From: WANG Xuerui <git@xxxxxxxxxx> Hi, While trying to add loongarch to the Rust kvm-bindings crate, I accidentally discovered faulty logic in the handling of CPUCFG IDs ("leaves" for those more familiar with x86), that could result in incorrectly accepting every possible int for the ID; fortunately it is 6.8 material that hasn't seen a release yet, so a fix is possible. The first patch contains the fix, while the rest are general drive-by refactoring and comment cleanups. Although it is currently the Chinese holiday season, Huacai told me over IM that he's able to test the series and handle the upstreaming, so going through the loongarch tree seems to be the way forward for the series. v3 changes: - Fixed the validation by accepting every CPUCFG IDs from 0 to 20 inclusive, instead of only 2; this was a misunderstanding of mine regarding the userland. (currently the only known user, the QEMU target/loongarch KVM code, expects to be able to set all these 21 CPUCFG leaves, even though 7~15 are undefined according to the LoongArch reference manual.) This also had the effect of squashing the first 2 patches. - Made the _kvm_get_cpucfg_mask return a mask in all valid cases, allowing the mask check to be lifted out of the CPUCFG2 case. - Swapped the "LoongArch:" and "KVM:" tags because right now the patches are likely to reach mainline through the loongarch tree, and having the "LoongArch:" prefix first is the convention here. v2 changes: - Squashed the v1 patches 4 and 5 according to Huacai's review - Reworded comments according to Huacai's suggestion - Use WARN_ON_ONCE (instead of BUG) to replace unreachable() for not crashing the kernel (per checkpatch.pl suggestion) WANG Xuerui (3): LoongArch: KVM: Fix input validation of _kvm_get_cpucfg and kvm_check_cpucfg LoongArch: KVM: Rename _kvm_get_cpucfg to _kvm_get_cpucfg_mask LoongArch: KVM: Streamline kvm_check_cpucfg and improve comments arch/loongarch/kvm/vcpu.c | 81 ++++++++++++++++++--------------------- 1 file changed, 38 insertions(+), 43 deletions(-) -- 2.43.0