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39965 commits

Author SHA1 Message Date
Dan Carpenter
bfbb307c62 KVM: VMX: Set failure code in prepare_vmcs02()
The error paths in the prepare_vmcs02() function are supposed to set
*entry_failure_code but this path does not.  It leads to using an
uninitialized variable in the caller.

Fixes: 71f7347025 ("KVM: nVMX: Load GUEST_IA32_PERF_GLOBAL_CTRL MSR on VM-Entry")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Message-Id: <20211130125337.GB24578@kili>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-02 04:12:11 -05:00
Paolo Bonzini
ef8b4b7203 KVM: ensure APICv is considered inactive if there is no APIC
kvm_vcpu_apicv_active() returns false if a virtual machine has no in-kernel
local APIC, however kvm_apicv_activated might still be true if there are
no reasons to disable APICv; in fact it is quite likely that there is none
because APICv is inhibited by specific configurations of the local APIC
and those configurations cannot be programmed.  This triggers a WARN:

   WARN_ON_ONCE(kvm_apicv_activated(vcpu->kvm) != kvm_vcpu_apicv_active(vcpu));

To avoid this, introduce another cause for APICv inhibition, namely the
absence of an in-kernel local APIC.  This cause is enabled by default,
and is dropped by either KVM_CREATE_IRQCHIP or the enabling of
KVM_CAP_IRQCHIP_SPLIT.

Reported-by: Ignat Korchagin <ignat@cloudflare.com>
Fixes: ee49a89329 ("KVM: x86: Move SVM's APICv sanity check to common x86", 2021-10-22)
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Tested-by: Ignat Korchagin <ignat@cloudflare.com>
Message-Id: <20211130123746.293379-1-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-02 04:12:11 -05:00
Like Xu
cb1d220da0 KVM: x86/pmu: Fix reserved bits for AMD PerfEvtSeln register
If we run the following perf command in an AMD Milan guest:

  perf stat \
  -e cpu/event=0x1d0/ \
  -e cpu/event=0x1c7/ \
  -e cpu/umask=0x1f,event=0x18e/ \
  -e cpu/umask=0x7,event=0x18e/ \
  -e cpu/umask=0x18,event=0x18e/ \
  ./workload

dmesg will report a #GP warning from an unchecked MSR access
error on MSR_F15H_PERF_CTLx.

This is because according to APM (Revision: 4.03) Figure 13-7,
the bits [35:32] of AMD PerfEvtSeln register is a part of the
event select encoding, which extends the EVENT_SELECT field
from 8 bits to 12 bits.

Opportunistically update pmu->reserved_bits for reserved bit 19.

Reported-by: Jim Mattson <jmattson@google.com>
Fixes: ca724305a2 ("KVM: x86/vPMU: Implement AMD vPMU code for KVM")
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20211118130320.95997-1-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-02 04:11:50 -05:00
Paolo Bonzini
7cfc5c653b KVM: fix avic_set_running for preemptable kernels
avic_set_running() passes the current CPU to avic_vcpu_load(), albeit
via vcpu->cpu rather than smp_processor_id().  If the thread is migrated
while avic_set_running runs, the call to avic_vcpu_load() can use a stale
value for the processor id.  Avoid this by blocking preemption over the
entire execution of avic_set_running().

Reported-by: Sean Christopherson <seanjc@google.com>
Fixes: 8221c13700 ("svm: Manage vcpu load/unload when enable AVIC")
Cc: stable@vger.kernel.org
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 07:40:48 -05:00
Paolo Bonzini
e90e51d5f0 KVM: VMX: clear vmx_x86_ops.sync_pir_to_irr if APICv is disabled
There is nothing to synchronize if APICv is disabled, since neither
other vCPUs nor assigned devices can set PIR.ON.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 07:40:47 -05:00
Paolo Bonzini
c9d61dcb0b KVM: SEV: accept signals in sev_lock_two_vms
Generally, kvm->lock is not taken for a long time, but
sev_lock_two_vms is different: it takes vCPU locks
inside, so userspace can hold it back just by calling
a vCPU ioctl.  Play it safe and use mutex_lock_killable.

Message-Id: <20211123005036.2954379-13-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:54:15 -05:00
Paolo Bonzini
10a37929ef KVM: SEV: do not take kvm->lock when destroying
Taking the lock is useless since there are no other references,
and there are already accesses (e.g. to sev->enc_context_owner)
that do not take it.  So get rid of it.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211123005036.2954379-12-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:54:14 -05:00
Paolo Bonzini
17d44a96f0 KVM: SEV: Prohibit migration of a VM that has mirrors
VMs that mirror an encryption context rely on the owner to keep the
ASID allocated.  Performing a KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM
would cause a dangling ASID:

1. copy context from A to B (gets ref to A)
2. move context from A to L (moves ASID from A to L)
3. close L (releases ASID from L, B still references it)

The right way to do the handoff instead is to create a fresh mirror VM
on the destination first:

1. copy context from A to B (gets ref to A)
[later] 2. close B (releases ref to A)
3. move context from A to L (moves ASID from A to L)
4. copy context from L to M

So, catch the situation by adding a count of how many VMs are
mirroring this one's encryption context.

