Sean Christopherson dea0d5a2fd KVM: x86: Exempt pending triple fault from event injection sanity check
Exempt pending triple faults, a.k.a. KVM_REQ_TRIPLE_FAULT, when asserting
that KVM didn't attempt to queue a new exception during event injection.
KVM needs to emulate the injection itself when emulating Real Mode due to
lack of unrestricted guest support (VMX) and will queue a triple fault if
that emulation fails.

Ideally the assertion would more precisely filter out the emulated Real
Mode triple fault case, but rmode.vm86_active is buried in vcpu_vmx and
can't be queried without a new kvm_x86_ops.  And unlike "regular"
exceptions, triple fault cannot put the vCPU into an infinite loop; the
triple fault will force either an exit to userspace or a nested VM-Exit,
and triple fault after nested VM-Exit will force an exit to userspace.
I.e. there is no functional issue, so just suppress the warning for
triple faults.

Opportunistically convert the warning to a one-time thing, when it
fires, it fires _a lot_, and is usually user triggerable, i.e. can be
used to spam the kernel log.

Fixes: 7055fb113116 ("KVM: x86: Treat pending TRIPLE_FAULT requests as pending exceptions")
Reported-by: kernel test robot <yujie.liu@intel.com>
Link: https://lore.kernel.org/r/202209301338.aca913c3-yujie.liu@intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220930230008.1636044-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-27 05:22:01 -04:00
..
2022-10-10 09:27:46 -07:00
2022-04-11 18:04:27 +02:00
2022-04-14 14:09:43 +02:00
2022-10-04 13:38:03 -07:00
2022-10-09 08:56:54 -07:00
2022-09-26 10:13:16 -07:00
2022-10-12 14:39:38 -07:00
2022-07-25 10:32:32 +02:00
2021-12-11 09:09:45 +01:00
2022-10-10 12:00:45 -07:00