From: Sean Christopherson <seanjc@google.com>
To: Kai Huang <kai.huang@intel.com>
Cc: Borislav Petkov <bp@alien8.de>,
kvm@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org,
linux-kernel@vger.kernel.org, jarkko@kernel.org, luto@kernel.org,
dave.hansen@intel.com, rick.p.edgecombe@intel.com,
haitao.huang@intel.com, pbonzini@redhat.com, tglx@linutronix.de,
mingo@redhat.com, hpa@zytor.com
Subject: Re: [PATCH v3 03/25] x86/sgx: Wipe out EREMOVE from sgx_free_epc_page()
Date: Tue, 23 Mar 2021 15:45:14 +0000 [thread overview]
Message-ID: <YFoNCvBYS2lIYjjc@google.com> (raw)
In-Reply-To: <20210323121643.e06403a1bc7819bab7c15d95@intel.com>
On Tue, Mar 23, 2021, Kai Huang wrote:
> On Mon, 22 Mar 2021 23:37:26 +0100 Borislav Petkov wrote:
> > "The instruction fails if the operand is not properly aligned or does
> > not refer to an EPC page or the page is in use by another thread, or
> > other threads are running in the enclave to which the page belongs. In
> > addition the instruction fails if the operand refers to an SECS with
> > associations."
> >
> > And I guess those conditions will become more in the future.
Yep, IME these types of bugs rarely, if ever, lead to isolated failures.
> > Now, let's play. I'm the cloud admin and you're cloud OS customer
> > support. I say:
> >
> > "I got this scary error message while running enclaves on my server
> >
> > "EREMOVE returned ... . EPC page leaked. Reboot required to retrieve leaked pages."
> >
> > but I cannot reboot that machine because there are guests running on it
> > and I'm getting paid for those guests and I might get sued if I do?"
> >
> > Your turn, go wild.
>
> I suppose admin can migrate those VMs, and then engineers can analyse the root
> cause of such failure, and then fix it.
That's more than likely what will happen, though there are a lot of "ifs" and
"buts" in any answer, e.g. things will go downhill fast if the majority of
systems in the fleet are running the buggy kernel and are triggering the error.
Practically speaking, "basic" deployments of SGX VMs will be insulated from
this bug. KVM doesn't support EPC oversubscription, so even if all EPC is
exhausted, new VMs will fail to launch, but existing VMs will continue to chug
along with no ill effects. There are again caveats, e.g. if EPC is being lazily
allocated for VMs, then running VMs will be affected if a VM starts using SGX
after the leak in the host occurs. But, IMO doing lazy allocation _and_ running
enclaves in the host falls firmly into the "advanced" bucket; anyone going that
route had better do their homework to understand the various EPC interactions.
next prev parent reply other threads:[~2021-03-23 15:46 UTC|newest]
Thread overview: 134+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-19 7:29 [PATCH v3 00/25] KVM SGX virtualization support Kai Huang
2021-03-19 7:22 ` [PATCH v3 01/25] x86/cpufeatures: Make SGX_LC feature bit depend on SGX bit Kai Huang
2021-04-07 10:03 ` [tip: x86/sgx] " tip-bot2 for Kai Huang
2021-03-19 7:22 ` [PATCH v3 02/25] x86/cpufeatures: Add SGX1 and SGX2 sub-features Kai Huang
2021-04-07 10:03 ` [tip: x86/sgx] " tip-bot2 for Sean Christopherson
2021-03-19 7:22 ` [PATCH v3 03/25] x86/sgx: Wipe out EREMOVE from sgx_free_epc_page() Kai Huang
