From: Marc Zyngier marc.zyngier@arm.com
[ Upstream commit 5d8d4af24460d079ecdb190254b14b528add1228 ]
The introduction of the SVE registers to userspace started with a refactoring of the way we expose any register via the ONE_REG interface.
Unfortunately, this change doesn't exactly behave as expected if the number of registers is non-zero and consider everything to be an error. The visible result is that QEMU barfs very early when creating vcpus.
Make sure we only exit early in case there is an actual error, rather than a positive number of registers...
Fixes: be25bbb392fa ("KVM: arm64: Factor out core register ID enumeration") Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Takahiro Itazuri itazur@amazon.com --- arch/arm64/kvm/guest.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index 6835ddf598a7..8ae0f408b89c 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -326,17 +326,17 @@ int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) int ret;
ret = kvm_arm_copy_core_reg_indices(uindices); - if (ret) + if (ret < 0) return ret; uindices += ret;
ret = kvm_arm_copy_fw_reg_indices(vcpu, uindices); - if (ret) + if (ret < 0) return ret; uindices += kvm_arm_get_fw_num_regs(vcpu);
ret = copy_timer_indices(vcpu, uindices); - if (ret) + if (ret < 0) return ret; uindices += NUM_TIMER_REGS;