[PATCH AUTOSEL 4.9 6/9] KVM: arm/arm64: Ensure vcpu target is unset on reset failure

From: Sasha Levin
Date: Thu May 16 2019 - 07:45:36 EST


From: Andrew Jones <drjones@xxxxxxxxxx>

[ Upstream commit 811328fc3222f7b55846de0cd0404339e2e1e6d7 ]

A failed KVM_ARM_VCPU_INIT should not set the vcpu target,
as the vcpu target is used by kvm_vcpu_initialized() to
determine if other vcpu ioctls may proceed. We need to set
the target before calling kvm_reset_vcpu(), but if that call
fails, we should then unset it and clear the feature bitmap
while we're at it.

Signed-off-by: Andrew Jones <drjones@xxxxxxxxxx>
[maz: Simplified patch, completed commit message]
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/arm/kvm/arm.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index a670c70f4def9..dfc00a5bdc10d 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -801,7 +801,7 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
const struct kvm_vcpu_init *init)
{
- unsigned int i;
+ unsigned int i, ret;
int phys_target = kvm_target_cpu();

if (init->target != phys_target)
@@ -836,9 +836,14 @@ static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
vcpu->arch.target = phys_target;

/* Now we know what it is, we can reset it. */
- return kvm_reset_vcpu(vcpu);
-}
+ ret = kvm_reset_vcpu(vcpu);
+ if (ret) {
+ vcpu->arch.target = -1;
+ bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
+ }

+ return ret;
+}

static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
struct kvm_vcpu_init *init)
--
2.20.1