGTABLE_LAST_LEVEL. So we
just need to change these macros.
The hardware sometimes encodes the new level differently from the
others: One such place is when reading the level from the FSC field in
the ESR_EL2 register. We never expect to see the lowest level (-1) here
since the stage 2 page tables always use concatenated tables for first
level lookup and therefore only use 4 levels of lookup. So we get away
with just adding a comment to explain why we are not being careful about
decoding level -1.
For stage2 VTCR_EL2.SL2 is introduced to encode the new start level.
However, since we always use concatenated page tables for first level
look up at stage2 (and therefore we will never need the new extra level)
we never touch this new field.
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231127111737.1897081-10-ryan.roberts@arm.com
|
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With the introduction of FEAT_LPA2, the Arm ARM adds a new level of
translation, level -1, so levels can now be in the range [-1;3]. 3 is
always the last level and the first level is determined based on the
number of VA bits in use.
Convert level variables to use a signed type in preparation for
supporting this new level -1.
Since the last level is always anchored at 3, and the first level varies
to suit the number of VA/IPA bits, take the opportunity to replace
KVM_PGTABLE_MAX_LEVELS with the 2 macros KVM_PGTABLE_FIRST_LEVEL and
KVM_PGTABLE_LAST_LEVEL. This removes the assumption from the code that
levels run from 0 to KVM_PGTABLE_MAX_LEVELS - 1, which will soon no
longer be true.
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231127111737.1897081-9-ryan.roberts@arm.com
|
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Pull kvm updates from Paolo Bonzini:
"ARM:
- Generalized infrastructure for 'writable' ID registers, effectively
allowing userspace to opt-out of certain vCPU features for its
guest
- Optimization for vSGI injection, opportunistically compressing
MPIDR to vCPU mapping into a table
- Improvements to KVM's PMU emulation, allowing userspace to select
the number of PMCs available to a VM
- Guest support for memory operation instructions (FEAT_MOPS)
- Cleanups to handling feature flags in KVM_ARM_VCPU_INIT, squashing
bugs and getting rid of useless code
- Changes to the way the SMCCC filter is constructed, avoiding wasted
memory allocations when not in use
- Load the stage-2 MMU context at vcpu_load() for VHE systems,
reducing the overhead of errata mitigations
- Miscellaneous kernel and selftest fixes
LoongArch:
- New architecture for kvm.
The hardware uses the same model as x86, s390 and RISC-V, where
guest/host mode is orthogonal to supervisor/user mode. The
virtualization extensions are very similar to MIPS, therefore the
code also has some similarities but it's been cleaned up to avoid
some of the historical bogosities that are found in arch/mips. The
kernel emulates MMU, timer and CSR accesses, while interrupt
controllers are only emulated in userspace, at least for now.
RISC-V:
- Support for the Smstateen and Zicond extensions
- Support for virtualizing senvcfg
- Support for virtualized SBI debug console (DBCN)
S390:
- Nested page table management can be monitored through tracepoints
and statistics
x86:
- Fix incorrect handling of VMX posted interrupt descriptor in
KVM_SET_LAPIC, which could result in a dropped timer IRQ
- Avoid WARN on systems with Intel IPI virtualization
- Add CONFIG_KVM_MAX_NR_VCPUS, to allow supporting up to 4096 vCPUs
without forcing more common use cases to eat the extra memory
overhead.
- Add virtualization support for AMD SRSO mitigation (IBPB_BRTYPE and
SBPB, aka Selective Branch Predictor Barrier).
- Fix a bug where restoring a vCPU snapshot that was taken within 1
second of creating the original vCPU would cause KVM to try to
synchronize the vCPU's TSC and thus clobber the correct TSC being
set by userspace.
- Compute guest wall clock using a single TSC read to avoid
generating an inaccurate time, e.g. if the vCPU is preempted
between multiple TSC reads.
