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When refreshing a gfn=>pfn cache, skip straight to unlocking if the cache
already valid instead of stuffing the "old" variables to turn the
unmapping outro into a nop.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
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Drop the @gpa param from the exported check()+refresh() helpers and limit
changing the cache's GPA to the activate path. All external users just
feed in gpc->gpa, i.e. this is a fancy nop.
Allowing users to change the GPA at check()+refresh() is dangerous as
those helpers explicitly allow concurrent calls, e.g. KVM could get into
a livelock scenario. It's also unclear as to what the expected behavior
should be if multiple tasks attempt to refresh with different GPAs.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
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Don't partially reinitialize a gfn=>pfn cache when activating the cache,
and instead assert that the cache is not valid during activation. Bug
the VM if the assertion fails, as use-after-free and/or data corruption
is all but guaranteed if KVM ends up with a valid-but-inactive cache.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
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Drop kvm_gpc_unmap() as it has no users and unclear requirements. The
API was added as part of the original gfn_to_pfn_cache support, but its
sole usage[*] was never merged. Fold the guts of kvm_gpc_unmap() into
the deactivate path and drop the API. Omit acquiring refresh_lock as
as concurrent calls to kvm_gpc_deactivate() are not allowed (this is
not enforced, e.g. via lockdep. due to it being called during vCPU
destruction).
If/when temporary unmapping makes a comeback, the desirable behavior is
likely to restrict temporary unmapping to vCPU-exclusive mappings and
require the vcpu->mutex be held to serialize unmap. Use of the
refresh_lock to protect unmapping was somewhat specuatively added by
commit 93984f19e7bc ("KVM: Fully serialize gfn=>pfn cache refresh via
mutex") to guard against concurrent unmaps, but the primary use case of
the temporary unmap, nested virtualization[*], doesn't actually need or
want concurrent unmaps.
[*] https://lore.kernel.org/all/20211210163625.2886-7-dwmw2@infradead.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
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Make kvm_gpc_refresh() use kvm instance cached in gfn_to_pfn_cache.
No functional change intended.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
[sean: leave kvm_gpc_unmap() as-is]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
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Make hva_to_pfn_retry() use kvm instance cached in gfn_to_pfn_cache.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
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Make kvm_gpc_check() use kvm instance cached in gfn_to_pfn_cache.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
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Move the assignment of immutable properties @kvm, @vcpu, and @usage to
the initializer. Make _activate() and _deactivate() use stored values.
Note, @len is also effectively immutable for most cases, but not in the
case of the Xen runstate cache, which may be split across two pages and
the length of the first segment will depend on its address.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
[sean: handle @len in a separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>
[dwmw2: acknowledge that @len can actually change for some use cases]
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
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This patch introduces compat version of struct sched_poll for
SCHEDOP_poll sub-operation of sched_op hypercall, reads correct amount
of data (16 bytes in 32-bit case, 24 bytes otherwise) by using new
compat_sched_poll struct, copies it to sched_poll properly, and lets
rest of the code run as is.
Signed-off-by: Metin Kaya <metikaya@amazon.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
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If a triple fault was fixed by kvm_x86_ops.nested_ops->triple_fault (by
turning it into a vmexit), there is no need to leave vcpu_enter_guest().
Any vcpu->requests will be caught later before the actual vmentry,
and in fact vcpu_enter_guest() was not initializing the "r" variable.
Depending on the compiler's whims, this could cause the
x86_64/triple_fault_event_test test to fail.
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Fixes: 92e7d5c83aff ("KVM: x86: allow L1 to not intercept triple fault")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Remove the unused @kvm argument from gpc_unmap_khva().
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Formalize "gpc" as the acronym and use it in function names.
No functional change intended.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Torture test the cases where the runstate crosses a page boundary, and
and especially the case where it's configured in 32-bit mode and doesn't,
but then switching to 64-bit mode makes it go onto the second page.
