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From: Dave Hansen <dave.hansen@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: x86@kernel.org, linux-sgx@vger.kernel.org, jarkko@kernel.org,
	dave.hansen@linux.intel.com, yang.zhong@intel.com
Subject: Re: [PATCH 1/2] x86: sgx_vepc: extract sgx_vepc_remove_page
Date: Mon, 13 Sep 2021 07:05:57 -0700	[thread overview]
Message-ID: <dc628588-3030-6c05-0ba4-d8fc6629c0d2@intel.com> (raw)
In-Reply-To: <20210913131153.1202354-2-pbonzini@redhat.com>

On 9/13/21 6:11 AM, Paolo Bonzini wrote:
> Windows expects all pages to be in uninitialized state on startup.
> In order to implement this, we will need a ioctl that performs
> EREMOVE on all pages mapped by a /dev/sgx_vepc file descriptor:
> other possibilities, such as closing and reopening the device,
> are racy.

Hi Paolo,

How does this end up happening in the first place?

All enclave pages should start out on 'sgx_dirty_page_list' and
ksgxd sanitizes them with EREMOVE before making them available.  That
should cover EREMOVE after reboots while SGX pages are initialized,
including kexec().

sgx_vepc_free_page() should do the same for pages that a guest not not
clean up properly.

sgx_encl_free_epc_page() does an EREMOVE after a normal enclave has used
a page.

Those are the only three cases that I can think of.  So, it sounds like
one of those is buggy, or there's another unexpected path out there.
Ultimately, I think it would be really handy if we could do this EREMOVE
implicitly and without any new ABI.

  reply	other threads:[~2021-09-13 14:09 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-13 13:11 [RFC/RFT PATCH 0/2] x86: sgx_vepc: implement ioctl to EREMOVE all pages Paolo Bonzini
2021-09-13 13:11 ` [PATCH 1/2] x86: sgx_vepc: extract sgx_vepc_remove_page Paolo Bonzini
2021-09-13 14:05   ` Dave Hansen [this message]
2021-09-13 14:24     ` Paolo Bonzini
2021-09-13 14:55       ` Dave Hansen
2021-09-13 15:14         ` Paolo Bonzini
2021-09-13 15:29           ` Dave Hansen
2021-09-13 18:35             ` Paolo Bonzini
2021-09-13 19:25               ` Dave Hansen
2021-09-13 21:16                 ` Jarkko Sakkinen
2021-09-13 21:15               ` Jarkko Sakkinen
2021-09-13 21:13           ` Jarkko Sakkinen
2021-09-14  5:36             ` Paolo Bonzini
2021-09-14 16:05               ` Jarkko Sakkinen
2021-09-13 21:12         ` Jarkko Sakkinen
2021-09-13 21:00       ` Jarkko Sakkinen
2021-09-13 20:33   ` Jarkko Sakkinen
2021-09-13 13:11 ` [PATCH 2/2] x86: sgx_vepc: implement SGX_IOC_VEPC_REMOVE ioctl Paolo Bonzini
2021-09-13 19:33   ` Dave Hansen
2021-09-13 21:11     ` Sean Christopherson
2021-09-13 22:43       ` Dave Hansen
2021-09-14 10:55   ` Kai Huang
2021-09-14  7:10 ` [RFC/RFT PATCH 0/2] x86: sgx_vepc: implement ioctl to EREMOVE all pages Yang Zhong
2021-09-14 10:19   ` Paolo Bonzini
2021-09-14 16:42     ` Jarkko Sakkinen
2021-09-14 17:07       ` Paolo Bonzini
2021-09-14 17:40         ` Jarkko Sakkinen
2021-09-14 17:44           ` Jarkko Sakkinen
2021-09-15  8:28     ` Yang Zhong
  -- strict thread matches above, loose matches on Subject: below --
2021-09-20 12:53 [PATCH " Paolo Bonzini
2021-09-20 12:54 ` [PATCH 1/2] x86: sgx_vepc: extract sgx_vepc_remove_page Paolo Bonzini
2021-09-21 19:44   ` Jarkko Sakkinen
2021-09-21 19:46     ` Jarkko Sakkinen
2021-09-23 12:08     ` Paolo Bonzini
2021-09-23 20:33       ` Jarkko Sakkinen

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