- "Virtualize" HWCR.TscFreqSel to make Linux guests happy, which
complain about a "Firmware Bug" if the bit isn't set for select
F/M/S combos. Likewise "virtualize" (ignore) MSR_AMD64_TW_CFG to
appease Windows Server 2022.
- Don't apply side effects to Hyper-V's synthetic timer on writes
from userspace to fix an issue where the auto-enable behavior can
trigger spurious interrupts, i.e. do auto-enabling only for guest
writes.
- Remove an unnecessary kick of all vCPUs when synchronizing the
dirty log without PML enabled.
- Advertise "support" for non-serializing FS/GS base MSR writes as
appropriate.
- Harden the fast page fault path to guard against encountering an
invalid root when walking SPTEs.
- Omit "struct kvm_vcpu_xen" entirely when CONFIG_KVM_XEN=n.
- Use the fast path directly from the timer callback when delivering
Xen timer events, instead of waiting for the next iteration of the
run loop. This was not done so far because previously proposed code
had races, but now care is taken to stop the hrtimer at critical
points such as restarting the timer or saving the timer information
for userspace.
- Follow the lead of upstream Xen and ignore the VCPU_SSHOTTMR_future
flag.
- Optimize injection of PMU interrupts that are simultaneous with
NMIs.
- Usual handful of fixes for typos and other warts.
x86 - MTRR/PAT fixes and optimizations:
- Clean up code that deals with honoring guest MTRRs when the VM has
non-coherent DMA and host MTRRs are ignored, i.e. EPT is enabled.
- Zap EPT entries when non-coherent DMA assignment stops/start to
prevent using stale entries with the wrong memtype.
- Don't ignore guest PAT for CR0.CD=1 && KVM_X86_QUIRK_CD_NW_CLEARED=y
This was done as a workaround for virtual machine BIOSes that did
not bother to clear CR0.CD (because ancient KVM/QEMU did not bother
to set it, in turn), and there's zero reason to extend the quirk to
also ignore guest PAT.
x86 - SEV fixes:
- Report KVM_EXIT_SHUTDOWN instead of EINVAL if KVM intercepts
SHUTDOWN while running an SEV-ES guest.
- Clean up the recognition of emulation failures on SEV guests, when
KVM would like to "skip" the instruction but it had already been
partially emulated. This makes it possible to drop a hack that
second guessed the (insufficient) information provided by the
emulator, and just do the right thing.
Documentation:
- Various updates and fixes, mostly for x86
- MTRR and PAT fixes and optimizations"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (164 commits)
KVM: selftests: Avoid using forced target for generating arm64 headers
tools headers arm64: Fix references to top srcdir in Makefile
KVM: arm64: Add tracepoint for MMIO accesses where ISV==0
KVM: arm64: selftest: Perform ISB before reading PAR_EL1
KVM: arm64: selftest: Add the missing .guest_prepare()
KVM: arm64: Always invalidate TLB for stage-2 permission faults
KVM: x86: Service NMI requests after PMI requests in VM-Enter path
KVM: arm64: Handle AArch32 SPSR_{irq,abt,und,fiq} as RAZ/WI
KVM: arm64: Do not let a L1 hypervisor access the *32_EL2 sysregs
KVM: arm64: Refine _EL2 system register list that require trap reinjection
arm64: Add missing _EL2 encodings
arm64: Add missing _EL12 encodings
KVM: selftests: aarch64: vPMU test for validating user accesses
KVM: selftests: aarch64: vPMU register test for unimplemented counters
KVM: selftests: aarch64: vPMU register test for implemented counters
KVM: selftests: aarch64: Introduce vpmu_counter_access test
tools: Import arm_pmuv3.h
KVM: arm64: PMU: Allow userspace to limit PMCR_EL0.N for the guest
KVM: arm64: Sanitize PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} before first run
KVM: arm64: Add {get,set}_user for PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR}
...
