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https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for 6.2
- Enable the per-vcpu dirty-ring tracking mechanism, together with an
option to keep the good old dirty log around for pages that are
dirtied by something other than a vcpu.
- Switch to the relaxed parallel fault handling, using RCU to delay
page table reclaim and giving better performance under load.
- Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping
option, which multi-process VMMs such as crosvm rely on.
- Merge the pKVM shadow vcpu state tracking that allows the hypervisor
to have its own view of a vcpu, keeping that state private.
- Add support for the PMUv3p5 architecture revision, bringing support
for 64bit counters on systems that support it, and fix the
no-quite-compliant CHAIN-ed counter support for the machines that
actually exist out there.
- Fix a handful of minor issues around 52bit VA/PA support (64kB pages
only) as a prefix of the oncoming support for 4kB and 16kB pages.
- Add/Enable/Fix a bunch of selftests covering memslots, breakpoints,
stage-2 faults and access tracking. You name it, we got it, we
probably broke it.
- Pick a small set of documentation and spelling fixes, because no
good merge window would be complete without those.
As a side effect, this tag also drags:
- The 'kvmarm-fixes-6.1-3' tag as a dependency to the dirty-ring
series
- A shared branch with the arm64 tree that repaints all the system
registers to match the ARM ARM's naming, and resulting in
interesting conflicts
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* kvm-arm64/pmu-unchained:
: .
: PMUv3 fixes and improvements:
:
: - Make the CHAIN event handling strictly follow the architecture
:
: - Add support for PMUv3p5 (64bit counters all the way)
:
: - Various fixes and cleanups
: .
KVM: arm64: PMU: Fix period computation for 64bit counters with 32bit overflow
KVM: arm64: PMU: Sanitise PMCR_EL0.LP on first vcpu run
KVM: arm64: PMU: Simplify PMCR_EL0 reset handling
KVM: arm64: PMU: Replace version number '0' with ID_AA64DFR0_EL1_PMUVer_NI
KVM: arm64: PMU: Make kvm_pmc the main data structure
KVM: arm64: PMU: Simplify vcpu computation on perf overflow notification
KVM: arm64: PMU: Allow PMUv3p5 to be exposed to the guest
KVM: arm64: PMU: Implement PMUv3p5 long counter support
KVM: arm64: PMU: Allow ID_DFR0_EL1.PerfMon to be set from userspace
KVM: arm64: PMU: Allow ID_AA64DFR0_EL1.PMUver to be set from userspace
KVM: arm64: PMU: Move the ID_AA64DFR0_EL1.PMUver limit to VM creation
KVM: arm64: PMU: Do not let AArch32 change the counters' top 32 bits
KVM: arm64: PMU: Simplify setting a counter to a specific value
KVM: arm64: PMU: Add counter_index_to_*reg() helpers
KVM: arm64: PMU: Only narrow counters that are not 64bit wide
KVM: arm64: PMU: Narrow the overflow checking when required
KVM: arm64: PMU: Distinguish between 64bit counter and 64bit overflow
KVM: arm64: PMU: Always advertise the CHAIN event
KVM: arm64: PMU: Align chained counter implementation with architecture pseudocode
arm64: Add ID_DFR0_EL1.PerfMon values for PMUv3p7 and IMP_DEF
Signed-off-by: Marc Zyngier <maz@kernel.org>
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* kvm-arm64/pkvm-vcpu-state: (25 commits)
: .
: Large drop of pKVM patches from Will Deacon and co, adding
: a private vm/vcpu state at EL2, managed independently from
: the EL1 state. From the cover letter:
:
: "This is version six of the pKVM EL2 state series, extending the pKVM
: hypervisor code so that it can dynamically instantiate and manage VM
: data structures without the host being able to access them directly.
: These structures consist of a hyp VM, a set of hyp vCPUs and the stage-2
: page-table for the MMU. The pages used to hold the hypervisor structures
: are returned to the host when the VM is destroyed."
: .
KVM: arm64: Use the pKVM hyp vCPU structure in handle___kvm_vcpu_run()
KVM: arm64: Don't unnecessarily map host kernel sections at EL2
KVM: arm64: Explicitly map 'kvm_vgic_global_state' at EL2
KVM: arm64: Maintain a copy of 'kvm_arm_vmid_bits' at EL2
KVM: arm64: Unmap 'kvm_arm_hyp_percpu_base' from the host
KVM: arm64: Return guest memory from EL2 via dedicated teardown memcache
KVM: arm64: Instantiate guest stage-2 page-tables at EL2
KVM: arm64: Consolidate stage-2 initialisation into a single function
KVM: arm64: Add generic hyp_memcache helpers
KVM: arm64: Provide I-cache invalidation by virtual address at EL2
KVM: arm64: Initialise hypervisor copies of host symbols unconditionally
KVM: arm64: Add per-cpu fixmap infrastructure at EL2
KVM: arm64: Instantiate pKVM hypervisor VM and vCPU structures from EL1
KVM: arm64: Add infrastructure to create and track pKVM instances at EL2
KVM: arm64: Rename 'host_kvm' to 'host_mmu'
KVM: arm64: Add hyp_spinlock_t static initializer
KVM: arm64: Include asm/kvm_mmu.h in nvhe/mem_protect.h
KVM: arm64: Add helpers to pin memory shared with the hypervisor at EL2
KVM: arm64: Prevent the donation of no-map pages
KVM: arm64: Implement do_donate() helper for donating memory
...
