In kvm_set_pte_rmapp, if the new mapping is writable, we need to remove all spte pointing to that page otherwisewe we only need to adjust the sptes to let them point to the new page. This patch clarifys the logic and makes the later patch more clean
[ Impact: no logic changed ] Signed-off-by: Xiao Guangrong <[email protected]> --- arch/x86/kvm/mmu.c | 17 ++++++++--------- 1 files changed, 8 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 68d4d5f..a0dc0d7 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1225,16 +1225,16 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp, WARN_ON(pte_huge(*ptep)); new_pfn = pte_pfn(*ptep); - for (sptep = rmap_get_first(*rmapp, &iter); sptep;) { - BUG_ON(!is_shadow_present_pte(*sptep)); - rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", sptep, *sptep); + if (pte_write(*ptep)) + need_flush = kvm_unmap_rmapp(kvm, rmapp, slot, data); + else + for (sptep = rmap_get_first(*rmapp, &iter); sptep;) { + BUG_ON(!is_shadow_present_pte(*sptep)); + rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", + sptep, *sptep); - need_flush = 1; + need_flush = 1; - if (pte_write(*ptep)) { - drop_spte(kvm, sptep); - sptep = rmap_get_first(*rmapp, &iter); - } else { new_spte = *sptep & ~PT64_BASE_ADDR_MASK; new_spte |= (u64)new_pfn << PAGE_SHIFT; @@ -1246,7 +1246,6 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp, mmu_spte_set(sptep, new_spte); sptep = rmap_get_next(&iter); } - } if (need_flush) kvm_flush_remote_tlbs(kvm); -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
