[3.16.y-ckt stable] Patch "arm/arm64: KVM: Correct KVM_ARM_VCPU_INIT power off option" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    arm/arm64: KVM: Correct KVM_ARM_VCPU_INIT power off option

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt12.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From a897742fcf09dea4e7823eaed4d48cb0fe46667a Mon Sep 17 00:00:00 2001
From: Christoffer Dall <christoffer.dall at linaro.org>
Date: Thu, 16 Oct 2014 16:14:43 +0200
Subject: arm/arm64: KVM: Correct KVM_ARM_VCPU_INIT power off option

commit 3ad8b3de526a76fbe9466b366059e4958957b88f upstream.

The implementation of KVM_ARM_VCPU_INIT is currently not doing what
userspace expects, namely making sure that a vcpu which may have been
turned off using PSCI is returned to its initial state, which would be
powered on if userspace does not set the KVM_ARM_VCPU_POWER_OFF flag.

Implement the expected functionality and clarify the ABI.

Acked-by: Marc Zyngier <marc.zyngier at arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
Signed-off-by: Shannon Zhao <shannon.zhao at linaro.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 Documentation/virtual/kvm/api.txt | 3 ++-
 arch/arm/kvm/arm.c                | 2 ++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 612e6e99d1e5..769c2cb7f9b3 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2382,7 +2382,8 @@ should be created before this ioctl is invoked.

 Possible features:
 	- KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state.
-	  Depends on KVM_CAP_ARM_PSCI.
+	  Depends on KVM_CAP_ARM_PSCI.  If not set, the CPU will be powered on
+	  and execute guest code when KVM_RUN is called.
 	- KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode.
 	  Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only).
 	- KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 for the CPU.
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index b38acec6c918..01c0511709e3 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -681,6 +681,8 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
 	 */
 	if (test_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features))
 		vcpu->arch.pause = true;
+	else
+		vcpu->arch.pause = false;

 	return 0;
 }