Signed-off-by: Marc Zyngier <maz@kernel.org>
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* kvm-arm64/dirty-ring:
: .
: Add support for the "per-vcpu dirty-ring tracking with a bitmap
: and sprinkles on top", courtesy of Gavin Shan.
:
: This branch drags the kvmarm-fixes-6.1-3 tag which was already
: merged in 6.1-rc4 so that the branch is in a working state.
: .
KVM: Push dirty information unconditionally to backup bitmap
KVM: selftests: Automate choosing dirty ring size in dirty_log_test
KVM: selftests: Clear dirty ring states between two modes in dirty_log_test
KVM: selftests: Use host page size to map ring buffer in dirty_log_test
KVM: arm64: Enable ring-based dirty memory tracking
KVM: Support dirty ring in conjunction with bitmap
KVM: Move declaration of kvm_cpu_dirty_log_size() to kvm_dirty_ring.h
KVM: x86: Introduce KVM_REQ_DIRTY_RING_SOFT_FULL
Signed-off-by: Marc Zyngier <maz@kernel.org>
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As further patches will enable the selection of a PMU revision
from userspace, sample the supported PMU revision at VM creation
time, rather than building each time the ID_AA64DFR0_EL1 register
is accessed.
This shouldn't result in any change in behaviour.
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221113163832.3154370-11-maz@kernel.org
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Sharing 'kvm_arm_vmid_bits' between EL1 and EL2 allows the host to
modify the variable arbitrarily, potentially leading to all sorts of
shenanians as this is used to configure the VTTBR register for the
guest stage-2.
In preparation for unmapping host sections entirely from EL2, maintain
a copy of 'kvm_arm_vmid_bits' in the pKVM hypervisor and initialise it
from the host value while it is still trusted.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-23-will@kernel.org
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When pKVM is enabled, the hypervisor at EL2 does not trust the host at
EL1 and must therefore prevent it from having unrestricted access to
internal hypervisor state.
The 'kvm_arm_hyp_percpu_base' array holds the offsets for hypervisor
per-cpu allocations, so move this this into the nVHE code where it
cannot be modified by the untrusted host at EL1.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-22-will@kernel.org
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The initialisation of guest stage-2 page-tables is currently split
across two functions: kvm_init_stage2_mmu() and kvm_arm_setup_stage2().
That is presumably for historical reasons as kvm_arm_setup_stage2()
originates from the (now defunct) KVM port for 32-bit Arm.
Simplify this code path by merging both functions into one, taking care
to map the 'struct kvm' into the hypervisor stage-1 early on in order to
simplify the failure path.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Co-developed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-19-will@kernel.org
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In preparation for handling cache maintenance of guest pages from within
the pKVM hypervisor at EL2, introduce an EL2 copy of icache_inval_pou()
which will later be plumbed into the stage-2 page-table cache
maintenance callbacks, ensuring that the initial contents of pages
mapped as executable into the guest stage-2 page-table is visible to the
instruction fetcher.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-17-will@kernel.org
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The nVHE object at EL2 maintains its own copies of some host variables
so that, when pKVM is enabled, the host cannot directly modify the
hypervisor state. When running in normal nVHE mode, however, these
variables are still mirrored at EL2 but are not initialised.
Initialise the hypervisor symbols from the host copies regardless of
pKVM, ensuring that any reference to this data at EL2 with normal nVHE
will return a sensibly initialised value.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-16-will@kernel.org
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With the pKVM hypervisor at EL2 now offering hypercalls to the host for
creating and destroying VM and vCPU structures, plumb these in to the
existing arm64 KVM backend to ensure that the hypervisor data structures
are allocated and initialised on first vCPU run for a pKVM guest.
In the host, 'struct kvm_protected_vm' is introduced to hold the handle
of the pKVM VM instance as well as to track references to the memory
donated to the hypervisor so that it can be freed back to the host
allocator following VM teardown. The stage-2 page-table, hypervisor VM
and vCPU structures are allocated separately so as to avoid the need for
a large physically-contiguous allocation in the host at run-time.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-14-will@kernel.org
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For nvhe and protected modes, the hyp stage 1 page-tables were previously
configured to have the same number of VA bits as the kernel's idmap.
