From: Ian Campbell <Ian.Campbell@citrix.com>
To: David Vrabel <dvrabel@cantab.net>
Cc: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
"linaro-dev@lists.linaro.org" <linaro-dev@lists.linaro.org>,
"arnd@arndb.de" <arnd@arndb.de>,
"konrad.wilk@oracle.com" <konrad.wilk@oracle.com>,
"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
"Tim (Xen.org)" <tim@xen.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls
Date: Fri, 27 Jul 2012 10:00:53 +0100 [thread overview]
Message-ID: <1343379653.6812.92.camel@zakaz.uk.xensource.com> (raw)
In-Reply-To: <501176AF.3000607@cantab.net>
On Thu, 2012-07-26 at 17:56 +0100, David Vrabel wrote:
> On 26/07/12 16:33, Stefano Stabellini wrote:
> >
> > + * The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
> > + * hypercall tag.
>
> Is this number, 0xea1, assigned to Xen by some external body?
The value and semantics of the hvc instructions immediate operand is
entirely up to the hypervisor authors. We could have chosen 0 or some
random number, we went for the latter because it increases the chances,
by some tiny amount, that we won't clash with some other hypervisors ABI
which makes supporting "foreign" guests that bit easier should it even
come to it.
IOW it's arbitrary in the same way that a Linux system calls used to use
int 0x80.
Ian.
WARNING: multiple messages have this Message-ID (diff)
From: Ian.Campbell@citrix.com (Ian Campbell)
To: linux-arm-kernel@lists.infradead.org
Subject: [Xen-devel] [PATCH 02/24] xen/arm: hypercalls
Date: Fri, 27 Jul 2012 10:00:53 +0100 [thread overview]
Message-ID: <1343379653.6812.92.camel@zakaz.uk.xensource.com> (raw)
In-Reply-To: <501176AF.3000607@cantab.net>
On Thu, 2012-07-26 at 17:56 +0100, David Vrabel wrote:
> On 26/07/12 16:33, Stefano Stabellini wrote:
> >
> > + * The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
> > + * hypercall tag.
>
> Is this number, 0xea1, assigned to Xen by some external body?
The value and semantics of the hvc instructions immediate operand is
entirely up to the hypervisor authors. We could have chosen 0 or some
random number, we went for the latter because it increases the chances,
by some tiny amount, that we won't clash with some other hypervisors ABI
which makes supporting "foreign" guests that bit easier should it even
come to it.
IOW it's arbitrary in the same way that a Linux system calls used to use
int 0x80.
Ian.
next prev parent reply other threads:[~2012-07-27 9:00 UTC|newest]
Thread overview: 283+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-26 15:33 [PATCH 00/24] Introduce Xen support on ARM Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 01/24] arm: initial Xen support Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 16:30 ` [Xen-devel] " Konrad Rzeszutek Wilk
2012-07-26 16:30 ` Konrad Rzeszutek Wilk
2012-07-27 11:56 ` Stefano Stabellini
2012-07-27 11:56 ` Stefano Stabellini
2012-07-27 11:56 ` Stefano Stabellini
2012-08-01 10:42 ` Konrad Rzeszutek Wilk
2012-08-01 10:42 ` Konrad Rzeszutek Wilk
2012-08-01 10:42 ` Konrad Rzeszutek Wilk
2012-08-06 10:55 ` Stefano Stabellini
2012-08-06 10:55 ` Stefano Stabellini
2012-08-06 10:55 ` Stefano Stabellini
2012-08-01 18:27 ` Rob Herring
2012-08-01 18:27 ` Rob Herring
2012-08-02 7:35 ` Ian Campbell
2012-08-02 7:35 ` Ian Campbell
2012-08-02 7:35 ` Ian Campbell
2012-08-02 14:13 ` [Xen-devel] " Konrad Rzeszutek Wilk
2012-08-02 14:13 ` Konrad Rzeszutek Wilk
2012-08-02 14:13 ` Konrad Rzeszutek Wilk
