From: "Paraschiv, Andra-Irina" <andraprs@amazon.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Greg KH <gregkh@linuxfoundation.org>
Cc: <linux-kernel@vger.kernel.org>,
Anthony Liguori <aliguori@amazon.com>,
Colm MacCarthaigh <colmmacc@amazon.com>,
Bjoern Doebel <doebel@amazon.de>,
David Woodhouse <dwmw@amazon.co.uk>,
Frank van der Linden <fllinden@amazon.com>,
Alexander Graf <graf@amazon.de>,
Martin Pohlack <mpohlack@amazon.de>, Matt Wilson <msw@amazon.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Balbir Singh <sblbir@amazon.com>,
Stefano Garzarella <sgarzare@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
Stewart Smith <trawets@amazon.com>,
Uwe Dannowski <uwed@amazon.de>, <kvm@vger.kernel.org>,
<ne-devel-upstream@amazon.com>
Subject: Re: [PATCH v3 02/18] nitro_enclaves: Define the PCI device interface
Date: Mon, 1 Jun 2020 10:07:11 +0300 [thread overview]
Message-ID: <1fbdc33c-8819-40b6-b0d3-5d64833c9932@amazon.com> (raw)
In-Reply-To: <ea25810cbd43974b75934f9cfb6ca3f007339dce.camel@kernel.crashing.org>
On 01/06/2020 05:59, Benjamin Herrenschmidt wrote:
> On Wed, 2020-05-27 at 00:21 +0200, Greg KH wrote:
>>> There are a couple of data structures with more than one member and multiple
>>> field sizes. And for the ones that are not, gathered as feedback from
>>> previous rounds of review that should consider adding a "flags" field in
>>> there for further extensibility.
>> Please do not do that in ioctls. Just create new calls instead of
>> trying to "extend" existing ones. It's always much easier.
>>
>>> I can modify to have "__packed" instead of the attribute callout.
>> Make sure you even need that, as I don't think you do for structures
>> like the above one, right?
> Hrm, my impression (granted I only just started to look at this code)
> is that these are protocol messages with the PCI devices, not strictly
> just ioctl arguments (though they do get conveyed via such ioctls).
>
> Andra-Irina, did I get that right ? :-)
Correct, these data structures having "__packed" attribute map the
messages (requests / replies) for the communication with the NE PCI device.
The data structures from the ioctl commands are not directly used as
part of the communication with the NE PCI device, but several fields of
them e.g. enclave start flags. Some of the fields from the NE PCI device
data structures e.g. the physical address of a memory region (gpa) are
set by the internal kernel logic.
>
> That said, I still think that by carefully ordering the fields and
> using explicit padding, we can avoid the need of the packed attributed.
Regarding your question in the previous mail from this thread and the
mention above on the same topic, that should be possible. IIRC, there
were 2 data structures remaining with "__packed" attribute.
Thank you, Ben.
Andra
Amazon Development Center (Romania) S.R.L. registered office: 27A Sf. Lazar Street, UBC5, floor 2, Iasi, Iasi County, 700045, Romania. Registered in Romania. Registration number J22/2621/2005.
