KVM: X86/MMU: Add sp_has_gptes()

Add sp_has_gptes() which equals to !sp->role.direct currently.

Shadow page having gptes needs to be write-protected, accounted and
responded to kvm_mmu_pte_write().

Use it in these places to replace !sp->role.direct and rename
for_each_gfn_indirect_valid_sp.

Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Message-Id: <20220420131204.2850-2-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 085e9b82f71d94bdaf139ef70a56dc44b1cbbed6..caa208a3fcdc11f8dc7e1fff621faea2bc7f0284 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1853,15 +1853,23 @@ static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp,
 static void kvm_mmu_commit_zap_page(struct kvm *kvm,
                                    struct list_head *invalid_list);
 
+static bool sp_has_gptes(struct kvm_mmu_page *sp)
+{
+       if (sp->role.direct)
+               return false;
+
+       return true;
+}
+
 #define for_each_valid_sp(_kvm, _sp, _list)                            \
        hlist_for_each_entry(_sp, _list, hash_link)                     \
                if (is_obsolete_sp((_kvm), (_sp))) {                    \
                } else
 
-#define for_each_gfn_indirect_valid_sp(_kvm, _sp, _gfn)                        \
+#define for_each_gfn_valid_sp_with_gptes(_kvm, _sp, _gfn)              \
        for_each_valid_sp(_kvm, _sp,                                    \
          &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)])     \
-               if ((_sp)->gfn != (_gfn) || (_sp)->role.direct) {} else
+               if ((_sp)->gfn != (_gfn) || !sp_has_gptes(_sp)) {} else
 
 static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
                         struct list_head *invalid_list)
@@ -2109,7 +2117,7 @@ trace_get_page:
        sp->gfn = gfn;
        sp->role = role;
        hlist_add_head(&sp->hash_link, sp_list);
-       if (!direct) {
+       if (sp_has_gptes(sp)) {
                account_shadowed(vcpu->kvm, sp);
                if (level == PG_LEVEL_4K && kvm_vcpu_write_protect_gfn(vcpu, gfn))
                        kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 1);
@@ -2318,7 +2326,7 @@ static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm,
        /* Zapping children means active_mmu_pages has become unstable. */
        list_unstable = *nr_zapped;
 
-       if (!sp->role.invalid && !sp->role.direct)
+       if (!sp->role.invalid && sp_has_gptes(sp))
                unaccount_shadowed(kvm, sp);
 
        if (sp->unsync)
@@ -2498,7 +2506,7 @@ int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
        pgprintk("%s: looking for gfn %llx\n", __func__, gfn);
        r = 0;
        write_lock(&kvm->mmu_lock);
-       for_each_gfn_indirect_valid_sp(kvm, sp, gfn) {
+       for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) {
                pgprintk("%s: gfn %llx role %x\n", __func__, gfn,
                         sp->role.word);
                r = 1;
@@ -2560,7 +2568,7 @@ int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot,
         * that case, KVM must complete emulation of the guest TLB flush before
         * allowing shadow pages to become unsync (writable by the guest).
         */
-       for_each_gfn_indirect_valid_sp(kvm, sp, gfn) {
+       for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) {
                if (!can_unsync)
                        return -EPERM;
 
@@ -5298,7 +5306,7 @@ static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
 
        ++vcpu->kvm->stat.mmu_pte_write;
 
-       for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn) {
+       for_each_gfn_valid_sp_with_gptes(vcpu->kvm, sp, gfn) {
                if (detect_write_misaligned(sp, gpa, bytes) ||
                      detect_write_flooding(sp)) {
                        kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list);