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From: Paolo Bonzini <pbonzini@redhat.com>
To: Kai Huang <kai.huang@intel.com>, Dave Hansen <dave.hansen@intel.com>
Cc: linux-sgx@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org,
	seanjc@google.com, jarkko@kernel.org, luto@kernel.org,
	haitao.huang@intel.com, bp@alien8.de, tglx@linutronix.de,
	mingo@redhat.com, hpa@zytor.com
Subject: Re: [RFC PATCH v3 04/27] x86/sgx: Wipe out EREMOVE from sgx_free_epc_page()
Date: Tue, 2 Feb 2021 19:00:48 +0100	[thread overview]
Message-ID: <32df1e72-b53d-bdf7-9018-a5eee4550dc4@redhat.com> (raw)
In-Reply-To: <20210127142537.9e831f66f925cbf82b9ab45d@intel.com>

On 27/01/21 02:25, Kai Huang wrote:
> On Tue, 26 Jan 2021 08:04:35 -0800 Dave Hansen wrote:
>> On 1/26/21 1:30 AM, Kai Huang wrote:
>>> From: Jarkko Sakkinen <jarkko@kernel.org>
>>>
>>> Encapsulate the snippet in sgx_free_epc_page() concerning EREMOVE to
>>> sgx_reset_epc_page(), which is a static helper function for
>>> sgx_encl_release().  It's the only function existing, which deals with
>>> initialized pages.
>>
>> Yikes.  I have no idea what that is saying.  Here's a rewrite:
>>
>> EREMOVE takes a pages and removes any association between that page and
>> an enclave.  It must be run on a page before it can be added into
>> another enclave.  Currently, EREMOVE is run as part of pages being freed
>> into the SGX page allocator.  It is not expected to fail.
>>
>> KVM does not track how guest pages are used, which means that SGX
>> virtualization use of EREMOVE might fail.
>>
>> Break out the EREMOVE call from the SGX page allocator.  This will allow
>> the SGX virtualization code to use the allocator directly.  (SGX/KVM
>> will also introduce a more permissive EREMOVE helper).
> 
> Thanks.
> 
> Hi Jarkko,
> 
> Do you want me to update your patch directly, or do you want to take the
> change, and send me the patch again?

I think you should treat all these 27 patches as yours now (including 
removing them, reordering them, adjusting commit message etc.).


>> OK, so if you're going to say "the caller must put the page in
>> uninitialized state", let's also add a comment to the place that *DO*
>> that, like the shiny new sgx_reset_epc_page().
> 
> Hi Dave,
> 
> Sorry I am a little bit confused here. Do you mean we should add a comment in
> sgx_reset_epc_page() to say, for instance: sgx_free_epc_page() requires the EPC
> page already been EREMOVE'd?

I also don't understand Dave's comment.  I would say

It's the caller's responsibility to make sure that the page is in 
uninitialized state with EREMOVE (sgx_reset_epc_page), EWB etc. before 
calling this function.

Paolo


  reply	other threads:[~2021-02-02 18:04 UTC|newest]

