Makes sense to me. On Thu, Nov 23, 2017 at 08:01:05PM +1100, Paul Mackerras wrote:
In an excess of caution, commit 6f63e81bda98 ("KVM: PPC: Book3S: Add MMIO emulation for FP and VSX instructions", 2017-02-21) included checks for the case that vcpu->arch.mmio_vsx_copy_nums is less than zero, even though its type is u8. This causes a Coverity warning, so we remove the check for < 0. We also adjust the associated comment to be more accurate ("4 or less" rather than "less than 4"). Signed-off-by: Paul Mackerras <paulus@xxxxxxxxxx>
Reviewed-by: Darren Kenny <darren.kenny@xxxxxxxxxx>
--- arch/powerpc/kvm/powerpc.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 6b6c53c..c2c7ef3 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -1101,11 +1101,9 @@ int kvmppc_handle_vsx_load(struct kvm_run *run, struct kvm_vcpu *vcpu, { enum emulation_result emulated = EMULATE_DONE; - /* Currently, mmio_vsx_copy_nums only allowed to be less than 4 */ - if ( (vcpu->arch.mmio_vsx_copy_nums > 4) || - (vcpu->arch.mmio_vsx_copy_nums < 0) ) { + /* Currently, mmio_vsx_copy_nums only allowed to be 4 or less */ + if (vcpu->arch.mmio_vsx_copy_nums > 4) return EMULATE_FAIL; - } while (vcpu->arch.mmio_vsx_copy_nums) { emulated = __kvmppc_handle_load(run, vcpu, rt, bytes, @@ -1247,11 +1245,9 @@ int kvmppc_handle_vsx_store(struct kvm_run *run, struct kvm_vcpu *vcpu, vcpu->arch.io_gpr = rs; - /* Currently, mmio_vsx_copy_nums only allowed to be less than 4 */ - if ( (vcpu->arch.mmio_vsx_copy_nums > 4) || - (vcpu->arch.mmio_vsx_copy_nums < 0) ) { + /* Currently, mmio_vsx_copy_nums only allowed to be 4 or less */ + if (vcpu->arch.mmio_vsx_copy_nums > 4) return EMULATE_FAIL; - } while (vcpu->arch.mmio_vsx_copy_nums) { if (kvmppc_get_vsr_data(vcpu, rs, &val) == -1) -- 2.7.4