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From: Borislav Petkov <bp@alien8.de>
To: Kai Huang <kai.huang@intel.com>
Cc: kvm@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org,
	linux-kernel@vger.kernel.org, seanjc@google.com,
	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: Mon, 22 Mar 2021 19:16:46 +0100	[thread overview]
Message-ID: <20210322181646.GG6481@zn.tnic> (raw)
In-Reply-To: <062acb801926b2ade2f9fe1672afb7113453a741.1616136308.git.kai.huang@intel.com>

On Fri, Mar 19, 2021 at 08:22:19PM +1300, Kai Huang wrote:
> +/**
> + * sgx_encl_free_epc_page - free EPC page assigned to an enclave
> + * @page:	EPC page to be freed
> + *
> + * Free EPC page assigned to an enclave.  It does EREMOVE for the page, and
> + * only upon success, it puts the page back to free page list.  Otherwise, it
> + * gives a WARNING to indicate page is leaked, and require reboot to retrieve
> + * leaked pages.
> + */
> +void sgx_encl_free_epc_page(struct sgx_epc_page *page)
> +{
> +	int ret;
> +
> +	WARN_ON_ONCE(page->flags & SGX_EPC_PAGE_RECLAIMER_TRACKED);
> +
> +	/*
> +	 * Give a message to remind EPC page is leaked when EREMOVE fails,
> +	 * and requires machine reboot to get leaked pages back. This can
> +	 * be improved in future by adding stats of leaked pages, etc.
> +	 */
> +#define EREMOVE_ERROR_MESSAGE \
> +	"EREMOVE returned %d (0x%x).  EPC page leaked.  Reboot required to retrieve leaked pages."

A reboot? Seriously? Why?

How are you going to explain to cloud people that they need to reboot
their fat server? The same cloud people who want to make sure Intel
supports late microcode loading no matter the effort just so to avoid
rebooting the machine.

But now all of a sudden, if they wanna have SGX enclaves in guests, they
need to get prepared for potential rebooting.

I sure hope I'm missing something...

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

  reply	other threads:[~2021-03-22 18:17 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 [this message]
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
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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