However, for kernel configs with VA_BITS=52 and where the kernel is
loaded in physical memory below 48 bits, the idmap VA bits is actually
smaller than the kernel's normal stage 1 VA bits. This can lead to
kernel addresses that can't be mapped into the hypervisor, leading to
kvm initialization failure during boot:
kvm [1]: IPA Size Limit: 48 bits
kvm [1]: Cannot map world-switch code
kvm [1]: error initializing Hyp mode: -34
Fix this by ensuring that the hyp stage 1 VA size is the maximum of
what's used for the idmap and the regular kernel stage 1. At the same
time, refactor the code so that the hyp VA bits is only calculated in
one place.
Prior to 7ba8f2b2d652, the idmap was always 52 bits for a 52 VA bits
kernel and therefore the hyp stage1 was also always 52 bits.
Fixes: 7ba8f2b2d652 ("arm64: mm: use a 48-bit ID map when possible on 52-bit VA builds")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
[maz: commit message fixes]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221103150507.32948-2-ryan.roberts@arm.com
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Enable ring-based dirty memory tracking on ARM64:
- Enable CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL.
- Enable CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP.
- Set KVM_DIRTY_LOG_PAGE_OFFSET for the ring buffer's physical page
offset.
- Add ARM64 specific kvm_arch_allow_write_without_running_vcpu() to
keep the site of saving vgic/its tables out of the no-running-vcpu
radar.
Signed-off-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110104914.31280-5-gshan@redhat.com
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virt/kvm/irqchip.c is including "irq.h" from the arch-specific KVM source
directory (i.e. not from arch/*/include) for the sole purpose of retrieving
irqchip_in_kernel.
Making the function inline in a header that is already included,
such as asm/kvm_host.h, is not possible because it needs to look at
struct kvm which is defined after asm/kvm_host.h is included. So add a
kvm_arch_irqchip_in_kernel non-inline function; irqchip_in_kernel() is
only performance critical on arm64 and x86, and the non-inline function
is enough on all other architectures.
irq.h can then be deleted from all architectures except x86.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for v6.1
- Fixes for single-stepping in the presence of an async
exception as well as the preservation of PSTATE.SS
- Better handling of AArch32 ID registers on AArch64-only
systems
- Fixes for the dirty-ring API, allowing it to work on
architectures with relaxed memory ordering
- Advertise the new kvmarm mailing list
- Various minor cleanups and spelling fixes
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KVM x86 updates for 6.1, batch #2:
- Misc PMU fixes and cleanups.
- Fixes for Hyper-V hypercall selftest
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KVM_REQ_UNHALT is now unnecessary because it is replaced by the return
value of kvm_vcpu_block/kvm_vcpu_halt. Remove it.
No functional change intended.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Message-Id: <20220921003201.1441511-13-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Ignore kvm-arm.mode if !is_hyp_mode_available(). Specifically, we want
to avoid switching kvm_mode to KVM_MODE_PROTECTED if hypervisor mode is
not available. This prevents "Protected KVM" cpu capability being
reported when Linux is booting in EL1 and would not have KVM enabled.
Reasonably though, we should warn if the command line is requesting a
KVM mode at all if KVM isn't actually available. Allow
"kvm-arm.mode=none" to skip the warning since this would disable KVM
anyway.
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220920190658.2880184-1-quic_eberman@quicinc.com
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With commit 0c24e061196c ("mm: kmemleak: add rbtree and store physical
address for objects allocated with PA"), kmemleak started to put the
objects allocated with physical address onto object_phys_tree_root tree.
The kmemleak_free_part() therefore no longer worked as expected on
physically allocated objects (hyp_mem_base in this case) as it attempted to
search and remove things in object_tree_root tree.
Fix it by using kmemleak_free_part_phys() to unregister hyp_mem_base. This
fixes an immediate crash when booting a KVM host in protected mode with
kmemleak enabled.
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220908130659.2021-1-yuzenghui@huawei.com
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git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 fixes for 6.0, take #1
- Fix unexpected sign extension of KVM_ARM_DEVICE_ID_MASK
- Tidy-up handling of AArch32 on asymmetric systems
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KVM does not support AArch32 on asymmetric systems. To that end, enforce
AArch64-only behavior on PMCR_EL1.LC when on an asymmetric system.
Fixes: 2122a833316f ("arm64: Allow mismatched 32-bit EL0 support")
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220816192554.1455559-2-oliver.upton@linux.dev
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git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for 5.20:
- Unwinder implementations for both nVHE modes (classic and
protected), complete with an overflow stack
- Rework of the sysreg access from userspace, with a complete
rewrite of the vgic-v3 view to allign with the rest of the
infrastructure
- Disagregation of the vcpu flags in separate sets to better track
their use model.
- A fix for the GICv2-on-v3 selftest
- A small set of cosmetic fixes
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* kvm-arm64/nvhe-stacktrace: (27 commits)
: .
