From: marc.zyngier@arm.com (Marc Zyngier)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC] arm64: Early printk support for virtio-mmio console devices.
Date: Thu, 18 Apr 2013 10:51:43 +0200 [thread overview]
Message-ID: <b67c5c681ce96942c3cc3bd05b8c80d2@localhost> (raw)
In-Reply-To: <CAFEAcA-38=zx-s3NaBAu-yvDNRbt=KcTs-3c1QJR3COB3G1n2A@mail.gmail.com>
On Thu, 18 Apr 2013 09:30:52 +0100, Peter Maydell
<peter.maydell@linaro.org> wrote:
> On 18 April 2013 07:49, Marc Zyngier <maz@misterjones.org> wrote:
>> If you need an early console, why not simply wire the 8250 emulation in
>> kvmtool to be useable from the MMIO bus? I reckon this would solve your
>> problem in a more elegant way...
>
> The other approach I thought of would be something involving
> defining a hypercall interface for console I/O, in the same
> way that we have hypercalls for "start cpu"/"stop cpu"/etc.
> Is there any mileage in considering that approach, or is it
> a non-starter?
That's always possible, but that becomes architecture dependent, which
means code duplication across architectures. I'd rather use the MMIO
infrastructure, which has some commonalities across the board.
M.
--
Fast, cheap, reliable. Pick two.
WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <marc.zyngier@arm.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: PranavkumarSawargaonkar <pranavkumar@linaro.org>,
<linaro-kernel@lists.linaro.org>, <patches@linaro.org>,
<linux-kernel@vger.kernel.org>, <kvmarm@lists.cs.columbia.edu>,
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [RFC] arm64: Early printk support for virtio-mmio console devices.
Date: Thu, 18 Apr 2013 10:51:43 +0200 [thread overview]
Message-ID: <b67c5c681ce96942c3cc3bd05b8c80d2@localhost> (raw)
In-Reply-To: <CAFEAcA-38=zx-s3NaBAu-yvDNRbt=KcTs-3c1QJR3COB3G1n2A@mail.gmail.com>
On Thu, 18 Apr 2013 09:30:52 +0100, Peter Maydell
<peter.maydell@linaro.org> wrote:
> On 18 April 2013 07:49, Marc Zyngier <maz@misterjones.org> wrote:
>> If you need an early console, why not simply wire the 8250 emulation in
>> kvmtool to be useable from the MMIO bus? I reckon this would solve your
>> problem in a more elegant way...
>
> The other approach I thought of would be something involving
> defining a hypercall interface for console I/O, in the same
> way that we have hypercalls for "start cpu"/"stop cpu"/etc.
> Is there any mileage in considering that approach, or is it
> a non-starter?
That's always possible, but that becomes architecture dependent, which
means code duplication across architectures. I'd rather use the MMIO
infrastructure, which has some commonalities across the board.
M.
--
Fast, cheap, reliable. Pick two.
next prev parent reply other threads:[~2013-04-18 8:51 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-18 5:52 [RFC] arm64: Early printk support for virtio-mmio console devices PranavkumarSawargaonkar
2013-04-18 5:52 ` PranavkumarSawargaonkar
2013-04-18 6:49 ` Marc Zyngier
2013-04-18 6:49 ` Marc Zyngier
2013-04-18 7:24 ` Pranavkumar Sawargaonkar
2013-04-18 7:24 ` Pranavkumar Sawargaonkar
[not found] ` <CAAHg+HhajHFC=1nh6YQNgpf=Na2FqcsYJ=t+ag9QiTg6TxUz9w@mail.gmail.com>
2013-04-18 7:36 ` Marc Zyngier
2013-04-18 7:36 ` Marc Zyngier
2013-04-18 8:48 ` Pranavkumar Sawargaonkar
2013-04-18 8:48 ` Pranavkumar Sawargaonkar
2013-04-18 8:53 ` Alexander Graf
2013-04-18 8:53 ` Alexander Graf
2013-04-19 9:05 ` Will Deacon
2013-04-19 9:05 ` Will Deacon
2013-04-19 9:25 ` Pranavkumar Sawargaonkar
2013-04-19 9:25 ` Pranavkumar Sawargaonkar
2013-04-19 9:27 ` Will Deacon
2013-04-19 9:27 ` Will Deacon
2013-04-19 9:30 ` Peter Maydell
2013-04-19 9:30 ` Peter Maydell
2013-04-19 9:34 ` Pranavkumar Sawargaonkar
2013-04-19 9:34 ` Pranavkumar Sawargaonkar
2013-04-19 9:39 ` Will Deacon
2013-04-19 9:39 ` Will Deacon
2013-04-19 10:05 ` Peter Maydell
2013-04-19 10:05 ` Peter Maydell
2013-04-19 16:12 ` Catalin Marinas
2013-04-19 16:12 ` Catalin Marinas
2013-04-19 16:14 ` Peter Maydell
2013-04-19 16:14 ` Peter Maydell
2013-04-19 16:22 ` Catalin Marinas
2013-04-19 16:22 ` Catalin Marinas
2013-04-19 16:33 ` Peter Maydell
2013-04-19 16:33 ` Peter Maydell
2013-04-19 17:14 ` Catalin Marinas
2013-04-19 17:14 ` Catalin Marinas
2013-04-19 17:40 ` Peter Maydell
2013-04-19 17:40 ` Peter Maydell
2013-04-19 9:36 ` Will Deacon
2013-04-19 9:36 ` Will Deacon
2013-04-18 19:06 ` Pranavkumar Sawargaonkar
2013-04-18 19:06 ` Pranavkumar Sawargaonkar
2013-04-18 8:30 ` Peter Maydell
2013-04-18 8:30 ` Peter Maydell
2013-04-18 8:51 ` Alexander Graf
2013-04-18 8:51 ` Alexander Graf
2013-04-18 8:51 ` Marc Zyngier [this message]
2013-04-18 8:51 ` Marc Zyngier
2013-04-18 6:51 ` Rusty Russell
2013-04-18 6:51 ` Rusty Russell
2013-04-18 7:32 ` Pranavkumar Sawargaonkar
2013-04-18 7:32 ` Pranavkumar Sawargaonkar
2013-04-18 8:44 ` Alexander Graf
2013-04-18 8:44 ` Alexander Graf
2013-04-18 8:55 ` Pranavkumar Sawargaonkar
2013-04-18 8:55 ` Pranavkumar Sawargaonkar
2013-04-18 10:01 ` Jean-Christophe PLAGNIOL-VILLARD
2013-04-18 10:01 ` Jean-Christophe PLAGNIOL-VILLARD
2013-04-22 1:21 ` Rusty Russell
2013-04-22 1:21 ` Rusty Russell
2013-04-22 3:10 ` Anup Patel
2013-04-22 3:10 ` Anup Patel
2013-04-22 5:15 ` Rusty Russell
2013-04-22 5:15 ` Rusty Russell
2013-04-23 5:53 ` Pranavkumar Sawargaonkar
2013-04-23 5:53 ` Pranavkumar Sawargaonkar
2013-04-22 14:50 ` Alexander Graf
2013-04-22 14:50 ` Alexander Graf
2013-04-18 15:25 ` Christopher Covington
2013-04-18 15:25 ` Christopher Covington
2013-04-18 15:59 ` Marc Zyngier
2013-04-18 15:59 ` Marc Zyngier
2013-04-18 18:59 ` Pranavkumar Sawargaonkar
2013-04-18 18:59 ` Pranavkumar Sawargaonkar
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