Document what the page table walker do when walker callback function returns a value. Current documentation is not correct as negative error of -EAGAIN on a non-shared page table walker doesn't terminate the walker and continues to the next step. There might be a better place to keep this information, for now this documentation will work as a reference guide until a better way is found. Signed-off-by: Vipin Sharma <vipinsh@xxxxxxxxxx> --- arch/arm64/include/asm/kvm_pgtable.h | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index 8ef7e8f3f054..957bc20dab00 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -711,8 +711,19 @@ int kvm_pgtable_stage2_split(struct kvm_pgtable *pgt, u64 addr, u64 size, * after invoking the walker callback, allowing the walker to descend into * a newly installed table. * - * Returning a negative error code from the walker callback function will - * terminate the walk immediately with the same error code. + * Depending on the return value from the walker callback function, the page + * table walk will continue or exit the walk. This is also dependent on the + * type of the walker, i.e. shared walker (vCPU fault handlers) or non-shared + * walker. + * + * Walker Type | Callback | Walker action + * -------------|------------------|-------------- + * Non-Shared | 0 | Continue + * Non-Shared | -EAGAIN | Continue + * Non-Shared | Any other | Exit + * -------------|------------------|-------------- + * Shared | 0 | Continue + * Shared | Any other | Exit * * Return: 0 on success, negative error code on failure. */ -- 2.41.0.rc0.172.g3f132b7071-goog
