From: Peter Xu <peterx@redhat.com>
To: Sean Christopherson <seanjc@google.com>
Cc: shuah@kernel.org, kvm@vger.kernel.org,
Marc Zyngier <maz@kernel.org>,
andrew.jones@linux.dev, dmatlack@google.com, will@kernel.org,
shan.gavin@gmail.com, bgardon@google.com, kvmarm@lists.linux.dev,
pbonzini@redhat.com, zhenyzha@redhat.com,
catalin.marinas@arm.com, kvmarm@lists.cs.columbia.edu,
ajones@ventanamicro.com
Subject: Re: [PATCH v7 1/9] KVM: x86: Introduce KVM_REQ_DIRTY_RING_SOFT_FULL
Date: Wed, 2 Nov 2022 12:43:16 -0400 [thread overview]
Message-ID: <Y2KeJGYUxnOOcXMj@x1n> (raw)
In-Reply-To: <Y2Kby0yXu0/Zi2P1@google.com>
On Wed, Nov 02, 2022 at 04:33:15PM +0000, Sean Christopherson wrote:
> On Wed, Nov 02, 2022, Peter Xu wrote:
> > Might be slightly off-topic: I didn't quickly spot how do we guarantee two
> > threads doing KVM_RUN ioctl on the same vcpu fd concurrently. I know
> > that's insane and could have corrupted things, but I just want to make sure
> > e.g. even a malicious guest app won't be able to trigger host warnings.
>
> kvm_vcpu_ioctl() takes the vCPU's mutex:
>
> static long kvm_vcpu_ioctl(struct file *filp,
> unsigned int ioctl, unsigned long arg)
> {
> ...
>
> /*
> * Some architectures have vcpu ioctls that are asynchronous to vcpu
> * execution; mutex_lock() would break them.
> */
> r = kvm_arch_vcpu_async_ioctl(filp, ioctl, arg);
> if (r != -ENOIOCTLCMD)
> return r;
>
> if (mutex_lock_killable(&vcpu->mutex))
> return -EINTR;
> switch (ioctl) {
> case KVM_RUN: {
Ah, makes sense, thanks!
--
Peter Xu
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WARNING: multiple messages have this Message-ID (diff)
From: Peter Xu <peterx@redhat.com>
To: Sean Christopherson <seanjc@google.com>
Cc: Marc Zyngier <maz@kernel.org>, Gavin Shan <gshan@redhat.com>,
kvmarm@lists.linux.dev, kvm@vger.kernel.org,
kvmarm@lists.cs.columbia.edu, andrew.jones@linux.dev,
ajones@ventanamicro.com, bgardon@google.com,
catalin.marinas@arm.com, dmatlack@google.com, will@kernel.org,
pbonzini@redhat.com, oliver.upton@linux.dev, james.morse@arm.com,
shuah@kernel.org, suzuki.poulose@arm.com,
alexandru.elisei@arm.com, zhenyzha@redhat.com,
shan.gavin@gmail.com
Subject: Re: [PATCH v7 1/9] KVM: x86: Introduce KVM_REQ_DIRTY_RING_SOFT_FULL
Date: Wed, 2 Nov 2022 12:43:16 -0400 [thread overview]
Message-ID: <Y2KeJGYUxnOOcXMj@x1n> (raw)
Message-ID: <20221102164316.Zw7UQVRqBq6UFOQrsNxjxPsLj1Non7rlfCAvVYvXpH8@z> (raw)
In-Reply-To: <Y2Kby0yXu0/Zi2P1@google.com>
On Wed, Nov 02, 2022 at 04:33:15PM +0000, Sean Christopherson wrote:
> On Wed, Nov 02, 2022, Peter Xu wrote:
> > Might be slightly off-topic: I didn't quickly spot how do we guarantee two
> > threads doing KVM_RUN ioctl on the same vcpu fd concurrently. I know
> > that's insane and could have corrupted things, but I just want to make sure
> > e.g. even a malicious guest app won't be able to trigger host warnings.
>
> kvm_vcpu_ioctl() takes the vCPU's mutex:
>
> static long kvm_vcpu_ioctl(struct file *filp,
> unsigned int ioctl, unsigned long arg)
> {
> ...
>
> /*
> * Some architectures have vcpu ioctls that are asynchronous to vcpu
> * execution; mutex_lock() would break them.
> */
> r = kvm_arch_vcpu_async_ioctl(filp, ioctl, arg);
> if (r != -ENOIOCTLCMD)
> return r;
>
> if (mutex_lock_killable(&vcpu->mutex))
> return -EINTR;
> switch (ioctl) {
> case KVM_RUN: {
Ah, makes sense, thanks!
