From: Sean Christopherson <seanjc@google.com>
To: Maxim Levitsky <mlevitsk@redhat.com>
Cc: kvm@vger.kernel.org, Joerg Roedel <joro@8bytes.org>,
Wanpeng Li <wanpengli@tencent.com>,
"open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<linux-kernel@vger.kernel.org>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>, Vitaly Kuznetsov <vkuznets@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Jim Mattson <jmattson@google.com>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 0/2] RFC: VMX: fix for disappearing L1->L2 event injection on L1 migration
Date: Wed, 6 Jan 2021 10:07:51 -0800 [thread overview]
Message-ID: <X/X8d2XijuPxLOGG@google.com> (raw)
In-Reply-To: <20210106105306.450602-1-mlevitsk@redhat.com>
On Wed, Jan 06, 2021, Maxim Levitsky wrote:
> This is VMX version of the same issue as I reproduced on SVM.
>
> Unlike SVM, this version has 2 pending issues to resolve.
>
> 1. This seems to break 'vmx' kvm-unit-test in
> 'error code <-> (!URG || prot_mode) [+]' case.
>
> The test basically tries to do nested vm entry with unrestricted guest disabled,
> real mode, and for some reason that works without patch 2 of this series and it
> doesn't cause the #GP to be injected, but with this patch the test complains
> about unexpected #GP.
An unexpected #GP for that test is very unlikely. The various sub-tests under
vmx_controls_test() should never fully enter the guest as GUEST.RFLAGS is set to
an invalid value. And, that specific test does VM-Enter with URG=0 and
CR0.PG/PE=0, which is also invalid. The unit test uses test_vmx_valid_controls(),
which is a wee bit misleading, as the "early" consistency checks that cause
VM-Fail are expected to succeed, while the VM-Enter is still expected to "fail"
due to a consistency check VM-Exit.
> I suspect that this test case is broken, but this has to be investigated.
>
> 2. L1 MTF injections are lost since kvm has no notion of them, this is TBD to
> be fixed.
>
> This was lightly tested on my nested migration test which no VMX sadly still
> crashes and burns on an (likely) unrelated issue.
>
> Best regards,
> Maxim Levitsky
>
> Maxim Levitsky (2):
> KVM: VMX: create vmx_process_injected_event
> KVM: nVMX: fix for disappearing L1->L2 event injection on L1 migration
>
> arch/x86/kvm/vmx/nested.c | 12 ++++----
> arch/x86/kvm/vmx/vmx.c | 60 ++++++++++++++++++++++++---------------
> arch/x86/kvm/vmx/vmx.h | 4 +++
> 3 files changed, 47 insertions(+), 29 deletions(-)
>
> --
> 2.26.2
>
>
prev parent reply other threads:[~2021-01-06 18:09 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-06 10:53 [PATCH 0/2] RFC: VMX: fix for disappearing L1->L2 event injection on L1 migration Maxim Levitsky
2021-01-06 10:53 ` [PATCH 1/2] KVM: VMX: create vmx_process_injected_event Maxim Levitsky
2021-01-06 10:53 ` [PATCH 2/2] KVM: nVMX: fix for disappearing L1->L2 event injection on L1 migration Maxim Levitsky
2021-01-06 18:17 ` Sean Christopherson
2021-01-07 2:38 ` Maxim Levitsky
2021-01-07 9:41 ` Maxim Levitsky
2021-01-06 18:07 ` Sean Christopherson [this message]
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