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>
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>
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>
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>
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>
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>
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>
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>
* 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
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>
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>
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>
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>
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>
And thus another call to kvm_vcpu_map() can die.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211115165030.7422-7-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Kill another mostly gratuitous kvm_vcpu_map() which could just use the
userspace HVA for it.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211115165030.7422-6-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211115165030.7422-4-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Using kvm_vcpu_map() for reading from the guest is entirely gratuitous,
when all we do is a single memcpy and unmap it again. Fix it up to use
kvm_read_guest()... but in fact I couldn't bring myself to do that
without also making it use a gfn_to_hva_cache for both that *and* the
copy in the other direction.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211115165030.7422-5-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In commit 319afe6856 ("KVM: xen: do not use struct gfn_to_hva_cache") we
stopped storing this in-kernel as a GPA, and started storing it as a GFN.
Which means we probably should have stopped calling gpa_to_gfn() on it
when userspace asks for it back.
Cc: stable@vger.kernel.org
Fixes: 319afe6856 ("KVM: xen: do not use struct gfn_to_hva_cache")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211115165030.7422-2-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Incorporate EFER.LMA into kvm_mmu_extended_role, as it used to compute the
guest root level and is not reflected in kvm_mmu_page_role.level when TDP
is in use. When simply running the guest, it is impossible for EFER.LMA
and kvm_mmu.root_level to get out of sync, as the guest cannot transition
from PAE paging to 64-bit paging without toggling CR0.PG, i.e. without
first bouncing through a different MMU context. And stuffing guest state
via KVM_SET_SREGS{,2} also ensures a full MMU context reset.
However, if KVM_SET_SREGS{,2} is followed by KVM_SET_NESTED_STATE, e.g. to
set guest state when migrating the VM while L2 is active, the vCPU state
will reflect L2, not L1. If L1 is using TDP for L2, then root_mmu will
have been configured using L2's state, despite not being used for L2. If
L2.EFER.LMA != L1.EFER.LMA, and L2 is using PAE paging, then root_mmu will
be configured for guest PAE paging, but will match the mmu_role for 64-bit
paging and cause KVM to not reconfigure root_mmu on the next nested VM-Exit.
Alternatively, the root_mmu's role could be invalidated after a successful
KVM_SET_NESTED_STATE that yields vcpu->arch.mmu != vcpu->arch.root_mmu,
i.e. that switches the active mmu to guest_mmu, but doing so is unnecessarily
tricky, and not even needed if L1 and L2 do have the same role (e.g., they
are both 64-bit guests and run with the same CR4).
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20211115131837.195527-3-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When loading nested state, don't use check vcpu->arch.efer to get the
L1 host's 64-bit vs. 32-bit state and don't check it for consistency
with respect to VM_EXIT_HOST_ADDR_SPACE_SIZE, as register state in vCPU
may be stale when KVM_SET_NESTED_STATE is called---and architecturally
does not exist. When restoring L2 state in KVM, the CPU is placed in
non-root where nested VMX code has no snapshot of L1 host state: VMX
(conditionally) loads host state fields loaded on VM-exit, but they need
not correspond to the state before entry. A simple case occurs in KVM
itself, where the host RIP field points to vmx_vmexit rather than the
instruction following vmlaunch/vmresume.
However, for the particular case of L1 being in 32- or 64-bit mode
on entry, the exit controls can be treated instead as the source of
truth regarding the state of L1 on entry, and can be used to check
that vmcs12.VM_EXIT_HOST_ADDR_SPACE_SIZE matches vmcs12.HOST_EFER if
vmcs12.VM_EXIT_LOAD_IA32_EFER is set. The consistency check on CPU
EFER vs. vmcs12.VM_EXIT_HOST_ADDR_SPACE_SIZE, instead, happens only
on VM-Enter. That's because, again, there's conceptually no "current"
L1 EFER to check on KVM_SET_NESTED_STATE.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20211115131837.195527-2-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In 64-bit mode, x86 instruction encoding allows us to use the low 8 bits
of any GPR as an 8-bit operand. In 32-bit mode, however, we can only use
the [abcd] registers. For which, GCC has the "q" constraint instead of
the less restrictive "r".
Also fix st->preempted, which is an input/output operand rather than an
input.
Fixes: 7e2175ebd6 ("KVM: x86: Fix recording of guest steal time / preempted status")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <89bf72db1b859990355f9c40713a34e0d2d86c98.camel@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The lack a static declaration currently results in:
arch/x86/kvm/cpuid.c:128:26: warning: no previous prototype for function 'kvm_find_kvm_cpuid_features'
when compiling with "W=1".