Fixes: 0b020f5af0 ("KVM: SEV: Add support for SEV-ES intra host migration")
Message-Id: <20211123005036.2954379-11-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:54:14 -05:00
Paolo Bonzini
bf42b02b19 KVM: SEV: Do COPY_ENC_CONTEXT_FROM with both VMs locked
Now that we have a facility to lock two VMs with deadlock
protection, use it for the creation of mirror VMs as well.  One of
COPY_ENC_CONTEXT_FROM(dst, src) and COPY_ENC_CONTEXT_FROM(src, dst)
would always fail, so the combination is nonsensical and it is okay to
return -EBUSY if it is attempted.

This sidesteps the question of what happens if a VM is
MOVE_ENC_CONTEXT_FROM'd at the same time as it is
COPY_ENC_CONTEXT_FROM'd: the locking prevents that from
happening.

Cc: Peter Gonda <pgonda@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211123005036.2954379-10-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:54:13 -05:00
Paolo Bonzini
642525e3bd KVM: SEV: move mirror status to destination of KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM
Allow intra-host migration of a mirror VM; the destination VM will be
a mirror of the same ASID as the source.

Fixes: b56639318b ("KVM: SEV: Add support for SEV intra host migration")
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211123005036.2954379-8-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:54:12 -05:00
Paolo Bonzini
2b347a3878 KVM: SEV: initialize regions_list of a mirror VM
This was broken before the introduction of KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM,
but technically harmless because the region list was unused for a mirror
VM.  However, it is untidy and it now causes a NULL pointer access when
attempting to move the encryption context of a mirror VM.

Fixes: 54526d1fd5 ("KVM: x86: Support KVM VMs sharing SEV context")
Message-Id: <20211123005036.2954379-7-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:54:12 -05:00
Paolo Bonzini
501b580c02 KVM: SEV: cleanup locking for KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM
Encapsulate the handling of the migration_in_progress flag for both VMs in
two functions sev_lock_two_vms and sev_unlock_two_vms.  It does not matter
if KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM locks the destination struct kvm a bit
later, and this change 1) keeps the cleanup chain of labels smaller 2)
makes it possible for KVM_CAP_VM_COPY_ENC_CONTEXT_FROM to reuse the logic.

Cc: Peter Gonda <pgonda@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Message-Id: <20211123005036.2954379-6-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:54:11 -05:00
Paolo Bonzini
4674164f0a KVM: SEV: do not use list_replace_init on an empty list
list_replace_init cannot be used if the source is an empty list,
because "new->next->prev = new" will overwrite "old->next":

				new				old
				prev = new, next = new		prev = old, next = old
new->next = old->next		prev = new, next = old		prev = old, next = old
new->next->prev = new		prev = new, next = old		prev = old, next = new
new->prev = old->prev		prev = old, next = old		prev = old, next = old
new->next->prev = new		prev = old, next = old		prev = new, next = new

The desired outcome instead would be to leave both old and new the same
as they were (two empty circular lists).  Use list_cut_before, which
already has the necessary check and is documented to discard the
previous contents of the list that will hold the result.

Fixes: b56639318b ("KVM: SEV: Add support for SEV intra host migration")
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211123005036.2954379-5-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:54:11 -05:00
Paolo Bonzini
53b7ca1a35 KVM: x86: Use a stable condition around all VT-d PI paths
Currently, checks for whether VT-d PI can be used refer to the current
status of the feature in the current vCPU; or they more or less pick
vCPU 0 in case a specific vCPU is not available.

However, these checks do not attempt to synchronize with changes to
the IRTE.  In particular, there is no path that updates the IRTE when
APICv is re-activated on vCPU 0; and there is no path to wakeup a CPU
that has APICv disabled, if the wakeup occurs because of an IRTE
that points to a posted interrupt.

To fix this, always go through the VT-d PI path as long as there are
assigned devices and APICv is available on both the host and the VM side.
Since the relevant condition was copied over three times, take the hint
and factor it into a separate function.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Message-Id: <20211123004311.2954158-5-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:53:14 -05:00
Paolo Bonzini
37c4dbf337 KVM: x86: check PIR even for vCPUs with disabled APICv
The IRTE for an assigned device can trigger a POSTED_INTR_VECTOR even
if APICv is disabled on the vCPU that receives it.  In that case, the
interrupt will just cause a vmexit and leave the ON bit set together
with the PIR bit corresponding to the interrupt.

