From a1ac9e17b7c934666a780772866135b9fea17f4c Mon Sep 17 00:00:00 2001 From: James Hogan Date: Tue, 6 Dec 2016 14:56:20 +0000 Subject: [PATCH] KVM: MIPS: Clean & flush on dirty page logging enable MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 --- arch/mips/kvm/mips.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) 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)