--
Peter Xu
next prev parent reply other threads:[~2022-11-02 16:43 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-31 0:36 [PATCH v7 0/9] KVM: arm64: Enable ring-based dirty memory tracking Gavin Shan
2022-10-31 0:36 ` Gavin Shan
2022-10-31 0:36 ` [PATCH v7 1/9] KVM: x86: Introduce KVM_REQ_DIRTY_RING_SOFT_FULL Gavin Shan
2022-10-31 0:36 ` Gavin Shan
2022-11-01 19:39 ` Sean Christopherson
2022-11-01 19:39 ` Sean Christopherson
2022-11-02 14:29 ` Peter Xu
2022-11-02 14:29 ` Peter Xu
2022-11-02 15:58 ` Marc Zyngier
2022-11-02 15:58 ` Marc Zyngier
2022-11-02 16:11 ` Sean Christopherson
2022-11-02 16:11 ` Sean Christopherson
2022-11-02 16:44 ` Marc Zyngier
2022-11-02 16:44 ` Marc Zyngier
2022-11-03 0:44 ` Gavin Shan
2022-11-03 0:44 ` Gavin Shan
2022-11-02 16:23 ` Peter Xu
2022-11-02 16:23 ` Peter Xu
2022-11-02 16:33 ` Sean Christopherson
2022-11-02 16:33 ` Sean Christopherson
2022-11-02 16:43 ` Peter Xu [this message]
2022-11-02 16:43 ` Peter Xu
2022-11-02 16:48 ` Marc Zyngier
2022-11-02 16:48 ` Marc Zyngier
2022-11-02 14:31 ` Marc Zyngier
2022-11-02 14:31 ` Marc Zyngier
2022-10-31 0:36 ` [PATCH v7 2/9] KVM: Move declaration of kvm_cpu_dirty_log_size() to kvm_dirty_ring.h Gavin Shan
2022-10-31 0:36 ` Gavin Shan
2022-10-31 0:36 ` [PATCH v7 3/9] KVM: Check KVM_CAP_DIRTY_LOG_{RING, RING_ACQ_REL} prior to enabling them Gavin Shan
2022-10-31 0:36 ` Gavin Shan
2022-10-31 9:18 ` Oliver Upton
2022-10-31 9:18 ` Oliver Upton
2022-10-31 0:36 ` [PATCH v7 4/9] KVM: Support dirty ring in conjunction with bitmap Gavin Shan
2022-10-31 0:36 ` Gavin Shan
2022-11-03 19:33 ` Peter Xu
2022-11-03 19:33 ` Peter Xu
2022-11-03 23:32 ` Oliver Upton
2022-11-03 23:32 ` Oliver Upton
2022-11-04 0:12 ` Gavin Shan
2022-11-04 0:12 ` Gavin Shan
2022-11-04 1:06 ` Oliver Upton
2022-11-04 1:06 ` Oliver Upton
2022-11-04 6:57 ` Gavin Shan
2022-11-04 6:57 ` Gavin Shan
2022-11-04 20:12 ` Oliver Upton
2022-11-04 20:12 ` Oliver Upton
2022-11-04 21:57 ` Gavin Shan
2022-11-04 21:57 ` Gavin Shan
2022-11-04 22:23 ` Oliver Upton
2022-11-04 22:23 ` Oliver Upton
2022-10-31 0:36 ` [PATCH v7 5/9] KVM: arm64: Improve no-running-vcpu report for dirty ring Gavin Shan
2022-10-31 0:36 ` Gavin Shan
2022-10-31 9:08 ` Oliver Upton
2022-10-31 9:08 ` Oliver Upton
2022-10-31 23:08 ` Gavin Shan
2022-10-31 23:08 ` Gavin Shan
2022-11-02 17:18 ` Marc Zyngier
2022-11-02 17:18 ` Marc Zyngier
2022-10-31 0:36 ` [PATCH v7 6/9] KVM: arm64: Enable ring-based dirty memory tracking Gavin Shan
2022-10-31 0:36 ` Gavin Shan
2022-10-31 0:36 ` [PATCH v7 7/9] KVM: selftests: Use host page size to map ring buffer in dirty_log_test Gavin Shan
2022-10-31 0:36 ` Gavin Shan
2022-10-31 0:36 ` [PATCH v7 8/9] KVM: selftests: Clear dirty ring states between two modes " Gavin Shan
2022-10-31 0:36 ` Gavin Shan
2022-10-31 0:36 ` [PATCH v7 9/9] KVM: selftests: Automate choosing dirty ring size " Gavin Shan
2022-10-31 0:36 ` Gavin Shan
2022-10-31 17:23 ` (subset) [PATCH v7 0/9] KVM: arm64: Enable ring-based dirty memory tracking Marc Zyngier
2022-10-31 17:23 ` Marc Zyngier
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