Right now, the interrupt would not be delivered until APICv is re-enabled.
However, fixing this is just a matter of always doing the PIR->IRR
synchronization, even if the vCPU has temporarily disabled APICv.

This is not a problem for performance, or if anything it is an
improvement.  First, in the common case where vcpu->arch.apicv_active is
true, one fewer check has to be performed.  Second, static_call_cond will
elide the function call if APICv is not present or disabled.  Finally,
in the case for AMD hardware we can remove the sync_pir_to_irr callback:
it is only needed for apic_has_interrupt_for_ppr, and that function
already has a fallback for !APICv.

Cc: stable@vger.kernel.org
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Message-Id: <20211123004311.2954158-4-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:52:39 -05:00
Paolo Bonzini
7e1901f6c8 KVM: VMX: prepare sync_pir_to_irr for running with APICv disabled
If APICv is disabled for this vCPU, assigned devices may still attempt to
post interrupts.  In that case, we need to cancel the vmentry and deliver
the interrupt with KVM_REQ_EVENT.  Extend the existing code that handles
injection of L1 interrupts into L2 to cover this case as well.

vmx_hwapic_irr_update is only called when APICv is active so it would be
confusing to add a check for vcpu->arch.apicv_active in there.  Instead,
just use vmx_set_rvi directly in vmx_sync_pir_to_irr.

Cc: stable@vger.kernel.org
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211123004311.2954158-3-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:51:58 -05:00
Sean Christopherson
f47491d7f3 KVM: x86/mmu: Handle "default" period when selectively waking kthread
Account for the '0' being a default, "let KVM choose" period, when
determining whether or not the recovery worker needs to be awakened in
response to userspace reducing the period.  Failure to do so results in
the worker not being awakened properly, e.g. when changing the period
from '0' to any small-ish value.

Fixes: 4dfe4f40d8 ("kvm: x86: mmu: Make NX huge page recovery period configurable")
Cc: stable@vger.kernel.org
Cc: Junaid Shahid <junaids@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211120015706.3830341-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:09:27 -05:00
Paolo Bonzini
28f091bc2f KVM: MMU: shadow nested paging does not have PKU
Initialize the mask for PKU permissions as if CR4.PKE=0, avoiding
incorrect interpretations of the nested hypervisor's page tables.

Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:09:26 -05:00
Sean Christopherson
4b85c921cd KVM: x86/mmu: Remove spurious TLB flushes in TDP MMU zap collapsible path
Drop the "flush" param and return values to/from the TDP MMU's helper for
zapping collapsible SPTEs.  Because the helper runs with mmu_lock held
for read, not write, it uses tdp_mmu_zap_spte_atomic(), and the atomic
zap handles the necessary remote TLB flush.

Similarly, because mmu_lock is dropped and re-acquired between zapping
legacy MMUs and zapping TDP MMUs, kvm_mmu_zap_collapsible_sptes() must
handle remote TLB flushes from the legacy MMU before calling into the TDP
MMU.

Fixes: e2209710cc ("KVM: x86/mmu: Skip rmap operations if rmaps not allocated")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211120045046.3940942-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:09:25 -05:00
Sean Christopherson
7533377215 KVM: x86/mmu: Use yield-safe TDP MMU root iter in MMU notifier unmapping
Use the yield-safe variant of the TDP MMU iterator when handling an
unmapping event from the MMU notifier, as most occurences of the event
allow yielding.

Fixes: e1eed5847b ("KVM: x86/mmu: Allow yielding during MMU notifier unmap/zap, if possible")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211120015008.3780032-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30 03:09:25 -05:00
Lai Jiangshan
05b29633c7 KVM: X86: Use vcpu->arch.walk_mmu for kvm_mmu_invlpg()
INVLPG operates on guest virtual address, which are represented by
vcpu->arch.walk_mmu.  In nested virtualization scenarios,
kvm_mmu_invlpg() was using the wrong MMU structure; if L2's invlpg were
emulated by L0 (in practice, it hardly happen) when nested two-dimensional
paging is enabled, the call to ->tlb_flush_gva() would be skipped and
the hardware TLB entry would not be invalidated.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20211124122055.64424-5-jiangshanlai@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-26 08:14:21 -05:00
Lai Jiangshan
12ec33a705 KVM: X86: Fix when shadow_root_level=5 && guest root_level<4
If the is an L1 with nNPT in 32bit, the shadow walk starts with
pae_root.

