From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
To: hpa@zytor.com, david.vrabel@citrix.com, JGross@suse.com
Cc: roger.pau@citrix.com, linux-kernel@vger.kernel.org,
xen-devel@lists.xenproject.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, Matt Fleming <matt@codeblueprint.co.uk>
Subject: Re: [PATCH 2/8] x86/head: Refactor 32-bit pgtable setup
Date: Fri, 14 Oct 2016 15:18:47 -0400 [thread overview]
Message-ID: <ad74b77d-2bbe-4137-c741-aa515881e0e7@oracle.com> (raw)
In-Reply-To: <CFB7B4F4-CE78-4129-BB4E-A599384E7A42@zytor.com>
On 10/14/2016 03:04 PM, hpa@zytor.com wrote:
> On October 14, 2016 11:44:18 AM PDT, Boris Ostrovsky <boris.ostrovsky@oracle.com> wrote:
>> On 10/14/2016 02:31 PM, hpa@zytor.com wrote:
>>> On October 14, 2016 11:05:12 AM PDT, Boris Ostrovsky
>> <boris.ostrovsky@oracle.com> wrote:
>>>> From: Matt Fleming <matt@codeblueprint.co.uk>
>>>>
>>>> The new Xen PVH entry point requires page tables to be setup by the
>>>> kernel since it is entered with paging disabled.
>>>>
>>>> Pull the common code out of head_32.S and into pgtable_32.S so that
>>>> setup_pgtable_32 can be invoked from both the new Xen entry point
>> and
>>>> the existing startup_32 code.
>>>>
>>> And why does it need a separate entry point as opposed to the plain
>> one?
>>
>> One reason is that we need to prepare boot_params before jumping to
>> startup_{32|64}.
>>
>> When the guest is loaded (always in 32-bit mode) the only thing we have
>> is a pointer to Xen-specific datastructure. The early PVH code will
>> prepare zeropage based on that structure and then jump to regular
>> startup_*() code.
>>
>> -boris
> And why not just resume execution at start_32 then?
I am not sure what start_32 is.
If you meant startup_32 then that's exactly what we do (for 32-bit
guests) once zeropage is set up.
-boris
-boris
next prev parent reply other threads:[~2016-10-14 19:18 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-14 18:05 [PATCH 0/8] PVH v2 support Boris Ostrovsky
2016-10-14 18:05 ` [PATCH 1/8] xen/x86: Remove PVH support Boris Ostrovsky
2016-10-14 18:31 ` [Xen-devel] " Konrad Rzeszutek Wilk
2016-10-18 13:46 ` Juergen Gross
2016-10-18 14:45 ` Boris Ostrovsky
2016-10-18 15:33 ` Juergen Gross
2016-10-18 15:42 ` Boris Ostrovsky
2016-10-14 18:05 ` [PATCH 2/8] x86/head: Refactor 32-bit pgtable setup Boris Ostrovsky
2016-10-14 18:31 ` hpa
2016-10-14 18:44 ` Boris Ostrovsky
2016-10-14 19:04 ` hpa
2016-10-14 19:18 ` Boris Ostrovsky [this message]
2016-10-31 12:33 ` Boris Ostrovsky
2016-12-01 15:33 ` Boris Ostrovsky
2016-12-02 9:45 ` Ingo Molnar
2016-12-02 14:04 ` Boris Ostrovsky
2016-12-02 16:08 ` Ingo Molnar
2016-12-02 17:52 ` hpa
2016-12-02 19:49 ` Boris Ostrovsky
2016-12-03 5:49 ` Ingo Molnar
2016-12-03 6:36 ` hpa
2016-10-14 18:05 ` [PATCH 3/8] xen/pvh: Import PVH-related Xen public interfaces Boris Ostrovsky
2016-10-14 18:34 ` [Xen-devel] " Konrad Rzeszutek Wilk
2016-10-21 10:58 ` Juergen Gross
2016-10-14 18:05 ` [PATCH 4/8] xen/pvh: Bootstrap PVH guest Boris Ostrovsky
2016-10-14 18:38 ` [Xen-devel] " Andrew Cooper
2016-10-14 18:55 ` Boris Ostrovsky
2016-10-14 19:12 ` Andrew Cooper
2016-10-14 19:14 ` Konrad Rzeszutek Wilk
2016-10-14 19:34 ` Boris Ostrovsky
2016-10-14 18:05 ` [PATCH 5/8] xen/pvh: Prevent PVH guests from using PIC, RTC and IOAPIC Boris Ostrovsky
2016-10-14 19:16 ` [Xen-devel] " Konrad Rzeszutek Wilk
2016-10-14 19:37 ` Boris Ostrovsky
2016-10-26 10:42 ` Roger Pau Monné
2016-10-26 14:50 ` Boris Ostrovsky
2016-10-26 15:18 ` Roger Pau Monné
2016-10-26 16:06 ` Boris Ostrovsky
2016-10-14 18:05 ` [PATCH 6/8] xen/pvh: Initialize grant table for PVH guests Boris Ostrovsky
2016-10-14 19:19 ` [Xen-devel] " Konrad Rzeszutek Wilk
2016-10-14 19:43 ` Boris Ostrovsky
2016-10-14 19:51 ` Konrad Rzeszutek Wilk
2016-10-14 20:02 ` Boris Ostrovsky
2016-10-18 16:08 ` Juergen Gross
2016-10-18 16:40 ` Boris Ostrovsky
2016-10-19 5:47 ` Juergen Gross
2016-10-14 18:05 ` [PATCH 7/8] xen/pvh: PVH guests always have PV devices Boris Ostrovsky
2016-10-14 19:17 ` [Xen-devel] " Konrad Rzeszutek Wilk
2016-10-18 15:54 ` Juergen Gross
2016-10-14 18:05 ` [PATCH 8/8] xen/pvh: Enable CPU hotplug Boris Ostrovsky
2016-10-14 18:41 ` [Xen-devel] " Andrew Cooper
2016-10-14 19:01 ` Boris Ostrovsky
2016-10-27 14:25 ` Boris Ostrovsky
2016-10-27 15:00 ` Andrew Cooper
2016-10-27 16:23 ` Boris Ostrovsky
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