[Patch v3 2/3] KVM: x86: a new pte_list_remove including mmu_spte_clear_track_bits

[Wei Yang <richard.weiyang@xxxxxxxxx>]

rmap_remove() would remove the sptep after locating the correct rmap_head.
While in several cases, the caller has already known the correct rmap_head.

This patch introduces a new pte_list_remove() which removes sptep directly
from rmap_head after clearing the track bits. Since it is for sure the spte
is present, it is safe to do the removal.

Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
---
 arch/x86/kvm/mmu.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index de673c073cf0..5b05a8079872 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1285,6 +1285,12 @@ static void __pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head)
 	}
 }
 
+static void pte_list_remove(struct kvm_rmap_head *rmap_head, u64 *sptep)
+{
+	mmu_spte_clear_track_bits(sptep);
+	__pte_list_remove(sptep, rmap_head);
+}
+
 static struct kvm_rmap_head *__gfn_to_rmap(gfn_t gfn, int level,
 					   struct kvm_memory_slot *slot)
 {
@@ -1669,7 +1675,7 @@ static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head)
 	while ((sptep = rmap_get_first(rmap_head, &iter))) {
 		rmap_printk("%s: spte %p %llx.\n", __func__, sptep, *sptep);
 
-		drop_spte(kvm, sptep);
+		pte_list_remove(rmap_head, sptep);
 		flush = true;
 	}
 
@@ -1705,7 +1711,7 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
 		need_flush = 1;
 
 		if (pte_write(*ptep)) {
-			drop_spte(kvm, sptep);
+			pte_list_remove(rmap_head, sptep);
 			goto restart;
 		} else {
 			new_spte = *sptep & ~PT64_BASE_ADDR_MASK;
@@ -5598,7 +5604,7 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm,
 		if (sp->role.direct &&
 			!kvm_is_reserved_pfn(pfn) &&
 			PageTransCompoundMap(pfn_to_page(pfn))) {
-			drop_spte(kvm, sptep);
+			pte_list_remove(rmap_head, sptep);
 			need_tlb_flush = 1;
 			goto restart;
 		}
-- 
2.15.1