To simplify this, make the KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST ioctl
also update the guest runstate area. It already did so if the actual
runstate changed, as a side-effect of kvm_xen_update_runstate(). So
doing it in the plain adjustment case is making it more consistent, as
well as giving us a nice way to trigger the update without actually
running the vCPU again and changing the values.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Closer inspection of the Xen code shows that we aren't supposed to be
using the XEN_RUNSTATE_UPDATE flag unconditionally. It should be
explicitly enabled by guests through the HYPERVISOR_vm_assist hypercall.
If we randomly set the top bit of ->state_entry_time for a guest that
hasn't asked for it and doesn't expect it, that could make the runtimes
fail to add up and confuse the guest. Without the flag it's perfectly
safe for a vCPU to read its own vcpu_runstate_info; just not for one
vCPU to read *another's*.
I briefly pondered adding a word for the whole set of VMASST_TYPE_*
flags but the only one we care about for HVM guests is this, so it
seemed a bit pointless.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20221127122210.248427-3-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The guest runstate area can be arbitrarily byte-aligned. In fact, even
when a sane 32-bit guest aligns the overall structure nicely, the 64-bit
fields in the structure end up being unaligned due to the fact that the
32-bit ABI only aligns them to 32 bits.
So setting the ->state_entry_time field to something|XEN_RUNSTATE_UPDATE
is buggy, because if it's unaligned then we can't update the whole field
atomically; the low bytes might be observable before the _UPDATE bit is.
Xen actually updates the *byte* containing that top bit, on its own. KVM
should do the same.
In addition, we cannot assume that the runstate area fits within a single
page. One option might be to make the gfn_to_pfn cache cope with regions
that cross a page — but getting a contiguous virtual kernel mapping of a
discontiguous set of IOMEM pages is a distinctly non-trivial exercise,
and it seems this is the *only* current use case for the GPC which would
benefit from it.
An earlier version of the runstate code did use a gfn_to_hva cache for
this purpose, but it still had the single-page restriction because it
used the uhva directly — because it needs to be able to do so atomically
when the vCPU is being scheduled out, so it used pagefault_disable()
around the accesses and didn't just use kvm_write_guest_cached() which
has a fallback path.
So... use a pair of GPCs for the first and potential second page covering
the runstate area. We can get away with locking both at once because
nothing else takes more than one GPC lock at a time so we can invent
a trivial ordering rule.
The common case where it's all in the same page is kept as a fast path,
but in both cases, the actual guest structure (compat or not) is built
up from the fields in @vx, following preset pointers to the state and
times fields. The only difference is whether those pointers point to
the kernel stack (in the split case) or to guest memory directly via
the GPC. The fast path is also fixed to use a byte access for the
XEN_RUNSTATE_UPDATE bit, then the only real difference is the dual
memcpy.
Finally, Xen also does write the runstate area immediately when it's
configured. Flip the kvm_xen_update_runstate() and …_guest() functions
and call the latter directly when the runstate area is set. This means
that other ioctls which modify the runstate also write it immediately
to the guest when they do so, which is also intended.
Update the xen_shinfo_test to exercise the pathological case where the
XEN_RUNSTATE_UPDATE flag in the top byte of the state_entry_time is
actually in a different page to the rest of the 64-bit word.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Does exactly what it says on the tin.
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221118211503.4049023-3-oliver.upton@linux.dev
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Signal that a test run is complete through perf_test_args instead of
having tests open code a similar solution. Ensure that the field resets
to false at the beginning of a test run as the structure is reused
between test runs, eliminating a couple of bugs:
access_tracking_perf_test hangs indefinitely on a subsequent test run,
as 'done' remains true. The bug doesn't amount to much right now, as x86
supports a single guest mode. However, this is a precondition of
enabling the test for other architectures with >1 guest mode, like
arm64.
memslot_modification_stress_test has the exact opposite problem, where
subsequent test runs complete immediately as 'run_vcpus' remains false.
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
[oliver: added commit message, preserve spin_wait_for_next_iteration()]
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221118211503.4049023-2-oliver.upton@linux.dev
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Document both the restriction on VM_MTE_ALLOWED mappings and
the relaxation for shared mappings.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221104011041.290951-9-pcc@google.com
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Certain VMMs such as crosvm have features (e.g. sandboxing) that depend
on being able to map guest memory as MAP_SHARED. The current restriction
on sharing MAP_SHARED pages with the guest is preventing the use of
those features with MTE. Now that the races between tasks concurrently
clearing tags on the same page have been fixed, remove this restriction.
