Re: [PATCH v7 1/6] KVM: x86: Fix potential race in KVM_GET_CLOCK
From: Marcelo Tosatti <hidden>
Date: 2021-08-19 18:46:05
Also in:
kvm, kvmarm
On Mon, Aug 16, 2021 at 12:11:25AM +0000, Oliver Upton wrote:
Sean noticed that KVM_GET_CLOCK was checking kvm_arch.use_master_clock outside of the pvclock sync lock. This is problematic, as the clock value written to the user may or may not actually correspond to a stable TSC. Fix the race by populating the entire kvm_clock_data structure behind the pvclock_gtod_sync_lock.
Oliver, Can you please describe the race in more detail? Is it about host TSC going unstable VS parallel KVM_GET_CLOCK ? _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel