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KVM: x86: fix WARN_ON check of an unsigned less than zero 

The check cpu->hv_clock.system_time < 0 is redundant since system_time
is a u64 and hence can never be less than zero.  But what was actually
meant is to check that the result is positive, since kernel_ns and
v->kvm->arch.kvmclock_offset are both s64.

Reported-by: Colin King <colin.king@canonical.com>
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Addresses-Coverity: ("Macro compares unsigned to 0")
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2020-02-12 13:27:10 +01:00
parent ff47902534
commit 9446e6fce0
1 changed files with 1 additions and 1 deletions
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arch/x86/kvm/x86.c
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@ -2444,7 +2444,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
vcpu->hv_clock.tsc_timestamp = tsc_timestamp;
vcpu->hv_clock.system_time = kernel_ns + v->kvm->arch.kvmclock_offset;
vcpu->last_guest_tsc = tsc_timestamp;
WARN_ON(vcpu->hv_clock.system_time < 0);
WARN_ON((s64)vcpu->hv_clock.system_time < 0);
/* If the host uses TSC clocksource, then it is stable */
pvclock_flags = 0;