Note that this is a relaxation of the ABI.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221104011041.290951-8-pcc@google.com
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Previously we allowed creating a memslot containing a private mapping that
was not VM_MTE_ALLOWED, but would later reject KVM_RUN with -EFAULT. Now
we reject the memory region at memslot creation time.
Since this is a minor tweak to the ABI (a VMM that created one of
these memslots would fail later anyway), no VMM to my knowledge has
MTE support yet, and the hardware with the necessary features is not
generally available, we can probably make this ABI change at this point.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221104011041.290951-7-pcc@google.com
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Initialising the tags and setting PG_mte_tagged flag for a page can race
between multiple set_pte_at() on shared pages or setting the stage 2 pte
via user_mem_abort(). Introduce a new PG_mte_lock flag as PG_arch_3 and
set it before attempting page initialisation. Given that PG_mte_tagged
is never cleared for a page, consider setting this flag to mean page
unlocked and wait on this bit with acquire semantics if the page is
locked:
- try_page_mte_tagging() - lock the page for tagging, return true if it
can be tagged, false if already tagged. No acquire semantics if it
returns true (PG_mte_tagged not set) as there is no serialisation with
a previous set_page_mte_tagged().
- set_page_mte_tagged() - set PG_mte_tagged with release semantics.
The two-bit locking is based on Peter Collingbourne's idea.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221104011041.290951-6-pcc@google.com
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As with PG_arch_2, this flag is only allowed on 64-bit architectures due
to the shortage of bits available. It will be used by the arm64 MTE code
in subsequent patches.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steven Price <steven.price@arm.com>
[catalin.marinas@arm.com: added flag preserving in __split_huge_page_tail()]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221104011041.290951-5-pcc@google.com
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Currently sanitise_mte_tags() checks if it's an online page before
attempting to sanitise the tags. Such detection should be done in the
caller via the VM_MTE_ALLOWED vma flag. Since kvm_set_spte_gfn() does
not have the vma, leave the page unmapped if not already tagged. Tag
initialisation will be done on a subsequent access fault in
user_mem_abort().
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[pcc@google.com: fix the page initializer]
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221104011041.290951-4-pcc@google.com
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Currently the PG_mte_tagged page flag mostly means the page contains
valid tags and it should be set after the tags have been cleared or
restored. However, in mte_sync_tags() it is set before setting the tags
to avoid, in theory, a race with concurrent mprotect(PROT_MTE) for
shared pages. However, a concurrent mprotect(PROT_MTE) with a copy on
write in another thread can cause the new page to have stale tags.
Similarly, tag reading via ptrace() can read stale tags if the
PG_mte_tagged flag is set before actually clearing/restoring the tags.
Fix the PG_mte_tagged semantics so that it is only set after the tags
have been cleared or restored. This is safe for swap restoring into a
MAP_SHARED or CoW page since the core code takes the page lock. Add two
functions to test and set the PG_mte_tagged flag with acquire and
release semantics. The downside is that concurrent mprotect(PROT_MTE) on
a MAP_SHARED page may cause tag loss. This is already the case for KVM
guests if a VMM changes the page protection while the guest triggers a
user_mem_abort().
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[pcc@google.com: fix build with CONFIG_ARM64_MTE disabled]
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221104011041.290951-3-pcc@google.com
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Commit 4beba9486abd ("mm: Add PG_arch_2 page flag") introduced a new
page flag for all 64-bit architectures. However, even if an architecture
is 64-bit, it may still have limited spare bits in the 'flags' member of
'struct page'. This may happen if an architecture enables SPARSEMEM
without SPARSEMEM_VMEMMAP as is the case with the newly added loongarch.
This architecture port needs 19 more bits for the sparsemem section
information and, while it is currently fine with PG_arch_2, adding any
more PG_arch_* flags will trigger build-time warnings.