Fixes: a717a780fc ("KVM: x86/mmu: Support shadowing NPT when 5-level paging is enabled in host)
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20211124122055.64424-2-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-26 08:14:20 -05:00
Vitaly Kuznetsov
feb627e8d6 KVM: x86: Forbid KVM_SET_CPUID{,2} after KVM_RUN
Commit 63f5a1909f ("KVM: x86: Alert userspace that KVM_SET_CPUID{,2}
after KVM_RUN is broken") officially deprecated KVM_SET_CPUID{,2} ioctls
after first successful KVM_RUN and promissed to make this sequence forbiden
in 5.16. It's time to fulfil the promise.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211122175818.608220-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-26 08:14:20 -05:00
Sean Christopherson
712494de96 KVM: nVMX: Emulate guest TLB flush on nested VM-Enter with new vpid12
Fully emulate a guest TLB flush on nested VM-Enter which changes vpid12,
i.e. L2's VPID, instead of simply doing INVVPID to flush real hardware's
TLB entries for vpid02.  From L1's perspective, changing L2's VPID is
effectively a TLB flush unless "hardware" has previously cached entries
for the new vpid12.  Because KVM tracks only a single vpid12, KVM doesn't
know if the new vpid12 has been used in the past and so must treat it as
a brand new, never been used VPID, i.e. must assume that the new vpid12
represents a TLB flush from L1's perspective.

For example, if L1 and L2 share a CR3, the first VM-Enter to L2 (with a
VPID) is effectively a TLB flush as hardware/KVM has never seen vpid12
and thus can't have cached entries in the TLB for vpid12.

Reported-by: Lai Jiangshan <jiangshanlai+lkml@gmail.com>
Fixes: 5c614b3583 ("KVM: nVMX: nested VPID emulation")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211125014944.536398-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-26 07:11:29 -05:00
Sean Christopherson
40e5f90804 KVM: nVMX: Abide to KVM_REQ_TLB_FLUSH_GUEST request on nested vmentry/vmexit
Like KVM_REQ_TLB_FLUSH_CURRENT, the GUEST variant needs to be serviced at
nested transitions, as KVM doesn't track requests for L1 vs L2.  E.g. if
there's a pending flush when a nested VM-Exit occurs, then the flush was
requested in the context of L2 and needs to be handled before switching
to L1, otherwise the flush for L2 would effectiely be lost.

Opportunistically add a helper to handle CURRENT and GUEST as a pair, the
logic for when they need to be serviced is identical as both requests are
tied to L1 vs. L2, the only difference is the scope of the flush.

Reported-by: Lai Jiangshan <jiangshanlai+lkml@gmail.com>
Fixes: 07ffaf343e ("KVM: nVMX: Sync all PGDs on nested transition with shadow paging")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211125014944.536398-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-26 07:07:49 -05:00
Sean Christopherson
2b4a5a5d56 KVM: nVMX: Flush current VPID (L1 vs. L2) for KVM_REQ_TLB_FLUSH_GUEST
Flush the current VPID when handling KVM_REQ_TLB_FLUSH_GUEST instead of
always flushing vpid01.  Any TLB flush that is triggered when L2 is
active is scoped to L2's VPID (if it has one), e.g. if L2 toggles CR4.PGE
and L1 doesn't intercept PGE writes, then KVM's emulation of the TLB
flush needs to be applied to L2's VPID.

Reported-by: Lai Jiangshan <jiangshanlai+lkml@gmail.com>
Fixes: 07ffaf343e ("KVM: nVMX: Sync all PGDs on nested transition with shadow paging")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211125014944.536398-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-26 07:06:58 -05:00
Paolo Bonzini
30d7c5d60a KVM: SEV: expose KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM capability
The capability, albeit present, was never exposed via KVM_CHECK_EXTENSION.

Fixes: b56639318b ("KVM: SEV: Add support for SEV intra host migration")
Cc: Peter Gonda <pgonda@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-26 06:43:30 -05:00
Paolo Bonzini
78311a5140 KVM: x86: ignore APICv if LAPIC is not enabled
Synchronize the two calls to kvm_x86_sync_pir_to_irr.  The one
in the reenter-guest fast path invoked the callback unconditionally
even if LAPIC is present but disabled.  In this case, there are
no interrupts to deliver, and therefore posted interrupts can
be ignored.

Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-26 06:43:29 -05:00
Paolo Bonzini
8503fea676 KVM: VMX: do not use uninitialized gfn_to_hva_cache
An uninitialized gfn_to_hva_cache has ghc->len == 0, which causes
the accessors to croak very loudly.  While a BUG_ON is definitely
_too_ loud and a bug on its own, there is indeed an issue of using
the caches in such a way that they could not have been initialized,
because ghc->gpa == 0 might match and thus kvm_gfn_to_hva_cache_init
would not be called.

For the vmcs12_cache, the solution is simply to invoke
kvm_gfn_to_hva_cache_init unconditionally: we already know
that the cache does not match the current VMCS pointer.
For the shadow_vmcs12_cache, there is no similar condition
that checks the VMCS link pointer, so invalidate the cache
on VMXON.

