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authorAnup Patel <anup.patel@linaro.org>2014-04-29 11:24:18 +0530
committerChristoffer Dall <christoffer.dall@linaro.org>2014-04-30 04:18:57 -0700
commite8e7fcc5e2710b31ef842ee799db99c07986c364 (patch)
tree2f9005ad128030c359da457486de308260ebba89 /arch/arm/kvm/psci.c
parent50bb0c94759bff8c62f1c7c8f774255e44ec1a41 (diff)
downloadlwn-e8e7fcc5e2710b31ef842ee799db99c07986c364.tar.gz
lwn-e8e7fcc5e2710b31ef842ee799db99c07986c364.zip
ARM/ARM64: KVM: Make kvm_psci_call() return convention more flexible
Currently, the kvm_psci_call() returns 'true' or 'false' based on whether the PSCI function call was handled successfully or not. This does not help us emulate system-level PSCI functions where the actual emulation work will be done by user space (QEMU or KVMTOOL). Examples of such system-level PSCI functions are: PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET. This patch updates kvm_psci_call() to return three types of values: 1) > 0 (success) 2) = 0 (success but exit to user space) 3) < 0 (errors) Signed-off-by: Anup Patel <anup.patel@linaro.org> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'arch/arm/kvm/psci.c')
-rw-r--r--arch/arm/kvm/psci.c28
1 files changed, 16 insertions, 12 deletions
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
index 8c42596cdbdf..14e6fa6c8e35 100644
--- a/arch/arm/kvm/psci.c
+++ b/arch/arm/kvm/psci.c
@@ -93,7 +93,7 @@ int kvm_psci_version(struct kvm_vcpu *vcpu)
return KVM_ARM_PSCI_0_1;
}
-static bool kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
+static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
{
unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
unsigned long val;
@@ -128,14 +128,14 @@ static bool kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
val = PSCI_RET_NOT_SUPPORTED;
break;
default:
- return false;
+ return -EINVAL;
}
*vcpu_reg(vcpu, 0) = val;
- return true;
+ return 1;
}
-static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
+static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
{
unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
unsigned long val;
@@ -153,11 +153,11 @@ static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
val = PSCI_RET_NOT_SUPPORTED;
break;
default:
- return false;
+ return -EINVAL;
}
*vcpu_reg(vcpu, 0) = val;
- return true;
+ return 1;
}
/**
@@ -165,12 +165,16 @@ static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
* @vcpu: Pointer to the VCPU struct
*
* Handle PSCI calls from guests through traps from HVC instructions.
- * The calling convention is similar to SMC calls to the secure world where
- * the function number is placed in r0 and this function returns true if the
- * function number specified in r0 is withing the PSCI range, and false
- * otherwise.
+ * The calling convention is similar to SMC calls to the secure world
+ * where the function number is placed in r0.
+ *
+ * This function returns: > 0 (success), 0 (success but exit to user
+ * space), and < 0 (errors)
+ *
+ * Errors:
+ * -EINVAL: Unrecognized PSCI function
*/
-bool kvm_psci_call(struct kvm_vcpu *vcpu)
+int kvm_psci_call(struct kvm_vcpu *vcpu)
{
switch (kvm_psci_version(vcpu)) {
case KVM_ARM_PSCI_0_2:
@@ -178,6 +182,6 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu)
case KVM_ARM_PSCI_0_1:
return kvm_psci_0_1_call(vcpu);
default:
- return false;
+ return -EINVAL;
};
}