Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751935AbbGIJsZ (ORCPT ); Thu, 9 Jul 2015 05:48:25 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39512 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751081AbbGIJsU (ORCPT ); Thu, 9 Jul 2015 05:48:20 -0400 Message-ID: <559E435E.9050608@redhat.com> Date: Thu, 09 Jul 2015 11:48:14 +0200 From: Laurent Vivier User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Thomas Huth , "Michael S. Tsirkin" , kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, kvm-ppc@vger.kernel.org, virtualization@lists.linux-foundation.org, Greg Kurz CC: linux-arm-kernel@lists.infradead.org, Gleb Natapov , Paolo Bonzini , Christoffer Dall , Marc Zyngier , Alexander Graf , Paul Mackerras , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, kraxel@redhat.com, Cornelia Huck , Linus Torvalds Subject: Re: [PATCH] KVM: Add Kconfig option to signal cross-endian guests References: <20150707195012-mutt-send-email-mst@redhat.com> <1436428145-29823-1-git-send-email-thuth@redhat.com> In-Reply-To: <1436428145-29823-1-git-send-email-thuth@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3406 Lines: 99 On 09/07/2015 09:49, Thomas Huth wrote: > The option for supporting cross-endianness legacy guests in > the vhost and tun code should only be available on systems > that support cross-endian guests. I'm sure I misunderstand something, but what happens if we use QEMU with TCG instead of KVM, i.e. a big endian powerpc kernel guest on x86_64 little endian host ? Do you forbid the use of vhost in this case ? > Signed-off-by: Thomas Huth > --- > arch/arm/kvm/Kconfig | 1 + > arch/arm64/kvm/Kconfig | 1 + > arch/powerpc/kvm/Kconfig | 1 + > drivers/net/Kconfig | 1 + > drivers/vhost/Kconfig | 1 + > virt/kvm/Kconfig | 3 +++ > 6 files changed, 8 insertions(+) > > diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig > index bfb915d..9d8f363 100644 > --- a/arch/arm/kvm/Kconfig > +++ b/arch/arm/kvm/Kconfig > @@ -31,6 +31,7 @@ config KVM > select KVM_VFIO > select HAVE_KVM_EVENTFD > select HAVE_KVM_IRQFD > + select KVM_CROSS_ENDIAN_GUESTS > depends on ARM_VIRT_EXT && ARM_LPAE && ARM_ARCH_TIMER > ---help--- > Support hosting virtualized guest machines. > diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig > index bfffe8f..9af39fe 100644 > --- a/arch/arm64/kvm/Kconfig > +++ b/arch/arm64/kvm/Kconfig > @@ -31,6 +31,7 @@ config KVM > select KVM_VFIO > select HAVE_KVM_EVENTFD > select HAVE_KVM_IRQFD > + select KVM_CROSS_ENDIAN_GUESTS > ---help--- > Support hosting virtualized guest machines. > > diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig > index 3caec2c..e028710 100644 > --- a/arch/powerpc/kvm/Kconfig > +++ b/arch/powerpc/kvm/Kconfig > @@ -79,6 +79,7 @@ config KVM_BOOK3S_64_HV > select KVM_BOOK3S_HV_POSSIBLE > select MMU_NOTIFIER > select CMA > + select KVM_CROSS_ENDIAN_GUESTS > ---help--- > Support running unmodified book3s_64 guest kernels in > virtual machines on POWER7 and PPC970 processors that have > diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig > index c18f9e6..0c4ce47 100644 > --- a/drivers/net/Kconfig > +++ b/drivers/net/Kconfig > @@ -261,6 +261,7 @@ config TUN > config TUN_VNET_CROSS_LE > bool "Support for cross-endian vnet headers on little-endian kernels" > default n > + depends on KVM_CROSS_ENDIAN_GUESTS > ---help--- > This option allows TUN/TAP and MACVTAP device drivers in a > little-endian kernel to parse vnet headers that come from a > diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig > index 533eaf0..4d8ae6b 100644 > --- a/drivers/vhost/Kconfig > +++ b/drivers/vhost/Kconfig > @@ -35,6 +35,7 @@ config VHOST > > config VHOST_CROSS_ENDIAN_LEGACY > bool "Cross-endian support for vhost" > + depends on KVM_CROSS_ENDIAN_GUESTS > default n > ---help--- > This option allows vhost to support guests with a different byte > diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig > index e2c876d..cc7b28a 100644 > --- a/virt/kvm/Kconfig > +++ b/virt/kvm/Kconfig > @@ -47,3 +47,6 @@ config KVM_GENERIC_DIRTYLOG_READ_PROTECT > config KVM_COMPAT > def_bool y > depends on COMPAT && !S390 > + > +config KVM_CROSS_ENDIAN_GUESTS > + bool > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/