2012-08-06 10:46 ` Stefano Stabellini
2012-08-06 10:46 ` Stefano Stabellini
2012-08-06 10:46 ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 02/24] xen/arm: hypercalls Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 16:33 ` [Xen-devel] " Konrad Rzeszutek Wilk
2012-07-26 16:33 ` Konrad Rzeszutek Wilk
2012-07-27 9:17 ` Ian Campbell
2012-07-27 9:17 ` Ian Campbell
2012-07-27 9:17 ` Ian Campbell
2012-07-27 13:02 ` Stefano Stabellini
2012-07-27 13:02 ` Stefano Stabellini
2012-07-27 13:02 ` Stefano Stabellini
2012-07-27 13:18 ` Ian Campbell
2012-07-27 13:18 ` Ian Campbell
2012-07-27 13:18 ` Ian Campbell
2012-07-27 13:41 ` Stefano Stabellini
2012-07-27 13:41 ` Stefano Stabellini
2012-07-27 13:41 ` Stefano Stabellini
2012-07-27 14:21 ` Russell King - ARM Linux
2012-07-27 14:21 ` Russell King - ARM Linux
2012-07-27 14:21 ` Russell King - ARM Linux
2012-07-27 14:36 ` Stefano Stabellini
2012-07-27 14:36 ` Stefano Stabellini
2012-07-27 14:36 ` Stefano Stabellini
2012-07-27 14:39 ` Ian Campbell
2012-07-27 14:39 ` Ian Campbell
2012-07-27 14:39 ` Ian Campbell
2012-07-27 14:59 ` Russell King - ARM Linux
2012-07-27 14:59 ` Russell King - ARM Linux
2012-07-27 14:59 ` Russell King - ARM Linux
2012-07-26 16:56 ` David Vrabel
2012-07-26 16:56 ` David Vrabel
2012-07-26 17:19 ` Stefano Stabellini
2012-07-26 17:19 ` Stefano Stabellini
2012-07-26 17:19 ` Stefano Stabellini
2012-07-27 9:00 ` Ian Campbell [this message]
2012-07-27 9:00 ` Ian Campbell
2012-07-27 9:00 ` Ian Campbell
2012-07-26 19:19 ` Christopher Covington
2012-07-26 19:19 ` Christopher Covington
2012-07-27 9:19 ` Ian Campbell
2012-07-27 9:19 ` Ian Campbell
2012-07-27 9:19 ` Ian Campbell
2012-07-27 12:56 ` Christopher Covington
2012-07-27 12:56 ` Christopher Covington
2012-07-27 12:56 ` Christopher Covington
2012-07-27 13:57 ` Stefano Stabellini
2012-07-27 13:57 ` Stefano Stabellini
2012-07-27 13:57 ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 03/24] xen/arm: page.h definitions Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 16:36 ` [Xen-devel] " Konrad Rzeszutek Wilk
2012-07-26 16:36 ` Konrad Rzeszutek Wilk
2012-07-27 13:47 ` Stefano Stabellini
2012-07-27 13:47 ` Stefano Stabellini
2012-07-27 13:47 ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 04/24] xen/arm: sync_bitops Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 16:37 ` [Xen-devel] " Konrad Rzeszutek Wilk
2012-07-26 16:37 ` Konrad Rzeszutek Wilk
2012-07-27 9:28 ` Ian Campbell
2012-07-27 9:28 ` Ian Campbell
2012-07-27 9:28 ` Ian Campbell
2012-08-01 14:35 ` Konrad Rzeszutek Wilk
2012-08-01 14:35 ` Konrad Rzeszutek Wilk
2012-08-01 14:35 ` Konrad Rzeszutek Wilk
2012-08-01 16:07 ` Stefano Stabellini
2012-08-01 16:07 ` Stefano Stabellini
2012-08-01 16:07 ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 05/24] xen/arm: empty implementation of grant_table arch specific functions Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-08-01 14:16 ` Konrad Rzeszutek Wilk
2012-08-01 14:16 ` Konrad Rzeszutek Wilk
2012-08-01 15:46 ` Stefano Stabellini
2012-08-01 15:46 ` Stefano Stabellini
2012-08-01 15:46 ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 06/24] xen: missing includes Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-27 6:57 ` [Xen-devel] " Jan Beulich
2012-07-27 6:57 ` Jan Beulich
2012-07-27 6:57 ` Jan Beulich
2012-07-27 16:47 ` Stefano Stabellini
2012-07-27 16:47 ` Stefano Stabellini
