Commit Graph

136 Commits

Author SHA1 Message Date
Linus Torvalds
4f712ee0cb Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
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
  ...
2024-03-15 13:03:13 -07:00
Ard Biesheuvel
7ac8d5b242 arm64: Add ESR decoding for exceptions involving translation level -1
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>
2024-02-16 12:42:37 +00:00
Marc Zyngier
94f29ab2d8 KVM: arm64: Force guest's HCR_EL2.E2H RES1 when NV1 is not implemented
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>
2024-02-08 15:12:45 +00:00
Marc Zyngier
d016264d07 Merge branch kvm-arm64/nv-6.8-prefix into kvmarm-master/next
* 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>
2023-12-19 10:06:58 +00:00
Marc Zyngier
111903d1f5 KVM: arm64: nv: Hoist vcpu_has_nv() into is_hyp_ctxt()
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>
2023-12-19 09:50:52 +00:00
Ard Biesheuvel
11e5ea5242 KVM: arm64: Use helpers to classify exception types reported via ESR
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
2023-11-30 10:45:28 +00:00
Ryan Roberts
0abc1b11a0 KVM: arm64: Support up to 5 levels of translation in kvm_pgtable
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
2023-11-27 15:03:50 +00:00
Ryan Roberts
419edf48d7 KVM: arm64: Convert translation level parameter to s8
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
2023-11-27 15:03:50 +00:00
Linus Torvalds
6803bd7956 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
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}
  ...
2023-11-02 15:45:15 -10:00
Oliver Upton
54b44ad26c Merge branch kvm-arm64/sgi-injection into kvmarm/next
* 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>
2023-10-30 20:19:13 +00:00
Mark Rutland
d8569fba13 arm64: kvm: Use cpus_have_final_cap() explicitly
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:

  d86de40dec ("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>
2023-10-16 12:57:56 +01:00
Marc Zyngier
0a2acd38d2 KVM: arm64: Simplify kvm_vcpu_get_mpidr_aff()
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>
2023-09-30 18:15:43 +00:00
Oliver Upton
1de10b7d13 KVM: arm64: Get rid of vCPU-scoped feature bitmap
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>
2023-09-21 18:13:29 +00:00
Fuad Tabba
375110ab51 KVM: arm64: Fix resetting SME trap values on reset for (h)VHE
Ensure that SME traps are disabled for (h)VHE when getting the
reset value for the architectural feature control register.

Fixes: 75c76ab5a6 ("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>
2023-07-26 17:08:30 +00:00
Fuad Tabba
7af0d5e500 KVM: arm64: Fix resetting SVE trap values on reset for hVHE
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: 75c76ab5a6 ("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>
2023-07-26 17:08:30 +00:00
Fuad Tabba
90ae31c65d KVM: arm64: Helper to write to appropriate feature trap register based on mode
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>
2023-07-26 17:08:29 +00:00
Oliver Upton
e1e315c4d5 Merge branch kvm-arm64/misc into kvmarm/next
* 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>
2023-06-15 13:09:43 +00:00
Oliver Upton
89a734b54c Merge branch kvm-arm64/configurable-id-regs into kvmarm/next
* 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>
2023-06-15 13:05:11 +00:00
Marc Zyngier
38cba55008 KVM: arm64: Force HCR_E2H in guest context when ARM64_KVM_HVHE is set
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>
2023-06-12 23:17:24 +00:00
Marc Zyngier
75c76ab5a6 KVM: arm64: Rework CPTR_EL2 programming for HVHE configuration
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>
2023-06-12 23:17:24 +00:00
Oliver Upton
2251e9ff15 KVM: arm64: Make vCPU feature flags consistent VM-wide
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>
2023-06-12 23:08:33 +00:00
Marc Zyngier
c876c3f182 KVM: arm64: Relax trapping of CTR_EL0 when FEAT_EVT is available
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>
2023-05-21 19:09:44 +00:00
Oliver Upton
0d3b2b4d23 Merge branch kvm-arm64/nv-prefix into kvmarm/next
* 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>
2023-02-13 23:33:41 +00:00
Oliver Upton
e8789ab704 Merge branch kvm-arm64/virtual-cache-geometry into kvmarm/next
* 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>
2023-02-13 22:32:40 +00:00
Jintack Lim
47f3a2fc76 KVM: arm64: nv: Support virtual EL2 exceptions
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>
2023-02-11 09:16:11 +00:00
Christoffer Dall
0043b29038 KVM: arm64: nv: Add nested virt VCPU primitives for vEL2 VCPU state
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>
2023-02-11 09:16:11 +00:00
Akihiko Odaki
8cc6dedaff KVM: arm64: Always set HCR_TID2
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>
2023-01-12 21:07:43 +00:00
Marc Zyngier
b0803ba72b KVM: arm64: Convert FSC_* over to ESR_ELx_FSC_*
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>
2023-01-03 10:01:52 +00:00
Marc Zyngier
406504c7b0 KVM: arm64: Fix S1PTW handling on RO memslots
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 c4ad98e4b7 ("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: c4ad98e4b7 ("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
2023-01-03 09:59:29 +00:00
Marc Zyngier
e19f2c6cd1 KVM: arm64: Warn when PENDING_EXCEPTION and INCREMENT_PC are set together
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>
2022-06-29 10:23:37 +01:00
Marc Zyngier
699bb2e0c6 KVM: arm64: Move vcpu PC/Exception flags to the input flag set
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>
2022-06-10 09:54:34 +01:00
Linus Torvalds
bf9095424d Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
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
  ...
2022-05-26 14:20:14 -07:00
Linus Torvalds
143a6252e1 Merge tag 'arm64-upstream' of 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
  ...
2022-05-23 21:06:11 -07:00
Marc Zyngier
d25f30fe41 Merge branch kvm-arm64/aarch32-idreg-trap into kvmarm-master/next
* 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>
2022-05-04 09:42:45 +01:00
Oliver Upton
fd1264c4ca KVM: arm64: Start trapping ID registers for 32 bit guests
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
2022-05-03 11:14:34 +01:00
Alexandru Elisei
0b12620fdd KVM: arm64: Treat ESR_EL2 as a 64-bit register
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>
2022-04-29 19:26:27 +01:00
Marc Zyngier
85ea6b1ec9 KVM: arm64: Inject exception on out-of-IPA-range translation fault
When taking a translation fault for an IPA that is outside of
the range defined by the hypervisor (between the HW PARange and
the IPA range), we stupidly treat it as an IO and forward the access
to userspace. Of course, userspace can't do much with it, and things
end badly.