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 760849b147 ("KVM: x86: Make sure KVM_CPUID_FEATURES really are KVM_CPUID_FEATURES")
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Message-Id: <20211115144131.5943-1-pdurrant@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that all state needed for VMX's PT interrupt handler is exposed to
vmx.c (specifically the currently running vCPU), move the handler into
vmx.c where it belongs.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20211111020738.2512932-14-seanjc@google.com
Move x86's perf guest callbacks into common KVM, as they are semantically
identical to arm64's callbacks (the only other such KVM callbacks).
arm64 will convert to the common versions in a future patch.
Implement the necessary arm64 arch hooks now to avoid having to provide
stubs or a temporary #define (from x86) to avoid arm64 compilation errors
when CONFIG_GUEST_PERF_EVENTS=y.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211111020738.2512932-13-seanjc@google.com
Differentiate between IRQ and NMI for KVM's PMC overflow callback, which
was originally invoked in response to an NMI that arrived while the guest
was running, but was inadvertantly changed to fire on IRQs as well when
support for perf without PMU/NMI was added to KVM. In practice, this
should be a nop as the PMC overflow callback shouldn't be reached, but
it's a cheap and easy fix that also better documents the situation.
Note, this also doesn't completely prevent false positives if perf
somehow ends up calling into KVM, e.g. an NMI can arrive in host after
KVM sets its flag.
Fixes: dd60d21706 ("KVM: x86: Fix perf timer mode IP reporting")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20211111020738.2512932-12-seanjc@google.com
Use the generic kvm_running_vcpu plus a new 'handling_intr_from_guest'
variable in kvm_arch_vcpu instead of the semi-redundant current_vcpu.
kvm_before/after_interrupt() must be called while the vCPU is loaded,
(which protects against preemption), thus kvm_running_vcpu is guaranteed
to be non-NULL when handling_intr_from_guest is non-zero.
Switching to kvm_get_running_vcpu() will allows moving KVM's perf
callbacks to generic code, and the new flag will be used in a future
patch to more precisely identify the "NMI from guest" case.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20211111020738.2512932-11-seanjc@google.com
Introduce GUEST_PERF_EVENTS and require architectures to select it to
allow registering and using guest callbacks in perf. This will hopefully
make it more difficult for new architectures to add useless "support" for
guest callbacks, e.g. via copy+paste.
Stubbing out the helpers has the happy bonus of avoiding a load of
perf_guest_cbs when GUEST_PERF_EVENTS=n on arm64/x86.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20211111020738.2512932-9-seanjc@google.com
To prepare for using static_calls to optimize perf's guest callbacks,
replace ->is_in_guest and ->is_user_mode with a new multiplexed hook
->state, tweak ->handle_intel_pt_intr to play nice with being called when
there is no active guest, and drop "guest" from ->get_guest_ip.
Return '0' from ->state and ->handle_intel_pt_intr to indicate "not in
guest" so that DEFINE_STATIC_CALL_RET0 can be used to define the static
calls, i.e. no callback == !guest.
[sean: extracted from static_call patch, fixed get_ip() bug, wrote changelog]
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Originally-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20211111020738.2512932-7-seanjc@google.com
Override the Processor Trace (PT) interrupt handler for guest mode if and
only if PT is configured for host+guest mode, i.e. is being used
independently by both host and guest. If PT is configured for system
mode, the host fully controls PT and must handle all events.
Fixes: 8479e04e7d ("KVM: x86: Inject PMI for KVM guest")
Reported-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reported-by: Artem Kashkanov <artem.kashkanov@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211111020738.2512932-4-seanjc@google.com
Wait to register perf callbacks until after doing vendor hardaware setup.
VMX's hardware_setup() configures Intel Processor Trace (PT) mode, and a
future fix to register the Intel PT guest interrupt hook if and only if
Intel PT is exposed to the guest will consume the configured PT mode.
Delaying registration to hardware setup is effectively a nop as KVM's perf
hooks all pivot on the per-CPU current_vcpu, which is non-NULL only when
KVM is handling an IRQ/NMI in a VM-Exit path. I.e. current_vcpu will be
NULL throughout both kvm_arch_init() and kvm_arch_hardware_setup().
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211111020738.2512932-3-seanjc@google.com
In vcpu_load_eoi_exitmap(), currently the eoi_exit_bitmap[4] array is
initialized only when Hyper-V context is available, in other path it is
just passed to kvm_x86_ops.load_eoi_exitmap() directly from on the stack,
which would cause unexpected interrupt delivery/handling issues, e.g. an
*old* linux kernel that relies on PIT to do clock calibration on KVM might
randomly fail to boot.
Fix it by passing ioapic_handled_vectors to load_eoi_exitmap() when Hyper-V
context is not available.