Add a new CONFIG_ARCH_USES_PG_ARCH_X option which can be selected by
architectures that need more PG_arch_* flags beyond PG_arch_1. Select it
on arm64.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[pcc@google.com: fix build with CONFIG_ARM64_MTE disabled]
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Price <steven.price@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221104011041.290951-2-pcc@google.com
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https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
- Second batch of the lazy destroy patches
- First batch of KVM changes for kernel virtual != physical address support
- Removal of a unused function
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Latest Intel platform Granite Rapids has introduced a new instruction -
PREFETCHIT0/1, which moves code to memory (cache) closer to the
processor depending on specific hints.
The bit definition:
CPUID.(EAX=7,ECX=1):EDX[bit 14]
PREFETCHIT0/1 is on a KVM-only subleaf. Plus an x86_FEATURE definition
for this feature bit to direct it to the KVM entry.
Advertise PREFETCHIT0/1 to KVM userspace. This is safe because there are
no new VMX controls or additional host enabling required for guests to
use this feature.
Signed-off-by: Jiaxi Chen <jiaxi.chen@linux.intel.com>
Message-Id: <20221125125845.1182922-9-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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AVX-NE-CONVERT is a new set of instructions which can convert low
precision floating point like BF16/FP16 to high precision floating point
FP32, and can also convert FP32 elements to BF16. This instruction
allows the platform to have improved AI capabilities and better
compatibility.
The bit definition:
CPUID.(EAX=7,ECX=1):EDX[bit 5]
AVX-NE-CONVERT is on a KVM-only subleaf. Plus an x86_FEATURE definition
for this feature bit to direct it to the KVM entry.
Advertise AVX-NE-CONVERT to KVM userspace. This is safe because there
are no new VMX controls or additional host enabling required for guests
to use this feature.
Signed-off-by: Jiaxi Chen <jiaxi.chen@linux.intel.com>
Message-Id: <20221125125845.1182922-8-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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AVX-VNNI-INT8 is a new set of instructions in the latest Intel platform
Sierra Forest, aims for the platform to have superior AI capabilities.
This instruction multiplies the individual bytes of two unsigned or
unsigned source operands, then adds and accumulates the results into the
destination dword element size operand.
The bit definition:
CPUID.(EAX=7,ECX=1):EDX[bit 4]
AVX-VNNI-INT8 is on a new and sparse CPUID leaf and all bits on this
leaf have no truly kernel use case for now. Given that and to save space
for kernel feature bits, move this new leaf to KVM-only subleaf and plus
an x86_FEATURE definition for AVX-VNNI-INT8 to direct it to the KVM
entry.
Advertise AVX-VNNI-INT8 to KVM userspace. This is safe because there are
no new VMX controls or additional host enabling required for guests to
use this feature.
Signed-off-by: Jiaxi Chen <jiaxi.chen@linux.intel.com>
Message-Id: <20221125125845.1182922-7-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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AVX-IFMA is a new instruction in the latest Intel platform Sierra
Forest. This instruction packed multiplies unsigned 52-bit integers and
adds the low/high 52-bit products to Qword Accumulators.
The bit definition:
CPUID.(EAX=7,ECX=1):EAX[bit 23]
AVX-IFMA is on an expected-dense CPUID leaf and some other bits on this
leaf have kernel usages. Given that, define this feature bit like
X86_FEATURE_<name> in kernel. Considering AVX-IFMA itself has no truly
kernel usages and /proc/cpuinfo has too much unreadable flags, hide this
one in /proc/cpuinfo.
Advertise AVX-IFMA to KVM userspace. This is safe because there are no
new VMX controls or additional host enabling required for guests to use
this feature.
Signed-off-by: Jiaxi Chen <jiaxi.chen@linux.intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Message-Id: <20221125125845.1182922-6-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Latest Intel platform Granite Rapids has introduced a new instruction -
AMX-FP16, which performs dot-products of two FP16 tiles and accumulates
the results into a packed single precision tile. AMX-FP16 adds FP16
capability and also allows a FP16 GPU trained model to run faster
without loss of accuracy or added SW overhead.