Arguably, the guest is braindead, but we should at least catch the
case and inject an exception.

Check the faulting IPA against:
- the sanitised PARange: inject an address size fault
- the IPA size: inject an abort

Reported-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-04-27 23:02:23 +01:00
Reiji Watanabe
26bf74bd9f KVM: arm64: mixed-width check should be skipped for uninitialized vCPUs
KVM allows userspace to configure either all EL1 32bit or 64bit vCPUs
for a guest.  At vCPU reset, vcpu_allowed_register_width() checks
if the vcpu's register width is consistent with all other vCPUs'.
Since the checking is done even against vCPUs that are not initialized
(KVM_ARM_VCPU_INIT has not been done) yet, the uninitialized vCPUs
are erroneously treated as 64bit vCPU, which causes the function to
incorrectly detect a mixed-width VM.

Introduce KVM_ARCH_FLAG_EL1_32BIT and KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED
bits for kvm->arch.flags.  A value of the EL1_32BIT bit indicates that
the guest needs to be configured with all 32bit or 64bit vCPUs, and
a value of the REG_WIDTH_CONFIGURED bit indicates if a value of the
EL1_32BIT bit is valid (already set up). Values in those bits are set at
the first KVM_ARM_VCPU_INIT for the guest based on KVM_ARM_VCPU_EL1_32BIT
configuration for the vCPU.

Check vcpu's register width against those new bits at the vcpu's
KVM_ARM_VCPU_INIT (instead of against other vCPUs' register width).

Fixes: 66e94d5caf ("KVM: arm64: Prevent mixed-width VM creation")
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220329031924.619453-2-reijiw@google.com
2022-04-06 12:29:45 +01:00
Paolo Bonzini
7fd55a02a4 Merge tag 'kvmarm-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for Linux 5.16

- Simplification of the 'vcpu first run' by integrating it into
  KVM's 'pid change' flow

- Refactoring of the FP and SVE state tracking, also leading to
  a simpler state and less shared data between EL1 and EL2 in
  the nVHE case

- Tidy up the header file usage for the nvhe hyp object

- New HYP unsharing mechanism, finally allowing pages to be
  unmapped from the Stage-1 EL2 page-tables

- Various pKVM cleanups around refcounting and sharing

- A couple of vgic fixes for bugs that would trigger once
  the vcpu xarray rework is merged, but not sooner

- Add minimal support for ARMv8.7's PMU extension

- Rework kvm_pgtable initialisation ahead of the NV work

- New selftest for IRQ injection

- Teach selftests about the lack of default IPA space and
  page sizes

- Expand sysreg selftest to deal with Pointer Authentication

- The usual bunch of cleanups and doc update
2022-01-07 10:42:19 -05:00
Fuad Tabba
500ca5241b KVM: arm64: Use defined value for SCTLR_ELx_EE
Replace the hardcoded value with the existing definition.