: Add an overflow stack to the nVHE EL2 code, allowing
: the implementation of an unwinder, courtesy of
: Kalesh Singh. From the cover letter (slightly edited):
:
: "nVHE has two modes of operation: protected (pKVM) and unprotected
: (conventional nVHE). Depending on the mode, a slightly different approach
: is used to dump the hypervisor stacktrace but the core unwinding logic
: remains the same.
:
: * Protected nVHE (pKVM) stacktraces:
:
: In protected nVHE mode, the host cannot directly access hypervisor memory.
:
: The hypervisor stack unwinding happens in EL2 and is made accessible to
: the host via a shared buffer. Symbolizing and printing the stacktrace
: addresses is delegated to the host and happens in EL1.
:
: * Non-protected (Conventional) nVHE stacktraces:
:
: In non-protected mode, the host is able to directly access the hypervisor
: stack pages.
:
: The hypervisor stack unwinding and dumping of the stacktrace is performed
: by the host in EL1, as this avoids the memory overhead of setting up
: shared buffers between the host and hypervisor."
:
: Additional patches from Oliver Upton and Marc Zyngier, tidying up
: the initial series.
: .
arm64: Update 'unwinder howto'
KVM: arm64: Don't open code ARRAY_SIZE()
KVM: arm64: Move nVHE-only helpers into kvm/stacktrace.c
KVM: arm64: Make unwind()/on_accessible_stack() per-unwinder functions
KVM: arm64: Move nVHE stacktrace unwinding into its own compilation unit
KVM: arm64: Move PROTECTED_NVHE_STACKTRACE around
KVM: arm64: Introduce pkvm_dump_backtrace()
KVM: arm64: Implement protected nVHE hyp stack unwinder
KVM: arm64: Save protected-nVHE (pKVM) hyp stacktrace
KVM: arm64: Stub implementation of pKVM HYP stack unwinder
KVM: arm64: Allocate shared pKVM hyp stacktrace buffers
KVM: arm64: Add PROTECTED_NVHE_STACKTRACE Kconfig
KVM: arm64: Introduce hyp_dump_backtrace()
KVM: arm64: Implement non-protected nVHE hyp stack unwinder
KVM: arm64: Prepare non-protected nVHE hypervisor stacktrace
KVM: arm64: Stub implementation of non-protected nVHE HYP stack unwinder
KVM: arm64: On stack overflow switch to hyp overflow_stack
arm64: stacktrace: Add description of stacktrace/common.h
arm64: stacktrace: Factor out common unwind()
arm64: stacktrace: Handle frame pointer from different address spaces
...
Signed-off-by: Marc Zyngier <maz@kernel.org>
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Implements the common framework necessary for unwind() to work
for non-protected nVHE mode:
- on_accessible_stack()
- on_overflow_stack()
- unwind_next()
Non-protected nVHE unwind() is used to unwind and dump the hypervisor
stacktrace by the host in EL1
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220726073750.3219117-11-kaleshsingh@google.com
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* kvm-arm64/sysreg-cleanup-5.20:
: .
: Long overdue cleanup of the sysreg userspace access,
: with extra scrubbing on the vgic side of things.
: From the cover letter:
:
: "Schspa Shi recently reported[1] that some of the vgic code interacting
: with userspace was reading uninitialised stack memory, and although
: that read wasn't used any further, it prompted me to revisit this part
: of the code.
:
: Needless to say, this area of the kernel is pretty crufty, and shows a
: bunch of issues in other parts of the KVM/arm64 infrastructure. This
: series tries to remedy a bunch of them:
:
: - Sanitise the way we deal with sysregs from userspace: at the moment,
: each and every .set_user/.get_user callback has to implement its own
: userspace accesses (directly or indirectly). It'd be much better if
: that was centralised so that we can reason about it.
:
: - Enforce that all AArch64 sysregs are 64bit. Always. This was sort of
: implied by the code, but it took some effort to convince myself that
: this was actually the case.
:
: - Move the vgic-v3 sysreg userspace accessors to the userspace
: callbacks instead of hijacking the vcpu trap callback. This allows
: us to reuse the sysreg infrastructure.
:
: - Consolidate userspace accesses for both GICv2, GICv3 and common code
: as much as possible.
:
: - Cleanup a bunch of not-very-useful helpers, tidy up some of the code
: as we touch it.
:
: [1] https://lore.kernel.org/r/m2h740zz1i.fsf@gmail.com"
: .