The bit definition:
CPUID.(EAX=7,ECX=1):EAX[bit 21]
AMX-FP16 is on an expected-dense CPUID leaf and some other bits on this
leaf have kernel usages. Given that, define this feature bit like
X86_FEATURE_<name> in kernel. Considering AMX-FP16 itself has no truly
kernel usages and /proc/cpuinfo has too much unreadable flags, hide this
one in /proc/cpuinfo.
Advertise AMX-FP16 to KVM userspace. This is safe because there are no
new VMX controls or additional host enabling required for guests to use
this feature.
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Jiaxi Chen <jiaxi.chen@linux.intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Message-Id: <20221125125845.1182922-5-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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CMPccXADD is a new set of instructions in the latest Intel platform
Sierra Forest. This new instruction set includes a semaphore operation
that can compare and add the operands if condition is met, which can
improve database performance.
The bit definition:
CPUID.(EAX=7,ECX=1):EAX[bit 7]
CMPccXADD is on an expected-dense CPUID leaf and some other bits on this
leaf have kernel usages. Given that, define this feature bit like
X86_FEATURE_<name> in kernel. Considering CMPccXADD itself has no truly
kernel usages and /proc/cpuinfo has too much unreadable flags, hide this
one in /proc/cpuinfo.
Advertise CMPCCXADD to KVM userspace. This is safe because there are no
new VMX controls or additional host enabling required for guests to use
this feature.
Signed-off-by: Jiaxi Chen <jiaxi.chen@linux.intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Message-Id: <20221125125845.1182922-4-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Rename kvm_cpu_cap_init_scattered() to kvm_cpu_cap_init_kvm_defined() in
anticipation of adding KVM-only CPUID leafs that aren't recognized by the
kernel and thus not scattered, i.e. for leafs that are 100% KVM-defined.
Adjust/add comments to kvm_only_cpuid_leafs and KVM_X86_FEATURE to
document how to create new kvm_only_cpuid_leafs entries for scattered
features as well as features that are entirely unknown to the kernel.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221125125845.1182922-3-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Add a compile-time assert in the SF() macro to detect improper usage,
i.e. to detect passing in an X86_FEATURE_* flag that isn't actually
scattered by the kernel. Upcoming feature flags will be 100% KVM-only
and will have X86_FEATURE_* macros that point at a kvm_only_cpuid_leafs
word, not a kernel-defined word. Using SF() and thus boot_cpu_has() for
such feature flags would access memory beyond x86_capability[NCAPINTS]
and at best incorrectly hide a feature, and at worst leak kernel state to
userspace.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221125125845.1182922-2-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Adding Paul as co-maintainer of Xen support to help ensure that things
don't fall through the cracks when I spend three months at a time
travelling...
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Architecture code might want to use it even if CONFIG_HAVE_KVM_IRQ_ROUTING
is false; for example PPC XICS has KVM_IRQ_LINE and wants to use
kvm_arch_irqchip_in_kernel from there, but it does not have
KVM_SET_GSI_ROUTING so the prototype was not provided.
Fixes: d663b8a28598 ("KVM: replace direct irq.h inclusion")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Userspace can play some dirty tricks on us by selecting a given
PMU version (such as PMUv3p5), restore a PMCR_EL0 value that
has PMCR_EL0.LP set, and then switch the PMU version to PMUv3p1,
for example. In this situation, we end-up with PMCR_EL0.LP being
set and spreading havoc in the PMU emulation.
This is specially hard as the first two step can be done on
one vcpu and the third step on another, meaning that we need
to sanitise *all* vcpus when the PMU version is changed.
In orer to avoid a pretty complicated locking situation,
defer the sanitisation of PMCR_EL0 to the point where the
vcpu is actually run for the first tine, using the existing
KVM_REQ_RELOAD_PMU request that calls into kvm_pmu_handle_pmcr().
There is still an obscure corner case where userspace could
do the above trick, and then save the VM without running it.
They would then observe an inconsistent state (PMUv3.1 + LP set),
but that state will be fixed on the first run anyway whenever
the guest gets restored on a host.
Reported-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
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Resetting PMCR_EL0 is a pretty involved process that includes
poisoning some of the writable bits, just because we can.