No functional change intended.

Signed-off-by: Fuad Tabba <tabba@google.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211208192810.657360-1-tabba@google.com
2021-12-20 13:55:48 +00:00
Sean Christopherson
6109c5a6ab KVM: arm64: Move vGIC v4 handling for WFI out arch callback hook
Move the put and reload of the vGIC out of the block/unblock callbacks
and into a dedicated WFI helper.  Functionally, this is nearly a nop as
the block hook is called at the very beginning of kvm_vcpu_block(), and
the only code in kvm_vcpu_block() after the unblock hook is to update the
halt-polling controls, i.e. can only affect the next WFI.

Back when the arch (un)blocking hooks were added by commits 3217f7c25b
("KVM: Add kvm_arch_vcpu_{un}blocking callbacks) and d35268da66
("arm/arm64: KVM: arch_timer: Only schedule soft timer on vcpu_block"),
the hooks were invoked only when KVM was about to "block", i.e. schedule
out the vCPU.  The use case at the time was to schedule a timer in the
host based on the earliest timer in the guest in order to wake the
blocking vCPU when the emulated guest timer fired.  Commit accb99bcd0
("KVM: arm/arm64: Simplify bg_timer programming") reworked the timer
logic to be even more precise, by waiting until the vCPU was actually
scheduled out, and so move the timer logic from the (un)blocking hooks to
vcpu_load/put.

In the meantime, the hooks gained usage for enabling vGIC v4 doorbells in
commit df9ba95993 ("KVM: arm/arm64: GICv4: Use the doorbell interrupt
as an unblocking source"), and added related logic for the VMCR in commit
5eeaf10eec ("KVM: arm/arm64: Sync ICH_VMCR_EL2 back when about to block").

Finally, commit 07ab0f8d9a ("KVM: Call kvm_arch_vcpu_blocking early
into the blocking sequence") hoisted the (un)blocking hooks so that they
wrapped KVM's halt-polling logic in addition to the core "block" logic.

In other words, the original need for arch hooks to take action _only_
in the block path is long since gone.

Cc: Oliver Upton <oupton@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211009021236.4122790-11-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08 04:24:49 -05:00
Marc Zyngier
69adec18e9 KVM: arm64: Fix reporting of endianess when the access originates at EL0
We currently check SCTLR_EL1.EE when computing the address of
a faulting guest access. However, the fault could have occured at
EL0, in which case the right bit to check would be SCTLR_EL1.E0E.

This is pretty unlikely to cause any issue in practice: You'd have
to have a guest with a LE EL1 and a BE EL0 (or the other way around),
and have mapped a device into the EL0 page tables.

Good luck with that!

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Link: https://lore.kernel.org/r/20211012112312.1247467-1-maz@kernel.org
2021-10-12 15:47:25 +01:00
Steven Price
ea7fc1bb1c KVM: arm64: Introduce MTE VM feature
Add a new VM feature 'KVM_ARM_CAP_MTE' which enables memory tagging
for a VM. This will expose the feature to the guest and automatically
tag memory pages touched by the VM as PG_mte_tagged (and clear the tag
storage) to ensure that the guest cannot see stale tags, and so that
the tags are correctly saved/restored across swap.

Actually exposing the new capability to user space happens in a later
patch.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
[maz: move VM_SHARED sampling into the critical section]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210621111716.37157-3-steven.price@arm.com
2021-06-22 14:08:05 +01:00
Marc Zyngier
66e94d5caf KVM: arm64: Prevent mixed-width VM creation
It looks like we have tolerated creating mixed-width VMs since...
forever. However, that was never the intention, and we'd rather
not have to support that pointless complexity.

Forbid such a setup by making sure all the vcpus have the same
register width.

Reported-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20210524170752.1549797-1-maz@kernel.org
2021-05-27 10:34:33 +01:00
Linus Torvalds
6a447b0e31 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
 "Much x86 work was pushed out to 5.12, but ARM more than made up for it.