next prev parent reply other threads:[~2020-06-01 7:07 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-25 22:13 [PATCH v3 00/18] Add support for Nitro Enclaves Andra Paraschiv
2020-05-25 22:13 ` [PATCH v3 01/18] nitro_enclaves: Add ioctl interface definition Andra Paraschiv
2020-05-27 8:49 ` Stefan Hajnoczi
2020-05-28 18:05 ` Paraschiv, Andra-Irina
2020-06-01 3:02 ` Benjamin Herrenschmidt
2020-06-01 7:20 ` Paraschiv, Andra-Irina
2020-06-05 8:15 ` Stefan Hajnoczi
2020-06-05 15:39 ` Paraschiv, Andra-Irina
2020-05-25 22:13 ` [PATCH v3 02/18] nitro_enclaves: Define the PCI device interface Andra Paraschiv
2020-05-26 6:44 ` Greg KH
2020-05-26 17:01 ` Paraschiv, Andra-Irina
2020-05-26 22:21 ` Greg KH
2020-05-28 16:37 ` Paraschiv, Andra-Irina
2020-06-01 2:59 ` Benjamin Herrenschmidt
2020-06-01 7:07 ` Paraschiv, Andra-Irina [this message]
2020-06-01 2:53 ` Benjamin Herrenschmidt
2020-05-25 22:13 ` [PATCH v3 03/18] nitro_enclaves: Define enclave info for internal bookkeeping Andra Paraschiv
2020-05-26 6:46 ` Greg KH
2020-05-26 17:20 ` Paraschiv, Andra-Irina
2020-05-25 22:13 ` [PATCH v3 04/18] nitro_enclaves: Init PCI device driver Andra Paraschiv
2020-05-26 6:48 ` Greg KH
2020-05-26 18:35 ` Paraschiv, Andra-Irina
2020-05-26 22:19 ` Greg KH
2020-05-28 16:26 ` Paraschiv, Andra-Irina
2020-06-01 2:55 ` Benjamin Herrenschmidt
2020-06-01 6:42 ` Paraschiv, Andra-Irina
2020-05-25 22:13 ` [PATCH v3 05/18] nitro_enclaves: Handle PCI device command requests Andra Paraschiv
2020-05-25 22:13 ` [PATCH v3 06/18] nitro_enclaves: Handle out-of-band PCI device events Andra Paraschiv
2020-05-25 22:13 ` [PATCH v3 07/18] nitro_enclaves: Init misc device providing the ioctl interface Andra Paraschiv
2020-05-26 6:51 ` Greg KH
2020-05-26 11:42 ` Alexander Graf
2020-05-26 12:33 ` Greg KH
2020-05-26 12:44 ` Alexander Graf
2020-05-26 13:17 ` Greg KH
2020-05-26 13:44 ` Alexander Graf
2020-05-26 22:24 ` Greg KH
2020-05-28 13:01 ` Alexander Graf
2020-05-28 13:12 ` Greg KH
2020-05-28 17:06 ` Paraschiv, Andra-Irina
2020-06-01 3:04 ` Benjamin Herrenschmidt
2020-06-09 10:47 ` Alexander Graf
2020-06-01 3:01 ` Benjamin Herrenschmidt
2020-06-01 2:51 ` Benjamin Herrenschmidt
2020-05-26 13:40 ` Paraschiv, Andra-Irina
2020-06-01 2:47 ` Benjamin Herrenschmidt
2020-06-01 5:48 ` Greg KH
2020-05-25 22:13 ` [PATCH v3 08/18] nitro_enclaves: Add logic for enclave vm creation Andra Paraschiv
2020-05-25 22:13 ` [PATCH v3 09/18] nitro_enclaves: Add logic for enclave vcpu creation Andra Paraschiv
2020-05-25 22:13 ` [PATCH v3 10/18] nitro_enclaves: Add logic for enclave image load metadata Andra Paraschiv
2020-05-25 22:13 ` [PATCH v3 11/18] nitro_enclaves: Add logic for enclave memory region set Andra Paraschiv
2020-05-25 22:13 ` [PATCH v3 12/18] nitro_enclaves: Add logic for enclave start Andra Paraschiv
2020-05-25 22:13 ` [PATCH v3 13/18] nitro_enclaves: Add logic for enclave termination Andra Paraschiv
2020-05-25 22:13 ` [PATCH v3 14/18] nitro_enclaves: Add Kconfig for the Nitro Enclaves driver Andra Paraschiv
2020-05-25 22:13 ` [PATCH v3 15/18] nitro_enclaves: Add Makefile " Andra Paraschiv
2020-05-25 22:13 ` [PATCH v3 16/18] nitro_enclaves: Add sample for ioctl interface usage Andra Paraschiv
2020-05-26 6:52 ` Greg KH
2020-05-25 22:13 ` [PATCH v3 17/18] nitro_enclaves: Add overview documentation Andra Paraschiv
2020-05-25 22:13 ` [PATCH v3 18/18] MAINTAINERS: Add entry for the Nitro Enclaves driver Andra Paraschiv
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