[PATCH 9/11] KVM/MMU: Flush tlb in the kvm_mmu_write_protect_pt_masked()

[lantianyu1986]

From: Lan Tianyu <tianyu....@microsoft.com>

This patch is to flush tlb in the kvm_mmu_write_protect_pt_masked() when
tlb range flush is available and make kvm_mmu_write_protect_pt_masked()
return flush request.

Signed-off-by: Lan Tianyu <tianyu....@microsoft.com>
---
 arch/x86/kvm/mmu.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 9d8ee6ea02db..30ed7a79335b 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1624,20 +1624,30 @@ static bool __rmap_set_dirty(struct kvm *kvm, struct 
kvm_rmap_head *rmap_head)
  * Used when we do not need to care about huge page mappings: e.g. during dirty
  * logging we do not have any such mappings.
  */
-static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm,
+static bool kvm_mmu_write_protect_pt_masked(struct kvm *kvm,
                                     struct kvm_memory_slot *slot,
                                     gfn_t gfn_offset, unsigned long mask)
 {
        struct kvm_rmap_head *rmap_head;
+       bool flush = false;
 
        while (mask) {
                rmap_head = __gfn_to_rmap(slot->base_gfn + gfn_offset + 
__ffs(mask),
                                          PT_PAGE_TABLE_LEVEL, slot);
-               __rmap_write_protect(kvm, rmap_head, false);
+               flush |= __rmap_write_protect(kvm, rmap_head, false);
 
                /* clear the first set bit */
                mask &= mask - 1;
        }
+
+       if (flush && kvm_available_flush_tlb_with_range()) {
+               kvm_flush_remote_tlbs_with_address(kvm,
+                               slot->base_gfn + gfn_offset,
+                               hweight_long(mask));
+               flush = false;
+       }
+
+       return flush;
 }
 
 /**
@@ -1683,13 +1693,14 @@ bool kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm 
*kvm,
                                struct kvm_memory_slot *slot,
                                gfn_t gfn_offset, unsigned long mask)
 {
-       if (kvm_x86_ops->enable_log_dirty_pt_masked)
+       if (kvm_x86_ops->enable_log_dirty_pt_masked) {
                kvm_x86_ops->enable_log_dirty_pt_masked(kvm, slot, gfn_offset,
                                mask);
-       else
-               kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
-
-       return true;
+               return true;
+       } else {
+               return kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset,
+                               mask);
+       }
 }
 
 /**
-- 
2.14.4