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* kvm-arm64/sgi-injection:
: vSGI injection improvements + fixes, courtesy Marc Zyngier
:
: Avoid linearly searching for vSGI targets using a compressed MPIDR to
: index a cache. While at it, fix some egregious bugs in KVM's mishandling
: of vcpuid (user-controlled value) and vcpu_idx.
KVM: arm64: Clarify the ordering requirements for vcpu/RD creation
KVM: arm64: vgic-v3: Optimize affinity-based SGI injection
KVM: arm64: Fast-track kvm_mpidr_to_vcpu() when mpidr_data is available
KVM: arm64: Build MPIDR to vcpu index cache at runtime
KVM: arm64: Simplify kvm_vcpu_get_mpidr_aff()
KVM: arm64: Use vcpu_idx for invalidation tracking
KVM: arm64: vgic: Use vcpu_idx for the debug information
KVM: arm64: vgic-v2: Use cpuid from userspace as vcpu_id
KVM: arm64: vgic-v3: Refactor GICv3 SGI generation
KVM: arm64: vgic-its: Treat the collection target address as a vcpu_id
KVM: arm64: vgic: Make kvm_vgic_inject_irq() take a vcpu pointer
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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Much of the arm64 KVM code uses cpus_have_const_cap() to check for
cpucaps, but this is unnecessary and it would be preferable to use
cpus_have_final_cap().
For historical reasons, cpus_have_const_cap() is more complicated than
it needs to be. Before cpucaps are finalized, it will perform a bitmap
test of the system_cpucaps bitmap, and once cpucaps are finalized it
will use an alternative branch. This used to be necessary to handle some
race conditions in the window between cpucap detection and the
subsequent patching of alternatives and static branches, where different
branches could be out-of-sync with one another (or w.r.t. alternative
sequences). Now that we use alternative branches instead of static
branches, these are all patched atomically w.r.t. one another, and there
are only a handful of cases that need special care in the window between
cpucap detection and alternative patching.
Due to the above, it would be nice to remove cpus_have_const_cap(), and
migrate callers over to alternative_has_cap_*(), cpus_have_final_cap(),
or cpus_have_cap() depending on when their requirements. This will
remove redundant instructions and improve code generation, and will make
it easier to determine how each callsite will behave before, during, and
after alternative patching.
KVM is initialized after cpucaps have been finalized and alternatives
have been patched. Since commit:
d86de40decaa14e6 ("arm64: cpufeature: upgrade hyp caps to final")
... use of cpus_have_const_cap() in hyp code is automatically converted
to use cpus_have_final_cap():
| static __always_inline bool cpus_have_const_cap(int num)
| {
| if (is_hyp_code())
| return cpus_have_final_cap(num);
| else if (system_capabilities_finalized())
| return __cpus_have_const_cap(num);
| else
| return cpus_have_cap(num);
| }
Thus, converting hyp code to use cpus_have_final_cap() directly will not
result in any functional change.
Non-hyp KVM code is also not executed until cpucaps have been finalized,
and it would be preferable to extent the same treatment to this code and
use cpus_have_final_cap() directly.
This patch converts instances of cpus_have_const_cap() in KVM-only code
over to cpus_have_final_cap(). As all of this code runs after cpucaps
have been finalized, there should be no functional change as a result of
this patch, but the redundant instructions generated by
cpus_have_const_cap() will be removed from the non-hyp KVM code.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
|
|
By definition, MPIDR_EL1 cannot be modified by the guest. This
means it is pointless to check whether this is loaded on the CPU.
Simplify the kvm_vcpu_get_mpidr_aff() helper to directly access
the in-memory value.
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Tested-by: Joey Gouly <joey.gouly@arm.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230927090911.3355209-8-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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The vCPU-scoped feature bitmap was left in place a couple of releases
ago in case the change to VM-scoped vCPU features broke anyone. Nobody
has complained and the interop between VM and vCPU bitmaps is pretty
gross. Throw it out.