2012-07-27 16:47 ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 07/24] xen/arm: Xen detection and shared_info page mapping Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-27 9:36 ` Ian Campbell
2012-07-27 9:36 ` Ian Campbell
2012-07-27 9:36 ` Ian Campbell
2012-07-27 14:48 ` Stefano Stabellini
2012-07-27 14:48 ` Stefano Stabellini
2012-07-27 14:48 ` Stefano Stabellini
2012-07-27 14:51 ` Ian Campbell
2012-07-27 14:51 ` Ian Campbell
2012-07-27 14:51 ` Ian Campbell
2012-08-01 14:19 ` Konrad Rzeszutek Wilk
2012-08-01 14:19 ` Konrad Rzeszutek Wilk
2012-08-01 15:45 ` Stefano Stabellini
2012-08-01 15:45 ` Stefano Stabellini
2012-08-01 15:45 ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 08/24] xen/arm: Introduce xen_pfn_t for pfn and mfn types Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-08-01 14:22 ` Konrad Rzeszutek Wilk
2012-08-01 14:22 ` Konrad Rzeszutek Wilk
2012-08-01 14:22 ` Konrad Rzeszutek Wilk
2012-08-01 15:50 ` Stefano Stabellini
2012-08-01 15:50 ` Stefano Stabellini
2012-08-01 15:50 ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 09/24] xen/arm: compile and run xenbus Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-08-01 14:28 ` Konrad Rzeszutek Wilk
2012-08-01 14:28 ` Konrad Rzeszutek Wilk
2012-08-01 14:28 ` Konrad Rzeszutek Wilk
2012-08-06 11:17 ` Stefano Stabellini
2012-08-06 11:17 ` Stefano Stabellini
2012-08-06 11:17 ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 10/24] xen: do not compile manage, balloon, pci, acpi and cpu_hotplug on ARM Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-27 7:01 ` [Xen-devel] " Jan Beulich
2012-07-27 7:01 ` Jan Beulich
2012-07-27 7:01 ` Jan Beulich
2012-07-27 16:51 ` Stefano Stabellini
2012-07-27 16:51 ` Stefano Stabellini
2012-07-27 16:51 ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 11/24] xen/arm: introduce CONFIG_XEN " Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-08-01 14:34 ` [Xen-devel] " Konrad Rzeszutek Wilk
2012-08-01 14:34 ` Konrad Rzeszutek Wilk
2012-07-26 15:33 ` [PATCH 12/24] xen/arm: Introduce xen_guest_init Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-27 9:42 ` Ian Campbell
2012-07-27 9:42 ` Ian Campbell
2012-07-27 9:42 ` Ian Campbell
2012-07-27 15:54 ` Stefano Stabellini
2012-07-27 15:54 ` Stefano Stabellini
2012-07-27 15:54 ` Stefano Stabellini
2012-07-27 16:11 ` Ian Campbell
2012-07-27 16:11 ` Ian Campbell
2012-07-27 16:11 ` Ian Campbell
2012-08-01 14:38 ` Konrad Rzeszutek Wilk
2012-08-01 14:38 ` Konrad Rzeszutek Wilk
2012-07-26 15:33 ` [PATCH 13/24] xen/arm: get privilege status Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-27 9:44 ` Ian Campbell
2012-07-27 9:44 ` Ian Campbell
2012-07-27 9:44 ` Ian Campbell
2012-07-27 14:25 ` Stefano Stabellini
2012-07-27 14:25 ` Stefano Stabellini
2012-07-27 14:25 ` Stefano Stabellini
2012-07-27 14:33 ` Ian Campbell
2012-07-27 14:33 ` Ian Campbell
2012-07-27 14:33 ` Ian Campbell
2012-08-01 14:39 ` Konrad Rzeszutek Wilk
2012-08-01 14:39 ` Konrad Rzeszutek Wilk
2012-08-01 14:39 ` Konrad Rzeszutek Wilk
2012-08-01 16:21 ` Stefano Stabellini
2012-08-01 16:21 ` Stefano Stabellini
2012-08-01 16:21 ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 14/24] xen/arm: initialize grant_table on ARM Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-08-01 14:40 ` Konrad Rzeszutek Wilk
2012-08-01 14:40 ` Konrad Rzeszutek Wilk
2012-08-01 17:08 ` Stefano Stabellini
2012-08-01 17:08 ` Stefano Stabellini
2012-08-01 17:08 ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 15/24] xen/arm: receive Xen events " Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-08-01 14:44 ` Konrad Rzeszutek Wilk