Thread overview: 156+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-26 10:10 [RFC PATCH v3 00/27] KVM SGX virtualization support Kai Huang
2021-01-26  9:29 ` Kai Huang
2021-01-26  9:30 ` [RFC PATCH v3 01/27] x86/cpufeatures: Add SGX1 and SGX2 sub-features Kai Huang
2021-01-26 15:34   ` Dave Hansen
2021-01-26 23:18     ` Kai Huang
2021-01-30 13:20       ` Jarkko Sakkinen
2021-02-01  0:01         ` Kai Huang
2021-02-02 17:17           ` Jarkko Sakkinen
2021-02-03  1:09             ` Kai Huang
2021-02-02 17:56           ` Paolo Bonzini
2021-02-02 18:00             ` Dave Hansen
2021-02-02 18:03               ` Paolo Bonzini
2021-02-02 18:42                 ` Sean Christopherson
2021-02-03  1:05                   ` Kai Huang
2021-01-30 13:11   ` Jarkko Sakkinen
2021-01-26  9:30 ` [RFC PATCH v3 02/27] x86/cpufeatures: Make SGX_LC feature bit depend on SGX bit Kai Huang
2021-01-26 15:35   ` Dave Hansen
2021-01-30 13:22   ` Jarkko Sakkinen
2021-02-01  0:08     ` Kai Huang
2021-01-26  9:30 ` [RFC PATCH v3 03/27] x86/sgx: Remove a warn from sgx_free_epc_page() Kai Huang
2021-01-26 15:39   ` Dave Hansen
2021-01-26 16:30     ` Sean Christopherson
2021-01-27  1:08     ` Kai Huang
2021-01-27  1:12       ` Dave Hansen
2021-01-27  1:26         ` Kai Huang
2021-02-01  0:11           ` Kai Huang
2021-02-03 10:03             ` Jarkko Sakkinen
2021-01-26  9:30 ` [RFC PATCH v3 04/27] x86/sgx: Wipe out EREMOVE " Kai Huang
2021-01-26 16:04   ` Dave Hansen
2021-01-27  1:25     ` Kai Huang
2021-02-02 18:00       ` Paolo Bonzini [this message]
2021-02-02 19:25         ` Kai Huang
2021-02-02 19:02       ` Dave Hansen
2021-01-26  9:30 ` [RFC PATCH v3 05/27] x86/sgx: Add SGX_CHILD_PRESENT hardware error code Kai Huang
2021-01-26 15:49   ` Dave Hansen
2021-01-27  0:00     ` Kai Huang
2021-01-27  0:21       ` Dave Hansen
2021-01-27  0:52         ` Kai Huang
2021-01-26  9:30 ` [RFC PATCH v3 06/27] x86/sgx: Introduce virtual EPC for use by KVM guests Kai Huang
2021-01-26 16:19   ` Dave Hansen
2021-01-27  0:16     ` Kai Huang
2021-01-27  0:27       ` Dave Hansen
2021-01-27  0:48         ` Kai Huang
2021-01-30 14:41   ` Jarkko Sakkinen
2021-01-26  9:30 ` [RFC PATCH v3 07/27] x86/cpu/intel: Allow SGX virtualization without Launch Control support Kai Huang
2021-01-26 16:26   ` Dave Hansen
2021-01-26 17:00     ` Sean Christopherson
2021-01-26 23:54       ` Kai Huang
2021-01-26 23:56     ` Kai Huang
2021-01-27  0:18       ` Dave Hansen
2021-01-27  2:02         ` Kai Huang
2021-01-27 17:13           ` Sean Christopherson
2021-01-30 14:42   ` Jarkko Sakkinen
2021-02-01  5:38     ` Kai Huang
2021-01-26  9:31 ` [RFC PATCH v3 08/27] x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled Kai Huang
2021-01-26 17:03   ` Dave Hansen
2021-01-26 18:10     ` Andy Lutomirski
2021-01-26 23:25       ` Kai Huang
2021-01-30 14:45   ` Jarkko Sakkinen
2021-02-01  5:40     ` Kai Huang
2021-02-01 15:25       ` Dave Hansen
2021-02-01 17:23         ` Sean Christopherson
2021-02-02  0:12           ` Kai Huang
2021-02-02 23:10             ` Jarkko Sakkinen
2021-02-02 23:07         ` Jarkko Sakkinen
2021-02-02 17:32       ` Jarkko Sakkinen
2021-02-02 18:20         ` Sean Christopherson
2021-02-02 23:16           ` Jarkko Sakkinen
2021-02-03  0:49             ` Kai Huang
2021-02-03 22:02               ` Jarkko Sakkinen
2021-02-03 22:59                 ` Sean Christopherson
2021-02-04  1:39                   ` Jarkko Sakkinen
2021-02-04  2:59                     ` Kai Huang
2021-02-04  3:05                       ` Jarkko Sakkinen
2021-02-04  3:09                         ` Jarkko Sakkinen
2021-02-04  3:20                           ` Kai Huang
2021-02-04 14:51                             ` Jarkko Sakkinen
2021-02-04 22:41                               ` Dave Hansen
2021-02-04 22:56                                 ` Kai Huang
2021-02-05  2:08                                 ` Jarkko Sakkinen
2021-02-05  3:00                                   ` Huang, Kai
2021-02-02 18:49         ` Kai Huang
2021-02-02 23:17           ` Jarkko Sakkinen
2021-01-26  9:31 ` [RFC PATCH v3 09/27] x86/sgx: Expose SGX architectural definitions to the kernel Kai Huang
2021-01-30 14:46   ` Jarkko Sakkinen
2021-01-26  9:31 ` [RFC PATCH v3 10/27] x86/sgx: Move ENCLS leaf definitions to sgx_arch.h Kai Huang