Link: https://lore.kernel.org/r/20230920195036.1169791-9-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
Ensure that SME traps are disabled for (h)VHE when getting the
reset value for the architectural feature control register.
Fixes: 75c76ab5a641 ("KVM: arm64: Rework CPTR_EL2 programming for HVHE configuration")
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230724123829.2929609-9-tabba@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
Ensure that SVE traps are disabled for hVHE, if the FPSIMD state
isn't owned by the guest, when getting the reset value for the
architectural feature control register.
Fixes: 75c76ab5a641 ("KVM: arm64: Rework CPTR_EL2 programming for HVHE configuration")
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230724123829.2929609-8-tabba@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
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Factor out the code that decides whether to write to the feature
trap registers, CPTR_EL2 or CPACR_EL1, based on the KVM mode,
i.e., (h)VHE or nVHE.
This function will be used in the subsequent patch.
No functional change intended.
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230724123829.2929609-6-tabba@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
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* kvm-arm64/misc:
: Miscellaneous updates
:
: - Avoid trapping CTR_EL0 on systems with FEAT_EVT, as the register is
: commonly read by userspace
:
: - Make use of FEAT_BTI at hyp stage-1, setting the Guard Page bit to 1
: for executable mappings
:
: - Use a separate set of pointer authentication keys for the hypervisor
: when running in protected mode (i.e. pKVM)
:
: - Plug a few holes in timer initialization where KVM fails to free the
: timer IRQ(s)
KVM: arm64: Use different pointer authentication keys for pKVM
KVM: arm64: timers: Fix resource leaks in kvm_timer_hyp_init()
KVM: arm64: Use BTI for nvhe
KVM: arm64: Relax trapping of CTR_EL0 when FEAT_EVT is available
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
* kvm-arm64/configurable-id-regs:
: Configurable ID register infrastructure, courtesy of Jing Zhang
:
: Create generalized infrastructure for allowing userspace to select the
: supported feature set for a VM, so long as the feature set is a subset
: of what hardware + KVM allows. This does not add any new features that
: are user-configurable, and instead focuses on the necessary refactoring
: to enable future work.
:
: As a consequence of the series, feature asymmetry is now deliberately
: disallowed for KVM. It is unlikely that VMMs ever configured VMs with
: asymmetry, nor does it align with the kernel's overall stance that
: features must be uniform across all cores in the system.
:
: Furthermore, KVM incorrectly advertised an IMP_DEF PMU to guests for
: some time. Migrations from affected kernels was supported by explicitly
: allowing such an ID register value from userspace, and forwarding that
: along to the guest. KVM now allows an IMP_DEF PMU version to be restored
: through the ID register interface, but reinterprets the user value as
: not implemented (0).
KVM: arm64: Rip out the vestiges of the 'old' ID register scheme
KVM: arm64: Handle ID register reads using the VM-wide values
KVM: arm64: Use generic sanitisation for ID_AA64PFR0_EL1
KVM: arm64: Use generic sanitisation for ID_(AA64)DFR0_EL1
KVM: arm64: Use arm64_ftr_bits to sanitise ID register writes
KVM: arm64: Save ID registers' sanitized value per guest
KVM: arm64: Reuse fields of sys_reg_desc for idreg
KVM: arm64: Rewrite IMPDEF PMU version as NI
KVM: arm64: Make vCPU feature flags consistent VM-wide
KVM: arm64: Relax invariance of KVM_ARM_VCPU_POWER_OFF
KVM: arm64: Separate out feature sanitisation and initialisation
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
Also make sure HCR_EL2.E2H is set when switching HCR_EL2 in guest
context.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230609162200.2024064-16-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
Just like we repainted the early arm64 code, we need to update
the CPTR_EL2 accesses that are taking place in the nVHE code
when hVHE is used, making them look as if they were CPACR_EL1
accesses. Just like the VHE code.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230609162200.2024064-14-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
To date KVM has allowed userspace to construct asymmetric VMs where
particular features may only be supported on a subset of vCPUs. This
wasn't really the intened usage pattern, and it is a total pain in the
ass to keep working in the kernel. What's more, this is at odds with CPU
features in host userspace, where asymmetric features are largely hidden
or disabled.