Fixes: cee66664dc ("KVM: nVMX: Use a gfn_to_hva_cache for vmptrld")
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Reported-by: syzbot+7b7db8bb4db6fd5e157b@syzkaller.appspotmail.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-26 06:43:28 -05:00
Paolo Bonzini
d5d1cf47d1 Merge branch 'kvm-5.16-fixes-pre-rc2' into HEAD 2021-11-26 06:43:01 -05:00
Linus Torvalds
40c93d7fff Two X86 fixes:
- Move the command line preparation and the early command line parsing
    earlier so that the command line parameters which affect
    early_reserve_memory(), e.g. efi=nosftreserve, are taken into
    account. This was broken when the invocation of early_reserve_memory()
    was moved recently.
 
  - Use an atomic type for the SGX page accounting, which is read and
    written lockless, to plug various race conditions related to it.
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Merge tag 'x86-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Thomas Gleixner:

 - Move the command line preparation and the early command line parsing
   earlier so that the command line parameters which affect
   early_reserve_memory(), e.g. efi=nosftreserve, are taken into
   account. This was broken when the invocation of
   early_reserve_memory() was moved recently.

 - Use an atomic type for the SGX page accounting, which is read and
   written locklessly, to plug various race conditions related to it.

* tag 'x86-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sgx: Fix free page accounting
  x86/boot: Pull up cmdline preparation and early param parsing
2021-11-21 11:25:19 -08:00
Linus Torvalds
af16bdeae8 A set of perf/X86 fixes:
- Remove unneded PEBS disabling when taking LBR snapshots to prevent an
    unchecked MSR access error.
 
  - Fix IIO event constraints for Snowridge and Skylake server chips.
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Merge tag 'perf-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 perf fixes from Thomas Gleixner:

 - Remove unneded PEBS disabling when taking LBR snapshots to prevent an
   unchecked MSR access error.

 - Fix IIO event constraints for Snowridge and Skylake server chips.

* tag 'perf-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/perf: Fix snapshot_branch_stack warning in VM
  perf/x86/intel/uncore: Fix IIO event constraints for Snowridge
  perf/x86/intel/uncore: Fix IIO event constraints for Skylake Server
  perf/x86/intel/uncore: Fix filter_tid mask for CHA events on Skylake Server
2021-11-21 11:17:50 -08:00
Linus Torvalds
6b38e2fb70 s390 updates for 5.16-rc2
- Add missing Kconfig option for ftrace direct multi sample, so it can
   be compiled again, and also add s390 support for this sample.
 
 - Update Christian Borntraeger's email address.
 
 - Various fixes for memory layout setup. Besides other this makes it
   possible to load shared DCSS segments again.
 
 - Fix copy to user space of swapped kdump oldmem.
 
 - Remove -mstack-guard and -mstack-size compile options when building
   vdso binaries. This can happen when CONFIG_VMAP_STACK is disabled
   and results in broken vdso code which causes more or less random
   exceptions. Also remove the not needed -nostdlib option.
 
 - Fix memory leak on cpu hotplug and return code handling in kexec
   code.
 
 - Wire up futex_waitv system call.
 
 - Replace snprintf with sysfs_emit where appropriate.
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Merge tag 's390-5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Heiko Carstens:

 - Add missing Kconfig option for ftrace direct multi sample, so it can
   be compiled again, and also add s390 support for this sample.

 - Update Christian Borntraeger's email address.

 - Various fixes for memory layout setup. Besides other this makes it
   possible to load shared DCSS segments again.

 - Fix copy to user space of swapped kdump oldmem.

 - Remove -mstack-guard and -mstack-size compile options when building
   vdso binaries. This can happen when CONFIG_VMAP_STACK is disabled and
   results in broken vdso code which causes more or less random
   exceptions. Also remove the not needed -nostdlib option.

 - Fix memory leak on cpu hotplug and return code handling in kexec
   code.

 - Wire up futex_waitv system call.

 - Replace snprintf with sysfs_emit where appropriate.

* tag 's390-5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  ftrace/samples: add s390 support for ftrace direct multi sample
  ftrace/samples: add missing Kconfig option for ftrace direct multi sample
  MAINTAINERS: update email address of Christian Borntraeger
  s390/kexec: fix memory leak of ipl report buffer
  s390/kexec: fix return code handling
  s390/dump: fix copying to user-space of swapped kdump oldmem
  s390: wire up sys_futex_waitv system call
  s390/vdso: filter out -mstack-guard and -mstack-size
  s390/vdso: remove -nostdlib compiler flag
  s390: replace snprintf in show functions with sysfs_emit
  s390/boot: simplify and fix kernel memory layout setup
  s390/setup: re-arrange memblock setup
  s390/setup: avoid using memblock_enforce_memory_limit
  s390/setup: avoid reserving memory above identity mapping
2021-11-20 10:55:50 -08:00
Linus Torvalds
7af959b5d5 Merge branch 'SA_IMMUTABLE-fixes-for-v5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull exit-vs-signal handling fixes from Eric Biederman:
 "This is a small set of changes where debuggers were no longer able to
  intercept synchronous SIGTRAP and SIGSEGV, introduced by the exit
  cleanups.

  This is essentially the change you suggested with all of i's dotted
  and the t's crossed so that ptrace can intercept all of the cases it
  has been able to intercept the past, and all of the cases that made it
  to exit without giving ptrace a chance still don't give ptrace a
  chance"

* 'SA_IMMUTABLE-fixes-for-v5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal: Replace force_fatal_sig with force_exit_sig when in doubt
  signal: Don't always set SA_IMMUTABLE for forced signals
2021-11-19 11:33:31 -08:00
Peter Zijlstra
0dc636b3b7 x86: Pin task-stack in __get_wchan()
When commit 5d1ceb3969 ("x86: Fix __get_wchan() for !STACKTRACE")
moved from stacktrace to native unwind_*() usage, the
try_get_task_stack() got lost, leading to use-after-free issues for
dying tasks.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Fixes: 5d1ceb3969 ("x86: Fix __get_wchan() for !STACKTRACE")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215031
Link: https://lore.kernel.org/stable/YZV02RCRVHIa144u@fedora64.linuxtx.org/
Reported-by: Justin Forbes <jmforbes@linuxtx.org>
Reported-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-19 10:14:57 -08:00
Eric W. Biederman
fcb116bc43 signal: Replace force_fatal_sig with force_exit_sig when in doubt
Recently to prevent issues with SECCOMP_RET_KILL and similar signals
being changed before they are delivered SA_IMMUTABLE was added.

Unfortunately this broke debuggers[1][2] which reasonably expect
to be able to trap synchronous SIGTRAP and SIGSEGV even when
the target process is not configured to handle those signals.

Add force_exit_sig and use it instead of force_fatal_sig where
historically the code has directly called do_exit.  This has the
implementation benefits of going through the signal exit path
(including generating core dumps) without the danger of allowing
userspace to ignore or change these signals.

This avoids userspace regressions as older kernels exited with do_exit
which debuggers also can not intercept.

In the future is should be possible to improve the quality of
implementation of the kernel by changing some of these force_exit_sig
calls to force_fatal_sig.  That can be done where it matters on
a case-by-case basis with careful analysis.

Reported-by: Kyle Huey <me@kylehuey.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
[1] https://lkml.kernel.org/r/CAP045AoMY4xf8aC_4QU_-j7obuEPYgTcnQQP3Yxk=2X90jtpjw@mail.gmail.com
[2] https://lkml.kernel.org/r/20211117150258.GB5403@xsang-OptiPlex-9020
Fixes: 00b06da29c ("signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed")
Fixes: a3616a3c02 ("signal/m68k: Use force_sigsegv(SIGSEGV) in fpsp040_die")
Fixes: 83a1f27ad7 ("signal/powerpc: On swapcontext failure force SIGSEGV")
Fixes: 9bc508cf07 ("signal/s390: Use force_sigsegv in default_trap_handler")
Fixes: 086ec444f8 ("signal/sparc32: In setup_rt_frame and setup_fram use force_fatal_sig")
Fixes: c317d306d5 ("signal/sparc32: Exit with a fatal signal when try_to_clear_window_buffer fails")
Fixes: 695dd0d634 ("signal/x86: In emulate_vsyscall force a signal instead of calling do_exit")
Fixes: 1fbd60df8a ("signal/vm86_32: Properly send SIGSEGV when the vm86 state cannot be saved.")
Fixes: 941edc5bf1 ("exit/syscall_user_dispatch: Send ordinary signals on failure")
Link: https://lkml.kernel.org/r/871r3dqfv8.fsf_-_@email.froward.int.ebiederm.org
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Kyle Huey <khuey@kylehuey.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-11-19 09:15:58 -06:00
Linus Torvalds
c46e8ece96 Selftest changes:
* Cleanups for the perf test infrastructure and mapping hugepages
 
 * Avoid contention on mmap_sem when the guests start to run
 
 * Add event channel upcall support to xen_shinfo_test
 
 x86 changes:
 
 * Fixes for Xen emulation
 
 * Kill kvm_map_gfn() / kvm_unmap_gfn() and broken gfn_to_pfn_cache
 
 * Fixes for migration of 32-bit nested guests on 64-bit hypervisor
 
 * Compilation fixes
 
 * More SEV cleanups
 
 Generic:
 
 * Cap the return value of KVM_CAP_NR_VCPUS to both KVM_CAP_MAX_VCPUS
 and num_online_cpus().  Most architectures were only using one of the two.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:
 "Selftest changes:

   - Cleanups for the perf test infrastructure and mapping hugepages

   - Avoid contention on mmap_sem when the guests start to run

   - Add event channel upcall support to xen_shinfo_test

  x86 changes:

