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authorChristoffer Dall <christoffer.dall@linaro.org>2014-10-16 16:40:53 +0200
committerChristoffer Dall <christoffer.dall@linaro.org>2014-12-13 14:15:26 +0100
commitf7fa034dc8559c7d7326bfc8bd1a26175abd931a (patch)
treeaa0458365535fcc65662a40fef2dec95a43a47a0 /arch/arm/kvm
parentarm/arm64: KVM: Reset the HCR on each vcpu when resetting the vcpu (diff)
downloadlinux-dev-f7fa034dc8559c7d7326bfc8bd1a26175abd931a.tar.xz
linux-dev-f7fa034dc8559c7d7326bfc8bd1a26175abd931a.zip
arm/arm64: KVM: Clarify KVM_ARM_VCPU_INIT ABI
It is not clear that this ioctl can be called multiple times for a given vcpu. Userspace already does this, so clarify the ABI. Also specify that userspace is expected to always make secondary and subsequent calls to the ioctl with the same parameters for the VCPU as the initial call (which userspace also already does). Add code to check that userspace doesn't violate that ABI in the future, and move the kvm_vcpu_set_target() function which is currently duplicated between the 32-bit and 64-bit versions in guest.c to a common static function in arm.c, shared between both architectures. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'arch/arm/kvm')
-rw-r--r--arch/arm/kvm/arm.c43
-rw-r--r--arch/arm/kvm/guest.c25
2 files changed, 43 insertions, 25 deletions
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 24c9ca4076b2..4043769583e7 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -263,6 +263,7 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
{
/* Force users to call KVM_ARM_VCPU_INIT */
vcpu->arch.target = -1;
+ bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
/* Set up the timer */
kvm_timer_vcpu_init(vcpu);
@@ -649,6 +650,48 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
return -EINVAL;
}
+static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
+ const struct kvm_vcpu_init *init)
+{
+ unsigned int i;
+ int phys_target = kvm_target_cpu();
+
+ if (init->target != phys_target)
+ return -EINVAL;
+
+ /*
+ * Secondary and subsequent calls to KVM_ARM_VCPU_INIT must
+ * use the same target.
+ */
+ if (vcpu->arch.target != -1 && vcpu->arch.target != init->target)
+ return -EINVAL;
+
+ /* -ENOENT for unknown features, -EINVAL for invalid combinations. */
+ for (i = 0; i < sizeof(init->features) * 8; i++) {
+ bool set = (init->features[i / 32] & (1 << (i % 32)));
+
+ if (set && i >= KVM_VCPU_MAX_FEATURES)
+ return -ENOENT;
+
+ /*
+ * Secondary and subsequent calls to KVM_ARM_VCPU_INIT must
+ * use the same feature set.
+ */
+ if (vcpu->arch.target != -1 && i < KVM_VCPU_MAX_FEATURES &&
+ test_bit(i, vcpu->arch.features) != set)
+ return -EINVAL;
+
+ if (set)
+ set_bit(i, vcpu->arch.features);
+ }
+
+ vcpu->arch.target = phys_target;
+
+ /* Now we know what it is, we can reset it. */
+ return kvm_reset_vcpu(vcpu);
+}
+
+
static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
struct kvm_vcpu_init *init)
{
diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
index 8c97208b9b97..384bab67c462 100644
--- a/arch/arm/kvm/guest.c
+++ b/arch/arm/kvm/guest.c
@@ -273,31 +273,6 @@ int __attribute_const__ kvm_target_cpu(void)
}
}
-int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
- const struct kvm_vcpu_init *init)
-{
- unsigned int i;
-
- /* We can only cope with guest==host and only on A15/A7 (for now). */
- if (init->target != kvm_target_cpu())
- return -EINVAL;
-
- vcpu->arch.target = init->target;
- bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
-
- /* -ENOENT for unknown features, -EINVAL for invalid combinations. */
- for (i = 0; i < sizeof(init->features) * 8; i++) {
- if (test_bit(i, (void *)init->features)) {
- if (i >= KVM_VCPU_MAX_FEATURES)
- return -ENOENT;
- set_bit(i, vcpu->arch.features);
- }
- }
-
- /* Now we know what it is, we can reset it. */
- return kvm_reset_vcpu(vcpu);
-}
-
int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init)
{
int target = kvm_target_cpu();