linux-kernel - Re: [PATCH v13 0/8] pv event interface between host and guest

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 4 Mar 2013 12:21:31 +0200
From:	Gleb Natapov <gleb@...hat.com>
To:	Paolo Bonzini <pbonzini@...hat.com>
Cc:	Hu Tao <hutao@...fujitsu.com>, kvm list <kvm@...r.kernel.org>,
	qemu-devel <qemu-devel@...gnu.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"Daniel P. Berrange" <berrange@...hat.com>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Jan Kiszka <jan.kiszka@...mens.com>,
	Blue Swirl <blauwirbel@...il.com>,
	Eric Blake <eblake@...hat.com>,
	Andrew Jones <drjones@...hat.com>,
	Marcelo Tosatti <mtosatti@...hat.com>,
	Sasha Levin <levinsasha928@...il.com>,
	Luiz Capitulino <lcapitulino@...hat.com>,
	Anthony Liguori <aliguori@...ibm.com>,
	Markus Armbruster <armbru@...hat.com>,
	Stefan Hajnoczi <stefanha@...hat.com>,
	Juan Quintela <quintela@...hat.com>,
	Orit Wasserman <owasserm@...hat.com>,
	Kevin Wolf <kwolf@...hat.com>,
	Wen Congyang <wency@...fujitsu.com>,
	"Michael S. Tsirkin" <mst@...hat.com>,
	Alexander Graf <agraf@...e.de>,
	Alex Williamson <alex.williamson@...hat.com>,
	Peter Maydell <peter.maydell@...aro.org>
Subject: Re: [PATCH v13 0/8] pv event interface between host and guest

On Mon, Mar 04, 2013 at 11:05:37AM +0100, Paolo Bonzini wrote:
> > Guest uses acpi_get_devices() to discover a platform device by
> > its name (QEMU0001).  Then you put the driver for the platform device
> > into drivers/platform/x86/ and QEMU/kvm/Xen all will be able to use it.
> 
> Just to clarify it for Hu Tao, the read from a random ioport is how the
> ACPI code will detect presence of the device.
> 
Actually no (at least in the long run, for the first version it may be
OK). Since we want to move DSDT generation into QEMU if device will not
be present QEMU will not generate corresponded Device() in DSDT, or it
will generate it with _STA() { Return (0x00)} hard coded. Seabios can do
the same if we will pass it info about device presence via fw_cfg. Not
sure Kevin will like it now when we plan to move DSDT into QEMU anyway :)

> Something like this should work (in SeaBIOS's src/acpi-dsdt-isa.dsl):
> 
>     Device(PEVT) {
>         Name(_HID, EisaId("QEMU0001"))
>         OperationRegion(PEOR, SystemIO, 0x505, 0x01)
>         Field(PEOR, ByteAcc, NoLock, Preserve) {
>             PEPT,   8,
>         }
> 
>         Method(_STA, 0, NotSerialized) {
>             Store(PEPT, Local0)
>             If (LEqual(Local0, Zero)) {
>                 Return (0x00)
>             } Else {
>                 Return (0x0F)
>             }
>         }
> 
>         Name(_CRS, ResourceTemplate() {
>             IO(Decode16, 0x505, 0x505, 0x01, 0x01)
>         })
>     }
> 
> Please test this with a QEMU option like "-M pc-1.4".  The device should
> _not_ be detected if you're doing it right.
> 

--
			Gleb.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/