2021-01-26  9:31 ` [RFC PATCH v3 11/27] x86/sgx: Add SGX2 ENCLS leaf definitions (EAUG, EMODPR and EMODT) Kai Huang
2021-01-26  9:31 ` [RFC PATCH v3 12/27] x86/sgx: Add encls_faulted() helper Kai Huang
2021-01-30 14:48   ` Jarkko Sakkinen
2021-01-26  9:31 ` [RFC PATCH v3 13/27] x86/sgx: Add helper to update SGX_LEPUBKEYHASHn MSRs Kai Huang
2021-01-30 14:49   ` Jarkko Sakkinen
2021-02-01  1:17     ` Kai Huang
2021-02-01 21:22       ` Dave Hansen
2021-01-26  9:31 ` [RFC PATCH v3 14/27] x86/sgx: Add helpers to expose ECREATE and EINIT to KVM Kai Huang
2021-01-30 14:51   ` Jarkko Sakkinen
2021-02-01  0:17     ` Kai Huang
2021-02-02 17:20       ` Jarkko Sakkinen
2021-02-02 20:35         ` Kai Huang
2021-02-04  3:53   ` Kai Huang
2021-02-05  0:32     ` Sean Christopherson
2021-02-05  1:39       ` Huang, Kai
2021-01-26  9:31 ` [RFC PATCH v3 15/27] x86/sgx: Move provisioning device creation out of SGX driver Kai Huang
2021-01-30 14:52   ` Jarkko Sakkinen
2021-01-26  9:31 ` [RFC PATCH v3 16/27] KVM: VMX: Convert vcpu_vmx.exit_reason to a union Kai Huang
2021-01-30 15:00   ` Jarkko Sakkinen
2021-02-01  0:32     ` Kai Huang
2021-02-02 17:24       ` Jarkko Sakkinen
2021-02-02 19:23         ` Kai Huang
2021-02-02 22:41           ` Jarkko Sakkinen
2021-02-03  0:42             ` Kai Huang
2021-02-01 17:12     ` Sean Christopherson
2021-02-02 22:38       ` Jarkko Sakkinen
2021-01-26  9:31 ` [RFC PATCH v3 17/27] KVM: x86: Export kvm_mmu_gva_to_gpa_{read,write}() for SGX (VMX) Kai Huang
2021-01-26  9:31 ` [RFC PATCH v3 18/27] KVM: x86: Define new #PF SGX error code bit Kai Huang
2021-01-26  9:31 ` [RFC PATCH v3 19/27] KVM: x86: Add support for reverse CPUID lookup of scattered features Kai Huang
2021-01-26  9:31 ` [RFC PATCH v3 20/27] KVM: x86: Add reverse-CPUID lookup support for scattered SGX features Kai Huang
2021-01-26  9:31 ` [RFC PATCH v3 21/27] KVM: VMX: Add basic handling of VM-Exit from SGX enclave Kai Huang
2021-01-26  9:31 ` [RFC PATCH v3 22/27] KVM: VMX: Frame in ENCLS handler for SGX virtualization Kai Huang
2021-01-26  9:31 ` [RFC PATCH v3 23/27] KVM: VMX: Add SGX ENCLS[ECREATE] handler to enforce CPUID restrictions Kai Huang
2021-02-03  0:52   ` Edgecombe, Rick P
2021-02-03  1:36     ` Sean Christopherson
2021-02-03  9:11       ` Kai Huang
2021-02-03 17:07         ` Sean Christopherson
2021-02-03 23:11           ` Kai Huang
2021-02-03 18:47   ` Edgecombe, Rick P
2021-02-03 19:36     ` Sean Christopherson
2021-02-03 23:29       ` Kai Huang
2021-02-03 23:36         ` Sean Christopherson
2021-02-03 23:45           ` Kai Huang
2021-02-03 23:59             ` Sean Christopherson
2021-02-04  0:11               ` Kai Huang
2021-02-04  2:01                 ` Sean Christopherson
2021-01-26  9:31 ` [RFC PATCH v3 24/27] KVM: VMX: Add emulation of SGX Launch Control LE hash MSRs Kai Huang
2021-01-26  9:31 ` [RFC PATCH v3 25/27] KVM: VMX: Add ENCLS[EINIT] handler to support SGX Launch Control (LC) Kai Huang
2021-01-26  9:31 ` [RFC PATCH v3 26/27] KVM: VMX: Enable SGX virtualization for SGX1, SGX2 and LC Kai Huang
2021-01-26  9:32 ` [RFC PATCH v3 27/27] KVM: x86: Add capability to grant VM access to privileged SGX attribute Kai Huang
2021-02-02 22:21 ` [RFC PATCH v3 00/27] KVM SGX virtualization support Edgecombe, Rick P
2021-02-02 22:33   ` Sean Christopherson
2021-02-02 23:21     ` Dave Hansen
2021-02-02 23:56       ` Sean Christopherson
2021-02-03  0:43         ` Dave Hansen
2021-02-03 15:10         ` Dave Hansen
2021-02-03 17:36           ` Sean Christopherson
2021-02-03 17:43             ` Paolo Bonzini
2021-02-03 17:46               ` Dave Hansen
2021-02-03 23:09                 ` Kai Huang
2021-02-03 23:32                   ` Sean Christopherson
2021-02-03 23:37                     ` Dave Hansen
2021-02-04  0:04                       ` Kai Huang
2021-02-04  0:28                         ` Sean Christopherson
2021-02-04  3:18                           ` Kai Huang
2021-02-04 16:28                             ` Sean Christopherson
2021-02-04 16:48                               ` Dave Hansen
2021-02-05 12:32                                 ` Kai Huang
2021-02-05 16:51                                   ` Sean Christopherson
2021-02-02 22:36   ` Dave Hansen

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