It makes it hard to reason about about what gets configured,
and just resetting things to 0 seems like a much saner option.
Reduce reset_pmcr() to just preserving PMCR_EL0.N from the host,
and setting PMCR_EL0.LC if we don't support AArch32.
Signed-off-by: Marc Zyngier <maz@kernel.org>
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kvm_host_pmu_init() returns when detected PMU is either not implemented, or
implementation defined. kvm_pmu_probe_armpmu() also has a similar situation.
Extracted ID_AA64DFR0_EL1_PMUVer value, when PMU is not implemented is '0',
which can be replaced with ID_AA64DFR0_EL1_PMUVer_NI defined as '0b0000'.
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-perf-users@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221128135629.118346-1-anshuman.khandual@arm.com
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This brings in a few important fixes for Xen emulation.
While nobody should be enabling it, the bug effectively
allows userspace to read arbitrary memory.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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In the case where a GPC is refreshed to a different location within the
same page, we didn't bother to update it. Mostly we don't need to, but
since the ->khva field also includes the offset within the page, that
does have to be updated.
Fixes: 3ba2c95ea180 ("KVM: Do not incorporate page offset into gfn=>pfn cache user address")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Cc: stable@kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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There are almost no hypercalls which are valid from CPL > 0, and definitely
none which are handled by the kernel.
Fixes: 2fd6df2f2b47 ("KVM: x86/xen: intercept EVTCHNOP_send from guests")
Reported-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Cc: stable@kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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We shouldn't allow guests to poll on arbitrary port numbers off the end
of the event channel table.
Fixes: 1a65105a5aba ("KVM: x86/xen: handle PV spinlocks slowpath")
[dwmw2: my bug though; the original version did check the validity as a
side-effect of an idr_find() which I ripped out in refactoring.]
Reported-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Cc: stable@kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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clang warns about an unused function:
arch/s390/kvm/interrupt.c:317:20:
error: unused function 'gisa_clear_ipm_gisc' [-Werror,-Wunused-function]
static inline void gisa_clear_ipm_gisc(struct kvm_s390_gisa *gisa, u32 gisc)
Remove gisa_clear_ipm_gisc(), since it is unused and get rid of this
warning.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Link: https://lore.kernel.org/r/20221118151133.2974602-1-hca@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
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Fix virtual vs physical address confusion (which currently are the same)
for the GISA when enabling the IRQ.
Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20221118100429.70453-1-nrb@linux.ibm.com
Message-Id: <20221118100429.70453-1-nrb@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
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Add the module parameter "async_destroy", to allow the asynchronous
destroy mechanism to be switched off. This might be useful for
debugging purposes.
The parameter is enabled by default since the feature is opt-in anyway.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
Link: https://lore.kernel.org/r/20221111170632.77622-7-imbrenda@linux.ibm.com
Message-Id: <20221111170632.77622-7-imbrenda@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
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Add support for the Destroy Secure Configuration Fast Ultravisor call,
and take advantage of it for asynchronous destroy.
When supported, the protected guest is destroyed immediately using the
new UVC, leaving only the memory to be cleaned up asynchronously.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Link: https://lore.kernel.org/r/20221111170632.77622-6-imbrenda@linux.ibm.com
Message-Id: <20221111170632.77622-6-imbrenda@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
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If the appropriate UV feature bit is set, there is no need to perform
an export before import.
The misc feature indicates, among other things, that importing a shared
page from a different protected VM will automatically also transfer its
ownership.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Link: https://lore.kernel.org/r/20221111170632.77622-5-imbrenda@linux.ibm.com
Message-Id: <20221111170632.77622-5-imbrenda@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
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Add KVM_CAP_S390_PROTECTED_ASYNC_DISABLE to signal that the
KVM_PV_ASYNC_DISABLE and KVM_PV_ASYNC_DISABLE_PREPARE commands for the
KVM_S390_PV_COMMAND ioctl are available.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20221111170632.77622-4-imbrenda@linux.ibm.com
Message-Id: <20221111170632.77622-4-imbrenda@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
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