KVM: X86: Reset the vcpu->run->flags at the beginning of vcpu_run

mainline inclusion
from mainline-v5.12-rc1
commit 15aad3be
category: feature
feature: KVM Bus Lock VM Exit
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I5RJCB
CVE: N/A
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/


commit/?id=15aad3be

Intel-SIG: commit 15aad3be ("KVM: X86: Reset the vcpu->run->flags at the beginning of vcpu_run")

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KVM: X86: Reset the vcpu->run->flags at the beginning of vcpu_run

Reset the vcpu->run->flags at the beginning of kvm_arch_vcpu_ioctl_run.
It can avoid every thunk of code that needs to set the flag clear it,
which increases the odds of missing a case and ending up with a flag in
an undefined state.

Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Message-Id: <20201106090315.18606-3-chenyi.qiang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Aichun Shi <aichun.shi@intel.com>