From: Marcelo Tosatti <mtosatti@redhat.com>
To: Oliver Upton <oupton@google.com>
Cc: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu,
Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Marc Zyngier <maz@kernel.org>, Peter Shier <pshier@google.com>,
Jim Mattson <jmattson@google.com>,
David Matlack <dmatlack@google.com>,
Ricardo Koller <ricarkol@google.com>,
Jing Zhang <jingzhangos@google.com>,
Raghavendra Rao Anata <rananta@google.com>,
James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
linux-arm-kernel@lists.infradead.org,
Andrew Jones <drjones@redhat.com>, Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>
Subject: Re: [PATCH v8 3/7] KVM: x86: Fix potential race in KVM_GET_CLOCK
Date: Wed, 29 Sep 2021 10:33:21 -0300 [thread overview]
Message-ID: <20210929133320.GA10977@fuller.cnet> (raw)
In-Reply-To: <20210916181538.968978-4-oupton@google.com>
On Thu, Sep 16, 2021 at 06:15:34PM +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.
>
> Suggested-by: Sean Christopherson <seanjc@google.com>
> Signed-off-by: Oliver Upton <oupton@google.com>
ACK patches 1-3, still reviewing the remaining ones...
next prev parent reply other threads:[~2021-09-29 13:33 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-16 18:15 [PATCH v8 0/7] KVM: x86: Add idempotent controls for migrating system counter state Oliver Upton
2021-09-16 18:15 ` [PATCH v8 1/7] kvm: x86: abstract locking around pvclock_update_vm_gtod_copy Oliver Upton
2021-09-16 18:15 ` [PATCH v8 2/7] KVM: x86: extract KVM_GET_CLOCK/KVM_SET_CLOCK to separate functions Oliver Upton
2021-09-16 18:15 ` [PATCH v8 3/7] KVM: x86: Fix potential race in KVM_GET_CLOCK Oliver Upton
2021-09-29 13:33 ` Marcelo Tosatti [this message]
2021-09-16 18:15 ` [PATCH v8 4/7] KVM: x86: Report host tsc and realtime values " Oliver Upton
2021-09-28 18:53 ` Marcelo Tosatti
2021-09-29 11:20 ` Paolo Bonzini
2021-09-29 18:56 ` Marcelo Tosatti
2021-09-30 19:21 ` Marcelo Tosatti
2021-09-30 23:02 ` Thomas Gleixner
2021-10-01 12:05 ` Marcelo Tosatti
2021-10-01 12:10 ` Marcelo Tosatti
2021-10-01 19:59 ` Thomas Gleixner
2021-10-01 21:03 ` Oliver Upton
2021-10-01 14:17 ` Paolo Bonzini
2021-10-01 14:39 ` Paolo Bonzini
2021-10-01 14:41 ` Paolo Bonzini
2021-10-01 15:39 ` Oliver Upton
2021-10-01 16:42 ` Paolo Bonzini
2024-01-17 14:28 ` David Woodhouse
2024-07-24 22:24 ` [PATCH v8 4/7] KVM: x86: Report host tsc and realtime values in KVM_GET_CLOCK' Sean Christopherson
2024-07-25 8:24 ` David Woodhouse
2021-09-16 18:15 ` [PATCH v8 5/7] kvm: x86: protect masterclock with a seqcount Oliver Upton
2021-09-24 16:42 ` Paolo Bonzini
2021-09-30 17:51 ` Marcelo Tosatti
2021-10-01 16:48 ` Paolo Bonzini
2021-09-16 18:15 ` [PATCH v8 6/7] KVM: x86: Refactor tsc synchronization code Oliver Upton
2021-09-16 18:15 ` [PATCH v8 7/7] KVM: x86: Expose TSC offset controls to userspace Oliver Upton
2021-09-30 19:14 ` Marcelo Tosatti
2021-10-01 9:17 ` Paolo Bonzini
2021-10-01 10:32 ` Marcelo Tosatti
2021-10-01 15:12 ` Paolo Bonzini
2021-10-01 19:11 ` Marcelo Tosatti
2021-10-01 19:33 ` Oliver Upton
2021-10-04 14:30 ` Marcelo Tosatti
2021-10-04 11:44 ` Paolo Bonzini
2021-10-05 15:22 ` Sean Christopherson
2022-02-23 10:02 ` David Woodhouse
2021-09-24 16:43 ` [PATCH v8 0/7] KVM: x86: Add idempotent controls for migrating system counter state Paolo Bonzini
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