Fixes: f2bc14b69c ("KVM: x86: hyper-v: Prepare to meet unallocated Hyper-V context")
Cc: stable@vger.kernel.org
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Huang Le <huangle1@jd.com>
Message-Id: <62115b277dab49ea97da5633f8522daf@jd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use the same cleanup code independent of whether the cgroup to be
uncharged and unref'd is the source or the destination cgroup. Use a
bool to track whether the destination cgroup has been charged, which also
fixes a bug in the error case: the destination cgroup must be uncharged
only if it does not match the source.
Fixes: b56639318b ("KVM: SEV: Add support for SEV intra host migration")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When UBSAN is enabled, the code emitted for the call to guest_pv_has
includes a call to __ubsan_handle_load_invalid_value. objtool
complains that this call happens with UACCESS enabled; to avoid
the warning, pull the calls to user_access_begin into both arms
of the "if" statement, after the check for guest_pv_has.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* Fix misuse of gfn-to-pfn cache when recording guest steal time / preempted status
* Fix selftests on APICv machines
* Fix sparse warnings
* Fix detection of KVM features in CPUID
* Cleanups for bogus writes to MSR_KVM_PV_EOI_EN
* Fixes and cleanups for MSR bitmap handling
* Cleanups for INVPCID
* Make x86 KVM_SOFT_MAX_VCPUS consistent with other architectures
Add support for AMD SEV and SEV-ES intra-host migration support. Intra
host migration provides a low-cost mechanism for userspace VMM upgrades.
In the common case for intra host migration, we can rely on the normal
ioctls for passing data from one VMM to the next. SEV, SEV-ES, and other
confidential compute environments make most of this information opaque, and
render KVM ioctls such as "KVM_GET_REGS" irrelevant. As a result, we need
the ability to pass this opaque metadata from one VMM to the next. The
easiest way to do this is to leave this data in the kernel, and transfer
ownership of the metadata from one KVM VM (or vCPU) to the next. In-kernel
hand off makes it possible to move any data that would be
unsafe/impossible for the kernel to hand directly to userspace, and
cannot be reproduced using data that can be handed to userspace.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM_CAP_NR_VCPUS is used to get the "recommended" maximum number of
VCPUs and arm64/mips/riscv report num_online_cpus(). Powerpc reports
either num_online_cpus() or num_present_cpus(), s390 has multiple
constants depending on hardware features. On x86, KVM reports an
arbitrary value of '710' which is supposed to be the maximum tested
value but it's possible to test all KVM_MAX_VCPUS even when there are
less physical CPUs available.
Drop the arbitrary '710' value and return num_online_cpus() on x86 as
well. The recommendation will match other architectures and will mean
'no CPU overcommit'.
For reference, QEMU only queries KVM_CAP_NR_VCPUS to print a warning
when the requested vCPU number exceeds it. The static limit of '710'
is quite weird as smaller systems with just a few physical CPUs should
certainly "recommend" less.
Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211111134733.86601-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Handle #GP on INVPCID due to an invalid type in the common switch
statement instead of relying on the callers (VMX and SVM) to manually
validate the type.
Unlike INVVPID and INVEPT, INVPCID is not explicitly documented to check
the type before reading the operand from memory, so deferring the
type validity check until after that point is architecturally allowed.
Signed-off-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109174426.2350547-3-vipinsh@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
handle_invept(), handle_invvpid(), handle_invpcid() read the same reg2
field in vmcs.VMX_INSTRUCTION_INFO to get the index of the GPR that
holds the invalidation type. Add a helper to retrieve reg2 from VMX
instruction info to consolidate and document the shift+mask magic.
Signed-off-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109174426.2350547-2-vipinsh@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Clean up the x2APIC MSR bitmap intereption code for L2, which is the last
holdout of open coded bitmap manipulations. Freshen up the SDM/PRM
comment, rename the function to make it abundantly clear the funky
behavior is x2APIC specific, and explain _why_ vmcs01's bitmap is ignored
(the previous comment was flat out wrong for x2APIC behavior).
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109013047.2041518-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add builder macros to generate the MSR bitmap helpers to reduce the
amount of copy-paste code, especially with respect to all the magic
numbers needed to calc the correct bit location.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109013047.2041518-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Always check vmcs01's MSR bitmap when merging L0 and L1 bitmaps for L2,
and always update the relevant bits in vmcs02. This fixes two distinct,
but intertwined bugs related to dynamic MSR bitmap modifications.
The first issue is that KVM fails to enable MSR interception in vmcs02
for the FS/GS base MSRs if L1 first runs L2 with interception disabled,
and later enables interception.
The second issue is that KVM fails to honor userspace MSR filtering when
preparing vmcs02.
Fix both issues simultaneous as fixing only one of the issues (doesn't
matter which) would create a mess that no one should have to bisect.
