Commit 5d8d4af2 authored Apr 02, 2019 by Marc Zyngier

arm64: KVM: Fix system register enumeration



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: be25bbb3 ("KVM: arm64: Factor out core register ID enumeration")
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

parent 50036ad0

arch/arm64/kvm/guest.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -604,22 +604,22 @@ int kvm_arm_copy_reg_indices(struct kvm_vcpu vcpu, u64 __user uindices)
		int ret;

		ret = copy_core_reg_indices(vcpu, uindices);
		if (ret)
		if (ret < 0)
		return ret;
		uindices += ret;

		ret = copy_sve_reg_indices(vcpu, 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;

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