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From: Arnd Bergmann <arnd@arndb.de>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
	"linaro-dev@lists.linaro.org" <linaro-dev@lists.linaro.org>,
	Ian Campbell <Ian.Campbell@citrix.com>,
	Pawel Moll <Pawel.Moll@arm.com>,
	Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"virtualization@lists.linux-foundation.org"
	<virtualization@lists.linux-foundation.org>,
	"android-virt@lists.cs.columbia.edu"
	<android-virt@lists.cs.columbia.edu>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"embeddedxen-devel@lists.sourceforge.net"
	<embeddedxen-devel@lists.sourceforge.net>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [Android-virt] [Embeddedxen-devel] [Xen-devel] [ANNOUNCE] Xen port to Cortex-A15 / ARMv7 with virt extensions
Date: Thu, 1 Dec 2011 15:42:19 +0000	[thread overview]
Message-ID: <201112011542.19377.arnd@arndb.de> (raw)
In-Reply-To: <20111201151043.GG27394@arm.com>

On Thursday 01 December 2011, Catalin Marinas wrote:
> Given the way register banking is done on AArch64, issuing an HVC on a
> 32-bit guest OS doesn't require translation on a 64-bit hypervisor. We
> have a similar implementation at the SVC level (for 32-bit user apps on
> a 64-bit kernel), the only modification was where a 32-bit SVC takes a
> 64-bit parameter in two separate 32-bit registers, so packing needs to
> be done in a syscall wrapper.

How do you deal with signed integer arguments passed into SVC or HVC from
a caller? If I understand the architecture correctly, the upper
halves of the argument register end up zero-padded, while the callee
expects sign-extension.

	Arnd

WARNING: multiple messages have this Message-ID (diff)
From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [Android-virt] [Embeddedxen-devel] [Xen-devel] [ANNOUNCE] Xen port to Cortex-A15 / ARMv7 with virt extensions
Date: Thu, 1 Dec 2011 15:42:19 +0000	[thread overview]
Message-ID: <201112011542.19377.arnd@arndb.de> (raw)
In-Reply-To: <20111201151043.GG27394@arm.com>

On Thursday 01 December 2011, Catalin Marinas wrote:
> Given the way register banking is done on AArch64, issuing an HVC on a
> 32-bit guest OS doesn't require translation on a 64-bit hypervisor. We
> have a similar implementation at the SVC level (for 32-bit user apps on
> a 64-bit kernel), the only modification was where a 32-bit SVC takes a
> 64-bit parameter in two separate 32-bit registers, so packing needs to
> be done in a syscall wrapper.

How do you deal with signed integer arguments passed into SVC or HVC from
a caller? If I understand the architecture correctly, the upper
halves of the argument register end up zero-padded, while the callee
expects sign-extension.

	Arnd

WARNING: multiple messages have this Message-ID (diff)
From: Arnd Bergmann <arnd@arndb.de>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>,
	Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>,
	"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
	"linaro-dev@lists.linaro.org" <linaro-dev@lists.linaro.org>,
	Pawel Moll <Pawel.Moll@arm.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"virtualization@lists.linux-foundation.org" 
	<virtualization@lists.linux-foundation.org>,
	"android-virt@lists.cs.columbia.edu" 
	<android-virt@lists.cs.columbia.edu>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"embeddedxen-devel@lists.sourceforge.net" 
	<embeddedxen-devel@lists.sourceforge.net>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [Android-virt] [Embeddedxen-devel] [Xen-devel] [ANNOUNCE] Xen port to Cortex-A15 / ARMv7 with virt extensions
Date: Thu, 1 Dec 2011 15:42:19 +0000	[thread overview]
Message-ID: <201112011542.19377.arnd@arndb.de> (raw)
In-Reply-To: <20111201151043.GG27394@arm.com>

On Thursday 01 December 2011, Catalin Marinas wrote:
> Given the way register banking is done on AArch64, issuing an HVC on a
> 32-bit guest OS doesn't require translation on a 64-bit hypervisor. We
> have a similar implementation at the SVC level (for 32-bit user apps on
> a 64-bit kernel), the only modification was where a 32-bit SVC takes a
> 64-bit parameter in two separate 32-bit registers, so packing needs to
> be done in a syscall wrapper.

How do you deal with signed integer arguments passed into SVC or HVC from
a caller? If I understand the architecture correctly, the upper
halves of the argument register end up zero-padded, while the callee
expects sign-extension.

