From: marc.zyngier@arm.com (Marc Zyngier)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH 2/5] ARM/ARM64: KVM: Forward PSCI SYSTEM_OFF and SYSTEM_RESET to user space
Date: Thu, 17 Oct 2013 09:37:39 +0100 [thread overview]
Message-ID: <525FA1D3.8060001@arm.com> (raw)
In-Reply-To: <1381942954-22388-3-git-send-email-anup.patel@linaro.org>
On 16/10/13 18:02, Anup Patel wrote:
> The PSCI SYSTEM_OFF and SYSTEM_RESET functions are VM or Guest level
> functions hence cannot be emulated by the in-kernel PSCI emulation code.
Why can't we implement system-wide functionality in the kernel? I fail
to see the issue here.
> To tackle this, we forward PSCI SYSTEM_OFF and SYSTEM_RESET function
> calls from Guest to user space (i.e. QEMU or KVMTOOL) via KVM run
> structure with KVM_EXIT_PSCI exit reason.
I'm really not keen on this approach. Having part of the PSCI
implementation offloaded to userspace means we don't have a complete
implementation in KVM anymore, and we end-up duplicating functionality
all over the place.
Also, OFF and RESET are not PSCI specific concepts, and could be
implemented in various ways. I'm more inclined to return a
*standardized* exit code that the various platforms can interpret.
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2013-10-17 8:37 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-16 17:02 [RFC PATCH 0/5] PSCI system off and reset for KVM ARM/ARM64 Anup Patel
2013-10-16 17:02 ` [RFC PATCH 1/5] ARM/ARM64: KVM: Update user space API header for PSCI emulation Anup Patel
2013-10-16 20:30 ` Christoffer Dall
2013-10-17 6:25 ` Anup Patel
2013-10-16 22:11 ` Christoffer Dall
2013-10-17 6:45 ` Anup Patel
2013-10-17 8:47 ` Marc Zyngier
2013-10-17 11:10 ` Anup Patel
2013-10-17 11:21 ` Marc Zyngier
2013-10-17 11:30 ` Anup Patel
2013-10-17 11:49 ` Alexander Graf
2013-10-17 11:55 ` Marc Zyngier
2013-10-17 12:01 ` Alexander Graf
2013-10-17 19:04 ` Christoffer Dall
2013-10-17 22:06 ` Alexander Graf
2013-10-17 22:24 ` Christoffer Dall
2013-10-17 22:26 ` Alexander Graf
2013-10-18 3:34 ` Christoffer Dall
2013-10-17 15:32 ` Anup Patel
2013-10-17 11:52 ` Marc Zyngier
2013-10-16 17:02 ` [RFC PATCH 2/5] ARM/ARM64: KVM: Forward PSCI SYSTEM_OFF and SYSTEM_RESET to user space Anup Patel
2013-10-16 22:22 ` Christoffer Dall
2013-10-17 5:52 ` Anup Patel
2013-10-17 8:37 ` Marc Zyngier [this message]
2013-10-17 9:10 ` Peter Maydell
2013-10-17 9:21 ` Marc Zyngier
2013-10-17 9:31 ` Peter Maydell
2013-10-17 18:34 ` Christoffer Dall
2013-10-18 4:18 ` Anup Patel
2013-10-17 11:07 ` Anup Patel
2013-10-17 11:13 ` Marc Zyngier
2013-10-17 11:13 ` Anup Patel
2013-10-17 18:29 ` Christoffer Dall
2013-10-16 17:02 ` [RFC PATCH 3/5] KVM: Add documentation for KVM_EXIT_PSCI exit reason Anup Patel
2013-10-16 17:02 ` [RFC PATCH 4/5] ARM: psci: Add support for system reboot and poweroff Anup Patel
2013-10-16 22:17 ` Rob Herring
2013-10-17 5:08 ` Anup Patel
2013-10-17 9:50 ` Marc Zyngier
2013-10-16 17:02 ` [RFC PATCH 5/5] ARM64: " Anup Patel
2013-10-16 17:08 ` [RFC PATCH 0/5] PSCI system off and reset for KVM ARM/ARM64 Anup Patel
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