[PATCH v3 5/5] KVM: s390: vsie: Use mmu cache to allocate rmap

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

Use kvm_s390_mmu_cache_alloc_rmap() to allocate the rmap in
gmap_insert_rmap(), instead of a normal kzalloc_obj() with GFP_ATOMIC.

This guarantees forward progress.

Fixes: a2c17f9270cc ("KVM: s390: New gmap code")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
CC: stable@vger.kernel.org # 7.1
---
 arch/s390/kvm/gaccess.c | 16 ++++++++--------
 arch/s390/kvm/gmap.c    |  7 ++++---
 arch/s390/kvm/gmap.h    |  3 ++-
 3 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 0584fc91606f..36102b2727fb 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -1419,8 +1419,8 @@ static int walk_guest_tables(struct gmap *sg, unsigned long saddr, struct pgtwal
 	return kvm_s390_get_guest_page(kvm, entries + LEVEL_MEM, table.pte.pfra, wr);
 }
 
-static int _do_shadow_pte(struct gmap *sg, gpa_t raddr, union pte *ptep_h, union pte *ptep,
-			  struct guest_fault *f, bool p)
+static int _do_shadow_pte(struct kvm_s390_mmu_cache *mc, struct gmap *sg, gpa_t raddr,
+			  union pte *ptep_h, union pte *ptep, struct guest_fault *f, bool p)
 {
 	union pgste pgste;
 	union pte newpte;
@@ -1430,7 +1430,7 @@ static int _do_shadow_pte(struct gmap *sg, gpa_t raddr, union pte *ptep_h, union
 	lockdep_assert_held(&sg->parent->children_lock);
 
 	scoped_guard(spinlock, &sg->host_to_rmap_lock)
-		rc = gmap_insert_rmap(sg, f->gfn, gpa_to_gfn(raddr), TABLE_TYPE_PAGE_TABLE);
+		rc = gmap_insert_rmap(mc, sg, f->gfn, gpa_to_gfn(raddr), TABLE_TYPE_PAGE_TABLE);
 	if (rc)
 		return rc;
 
@@ -1462,8 +1462,8 @@ static int _do_shadow_pte(struct gmap *sg, gpa_t raddr, union pte *ptep_h, union
 	return 0;
 }
 
-static int _do_shadow_crste(struct gmap *sg, gpa_t raddr, union crste *host, union crste *table,
-			    struct guest_fault *f, bool p)
+static int _do_shadow_crste(struct kvm_s390_mmu_cache *mc, struct gmap *sg, gpa_t raddr,
+			    union crste *host, union crste *table, struct guest_fault *f, bool p)
 {
 	union crste newcrste, oldcrste;
 	unsigned long mask;
@@ -1476,7 +1476,7 @@ static int _do_shadow_crste(struct gmap *sg, gpa_t raddr, union crste *host, uni
 	mask = is_pmd(*table) ? _SEGMENT_FR_MASK : _REGION3_FR_MASK;
 	r_gfn = gpa_to_gfn(raddr) & mask;
 	scoped_guard(spinlock, &sg->host_to_rmap_lock)
-		rc = gmap_insert_rmap(sg, f->gfn & mask, r_gfn, host->h.tt);
+		rc = gmap_insert_rmap(mc, sg, f->gfn & mask, r_gfn, host->h.tt);
 	if (rc)
 		return rc;
 
@@ -1578,8 +1578,8 @@ static int _gaccess_do_shadow(struct kvm_s390_mmu_cache *mc, struct gmap *sg,
 	if (KVM_BUG_ON(l > TABLE_TYPE_REGION3, sg->kvm))
 		return -EFAULT;
 	if (l == TABLE_TYPE_PAGE_TABLE)
-		return _do_shadow_pte(sg, saddr, ptep_h, ptep, entries + LEVEL_MEM, w->p);
-	return _do_shadow_crste(sg, saddr, host, table, entries + LEVEL_MEM, w->p);
+		return _do_shadow_pte(mc, sg, saddr, ptep_h, ptep, entries + LEVEL_MEM, w->p);
+	return _do_shadow_crste(mc, sg, saddr, host, table, entries + LEVEL_MEM, w->p);
 }
 
 static inline int ___gaccess_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *sg, gpa_t saddr,
diff --git a/arch/s390/kvm/gmap.c b/arch/s390/kvm/gmap.c
index 52d55ddea8d4..1d289f8fa3b2 100644
--- a/arch/s390/kvm/gmap.c
+++ b/arch/s390/kvm/gmap.c
@@ -1000,7 +1000,8 @@ int gmap_pv_destroy_range(struct gmap *gmap, gfn_t start, gfn_t end, bool interr
 	return 0;
 }
 
-int gmap_insert_rmap(struct gmap *sg, gfn_t p_gfn, gfn_t r_gfn, int level)
+int gmap_insert_rmap(struct kvm_s390_mmu_cache *mc, struct gmap *sg, gfn_t p_gfn,
+		     gfn_t r_gfn, int level)
 {
 	struct vsie_rmap *rmap __free(kvfree) = NULL;
 	struct vsie_rmap *temp;
@@ -1010,7 +1011,7 @@ int gmap_insert_rmap(struct gmap *sg, gfn_t p_gfn, gfn_t r_gfn, int level)
 	KVM_BUG_ON(!is_shadow(sg), sg->kvm);
 	lockdep_assert_held(&sg->host_to_rmap_lock);
 
-	rmap = kzalloc_obj(*rmap, GFP_ATOMIC);
+	rmap = kvm_s390_mmu_cache_alloc_rmap(mc);
 	if (!rmap)
 		return -ENOMEM;
 
@@ -1057,7 +1058,7 @@ int gmap_protect_rmap(struct kvm_s390_mmu_cache *mc, struct gmap *sg, gfn_t p_gf
 	if (level <= TABLE_TYPE_REGION1) {
 		bitmask = -1UL << (8 + 11 * level);
 		scoped_guard(spinlock, &sg->host_to_rmap_lock)
-			rc = gmap_insert_rmap(sg, p_gfn, r_gfn & bitmask, level);
+			rc = gmap_insert_rmap(mc, sg, p_gfn, r_gfn & bitmask, level);
 	}
 	if (rc)
 		return rc;
diff --git a/arch/s390/kvm/gmap.h b/arch/s390/kvm/gmap.h
index 20881e3ce9d8..1c040472f56d 100644
--- a/arch/s390/kvm/gmap.h
+++ b/arch/s390/kvm/gmap.h
@@ -100,7 +100,8 @@ int gmap_ucas_map(struct gmap *gmap, gfn_t p_gfn, gfn_t c_gfn, unsigned long cou
 void gmap_ucas_unmap(struct gmap *gmap, gfn_t c_gfn, unsigned long count);
 int gmap_enable_skeys(struct gmap *gmap);
 int gmap_pv_destroy_range(struct gmap *gmap, gfn_t start, gfn_t end, bool interruptible);
-int gmap_insert_rmap(struct gmap *sg, gfn_t p_gfn, gfn_t r_gfn, int level);
+int gmap_insert_rmap(struct kvm_s390_mmu_cache *mc, struct gmap *sg, gfn_t p_gfn,
+		     gfn_t r_gfn, int level);
 int gmap_protect_rmap(struct kvm_s390_mmu_cache *mc, struct gmap *sg, gfn_t p_gfn, gfn_t r_gfn,
 		      kvm_pfn_t pfn, int level, bool wr);
 void gmap_set_cmma_all_dirty(struct gmap *gmap);
-- 
2.54.0