It's time to put an end to the whole game. Require all vCPUs in the VM
to have the same feature set, rejecting deviants in the
KVM_ARM_VCPU_INIT ioctl. Preserve some of the vestiges of per-vCPU
feature flags in case we need to reinstate the old behavior for some
limited configurations. Yes, this is a sign of cowardice around a
user-visibile change.
Hoist all of the 32-bit limitations into kvm_vcpu_init_check_features()
to avoid nested attempts to acquire the config_lock, which won't end
well.
Link: https://lore.kernel.org/r/20230609190054.1542113-4-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
CTR_EL0 can often be used in userspace, and it would be nice if
KVM didn't have to emulate it unnecessarily.
While it isn't possible to trap the cache configuration registers
independently from CTR_EL0 in the base ARMv8.0 architecture, FEAT_EVT
allows these cache configuration registers (CCSIDR_EL1, CCSIDR2_EL1,
CLIDR_EL1 and CSSELR_EL1) to be trapped independently by setting
HCR_EL2.TID4.
Switch to using TID4 instead of TID2 in the cases where FEAT_EVT
is available *and* that KVM doesn't need to sanitise CTR_EL0 to
paper over mismatched cache configurations.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230515170016.965378-1-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
* kvm-arm64/nv-prefix:
: Preamble to NV support, courtesy of Marc Zyngier.
:
: This brings in a set of prerequisite patches for supporting nested
: virtualization in KVM/arm64. Of course, there is a long way to go until
: NV is actually enabled in KVM.
:
: - Introduce cpucap / vCPU feature flag to pivot the NV code on
:
: - Add support for EL2 vCPU register state
:
: - Basic nested exception handling
:
: - Hide unsupported features from the ID registers for NV-capable VMs
KVM: arm64: nv: Use reg_to_encoding() to get sysreg ID
KVM: arm64: nv: Only toggle cache for virtual EL2 when SCTLR_EL2 changes
KVM: arm64: nv: Filter out unsupported features from ID regs
KVM: arm64: nv: Emulate EL12 register accesses from the virtual EL2
KVM: arm64: nv: Allow a sysreg to be hidden from userspace only
KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisor
KVM: arm64: nv: Add accessors for SPSR_EL1, ELR_EL1 and VBAR_EL1 from virtual EL2
KVM: arm64: nv: Handle SMCs taken from virtual EL2
KVM: arm64: nv: Handle trapped ERET from virtual EL2
KVM: arm64: nv: Inject HVC exceptions to the virtual EL2
KVM: arm64: nv: Support virtual EL2 exceptions
KVM: arm64: nv: Handle HCR_EL2.NV system register traps
KVM: arm64: nv: Add nested virt VCPU primitives for vEL2 VCPU state
KVM: arm64: nv: Add EL2 system registers to vcpu context
KVM: arm64: nv: Allow userspace to set PSR_MODE_EL2x
KVM: arm64: nv: Reset VCPU to EL2 registers if VCPU nested virt is set
KVM: arm64: nv: Introduce nested virtualization VCPU feature
KVM: arm64: Use the S2 MMU context to iterate over S2 table
arm64: Add ARM64_HAS_NESTED_VIRT cpufeature
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
* kvm-arm64/virtual-cache-geometry:
: Virtualized cache geometry for KVM guests, courtesy of Akihiko Odaki.
:
: KVM/arm64 has always exposed the host cache geometry directly to the
: guest, even though non-secure software should never perform CMOs by
: Set/Way. This was slightly wrong, as the cache geometry was derived from
: the PE on which the vCPU thread was running and not a sanitized value.