KVM: arm64: Get rid or outdated comments
KVM: arm64: Descope kvm_arm_sys_reg_{get,set}_reg()
KVM: arm64: Get rid of find_reg_by_id()
KVM: arm64: vgic: Tidy-up calls to vgic_{get,set}_common_attr()
KVM: arm64: vgic: Consolidate userspace access for base address setting
KVM: arm64: vgic-v2: Add helper for legacy dist/cpuif base address setting
KVM: arm64: vgic: Use {get,put}_user() instead of copy_{from.to}_user
KVM: arm64: vgic-v2: Consolidate userspace access for MMIO registers
KVM: arm64: vgic-v3: Consolidate userspace access for MMIO registers
KVM: arm64: vgic-v3: Use u32 to manage the line level from userspace
KVM: arm64: vgic-v3: Convert userspace accessors over to FIELD_GET/FIELD_PREP
KVM: arm64: vgic-v3: Make the userspace accessors use sysreg API
KVM: arm64: vgic-v3: Push user access into vgic_v3_cpu_sysregs_uaccess()
KVM: arm64: vgic-v3: Simplify vgic_v3_has_cpu_sysregs_attr()
KVM: arm64: Get rid of reg_from/to_user()
KVM: arm64: Consolidate sysreg userspace accesses
KVM: arm64: Rely on index_to_param() for size checks on userspace access
KVM: arm64: Introduce generic get_user/set_user helpers for system registers
KVM: arm64: Reorder handling of invariant sysregs from userspace
KVM: arm64: Add get_reg_by_id() as a sys_reg_desc retrieving helper
Signed-off-by: Marc Zyngier <maz@kernel.org>
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We carry a legacy interface to set the base addresses for GICv2.
As this is currently plumbed into the same handling code as
the modern interface, it limits the evolution we can make there.
Add a helper dedicated to this handling, with a view of maybe
removing this in the future.
Signed-off-by: Marc Zyngier <maz@kernel.org>
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* kvm-arm64/burn-the-flags:
: .
: Rework the per-vcpu flags to make them more manageable,
: splitting them in different sets that have specific
: uses:
:
: - configuration flags
: - input to the world-switch
: - state bookkeeping for the kernel itself
:
: The FP tracking is also simplified and tracked outside
: of the flags as a separate state.
: .
KVM: arm64: Move the handling of !FP outside of the fast path
KVM: arm64: Document why pause cannot be turned into a flag
KVM: arm64: Reduce the size of the vcpu flag members
KVM: arm64: Add build-time sanity checks for flags
KVM: arm64: Warn when PENDING_EXCEPTION and INCREMENT_PC are set together
KVM: arm64: Convert vcpu sysregs_loaded_on_cpu to a state flag
KVM: arm64: Kill unused vcpu flags field
KVM: arm64: Move vcpu WFIT flag to the state flag set
KVM: arm64: Move vcpu ON_UNSUPPORTED_CPU flag to the state flag set
KVM: arm64: Move vcpu SVE/SME flags to the state flag set
KVM: arm64: Move vcpu debug/SPE/TRBE flags to the input flag set
KVM: arm64: Move vcpu PC/Exception flags to the input flag set
KVM: arm64: Move vcpu configuration flags into their own set
KVM: arm64: Add three sets of flags to the vcpu state
KVM: arm64: Add helpers to manipulate vcpu flags among a set
KVM: arm64: Move FP state ownership from flag to a tristate
KVM: arm64: Drop FP_FOREIGN_STATE from the hypervisor code
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
We currently start by assuming that the host owns the FP unit
at load time, then check again whether this is the case as
we are about to run. Only at this point do we account for the
fact that there is a (vanishingly small) chance that we're running
on a system without a FPSIMD unit (yes, this is madness).
We can actually move this FPSIMD check as early as load-time,
and drop the check at run time.
No intended change in behaviour.
Suggested-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
The host kernel uses the WFIT flag to remember that a vcpu has used
this instruction and wake it up as required. Move it to the state
set, as nothing in the hypervisor uses this information.
Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
Commit a7259df76702 ("memblock: make memblock_find_in_range method
private") changed the API using which memory is reserved for the pKVM
hypervisor. However, memblock_phys_alloc() differs from the original API in
terms of kmemleak semantics -- the old one didn't report the reserved
regions to kmemleak while the new one does. Unfortunately, when protected
KVM is enabled, all kernel accesses to pKVM-private memory result in a
fatal exception, which can now happen because of kmemleak scans:
$ echo scan > /sys/kernel/debug/kmemleak
[ 34.991354] kvm [304]: nVHE hyp BUG at: [<ffff800008fa3750>] __kvm_nvhe_handle_host_mem_abort+0x270/0x290!