Fixing only the first bug would exacerbate the MSR filtering issue as
userspace would see inconsistent behavior depending on the whims of L1.
Fixing only the second bug (MSR filtering) effectively requires fixing
the first, as the nVMX code only knows how to transition vmcs02's
bitmap from 1->0.
Move the various accessor/mutators that are currently buried in vmx.c
into vmx.h so that they can be shared by the nested code.
Fixes: 1a155254ff ("KVM: x86: Introduce MSR filtering")
Fixes: d69129b4e4 ("KVM: nVMX: Disable intercept for FS/GS base MSRs in vmcs02 when possible")
Cc: stable@vger.kernel.org
Cc: Alexander Graf <graf@amazon.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109013047.2041518-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Check the current VMCS controls to determine if an MSR write will be
intercepted due to MSR bitmaps being disabled. In the nested VMX case,
KVM will disable MSR bitmaps in vmcs02 if they're disabled in vmcs12 or
if KVM can't map L1's bitmaps for whatever reason.
Note, the bad behavior is relatively benign in the current code base as
KVM sets all bits in vmcs02's MSR bitmap by default, clears bits if and
only if L0 KVM also disables interception of an MSR, and only uses the
buggy helper for MSR_IA32_SPEC_CTRL. Because KVM explicitly tests WRMSR
before disabling interception of MSR_IA32_SPEC_CTRL, the flawed check
will only result in KVM reading MSR_IA32_SPEC_CTRL from hardware when it
isn't strictly necessary.
Tag the fix for stable in case a future fix wants to use
msr_write_intercepted(), in which case a buggy implementation in older
kernels could prove subtly problematic.
Fixes: d28b387fb7 ("KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109013047.2041518-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When kvm_gfn_to_hva_cache_init() call from kvm_lapic_set_pv_eoi() fails,
MSR write to MSR_KVM_PV_EOI_EN results in #GP so it is reasonable to
expect that the value we keep internally in KVM wasn't updated.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211108152819.12485-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kvm_lapic_enable_pv_eoi() is a misnomer as the function is also
used to disable PV EOI. Rename it to kvm_lapic_set_pv_eoi().
No functional change intended.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211108152819.12485-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently when kvm_update_cpuid_runtime() runs, it assumes that the
KVM_CPUID_FEATURES leaf is located at 0x40000001. This is not true,
however, if Hyper-V support is enabled. In this case the KVM leaves will
be offset.
This patch introdues as new 'kvm_cpuid_base' field into struct
kvm_vcpu_arch to track the location of the KVM leaves and function
kvm_update_kvm_cpuid_base() (called from kvm_set_cpuid()) to locate the
leaves using the 'KVMKVMKVM\0\0\0' signature (which is now given a
definition in kvm_para.h). Adjustment of KVM_CPUID_FEATURES will hence now
target the correct leaf.
NOTE: A new for_each_possible_hypervisor_cpuid_base() macro is intoduced
into processor.h to avoid having duplicate code for the iteration
over possible hypervisor base leaves.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Message-Id: <20211105095101.5384-3-pdurrant@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move the core logic of SET_CPUID and SET_CPUID2 to a common helper, the
only difference between the two ioctls() is the format of the userspace
struct. A future fix will add yet more code to the core logic.
No functional change intended.
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211105095101.5384-2-pdurrant@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The fast page fault path bails out on write faults to huge pages in
order to accommodate dirty logging. This change adds a check to do that
only when dirty logging is actually enabled, so that access tracking for
huge pages can still use the fast path for write faults in the common
case.
Signed-off-by: Junaid Shahid <junaids@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211104003359.2201967-1-junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Wrap the read of iter->sptep in tdp_mmu_map_handle_target_level() with
rcu_dereference(). Shadow pages in the TDP MMU, and thus their SPTEs,
are protected by rcu.
This fixes a Sparse warning at tdp_mmu.c:900:51:
warning: incorrect type in argument 1 (different address spaces)
expected unsigned long long [usertype] *sptep
got unsigned long long [noderef] [usertype] __rcu *[usertype] sptep
Fixes: 7158bee4b4 ("KVM: MMU: pass kvm_mmu_page struct to make_spte")
Cc: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211103161833.3769487-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM_GUESTDBG_BLOCKIRQ relies on interrupts being injected using
standard kvm's inject_pending_event, and not via APICv/AVIC.
Since this is a debug feature, just inhibit APICv/AVIC while
KVM_GUESTDBG_BLOCKIRQ is in use on at least one vCPU.
Fixes: 61e5f69ef0 ("KVM: x86: implement KVM_GUESTDBG_BLOCKIRQ")
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Tested-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211108090245.166408-1-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