:
: All together this leads to issues migrating VMs on heterogeneous
: systems, as the cache geometry saved/restored could be inconsistent.
:
: KVM/arm64 now presents 1 level of cache with 1 set and 1 way. The cache
: geometry is entirely controlled by userspace, such that migrations from
: older kernels continue to work.
KVM: arm64: Mark some VM-scoped allocations as __GFP_ACCOUNT
KVM: arm64: Normalize cache configuration
KVM: arm64: Mask FEAT_CCIDX
KVM: arm64: Always set HCR_TID2
arm64/cache: Move CLIDR macro definitions
arm64/sysreg: Add CCSIDR2_EL1
arm64/sysreg: Convert CCSIDR_EL1 to automatic generation
arm64: Allow the definition of UNKNOWN system register fields
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
Support injecting exceptions and performing exception returns to and
from virtual EL2. This must be done entirely in software except when
taking an exception from vEL0 to vEL2 when the virtual HCR_EL2.{E2H,TGE}
== {1,1} (a VHE guest hypervisor).
[maz: switch to common exception injection framework, illegal exeption
return handling]
Reviewed-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>
Signed-off-by: Jintack Lim <jintack.lim@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230209175820.1939006-10-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
When running a nested hypervisor we commonly have to figure out if
the VCPU mode is running in the context of a guest hypervisor or guest
guest, or just a normal guest.
Add convenient primitives for this.
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230209175820.1939006-8-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
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Always set HCR_TID2 to trap CTR_EL0, CCSIDR2_EL1, CLIDR_EL1, and
CSSELR_EL1. This saves a few lines of code and allows to employ their
access trap handlers for more purposes anticipated by the old
condition for setting HCR_TID2.
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Link: https://lore.kernel.org/r/20230112023852.42012-6-akihiko.odaki@daynix.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
The former is an AArch32 legacy, so let's move over to the
verbose (and strictly identical) version.
This involves moving some of the #defines that were private
to KVM into the more generic esr.h.
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
A recent development on the EFI front has resulted in guests having
their page tables baked in the firmware binary, and mapped into the
IPA space as part of a read-only memslot. Not only is this legitimate,
but it also results in added security, so thumbs up.
It is possible to take an S1PTW translation fault if the S1 PTs are
unmapped at stage-2. However, KVM unconditionally treats S1PTW as a
write to correctly handle hardware AF/DB updates to the S1 PTs.
Furthermore, KVM injects an exception into the guest for S1PTW writes.
In the aforementioned case this results in the guest taking an abort
it won't recover from, as the S1 PTs mapping the vectors suffer from
the same problem.
So clearly our handling is... wrong.
Instead, switch to a two-pronged approach:
- On S1PTW translation fault, handle the fault as a read
- On S1PTW permission fault, handle the fault as a write
This is of no consequence to SW that *writes* to its PTs (the write
will trigger a non-S1PTW fault), and SW that uses RO PTs will not
use HW-assisted AF/DB anyway, as that'd be wrong.
Only in the case described in c4ad98e4b72c ("KVM: arm64: Assume write
fault on S1PTW permission fault on instruction fetch") do we end-up
with two back-to-back faults (page being evicted and faulted back).
I don't think this is a case worth optimising for.
Fixes: c4ad98e4b72c ("KVM: arm64: Assume write fault on S1PTW permission fault on instruction fetch")
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Regression-tested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
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We really don't want PENDING_EXCEPTION and INCREMENT_PC to ever be
set at the same time, as they are mutually exclusive. Add checks
that will generate a warning should this ever happen.
Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
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The PC update flags (which also deal with exception injection)
is one of the most complicated use of the flag we have. Make it
more fool prof by:
- moving it over to the new accessors and assign it to the
input flag set
- turn the combination of generic ELx flags with another flag
indicating the target EL itself into an explicit set of
flags for each EL and vector combination
- add a new accessor to pend the exception
This is otherwise a pretty straightformward conversion.
Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
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Pull kvm updates from Paolo Bonzini:
"S390:
- ultravisor communication device driver
- fix TEID on terminating storage key ops
RISC-V:
- Added Sv57x4 support for G-stage page table
- Added range based local HFENCE functions
- Added remote HFENCE functions based on VCPU requests
- Added ISA extension registers in ONE_REG interface
- Updated KVM RISC-V maintainers entry to cover selftests support
ARM:
- Add support for the ARMv8.6 WFxT extension
- Guard pages for the EL2 stacks
- Trap and emulate AArch32 ID registers to hide unsupported features
- Ability to select and save/restore the set of hypercalls exposed to
the guest
- Support for PSCI-initiated suspend in collaboration with userspace
- GICv3 register-based LPI invalidation support
- Move host PMU event merging into the vcpu data structure
- GICv3 ITS save/restore fixes
- The usual set of small-scale cleanups and fixes
x86:
- New ioctls to get/set TSC frequency for a whole VM
- Allow userspace to opt out of hypercall patching
- Only do MSR filtering for MSRs accessed by rdmsr/wrmsr
AMD SEV improvements:
- Add KVM_EXIT_SHUTDOWN metadata for SEV-ES
- V_TSC_AUX support
Nested virtualization improvements for AMD:
- Support for "nested nested" optimizations (nested vVMLOAD/VMSAVE,
nested vGIF)
- Allow AVIC to co-exist with a nested guest running
- Fixes for LBR virtualizations when a nested guest is running, and
nested LBR virtualization support
- PAUSE filtering for nested hypervisors
Guest support:
- Decoupling of vcpu_is_preempted from PV spinlocks"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (199 commits)
KVM: x86: Fix the intel_pt PMI handling wrongly considered from guest
KVM: selftests: x86: Sync the new name of the test case to .gitignore
Documentation: kvm: reorder ARM-specific section about KVM_SYSTEM_EVENT_SUSPEND
x86, kvm: use correct GFP flags for preemption disabled
KVM: LAPIC: Drop pending LAPIC timer injection when canceling the timer
x86/kvm: Alloc dummy async #PF token outside of raw spinlock
KVM: x86: avoid calling x86 emulator without a decoded instruction
KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak
x86/fpu: KVM: Set the base guest FPU uABI size to sizeof(struct kvm_xsave)
s390/uv_uapi: depend on CONFIG_S390
KVM: selftests: x86: Fix test failure on arch lbr capable platforms
KVM: LAPIC: Trace LAPIC timer expiration on every vmentry
KVM: s390: selftest: Test suppression indication on key prot exception
KVM: s390: Don't indicate suppression on dirtying, failing memop
selftests: drivers/s390x: Add uvdevice tests
drivers/s390/char: Add Ultravisor io device
MAINTAINERS: Update KVM RISC-V entry to cover selftests support
RISC-V: KVM: Introduce ISA extension register
RISC-V: KVM: Cleanup stale TLB entries when host CPU changes
RISC-V: KVM: Add remote HFENCE functions based on VCPU requests
...
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git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas:
- Initial support for the ARMv9 Scalable Matrix Extension (SME).
SME takes the approach used for vectors in SVE and extends this to
provide architectural support for matrix operations. No KVM support
yet, SME is disabled in guests.
- Support for crashkernel reservations above ZONE_DMA via the
'crashkernel=X,high' command line option.
- btrfs search_ioctl() fix for live-lock with sub-page faults.
- arm64 perf updates: support for the Hisilicon "CPA" PMU for
monitoring coherent I/O traffic, support for Arm's CMN-650 and
CMN-700 interconnect PMUs, minor driver fixes, kerneldoc cleanup.
- Kselftest updates for SME, BTI, MTE.
- Automatic generation of the system register macros from a 'sysreg'
file describing the register bitfields.