2021-03-22 18:16 ` Borislav Petkov
2021-03-22 18:56 ` Sean Christopherson
2021-03-22 19:11 ` Paolo Bonzini
2021-03-22 20:43 ` Kai Huang
2021-03-23 16:40 ` Paolo Bonzini
2021-03-22 19:15 ` Borislav Petkov
2021-03-22 19:37 ` Sean Christopherson
2021-03-22 20:36 ` Kai Huang
2021-03-22 21:06 ` Borislav Petkov
2021-03-22 22:06 ` Kai Huang
2021-03-22 22:37 ` Borislav Petkov
2021-03-22 23:16 ` Kai Huang
2021-03-23 15:45 ` Sean Christopherson [this message]
2021-03-23 16:06 ` Borislav Petkov
2021-03-23 16:21 ` Sean Christopherson
2021-03-23 16:32 ` Borislav Petkov
2021-03-23 16:51 ` Sean Christopherson
2021-03-24 9:38 ` Kai Huang
2021-03-24 10:09 ` Paolo Bonzini
2021-03-24 10:48 ` Kai Huang
2021-03-24 11:24 ` Paolo Bonzini
2021-03-24 23:23 ` Kai Huang
2021-03-24 23:39 ` Paolo Bonzini
2021-03-24 23:46 ` Kai Huang
2021-03-25 8:42 ` Borislav Petkov
2021-03-25 9:38 ` Kai Huang
2021-03-25 16:52 ` Borislav Petkov
2021-03-24 9:28 ` Jarkko Sakkinen
2021-03-23 16:38 ` Paolo Bonzini
2021-03-23 17:02 ` Sean Christopherson
2021-03-23 17:06 ` Paolo Bonzini
2021-03-23 17:16 ` Sean Christopherson
2021-03-23 18:16 ` Borislav Petkov
2021-03-24 9:26 ` Jarkko Sakkinen
2021-03-22 22:23 ` Kai Huang
2021-03-25 9:30 ` [PATCH v4 " Kai Huang
2021-03-26 19:48 ` Jarkko Sakkinen
2021-03-26 20:38 ` Kai Huang
2021-03-26 21:39 ` Jarkko Sakkinen
2021-04-07 10:03 ` [tip: x86/sgx] " tip-bot2 for Kai Huang
2021-03-19 7:22 ` [PATCH v3 04/25] x86/sgx: Add SGX_CHILD_PRESENT hardware error code Kai Huang
2021-04-07 10:03 ` [tip: x86/sgx] " tip-bot2 for Sean Christopherson
2021-03-19 7:22 ` [PATCH v3 05/25] x86/sgx: Introduce virtual EPC for use by KVM guests Kai Huang
2021-03-25 9:36 ` Kai Huang
2021-03-26 15:03 ` Borislav Petkov
2021-03-26 15:17 ` Dave Hansen
2021-03-26 15:29 ` Borislav Petkov
2021-03-26 15:35 ` Dave Hansen
2021-03-26 17:02 ` Borislav Petkov
2021-03-31 1:10 ` Kai Huang
2021-03-31 6:44 ` Boris Petkov
2021-03-31 6:51 ` Kai Huang
2021-03-31 7:44 ` Boris Petkov
2021-03-31 8:53 ` Kai Huang
2021-03-31 12:20 ` Kai Huang
2021-04-01 18:31 ` Borislav Petkov
2021-04-01 23:38 ` Kai Huang
2021-04-01 9:45 ` Kai Huang
2021-04-01 9:42 ` [PATCH v4 " Kai Huang
2021-04-05 9:01 ` [PATCH v3 " Borislav Petkov
2021-04-05 21:46 ` Kai Huang
2021-04-06 8:28 ` Borislav Petkov
2021-04-06 9:04 ` Kai Huang
2021-04-07 10:03 ` [tip: x86/sgx] " tip-bot2 for Sean Christopherson
2021-03-19 7:22 ` [PATCH v3 06/25] x86/cpu/intel: Allow SGX virtualization without Launch Control support Kai Huang
2021-04-07 10:03 ` [tip: x86/sgx] " tip-bot2 for Sean Christopherson
2021-03-19 7:23 ` [PATCH v3 07/25] x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled Kai Huang
2021-04-02 9:48 ` Borislav Petkov
2021-04-02 11:08 ` Kai Huang
2021-04-02 11:22 ` Borislav Petkov
2021-04-02 11:38 ` Kai Huang
2021-04-02 15:42 ` Sean Christopherson
2021-04-02 19:08 ` Kai Huang
2021-04-02 19:19 ` Borislav Petkov
2021-04-02 19:30 ` Sean Christopherson
2021-04-02 19:46 ` Borislav Petkov
2021-04-07 10:03 ` [tip: x86/sgx] " tip-bot2 for Kai Huang
2021-03-19 7:23 ` [PATCH v3 08/25] x86/sgx: Expose SGX architectural definitions to the kernel Kai Huang
2021-04-07 10:03 ` [tip: x86/sgx] " tip-bot2 for Sean Christopherson
2021-03-19 7:23 ` [PATCH v3 09/25] x86/sgx: Move ENCLS leaf definitions to sgx.h Kai Huang