  ARM:
   - PSCI relay at EL2 when "protected KVM" is enabled
   - New exception injection code
   - Simplification of AArch32 system register handling
   - Fix PMU accesses when no PMU is enabled
   - Expose CSV3 on non-Meltdown hosts
   - Cache hierarchy discovery fixes
   - PV steal-time cleanups
   - Allow function pointers at EL2
   - Various host EL2 entry cleanups
   - Simplification of the EL2 vector allocation

  s390:
   - memcg accouting for s390 specific parts of kvm and gmap
   - selftest for diag318
   - new kvm_stat for when async_pf falls back to sync

  x86:
   - Tracepoints for the new pagetable code from 5.10
   - Catch VFIO and KVM irqfd events before userspace
   - Reporting dirty pages to userspace with a ring buffer
   - SEV-ES host support
   - Nested VMX support for wait-for-SIPI activity state
   - New feature flag (AVX512 FP16)
   - New system ioctl to report Hyper-V-compatible paravirtualization features

  Generic:
   - Selftest improvements"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (171 commits)
  KVM: SVM: fix 32-bit compilation
  KVM: SVM: Add AP_JUMP_TABLE support in prep for AP booting
  KVM: SVM: Provide support to launch and run an SEV-ES guest
  KVM: SVM: Provide an updated VMRUN invocation for SEV-ES guests
  KVM: SVM: Provide support for SEV-ES vCPU loading
  KVM: SVM: Provide support for SEV-ES vCPU creation/loading
  KVM: SVM: Update ASID allocation to support SEV-ES guests
  KVM: SVM: Set the encryption mask for the SVM host save area
  KVM: SVM: Add NMI support for an SEV-ES guest
  KVM: SVM: Guest FPU state save/restore not needed for SEV-ES guest
  KVM: SVM: Do not report support for SMM for an SEV-ES guest
  KVM: x86: Update __get_sregs() / __set_sregs() to support SEV-ES
  KVM: SVM: Add support for CR8 write traps for an SEV-ES guest
  KVM: SVM: Add support for CR4 write traps for an SEV-ES guest
  KVM: SVM: Add support for CR0 write traps for an SEV-ES guest
  KVM: SVM: Add support for EFER write traps for an SEV-ES guest
  KVM: SVM: Support string IO operations for an SEV-ES guest
  KVM: SVM: Support MMIO for an SEV-ES guest
  KVM: SVM: Create trace events for VMGEXIT MSR protocol processing
  KVM: SVM: Create trace events for VMGEXIT processing
  ...
2020-12-20 10:44:05 -08:00
Yanan Wang
7d894834a3 KVM: arm64: Add usage of stage 2 fault lookup level in user_mem_abort()
If we get a FSC_PERM fault, just using (logging_active && writable) to
determine calling kvm_pgtable_stage2_map(). There will be two more cases
we should consider.

(1) After logging_active is configged back to false from true. When we
get a FSC_PERM fault with write_fault and adjustment of hugepage is needed,
we should merge tables back to a block entry. This case is ignored by still
calling kvm_pgtable_stage2_relax_perms(), which will lead to an endless
loop and guest panic due to soft lockup.

(2) We use (FSC_PERM && logging_active && writable) to determine
collapsing a block entry into a table by calling kvm_pgtable_stage2_map().
But sometimes we may only need to relax permissions when trying to write
to a page other than a block.
In this condition,using kvm_pgtable_stage2_relax_perms() will be fine.

The ISS filed bit[1:0] in ESR_EL2 regesiter indicates the stage2 lookup
level at which a D-abort or I-abort occurred. By comparing granule of
the fault lookup level with vma_pagesize, we can strictly distinguish
conditions of calling kvm_pgtable_stage2_relax_perms() or
kvm_pgtable_stage2_map(), and the above two cases will be well considered.

Suggested-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201201201034.116760-4-wangyanan55@huawei.com
2020-12-02 09:53:29 +00:00
Marc Zyngier
90c1f934ed KVM: arm64: Get rid of the AArch32 register mapping code
The only use of the register mapping code was for the sake of the LR
mapping, which we trivially solved in a previous patch. Get rid of
the whole thing now.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-11-10 08:34:27 +00:00
Marc Zyngier
dcfba39932 KVM: arm64: Consolidate exception injection
Move the AArch32 exception injection code back into the inject_fault.c
file, removing the need for a few non-static functions now that AArch32
host support is a thing of the past.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-11-10 08:34:26 +00:00
Marc Zyngier
7d76b8a603 KVM: arm64: Remove SPSR manipulation primitives
The SPSR setting code is now completely unused, including that dealing
with banked AArch32 SPSRs. Cleanup time.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-11-10 08:34:26 +00:00
Marc Zyngier
bb666c472c KVM: arm64: Inject AArch64 exceptions from HYP
Move the AArch64 exception injection code from EL1 to HYP, leaving
only the ESR_EL1 updates to EL1. In order to come with the differences
between VHE and nVHE, two set of system register accessors are provided.

SPSR, ELR, PC and PSTATE are now completely handled in the hypervisor.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-11-10 08:34:26 +00:00