[ 34.991580] kvm [304]: Hyp Offset: 0xfffe8be807e00000
[ 34.991813] Kernel panic - not syncing: HYP panic:
[ 34.991813] PS:600003c9 PC:0000f418011a3750 ESR:00000000f2000800
[ 34.991813] FAR:ffff000439200000 HPFAR:0000000004792000 PAR:0000000000000000
[ 34.991813] VCPU:0000000000000000
[ 34.993660] CPU: 0 PID: 304 Comm: bash Not tainted 5.19.0-rc2 #102
[ 34.994059] Hardware name: linux,dummy-virt (DT)
[ 34.994452] Call trace:
[ 34.994641] dump_backtrace.part.0+0xcc/0xe0
[ 34.994932] show_stack+0x18/0x6c
[ 34.995094] dump_stack_lvl+0x68/0x84
[ 34.995276] dump_stack+0x18/0x34
[ 34.995484] panic+0x16c/0x354
[ 34.995673] __hyp_pgtable_total_pages+0x0/0x60
[ 34.995933] scan_block+0x74/0x12c
[ 34.996129] scan_gray_list+0xd8/0x19c
[ 34.996332] kmemleak_scan+0x2c8/0x580
[ 34.996535] kmemleak_write+0x340/0x4a0
[ 34.996744] full_proxy_write+0x60/0xbc
[ 34.996967] vfs_write+0xc4/0x2b0
[ 34.997136] ksys_write+0x68/0xf4
[ 34.997311] __arm64_sys_write+0x20/0x2c
[ 34.997532] invoke_syscall+0x48/0x114
[ 34.997779] el0_svc_common.constprop.0+0x44/0xec
[ 34.998029] do_el0_svc+0x2c/0xc0
[ 34.998205] el0_svc+0x2c/0x84
[ 34.998421] el0t_64_sync_handler+0xf4/0x100
[ 34.998653] el0t_64_sync+0x18c/0x190
[ 34.999252] SMP: stopping secondary CPUs
[ 35.000034] Kernel Offset: disabled
[ 35.000261] CPU features: 0x800,00007831,00001086
[ 35.000642] Memory Limit: none
[ 35.001329] ---[ end Kernel panic - not syncing: HYP panic:
[ 35.001329] PS:600003c9 PC:0000f418011a3750 ESR:00000000f2000800
[ 35.001329] FAR:ffff000439200000 HPFAR:0000000004792000 PAR:0000000000000000
[ 35.001329] VCPU:0000000000000000 ]---
Fix this by explicitly excluding the hypervisor's memory pool from
kmemleak like we already do for the hyp BSS.
Cc: Mike Rapoport <rppt@kernel.org>
Fixes: a7259df76702 ("memblock: make memblock_find_in_range method private")
Signed-off-by: Quentin Perret <qperret@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220616161135.3997786-1-qperret@google.com
|
|
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>
|
|
Ignore 'kvm-arm.mode=protected' when using VHE so that kvm_get_mode()
only returns KVM_MODE_PROTECTED on systems where the feature is available.
Cc: David Brazdil <dbrazdil@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220609121223.2551-4-will@kernel.org
|
|
If we fail to allocate the 'supported_cpus' cpumask in kvm_arch_init_vm()
then be sure to return -ENOMEM instead of success (0) on the failure
path.
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220609121223.2551-2-will@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/kvmarm/kvmarm into HEAD
KVM/arm64 updates for 5.19
- 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
[Due to the conflict, KVM_SYSTEM_EVENT_SEV_TERM is relocated
from 4 to 6. - Paolo]
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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/misc-5.19:
: .
: Misc fixes and general improvements for KVMM/arm64:
:
: - Better handle out of sequence sysregs in the global tables
:
: - Remove a couple of unnecessary loads from constant pool
:
: - Drop unnecessary pKVM checks
:
: - Add all known M1 implementations to the SEIS workaround
:
: - Cleanup kerneldoc warnings
: .
KVM: arm64: vgic-v3: List M1 Pro/Max as requiring the SEIS workaround
KVM: arm64: pkvm: Don't mask already zeroed FEAT_SVE
KVM: arm64: pkvm: Drop unnecessary FP/SIMD trap handler
KVM: arm64: nvhe: Eliminate kernel-doc warnings
KVM: arm64: Avoid unnecessary absolute addressing via literals
KVM: arm64: Print emulated register table name when it is unsorted
KVM: arm64: Don't BUG_ON() if emulated register table is unsorted
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
* kvm-arm64/per-vcpu-host-pmu-data:
: .
: Pass the host PMU state in the vcpu to avoid the use of additional
: shared memory between EL1 and EL2 (this obviously only applies
: to nVHE and Protected setups).
:
: Patches courtesy of Fuad Tabba.
: .
KVM: arm64: pmu: Restore compilation when HW_PERF_EVENTS isn't selected
KVM: arm64: Reenable pmu in Protected Mode
KVM: arm64: Pass pmu events to hyp via vcpu
KVM: arm64: Repack struct kvm_pmu to reduce size
KVM: arm64: Wrapper for getting pmu_events
Signed-off-by: Marc Zyngier <maz@kernel.org>
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|
* kvm-arm64/psci-suspend:
: .
: Add support for PSCI SYSTEM_SUSPEND and allow userspace to
: filter the wake-up events.
:
: Patches courtesy of Oliver.
: .