- Update the type of the function argument holding the ESR_ELx register
value to unsigned long to match the architecture register size
(originally 32-bit but extended since ARMv8.0).
- stacktrace cleanups.
- ftrace cleanups.
- Miscellaneous updates, most notably: arm64-specific huge_ptep_get(),
avoid executable mappings in kexec/hibernate code, drop TLB flushing
from get_clear_flush() (and rename it to get_clear_contig()),
ARCH_NR_GPIO bumped to 2048 for ARCH_APPLE.
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (145 commits)
arm64/sysreg: Generate definitions for FAR_ELx
arm64/sysreg: Generate definitions for DACR32_EL2
arm64/sysreg: Generate definitions for CSSELR_EL1
arm64/sysreg: Generate definitions for CPACR_ELx
arm64/sysreg: Generate definitions for CONTEXTIDR_ELx
arm64/sysreg: Generate definitions for CLIDR_EL1
arm64/sve: Move sve_free() into SVE code section
arm64: Kconfig.platforms: Add comments
arm64: Kconfig: Fix indentation and add comments
arm64: mm: avoid writable executable mappings in kexec/hibernate code
arm64: lds: move special code sections out of kernel exec segment
arm64/hugetlb: Implement arm64 specific huge_ptep_get()
arm64/hugetlb: Use ptep_get() to get the pte value of a huge page
arm64: kdump: Do not allocate crash low memory if not needed
arm64/sve: Generate ZCR definitions
arm64/sme: Generate defintions for SVCR
arm64/sme: Generate SMPRI_EL1 definitions
arm64/sme: Automatically generate SMPRIMAP_EL2 definitions
arm64/sme: Automatically generate SMIDR_EL1 defines
arm64/sme: Automatically generate defines for SMCR
...
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* kvm-arm64/aarch32-idreg-trap:
: .
: Add trapping/sanitising infrastructure for AArch32 systen registers,
: allowing more control over what we actually expose (such as the PMU).
:
: Patches courtesy of Oliver and Alexandru.
: .
KVM: arm64: Fix new instances of 32bit ESRs
KVM: arm64: Hide AArch32 PMU registers when not available
KVM: arm64: Start trapping ID registers for 32 bit guests
KVM: arm64: Plumb cp10 ID traps through the AArch64 sysreg handler
KVM: arm64: Wire up CP15 feature registers to their AArch64 equivalents
KVM: arm64: Don't write to Rt unless sys_reg emulation succeeds
KVM: arm64: Return a bool from emulate_cp()
Signed-off-by: Marc Zyngier <maz@kernel.org>
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To date KVM has not trapped ID register accesses from AArch32, meaning
that guests get an unconstrained view of what hardware supports. This
can be a serious problem because we try to base the guest's feature
registers on values that are safe system-wide. Furthermore, KVM does not
implement the latest ISA in the PMU and Debug architecture, so we
constrain these fields to supported values.
Since KVM now correctly handles CP15 and CP10 register traps, we no
longer need to clear HCR_EL2.TID3 for 32 bit guests and will instead
emulate reads with their safe values.
Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220503060205.2823727-6-oupton@google.com
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ESR_EL2 was defined as a 32-bit register in the initial release of the
ARM Architecture Manual for Armv8-A, and was later extended to 64 bits,
with bits [63:32] RES0. ARMv8.7 introduced FEAT_LS64, which makes use of
bits [36:32].
KVM treats ESR_EL1 as a 64-bit register when saving and restoring the
guest context, but ESR_EL2 is handled as a 32-bit register. Start
treating ESR_EL2 as a 64-bit register to allow KVM to make use of the
most significant 32 bits in the future.
The type chosen to represent ESR_EL2 is u64, as that is consistent with the
notation KVM overwhelmingly uses today (u32), and how the rest of the
registers are declared.
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220425114444.368693-5-alexandru.elisei@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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