   - Fixes for Xen emulation

   - Kill kvm_map_gfn() / kvm_unmap_gfn() and broken gfn_to_pfn_cache

   - Fixes for migration of 32-bit nested guests on 64-bit hypervisor

   - Compilation fixes

   - More SEV cleanups

  Generic:

   - Cap the return value of KVM_CAP_NR_VCPUS to both KVM_CAP_MAX_VCPUS
     and num_online_cpus(). Most architectures were only using one of
     the two"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (42 commits)
  KVM: x86: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS
  KVM: s390: Cap KVM_CAP_NR_VCPUS by num_online_cpus()
  KVM: RISC-V: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS
  KVM: PPC: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS
  KVM: MIPS: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS
  KVM: arm64: Cap KVM_CAP_NR_VCPUS by kvm_arm_default_max_vcpus()
  KVM: x86: Assume a 64-bit hypercall for guests with protected state
  selftests: KVM: Add /x86_64/sev_migrate_tests to .gitignore
  riscv: kvm: fix non-kernel-doc comment block
  KVM: SEV: Fix typo in and tweak name of cmd_allowed_from_miror()
  KVM: SEV: Drop a redundant setting of sev->asid during initialization
  KVM: SEV: WARN if SEV-ES is marked active but SEV is not
  KVM: SEV: Set sev_info.active after initial checks in sev_guest_init()
  KVM: SEV: Disallow COPY_ENC_CONTEXT_FROM if target has created vCPUs
  KVM: Kill kvm_map_gfn() / kvm_unmap_gfn() and gfn_to_pfn_cache
  KVM: nVMX: Use a gfn_to_hva_cache for vmptrld
  KVM: nVMX: Use kvm_read_guest_offset_cached() for nested VMCS check
  KVM: x86/xen: Use sizeof_field() instead of open-coding it
  KVM: nVMX: Use kvm_{read,write}_guest_cached() for shadow_vmcs12
  KVM: x86/xen: Fix get_attr of KVM_XEN_ATTR_TYPE_SHARED_INFO
  ...
2021-11-18 12:05:22 -08:00
Heiko Carstens
503e451084 ftrace/samples: add missing Kconfig option for ftrace direct multi sample
Currently it is not possible to build the ftrace direct multi example
anymore due to broken config dependencies. Fix this by adding
SAMPLE_FTRACE_DIRECT_MULTI config option.

This broke when merging s390-5.16-1 due to an incorrect merge conflict
resolution proposed by me.

Also rename SAMPLE_FTRACE_MULTI_DIRECT to SAMPLE_FTRACE_DIRECT_MULTI
so it matches the module name.

Fixes: 0b707e572a ("Merge tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux")
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20211115195614.3173346-2-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-11-18 17:50:54 +01:00
Hou Wenlong
8ed716ca7d KVM: x86/mmu: Pass parameter flush as false in kvm_tdp_mmu_zap_collapsible_sptes()
Since tlb flush has been done for legacy MMU before
kvm_tdp_mmu_zap_collapsible_sptes(), so the parameter flush
should be false for kvm_tdp_mmu_zap_collapsible_sptes().

Fixes: e2209710cc ("KVM: x86/mmu: Skip rmap operations if rmaps not allocated")
Signed-off-by: Hou Wenlong <houwenlong93@linux.alibaba.com>
Message-Id: <21453a1d2533afb6e59fb6c729af89e771ff2e76.1637140154.git.houwenlong93@linux.alibaba.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 07:05:58 -05:00
Hou Wenlong
c7785d85b6 KVM: x86/mmu: Skip tlb flush if it has been done in zap_gfn_range()
If the parameter flush is set, zap_gfn_range() would flush remote tlb
when yield, then tlb flush is not needed outside. So use the return
value of zap_gfn_range() directly instead of OR on it in
kvm_unmap_gfn_range() and kvm_tdp_mmu_unmap_gfn_range().

Fixes: 3039bcc744 ("KVM: Move x86's MMU notifier memslot walkers to generic code")
Signed-off-by: Hou Wenlong <houwenlong93@linux.alibaba.com>
Message-Id: <5e16546e228877a4d974f8c0e448a93d52c7a5a9.1637140154.git.houwenlong93@linux.alibaba.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 07:05:57 -05:00
Juergen Gross
9dba4d24cb x86/kvm: remove unused ack_notifier callbacks
Commit f52447261b ("KVM: irq ack notification") introduced an
ack_notifier() callback in struct kvm_pic and in struct kvm_ioapic
without using them anywhere. Remove those callbacks again.

Signed-off-by: Juergen Gross <jgross@suse.com>
Message-Id: <20211117071617.19504-1-jgross@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 07:05:57 -05:00
Ben Gardon
574c3c55e9 KVM: x86/mmu: Fix TLB flush range when handling disconnected pt
When recursively clearing out disconnected pts, the range based TLB
flush in handle_removed_tdp_mmu_page uses the wrong starting GFN,
resulting in the flush mostly missing the affected range. Fix this by
using base_gfn for the flush.