Documentation: KVM: Fix title level for PSCI_SUSPEND
selftests: KVM: Test SYSTEM_SUSPEND PSCI call
selftests: KVM: Refactor psci_test to make it amenable to new tests
selftests: KVM: Use KVM_SET_MP_STATE to power off vCPU in psci_test
selftests: KVM: Create helper for making SMCCC calls
selftests: KVM: Rename psci_cpu_on_test to psci_test
KVM: arm64: Implement PSCI SYSTEM_SUSPEND
KVM: arm64: Add support for userspace to suspend a vCPU
KVM: arm64: Return a value from check_vcpu_requests()
KVM: arm64: Rename the KVM_REQ_SLEEP handler
KVM: arm64: Track vCPU power state using MP state values
KVM: arm64: Dedupe vCPU power off helpers
KVM: arm64: Don't depend on fallthrough to hide SYSTEM_RESET2
Signed-off-by: Marc Zyngier <maz@kernel.org>
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|
* kvm-arm64/hcall-selection:
: .
: Introduce a new set of virtual sysregs for userspace to
: select the hypercalls it wants to see exposed to the guest.
:
: Patches courtesy of Raghavendra and Oliver.
: .
KVM: arm64: Fix hypercall bitmap writeback when vcpus have already run
KVM: arm64: Hide KVM_REG_ARM_*_BMAP_BIT_COUNT from userspace
Documentation: Fix index.rst after psci.rst renaming
selftests: KVM: aarch64: Add the bitmap firmware registers to get-reg-list
selftests: KVM: aarch64: Introduce hypercall ABI test
selftests: KVM: Create helper for making SMCCC calls
selftests: KVM: Rename psci_cpu_on_test to psci_test
tools: Import ARM SMCCC definitions
Docs: KVM: Add doc for the bitmap firmware registers
Docs: KVM: Rename psci.rst to hypercalls.rst
KVM: arm64: Add vendor hypervisor firmware register
KVM: arm64: Add standard hypervisor firmware register
KVM: arm64: Setup a framework for hypercall bitmap firmware registers
KVM: arm64: Factor out firmware register handling from psci.c
Signed-off-by: Marc Zyngier <maz@kernel.org>
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Moving kvm_pmu_events into the vcpu (and refering to it) broke the
somewhat unusual case where the kernel has no support for a PMU
at all.
In order to solve this, move things around a bit so that we can
easily avoid refering to the pmu structure outside of PMU-aware
code. As a bonus, pmu.c isn't compiled in when HW_PERF_EVENTS
isn't selected.
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/202205161814.KQHpOzsJ-lkp@intel.com
|
|
Will reported the following splat when running with Protected KVM
enabled:
[ 2.427181] ------------[ cut here ]------------
[ 2.427668] WARNING: CPU: 3 PID: 1 at arch/arm64/kvm/mmu.c:489 __create_hyp_private_mapping+0x118/0x1ac
[ 2.428424] Modules linked in:
[ 2.429040] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.18.0-rc2-00084-g8635adc4efc7 #1
[ 2.429589] Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
[ 2.430286] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 2.430734] pc : __create_hyp_private_mapping+0x118/0x1ac
[ 2.431091] lr : create_hyp_exec_mappings+0x40/0x80
[ 2.431377] sp : ffff80000803baf0
[ 2.431597] x29: ffff80000803bb00 x28: 0000000000000000 x27: 0000000000000000
[ 2.432156] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
[ 2.432561] x23: ffffcd96c343b000 x22: 0000000000000000 x21: ffff80000803bb40
[ 2.433004] x20: 0000000000000004 x19: 0000000000001800 x18: 0000000000000000
[ 2.433343] x17: 0003e68cf7efdd70 x16: 0000000000000004 x15: fffffc81f602a2c8
[ 2.434053] x14: ffffdf8380000000 x13: ffffcd9573200000 x12: ffffcd96c343b000
[ 2.434401] x11: 0000000000000004 x10: ffffcd96c1738000 x9 : 0000000000000004
[ 2.434812] x8 : ffff80000803bb40 x7 : 7f7f7f7f7f7f7f7f x6 : 544f422effff306b
[ 2.435136] x5 : 000000008020001e x4 : ffff207d80a88c00 x3 : 0000000000000005
[ 2.435480] x2 : 0000000000001800 x1 : 000000014f4ab800 x0 : 000000000badca11
[ 2.436149] Call trace:
[ 2.436600] __create_hyp_private_mapping+0x118/0x1ac
[ 2.437576] create_hyp_exec_mappings+0x40/0x80
[ 2.438180] kvm_init_vector_slots+0x180/0x194
[ 2.458941] kvm_arch_init+0x80/0x274
[ 2.459220] kvm_init+0x48/0x354
[ 2.459416] arm_init+0x20/0x2c
[ 2.459601] do_one_initcall+0xbc/0x238
[ 2.459809] do_initcall_level+0x94/0xb4
[ 2.460043] do_initcalls+0x54/0x94
[ 2.460228] do_basic_setup+0x1c/0x28
[ 2.460407] kernel_init_freeable+0x110/0x178
[ 2.460610] kernel_init+0x20/0x1a0
[ 2.460817] ret_from_fork+0x10/0x20
[ 2.461274] ---[ end trace 0000000000000000 ]---
Indeed, the Protected KVM mode promotes __create_hyp_private_mapping()
to a hypercall as EL1 no longer has access to the hypervisor's stage-1
page-table. However, the call from kvm_init_vector_slots() happens after
pKVM has been initialized on the primary CPU, but before it has been
initialized on secondaries. As such, if the KVM initcall procedure is
migrated from one CPU to another in this window, the hypercall may end up
running on a CPU for which EL2 has not been initialized.