2021-04-07 10:03 ` [tip: x86/sgx] " tip-bot2 for Sean Christopherson
2021-03-19 7:23 ` [PATCH v3 10/25] x86/sgx: Add SGX2 ENCLS leaf definitions (EAUG, EMODPR and EMODT) Kai Huang
2021-04-07 10:03 ` [tip: x86/sgx] " tip-bot2 for Sean Christopherson
2021-03-19 7:23 ` [PATCH v3 11/25] x86/sgx: Add encls_faulted() helper Kai Huang
2021-04-07 10:03 ` [tip: x86/sgx] " tip-bot2 for Sean Christopherson
2021-03-19 7:23 ` [PATCH v3 12/25] x86/sgx: Add helper to update SGX_LEPUBKEYHASHn MSRs Kai Huang
2021-04-07 10:03 ` [tip: x86/sgx] " tip-bot2 for Kai Huang
2021-03-19 7:23 ` [PATCH v3 13/25] x86/sgx: Add helpers to expose ECREATE and EINIT to KVM Kai Huang
2021-04-05 9:07 ` Borislav Petkov
2021-04-05 21:44 ` Kai Huang
2021-04-06 7:40 ` Borislav Petkov
2021-04-06 8:59 ` Kai Huang
2021-04-06 9:09 ` Borislav Petkov
2021-04-06 9:24 ` Kai Huang
2021-04-06 9:32 ` Borislav Petkov
2021-04-06 9:41 ` Kai Huang
2021-04-06 17:08 ` Borislav Petkov
2021-04-06 20:33 ` Kai Huang
2021-04-07 10:03 ` [tip: x86/sgx] " tip-bot2 for Sean Christopherson
2021-03-19 7:23 ` [PATCH v3 14/25] x86/sgx: Move provisioning device creation out of SGX driver Kai Huang
2021-04-07 10:03 ` [tip: x86/sgx] " tip-bot2 for Sean Christopherson
2021-03-19 7:23 ` [PATCH v3 15/25] KVM: x86: Export kvm_mmu_gva_to_gpa_{read,write}() for SGX (VMX) Kai Huang
2021-03-19 7:23 ` [PATCH v3 16/25] KVM: x86: Define new #PF SGX error code bit Kai Huang
2021-03-19 7:23 ` [PATCH v3 17/25] KVM: x86: Add support for reverse CPUID lookup of scattered features Kai Huang
2021-03-19 7:23 ` [PATCH v3 18/25] KVM: x86: Add reverse-CPUID lookup support for scattered SGX features Kai Huang
2021-03-19 7:23 ` [PATCH v3 19/25] KVM: VMX: Add basic handling of VM-Exit from SGX enclave Kai Huang
2021-03-19 7:23 ` [PATCH v3 20/25] KVM: VMX: Frame in ENCLS handler for SGX virtualization Kai Huang
2021-03-19 7:23 ` [PATCH v3 21/25] KVM: VMX: Add SGX ENCLS[ECREATE] handler to enforce CPUID restrictions Kai Huang
2021-03-19 7:23 ` [PATCH v3 22/25] KVM: VMX: Add emulation of SGX Launch Control LE hash MSRs Kai Huang
2021-03-19 7:23 ` [PATCH v3 23/25] KVM: VMX: Add ENCLS[EINIT] handler to support SGX Launch Control (LC) Kai Huang
2021-03-19 7:23 ` [PATCH v3 24/25] KVM: VMX: Enable SGX virtualization for SGX1, SGX2 and LC Kai Huang
2021-03-19 7:24 ` [PATCH v3 25/25] KVM: x86: Add capability to grant VM access to privileged SGX attribute Kai Huang
2021-03-19 14:52 ` [PATCH v3 00/25] KVM SGX virtualization support Jarkko Sakkinen
2021-03-22 10:03 ` Kai Huang
2021-03-22 10:31 ` Borislav Petkov
2021-03-26 22:46 ` Jarkko Sakkinen
2021-03-28 21:01 ` Huang, Kai
2021-03-31 23:23 ` Jarkko Sakkinen
-- strict thread matches above, loose matches on Subject: below --
2021-03-09 1:39 [PATCH v2 03/25] x86/sgx: Wipe out EREMOVE from sgx_free_epc_page() Kai Huang
2021-03-11 2:01 ` [PATCH v3 " Kai Huang
2021-03-12 21:21 ` Sean Christopherson
2021-03-13 10:45 ` Jarkko Sakkinen
2021-03-15 7:12 ` Kai Huang
2021-03-15 13:18 ` Jarkko Sakkinen
2021-03-15 13:19 ` Jarkko Sakkinen
2021-03-15 20:29 ` Kai Huang
2021-03-15 22:59 ` Jarkko Sakkinen
2021-03-15 23:50 ` Kai Huang
2021-03-15 23:11 ` Jarkko Sakkinen
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