From: Sean Christopherson <seanjc@google.com>
To: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Xiaoyao Li <xiaoyao.li@intel.com>,
rangemachine@gmail.com, whanos@sergal.fun
Subject: Re: [PATCH v2 3/5] KVM: SVM: Manually context switch DEBUGCTL if LBR virtualization is disabled
Date: Thu, 27 Feb 2025 06:30:58 -0800 [thread overview]
Message-ID: <Z8B3IvwtGqz8aCHD@google.com> (raw)
In-Reply-To: <1fe17606-d696-43f3-b80d-253b6aa80da7@amd.com>
On Thu, Feb 27, 2025, Ravi Bangoria wrote:
> > Somewhat related but independent: CPU automatically clears DEBUGCTL[BTF]
> > on #DB exception. So, when DEBUGCTL is save/restored by KVM (i.e. when
> > LBR virtualization is disabled), it's KVM's responsibility to clear
> > DEBUGCTL[BTF].
>
> Found this with below KUT test.
>
> (I wasn't sure whether I should send a separate series for kernel fix + KUT
> patch, or you can squash kernel fix in your patch and I shall send only KUT
> patch. So for now, sending it as a reply here.)
Go ahead and send the KUT test. They two repositories evolve independently no
matter the order, just put a Link to lore of the kernel fix/discussion.
Thanks a ton for writing a test!
next prev parent reply other threads:[~2025-02-27 14:31 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-27 1:13 [PATCH v2 0/5] KVM: SVM: Fix DEBUGCTL bugs Sean Christopherson
2025-02-27 1:13 ` [PATCH v2 1/5] KVM: SVM: Drop DEBUGCTL[5:2] from guest's effective value Sean Christopherson
2025-02-27 1:13 ` [PATCH v2 2/5] KVM: x86: Snapshot the host's DEBUGCTL in common x86 Sean Christopherson
2025-02-27 1:13 ` [PATCH v2 3/5] KVM: SVM: Manually context switch DEBUGCTL if LBR virtualization is disabled Sean Christopherson
2025-02-27 13:59 ` Ravi Bangoria
2025-02-27 14:09 ` Ravi Bangoria
2025-02-27 14:30 ` Sean Christopherson [this message]
2025-02-27 17:20 ` Sean Christopherson
2025-02-27 17:55 ` Sean Christopherson
2025-02-27 14:29 ` Sean Christopherson
2025-02-27 14:44 ` Ravi Bangoria
2025-02-27 1:13 ` [PATCH v2 4/5] KVM: x86: Snapshot the host's DEBUGCTL after disabling IRQs Sean Christopherson
2025-02-27 1:13 ` [PATCH v2 5/5] KVM: SVM: Treat DEBUGCTL[5:2] as reserved Sean Christopherson
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