Fortunately, the pKVM hypervisor doesn't rely on the host to re-map the
vectors in the private range, so the hypercall in question is in fact
superfluous. Skip it when pKVM is enabled.
Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
[maz: simplified the checks slightly]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220513092607.35233-1-qperret@google.com
|
|
Instead of the host accessing hyp data directly, pass the pmu
events of the current cpu to hyp via the vcpu.
This adds 64 bits (in two fields) to the vcpu that need to be
synced before every vcpu run in nvhe and protected modes.
However, it isolates the hypervisor from the host, which allows
us to use pmu in protected mode in a subsequent patch.
No visible side effects in behavior intended.
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220510095710.148178-4-tabba@google.com
|
|
To emulate a register access, KVM uses a table of registers sorted by
register encoding to speed up queries using binary search.
When Linux boots, KVM checks that the table is sorted and uses a BUG_ON()
statement to let the user know if it's not. The unfortunate side effect is
that an unsorted sysreg table brings down the whole kernel, not just KVM,
even though the rest of the kernel can function just fine without KVM. To
make matters worse, on machines which lack a serial console, the user is
left pondering why the machine is taking so long to boot.
Improve this situation by returning an error from kvm_arch_init() if the
sysreg tables are not in the correct order. The machine is still very much
usable for the user, with the exception of virtualization, who can now
easily determine what went wrong.
A minor typo has also been corrected in the check_sysreg_table() function.
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220428103405.70884-2-alexandru.elisei@arm.com
|
|
* kvm-arm64/hyp-stack-guard:
: .
: Harden the EL2 stack by providing stack guards, courtesy of
: Kalesh Singh.
: .
KVM: arm64: Symbolize the nVHE HYP addresses
KVM: arm64: Detect and handle hypervisor stack overflows
KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
KVM: arm64: Add guard pages for KVM nVHE hypervisor stack
KVM: arm64: Introduce pkvm_alloc_private_va_range()
KVM: arm64: Introduce hyp_alloc_private_va_range()
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
ARM DEN0022D.b 5.19 "SYSTEM_SUSPEND" describes a PSCI call that allows
software to request that a system be placed in the deepest possible
low-power state. Effectively, software can use this to suspend itself to
RAM.
Unfortunately, there really is no good way to implement a system-wide
PSCI call in KVM. Any precondition checks done in the kernel will need
to be repeated by userspace since there is no good way to protect a
critical section that spans an exit to userspace. SYSTEM_RESET and
SYSTEM_OFF are equally plagued by this issue, although no users have
seemingly cared for the relatively long time these calls have been
supported.
The solution is to just make the whole implementation userspace's
problem. Introduce a new system event, KVM_SYSTEM_EVENT_SUSPEND, that
indicates to userspace a calling vCPU has invoked PSCI SYSTEM_SUSPEND.
Additionally, add a CAP to get buy-in from userspace for this new exit
type.
Only advertise the SYSTEM_SUSPEND PSCI call if userspace has opted in.
If a vCPU calls SYSTEM_SUSPEND, punt straight to userspace. Provide
explicit documentation of userspace's responsibilites for the exit and
point to the PSCI specification to describe the actual PSCI call.
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220504032446.4133305-8-oupton@google.com
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Introduce a new MP state, KVM_MP_STATE_SUSPENDED, which indicates a vCPU
is in a suspended state. In the suspended state the vCPU will block
until a wakeup event (pending interrupt) is recognized.
Add a new system event type, KVM_SYSTEM_EVENT_WAKEUP, to indicate to
userspace that KVM has recognized one such wakeup event. It is the
responsibility of userspace to then make the vCPU runnable, or leave it
suspended until the next wakeup event.
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220504032446.4133305-7-oupton@google.com
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|
A subsequent change to KVM will introduce a vCPU request that could
result in an exit to userspace. Change check_vcpu_requests() to return a
value and document the function. Unconditionally return 1 for now.
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220504032446.4133305-6-oupton@google.com
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The naming of the kvm_req_sleep function is confusing: the function
itself sleeps the vCPU, it does not request such an event. Rename the
function to make its purpose more clear.
No functional change intended.
Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220504032446.4133305-5-oupton@google.com
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A subsequent change to KVM will add support for additional power states.
Store the MP state by value rather than keeping track of it as a
boolean.
No functional change intended.
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/20220504032446.4133305-4-oupton@google.com
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