2012-08-01 14:44 ` Konrad Rzeszutek Wilk
2012-08-01 14:44 ` Konrad Rzeszutek Wilk
2012-08-06 10:31 ` Stefano Stabellini
2012-08-06 10:31 ` Stefano Stabellini
2012-08-06 10:31 ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 16/24] xen/arm: implement alloc/free_xenballooned_pages with alloc_pages/kfree Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` [PATCH 17/24] xen: allow privcmd for HVM guests Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-26 15:33 ` Stefano Stabellini
2012-07-27 7:04 ` [Xen-devel] " Jan Beulich
2012-07-27 7:04 ` Jan Beulich
2012-07-27 7:04 ` Jan Beulich
2012-07-27 14:10 ` Stefano Stabellini
2012-07-27 14:10 ` Stefano Stabellini
2012-07-27 14:10 ` Stefano Stabellini
2012-08-01 14:47 ` Konrad Rzeszutek Wilk
2012-08-01 14:47 ` Konrad Rzeszutek Wilk
2012-08-01 14:47 ` Konrad Rzeszutek Wilk
2012-07-26 15:34 ` [PATCH 18/24] xen/arm: compile blkfront and blkback Stefano Stabellini
2012-07-26 15:34 ` Stefano Stabellini
2012-07-26 15:34 ` Stefano Stabellini
2012-07-27 9:48 ` Ian Campbell
2012-07-27 9:48 ` Ian Campbell
2012-07-27 9:48 ` Ian Campbell
2012-07-27 16:25 ` Stefano Stabellini
2012-07-27 16:25 ` Stefano Stabellini
2012-07-27 16:25 ` Stefano Stabellini
2012-08-01 14:48 ` Konrad Rzeszutek Wilk
2012-08-01 14:48 ` Konrad Rzeszutek Wilk
2012-08-01 14:48 ` Konrad Rzeszutek Wilk
2012-08-01 16:19 ` Stefano Stabellini
2012-08-01 16:19 ` Stefano Stabellini
2012-08-01 16:19 ` Stefano Stabellini
2012-07-26 15:34 ` [PATCH 19/24] xen/arm: compile netback Stefano Stabellini
2012-07-26 15:34 ` Stefano Stabellini
2012-07-26 15:34 ` Stefano Stabellini
2012-07-26 15:34 ` [PATCH 20/24] xen: update xen_add_to_physmap interface Stefano Stabellini
2012-07-26 15:34 ` Stefano Stabellini
2012-07-26 15:34 ` Stefano Stabellini
2012-08-01 14:52 ` Konrad Rzeszutek Wilk
2012-08-01 14:52 ` Konrad Rzeszutek Wilk
2012-08-01 16:18 ` Stefano Stabellini
2012-08-01 16:18 ` Stefano Stabellini
2012-08-01 16:18 ` Stefano Stabellini
2012-08-01 18:19 ` Mukesh Rathor
2012-08-01 18:19 ` Mukesh Rathor
2012-08-01 18:19 ` Mukesh Rathor
2012-07-26 15:34 ` [PATCH 21/24] arm/v2m: initialize arch_timers even if v2m_timer is not present Stefano Stabellini
2012-07-26 15:34 ` Stefano Stabellini
2012-07-26 15:34 ` Stefano Stabellini
2012-08-01 14:52 ` Konrad Rzeszutek Wilk
2012-08-01 14:52 ` Konrad Rzeszutek Wilk
2012-08-01 14:52 ` Konrad Rzeszutek Wilk
2012-08-01 16:06 ` Stefano Stabellini
2012-08-01 16:06 ` Stefano Stabellini
2012-08-01 16:06 ` Stefano Stabellini
2012-07-26 15:34 ` [PATCH 22/24] ARM: enable earlyprintk=xen Stefano Stabellini
2012-07-26 15:34 ` Stefano Stabellini
2012-07-26 15:34 ` Stefano Stabellini
2012-07-26 15:34 ` [PATCH 23/24] hvc_xen: allow dom0_write_console for HVM guests Stefano Stabellini
2012-07-26 15:34 ` Stefano Stabellini
2012-07-26 15:34 ` Stefano Stabellini
2012-08-01 14:54 ` Konrad Rzeszutek Wilk
2012-08-01 14:54 ` Konrad Rzeszutek Wilk
2012-08-01 16:04 ` Stefano Stabellini
2012-08-01 16:04 ` Stefano Stabellini
2012-08-01 16:04 ` Stefano Stabellini
2012-07-26 15:34 ` [PATCH 24/24] [HACK] xen/arm: implement xen_remap_domain_mfn_range Stefano Stabellini
2012-07-26 15:34 ` Stefano Stabellini
2012-07-26 15:34 ` Stefano Stabellini
2012-08-01 14:56 ` Konrad Rzeszutek Wilk
2012-08-01 14:56 ` Konrad Rzeszutek Wilk
2012-08-01 14:56 ` Konrad Rzeszutek Wilk
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