In response to feedback from David Matlack on the RFC version of this
patch, also move a few definitions into the for loop in the function to
prevent unintended references to them in the future.

Fixes: a066e61f13 ("KVM: x86/mmu: Factor out handling of removed page tables")
CC: stable@vger.kernel.org
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20211115211704.2621644-1-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:15:19 -05:00
Vitaly Kuznetsov
2845e7353b KVM: x86: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS
It doesn't make sense to return the recommended maximum number of
vCPUs which exceeds the maximum possible number of vCPUs.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211116163443.88707-7-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:12:15 -05:00
Tom Lendacky
b5aead0064 KVM: x86: Assume a 64-bit hypercall for guests with protected state
When processing a hypercall for a guest with protected state, currently
SEV-ES guests, the guest CS segment register can't be checked to
determine if the guest is in 64-bit mode. For an SEV-ES guest, it is
expected that communication between the guest and the hypervisor is
performed to shared memory using the GHCB. In order to use the GHCB, the
guest must have been in long mode, otherwise writes by the guest to the
GHCB would be encrypted and not be able to be comprehended by the
hypervisor.

Create a new helper function, is_64_bit_hypercall(), that assumes the
guest is in 64-bit mode when the guest has protected state, and returns
true, otherwise invoking is_64_bit_mode() to determine the mode. Update
the hypercall related routines to use is_64_bit_hypercall() instead of
is_64_bit_mode().

Add a WARN_ON_ONCE() to is_64_bit_mode() to catch occurences of calls to
this helper function for a guest running with protected state.

Fixes: f1c6366e30 ("KVM: SVM: Add required changes to support intercepts under SEV-ES")
Reported-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <e0b20c770c9d0d1403f23d83e785385104211f74.1621878537.git.thomas.lendacky@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:12:13 -05:00
Paolo Bonzini
817506df9d Merge branch 'kvm-5.16-fixes' into kvm-master
* Fixes for Xen emulation

* Kill kvm_map_gfn() / kvm_unmap_gfn() and broken gfn_to_pfn_cache

* Fixes for migration of 32-bit nested guests on 64-bit hypervisor

* Compilation fixes

* More SEV cleanups
2021-11-18 02:11:57 -05:00
Sean Christopherson
8e38e96a4e KVM: SEV: Fix typo in and tweak name of cmd_allowed_from_miror()
Rename cmd_allowed_from_miror() to is_cmd_allowed_from_mirror(), fixing
a typo and making it obvious that the result is a boolean where
false means "not allowed".

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109215101.2211373-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:10:28 -05:00
Sean Christopherson
ea410ef4da KVM: SEV: Drop a redundant setting of sev->asid during initialization
Remove a fully redundant write to sev->asid during SEV/SEV-ES guest
initialization.  The ASID is set a few lines earlier prior to the call to
sev_platform_init(), which doesn't take "sev" as a param, i.e. can't
muck with the ASID barring some truly magical behind-the-scenes code.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109215101.2211373-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:10:27 -05:00
Sean Christopherson
1bd00a4257 KVM: SEV: WARN if SEV-ES is marked active but SEV is not
WARN if the VM is tagged as SEV-ES but not SEV.  KVM relies on SEV and
SEV-ES being set atomically, and guards common flows with "is SEV", i.e.
observing SEV-ES without SEV means KVM has a fatal bug.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109215101.2211373-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:10:27 -05:00
Sean Christopherson
a41fb26e61 KVM: SEV: Set sev_info.active after initial checks in sev_guest_init()
Set sev_info.active during SEV/SEV-ES activation before calling any code
that can potentially consume sev_info.es_active, e.g. set "active" and
"es_active" as a pair immediately after the initial sanity checks.  KVM
generally expects that es_active can be true if and only if active is
true, e.g. sev_asid_new() deliberately avoids sev_es_guest() so that it
doesn't get a false negative.  This will allow WARNing in sev_es_guest()
if the VM is tagged as SEV-ES but not SEV.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109215101.2211373-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:10:27 -05:00
Sean Christopherson
79b1114276 KVM: SEV: Disallow COPY_ENC_CONTEXT_FROM if target has created vCPUs
Reject COPY_ENC_CONTEXT_FROM if the destination VM has created vCPUs.
KVM relies on SEV activation to occur before vCPUs are created, e.g. to
set VMCB flags and intercepts correctly.

Fixes: 54526d1fd5 ("KVM: x86: Support KVM VMs sharing SEV context")
Cc: stable@vger.kernel.org
Cc: Peter Gonda <pgonda@google.com>
Cc: Marc Orr <marcorr@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Nathan Tempelman <natet@google.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109215101.2211373-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:10:27 -05:00