From: Jarkko Sakkinen <jarkko@kernel.org>
To: Dave Hansen <dave.hansen@intel.com>,
Paolo Bonzini <pbonzini@redhat.com>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: x86@kernel.org, linux-sgx@vger.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: Tue, 14 Sep 2021 00:12:36 +0300 [thread overview]
Message-ID: <fdf41507948023b600ef7febfd27951d8435a7dd.camel@kernel.org> (raw)
In-Reply-To: <06db5a41-3485-9141-10b5-56ca57ed1792@intel.com>
On Mon, 2021-09-13 at 07:55 -0700, Dave Hansen wrote:
> On 9/13/21 7:24 AM, Paolo Bonzini wrote:
> > > 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().
> >
> > By "Windows startup" I mean even after guest reboot. Because another
> > process could sneak in and steal your EPC pages between a close() and an
> > open(), I'd like to have a way to EREMOVE the pages while keeping them
> > assigned to the specific vEPC instance, i.e. *without* going through
> > sgx_vepc_free_page().
>
> Oh, so you want fresh EPC state for the guest, but you're concerned that
> the previous guest might have left them in a bad state. The current
> method of getting a new vepc instance (which guarantees fresh state) has
> some other downsides.
>
> Can't another process steal pages via sgxd and reclaim at any time?
> What's the extra concern here about going through a close()/open()
> cycle? Performance?
sgxd does not steal anything from vepc regions.
They are not part of the reclaiming process.
/Jarkko
next prev parent reply other threads:[~2021-09-13 21:12 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
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 [this message]
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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