	Arnd

  reply	other threads:[~2011-12-01 15:42 UTC|newest]

Thread overview: 79+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-29 14:53 [ANNOUNCE] Xen port to Cortex-A15 / ARMv7 with virt extensions Stefano Stabellini
2011-11-29 14:53 ` Stefano Stabellini
2011-11-29 14:53 ` Stefano Stabellini
2011-11-29 14:53 ` Stefano Stabellini
2011-11-29 21:29 ` Arnd Bergmann
2011-11-29 21:29 ` Arnd Bergmann
2011-11-29 21:29   ` Arnd Bergmann
     [not found]   ` <201111292129.20444.arnd-r2nGTMty4D4@public.gmane.org>
2011-11-30  4:42     ` Anup Patel
2011-11-30 11:41       ` Stefano Stabellini
2011-11-30 11:41         ` Stefano Stabellini
2011-11-30 11:41         ` Stefano Stabellini
2011-11-30  4:42   ` Anup Patel
2011-11-30 11:39   ` Stefano Stabellini
2011-11-30 11:39     ` Stefano Stabellini
2011-11-30 11:39     ` Stefano Stabellini
2011-11-30 13:03     ` Arnd Bergmann
2011-11-30 13:03       ` Arnd Bergmann
2011-11-30 13:25       ` [Xen-devel] " Ian Campbell
2011-11-30 13:25       ` Ian Campbell
2011-11-30 13:25         ` Ian Campbell
2011-11-30 14:32         ` Arnd Bergmann
2011-11-30 14:32         ` Arnd Bergmann
2011-11-30 14:32           ` Arnd Bergmann
2011-11-30 14:32           ` Arnd Bergmann
2011-11-30 14:51           ` Pawel Moll
2011-11-30 14:51           ` Pawel Moll
2011-11-30 14:51             ` Pawel Moll
2011-11-30 16:27           ` Ian Campbell
2011-11-30 16:27             ` Ian Campbell
2011-11-30 16:27             ` Ian Campbell
2011-11-30 18:15             ` Arnd Bergmann
2011-11-30 18:15             ` Arnd Bergmann
2011-11-30 18:15               ` Arnd Bergmann
2011-11-30 18:15               ` Arnd Bergmann
2011-11-30 18:32               ` [Embeddedxen-devel] " Stefano Stabellini
2011-11-30 18:32                 ` Stefano Stabellini
2011-11-30 18:32                 ` Stefano Stabellini
2011-12-01 10:26                 ` Ian Campbell
2011-12-01 10:26                   ` Ian Campbell
2011-12-01 10:26                   ` Ian Campbell
2011-12-01 15:10                   ` [Android-virt] " Catalin Marinas
2011-12-01 15:10                   ` Catalin Marinas
2011-12-01 15:10                     ` Catalin Marinas
2011-12-01 15:10                     ` Catalin Marinas
2011-12-01 15:42                     ` Arnd Bergmann [this message]
2011-12-01 15:42                       ` Arnd Bergmann
2011-12-01 15:42                       ` Arnd Bergmann
2011-12-01 16:02                       ` Catalin Marinas
2011-12-01 16:02                         ` Catalin Marinas
2011-12-01 16:02                         ` Catalin Marinas
2011-12-01 16:44                         ` Arnd Bergmann
2011-12-01 16:44                           ` Arnd Bergmann
2011-12-01 16:44                           ` Arnd Bergmann
2011-12-01 16:57                           ` Catalin Marinas
2011-12-01 16:57                             ` Catalin Marinas
2011-12-01 16:57                             ` Catalin Marinas
2011-12-01 15:52                     ` Ian Campbell
2011-12-01 15:52                       ` Ian Campbell
2011-12-01 15:52                       ` Ian Campbell
2011-12-01 15:12                   ` Stefano Stabellini
2011-12-01 15:12                     ` Stefano Stabellini
2011-12-01 15:12                     ` Stefano Stabellini
2011-12-01 10:34               ` Ian Campbell
2011-12-01 10:34                 ` Ian Campbell
2011-11-30 13:03     ` Arnd Bergmann
2011-11-30 14:11     ` Catalin Marinas
2011-11-30 14:11       ` Catalin Marinas
2011-11-30 14:20       ` Stefano Stabellini
2011-11-30 14:20         ` Stefano Stabellini
2011-11-30 14:20         ` Stefano Stabellini
2011-12-16 15:43       ` [Xen-devel] " David Vrabel
2011-12-16 15:43         ` David Vrabel
2011-12-16 16:54         ` Catalin Marinas
2011-12-16 16:54           ` Catalin Marinas
2011-12-16 17:38           ` David Vrabel
2011-12-16 17:38             ` David Vrabel
2011-12-16 17:47             ` Catalin Marinas
2011-12-16 17:47               ` Catalin Marinas
2011-11-30 14:11     ` Catalin Marinas

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