From 17992d52dd8b8dcabf1100839b6d0e45787a9381 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 2 Apr 2019 03:28:39 +0100 Subject: [PATCH] arm64: KVM: Fix system register enumeration commit 5d8d4af24460d079ecdb190254b14b528add1228 upstream. 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 Signed-off-by: Takahiro Itazuri Signed-off-by: Greg Kroah-Hartman --- 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 563a9f31b83d3..b509afa054701 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -333,17 +333,17 @@ 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;