From: James Hogan Date: Tue, 6 Dec 2016 14:56:20 +0000 (+0000) Subject: KVM: MIPS: Clean & flush on dirty page logging enable X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=a1ac9e17b7c934666a780772866135b9fea17f4c;p=openwrt%2Fstaging%2Fblogic.git KVM: MIPS: Clean & flush on dirty page logging enable When an existing memory region has dirty page logging enabled, make the entire slot clean (read only) so that writes will immediately start logging dirty pages (once the dirty bit is transferred from GPA to GVA page tables in an upcoming patch). Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org --- diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index 0b84b336ee4d..475c4cc78bd6 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -197,9 +197,33 @@ void kvm_arch_commit_memory_region(struct kvm *kvm, const struct kvm_memory_slot *new, enum kvm_mr_change change) { + int needs_flush; + kvm_debug("%s: kvm: %p slot: %d, GPA: %llx, size: %llx, QVA: %llx\n", __func__, kvm, mem->slot, mem->guest_phys_addr, mem->memory_size, mem->userspace_addr); + + /* + * If dirty page logging is enabled, write protect all pages in the slot + * ready for dirty logging. + * + * There is no need to do this in any of the following cases: + * CREATE: No dirty mappings will already exist. + * MOVE/DELETE: The old mappings will already have been cleaned up by + * kvm_arch_flush_shadow_memslot() + */ + if (change == KVM_MR_FLAGS_ONLY && + (!(old->flags & KVM_MEM_LOG_DIRTY_PAGES) && + new->flags & KVM_MEM_LOG_DIRTY_PAGES)) { + spin_lock(&kvm->mmu_lock); + /* Write protect GPA page table entries */ + needs_flush = kvm_mips_mkclean_gpa_pt(kvm, new->base_gfn, + new->base_gfn + new->npages - 1); + /* Let implementation do the rest */ + if (needs_flush) + kvm_mips_callbacks->flush_shadow_memslot(kvm, new); + spin_unlock(&kvm->mmu_lock); + } } static inline void dump_handler(const char *symbol, void *start, void *end)