From: Avi Kivity <avi@redhat.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: Jan Kiszka <jan.kiszka@web.de>,
qemu-devel@nongnu.org, Marcelo Tosatti <mtosatti@redhat.com>,
patches@linaro.org, kvm <kvm@vger.kernel.org>,
Alexander Graf <agraf@suse.de>
Subject: Re: [PATCH] kvm: Move kvm_allows_irq0_override() to target-i386
Date: Mon, 23 Jul 2012 17:30:06 +0300 [thread overview]
Message-ID: <500D5FEE.1010006@redhat.com> (raw)
In-Reply-To: <CAFEAcA_WCT1VLMSLjDyfWKw1=8gzoAT+di5LtHytDEYtYGZQbA@mail.gmail.com>
On 07/23/2012 04:50 PM, Peter Maydell wrote:
>>
>> Yet.
>
> There is no mechanism in the virtualization extensions to either
> trap on or present a false value for guest accesses to the CPSR
> mode bits. So you can't make the guest OS think it is in Hypervisor
> mode. Therefore you can't provide the guest with the virtualization
> extensions. (The same argument applies for Monitor mode and means
> you can't provide the Security extensions (TrustZone) to the guest
> either.) I guess you could handle all code in the guest hypervisor
> under TCG but implementing a hybrid TCG+KVM mode would be a lot
> of effort and probably not really perform very well anyway...
Gaah, people add virtualization extensions to fix an ISA's
non-virtualizability, then do the same mistake again.
But I was only joking. Nested virtualization is interesting technically
but so far I haven't seen any huge or even small uptake.
--
error compiling committee.c: too many arguments to function
WARNING: multiple messages have this Message-ID (diff)
From: Avi Kivity <avi@redhat.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: kvm <kvm@vger.kernel.org>,
patches@linaro.org, Marcelo Tosatti <mtosatti@redhat.com>,
Alexander Graf <agraf@suse.de>,
qemu-devel@nongnu.org, Jan Kiszka <jan.kiszka@web.de>
Subject: Re: [Qemu-devel] [PATCH] kvm: Move kvm_allows_irq0_override() to target-i386
Date: Mon, 23 Jul 2012 17:30:06 +0300 [thread overview]
Message-ID: <500D5FEE.1010006@redhat.com> (raw)
In-Reply-To: <CAFEAcA_WCT1VLMSLjDyfWKw1=8gzoAT+di5LtHytDEYtYGZQbA@mail.gmail.com>
On 07/23/2012 04:50 PM, Peter Maydell wrote:
>>
>> Yet.
>
> There is no mechanism in the virtualization extensions to either
> trap on or present a false value for guest accesses to the CPSR
> mode bits. So you can't make the guest OS think it is in Hypervisor
> mode. Therefore you can't provide the guest with the virtualization
> extensions. (The same argument applies for Monitor mode and means
> you can't provide the Security extensions (TrustZone) to the guest
> either.) I guess you could handle all code in the guest hypervisor
> under TCG but implementing a hybrid TCG+KVM mode would be a lot
> of effort and probably not really perform very well anyway...
Gaah, people add virtualization extensions to fix an ISA's
non-virtualizability, then do the same mistake again.
