From: "Philippe Mathieu-Daudé" <f4bug@amsat.org>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: "QEMU Developers" <qemu-devel@nongnu.org>,
"Richard Henderson" <richard.henderson@linaro.org>,
kvm-devel <kvm@vger.kernel.org>, "Fam Zheng" <fam@euphon.net>,
"Thomas Huth" <thuth@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Philippe Mathieu-Daudé" <philmd@redhat.com>,
"Richard Henderson" <rth@twiddle.net>,
"Claudio Fontana" <cfontana@suse.de>,
"Alex Bennée" <alex.bennee@linaro.org>,
qemu-arm <qemu-arm@nongnu.org>
Subject: Re: [PATCH v5 03/11] target/arm: Restrict ARMv4 cpus to TCG accel
Date: Sun, 31 Jan 2021 16:35:57 +0100 [thread overview]
Message-ID: <40ca4720-7adf-8469-2593-6e6689d03fd6@amsat.org> (raw)
In-Reply-To: <CAFEAcA-W1tcRREaPTfMw98cNsHs7JHk4gjaJWaJNLpxZoVnKaw@mail.gmail.com>
On 1/30/21 7:54 PM, Peter Maydell wrote:
> On Sat, 30 Jan 2021 at 18:36, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
>>
>> Hi Peter,
>>
>> On 1/30/21 4:37 PM, Peter Maydell wrote:
>>> On Sat, 30 Jan 2021 at 01:52, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
>>>>
>>>> KVM requires a cpu based on (at least) the ARMv7 architecture.
>>>
>>> These days it requires ARMv8, because we dropped 32-bit host
>>> support, and all 64-bit host CPUs are v8.
>>
>> Oh, this comment is about the target, to justify it is pointless to
>> include pre-v7 target cpus/machines in a KVM-only binary.
>>
>> I'll update as:
>>
>> "KVM requires the target cpu based on (at least) the ARMv7
>> architecture."
>
> KVM requires the target CPU to be at least ARMv8, because
> we only support the "host" cpu type, and all KVM host CPUs
> are v8, which means you can't pass a v7 CPU as the target CPU.
> (This used to not be true when we still supported running
> KVM on a v7 CPU like the Cortex-A15, in which case you could
> pass it to the guest.)
Indeed:
$ qemu-system-aarch64 -M xilinx-zynq-a9
qemu-system-aarch64: KVM is not supported for this guest CPU type
qemu-system-aarch64: kvm_init_vcpu: kvm_arch_init_vcpu failed (0):
Invalid argument
next prev parent reply other threads:[~2021-01-31 15:37 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-30 1:52 [PATCH v5 00/11] Support disabling TCG on ARM (part 2) Philippe Mathieu-Daudé
2021-01-30 1:52 ` [PATCH v5 01/11] exec: Restrict TCG specific headers Philippe Mathieu-Daudé
2021-01-30 1:52 ` [PATCH v5 02/11] default-configs: Remove unnecessary SEMIHOSTING selection Philippe Mathieu-Daudé
2021-01-30 1:52 ` [PATCH v5 03/11] target/arm: Restrict ARMv4 cpus to TCG accel Philippe Mathieu-Daudé
2021-01-30 14:48 ` Philippe Mathieu-Daudé
2021-01-30 15:37 ` Peter Maydell
2021-01-30 18:36 ` Philippe Mathieu-Daudé
2021-01-30 18:54 ` Peter Maydell
2021-01-31 15:35 ` Philippe Mathieu-Daudé [this message]
2021-01-30 1:52 ` [PATCH v5 04/11] target/arm: Restrict ARMv5 " Philippe Mathieu-Daudé
2021-01-30 1:52 ` [PATCH v5 05/11] target/arm: Restrict ARMv6 " Philippe Mathieu-Daudé
2021-01-30 1:52 ` [PATCH v5 06/11] target/arm: Restrict ARMv7 R-profile " Philippe Mathieu-Daudé
2021-01-30 1:52 ` [PATCH v5 07/11] target/arm: Restrict ARMv7 M-profile " Philippe Mathieu-Daudé
2021-01-30 1:52 ` [PATCH v5 08/11] target/arm: Make m_helper.c optional via CONFIG_ARM_V7M Philippe Mathieu-Daudé
2021-01-30 1:52 ` [PATCH v5 09/11] target/arm: Reorder meson.build rules Philippe Mathieu-Daudé
2021-01-30 1:52 ` [PATCH v5 10/11] target/arm: Do not build TCG objects when TCG is off Philippe Mathieu-Daudé
2021-01-30 1:52 ` [PATCH v5 11/11] .travis.yml: Add a KVM-only Aarch64 job Philippe Mathieu-Daudé
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