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| author | Wanpeng Li <wanpengli@tencent.com> | 2021-04-09 12:18:31 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-04-19 18:04:46 -0400 |
| commit | a1fa4cbd53d9bc7bb0eaa7bcf7c8a5904372a4ec (patch) | |
| tree | 79403ec43ea41295aa61a6e26d61b296d2ebe8f8 | |
| parent | KVM: X86: Count attempted/successful directed yield (diff) | |
| download | linux-a1fa4cbd53d9bc7bb0eaa7bcf7c8a5904372a4ec.tar.gz linux-a1fa4cbd53d9bc7bb0eaa7bcf7c8a5904372a4ec.zip | |
KVM: X86: Do not yield to self
If the target is self we do not need to yield, we can avoid malicious
guest to play this.
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1617941911-5338-3-git-send-email-wanpengli@tencent.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/x86.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 05a4bce181d7..66d2ab074a5f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8228,6 +8228,10 @@ static void kvm_sched_yield(struct kvm_vcpu *vcpu, unsigned long dest_id) if (!target || !READ_ONCE(target->ready)) goto no_yield; + /* Ignore requests to yield to self */ + if (vcpu == target) + goto no_yield; + if (kvm_vcpu_yield_to(target) <= 0) goto no_yield; |