But I was only joking. Nested virtualization is interesting technically
but so far I haven't seen any huge or even small uptake.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2012-07-23 14:30 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-20 19:14 [Qemu-devel] [PATCH] kvm: Move kvm_allows_irq0_override() to target-i386 Peter Maydell
2012-07-21 6:57 ` Jan Kiszka
2012-07-21 6:57 ` [Qemu-devel] " Jan Kiszka
2012-07-21 8:54 ` Peter Maydell
2012-07-21 8:54 ` [Qemu-devel] " Peter Maydell
2012-07-21 9:14 ` Jan Kiszka
2012-07-21 9:14 ` [Qemu-devel] " Jan Kiszka
2012-07-21 9:30 ` Peter Maydell
2012-07-21 9:30 ` [Qemu-devel] " Peter Maydell
2012-07-21 9:44 ` Jan Kiszka
2012-07-21 9:44 ` [Qemu-devel] " Jan Kiszka
2012-07-21 9:56 ` Peter Maydell
2012-07-21 9:56 ` [Qemu-devel] " Peter Maydell
2012-07-21 10:22 ` Jan Kiszka
2012-07-21 10:22 ` [Qemu-devel] " Jan Kiszka
2012-07-21 10:53 ` Peter Maydell
2012-07-21 10:53 ` [Qemu-devel] " Peter Maydell
2012-07-21 11:08 ` Jan Kiszka
2012-07-21 11:08 ` [Qemu-devel] " Jan Kiszka
2012-07-21 12:17 ` Peter Maydell
2012-07-21 12:17 ` [Qemu-devel] " Peter Maydell
2012-07-21 12:35 ` Jan Kiszka
2012-07-21 12:35 ` [Qemu-devel] " Jan Kiszka
2012-07-21 12:57 ` Peter Maydell
2012-07-21 12:57 ` [Qemu-devel] " Peter Maydell
2012-07-21 13:16 ` Jan Kiszka
2012-07-21 13:16 ` [Qemu-devel] " Jan Kiszka
2012-07-23 12:04 ` Cornelia Huck
2012-07-23 12:04 ` [Qemu-devel] " Cornelia Huck
2012-07-23 12:18 ` Avi Kivity
2012-07-23 12:18 ` [Qemu-devel] " Avi Kivity
2012-07-23 12:25 ` Peter Maydell
2012-07-23 12:25 ` [Qemu-devel] " Peter Maydell
2012-07-23 12:31 ` Avi Kivity
2012-07-23 12:31 ` [Qemu-devel] " Avi Kivity
2012-07-23 12:34 ` Avi Kivity
2012-07-23 12:34 ` [Qemu-devel] " Avi Kivity
2012-07-23 13:06 ` Cornelia Huck
2012-07-23 13:06 ` [Qemu-devel] " Cornelia Huck
2012-07-23 13:14 ` Avi Kivity
2012-07-23 13:14 ` [Qemu-devel] " Avi Kivity
2012-07-23 13:55 ` Cornelia Huck
2012-07-23 13:55 ` [Qemu-devel] " Cornelia Huck
2012-07-23 14:27 ` Avi Kivity
2012-07-23 14:27 ` [Qemu-devel] " Avi Kivity
2012-07-23 15:01 ` Cornelia Huck
2012-07-23 15:01 ` [Qemu-devel] " Cornelia Huck
2012-07-23 12:26 ` Avi Kivity
2012-07-23 12:26 ` [Qemu-devel] " Avi Kivity
2012-07-23 12:58 ` Peter Maydell
2012-07-23 12:58 ` [Qemu-devel] " Peter Maydell
2012-07-23 13:09 ` Avi Kivity
2012-07-23 13:09 ` [Qemu-devel] " Avi Kivity
2012-07-23 13:27 ` Peter Maydell
2012-07-23 13:27 ` [Qemu-devel] " Peter Maydell
2012-07-23 13:38 ` Avi Kivity
2012-07-23 13:38 ` [Qemu-devel] " Avi Kivity
2012-07-23 13:50 ` Peter Maydell
2012-07-23 13:50 ` [Qemu-devel] " Peter Maydell
2012-07-23 14:30 ` Avi Kivity [this message]
2012-07-23 14:30 ` Avi Kivity
2012-07-23 17:58 ` Peter Maydell
2012-07-23 17:58 ` [Qemu-devel] " Peter Maydell
2012-07-24 8:50 ` Avi Kivity
2012-07-24 8:50 ` [Qemu-devel] " Avi Kivity
2012-07-24 8:54 ` Peter Maydell
2012-07-24 8:54 ` [Qemu-devel] " Peter Maydell
2012-07-24 8:58 ` Jan Kiszka
2012-07-24 8:58 ` [Qemu-devel] " Jan Kiszka
2012-07-23 15:19 ` Peter Maydell
2012-07-23 15:19 ` [Qemu-devel] " Peter Maydell
2012-07-23 16:55 ` Jan Kiszka
2012-07-23 16:55 ` [Qemu-devel] " Jan Kiszka
2012-07-23 17:41 ` Peter Maydell
2012-07-23 17:41 ` [Qemu-devel] " Peter Maydell
2012-07-23 17:51 ` Jan Kiszka
2012-07-23 17:51 ` [Qemu-devel] " Jan Kiszka
2012-07-24 8:56 ` Avi Kivity
2012-07-24 8:56 ` [Qemu-devel] " Avi Kivity
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