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Wed, 4 Feb 2026 15:03:03 +0000 (GMT) From: Claudio Imbrenda To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, borntraeger@de.ibm.com, frankja@linux.ibm.com, nsg@linux.ibm.com, nrb@linux.ibm.com, seiden@linux.ibm.com, gra@linux.ibm.com, schlameuss@linux.ibm.com, hca@linux.ibm.com, svens@linux.ibm.com, agordeev@linux.ibm.com, gor@linux.ibm.com, david@kernel.org, gerald.schaefer@linux.ibm.com Subject: [PATCH v7 13/29] KVM: s390: KVM page table management functions: allocation Date: Wed, 4 Feb 2026 16:02:42 +0100 Message-ID: <20260204150259.60425-14-imbrenda@linux.ibm.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260204150259.60425-1-imbrenda@linux.ibm.com> References: <20260204150259.60425-1-imbrenda@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMjA0MDExMyBTYWx0ZWRfX2gb73XrOvkCa E6oQTTev2NneT4uw/poewtbnnnMiHy7kpHq1LURMtkW5M1j+USr8WvqbebJKnAW2VQBslyuJduF iexRk/br0x/lp1g4KaOrbRVW8fEeP51sMZQfjOGCzenzNbJSWmLF+5dKQOCbiwOToxVvyBHJOTv fAd8ILYsPzzA97I9BTGK10FAKueuVZAahqnLkPWPE+fZID+C61vmbQfFpFp7X9UANTNFpABy63R uvCR+L2HtrvwXO1yQzgqWLV8LxGUJMR8Do8LYduJorYkt7OBMcCwHLP1jgMvabtg1FhXN+pF2Eo MO8N+PRD2cBNvUbp56DGxAkxNi5t9rAtHYtRLwrakOWwmvuUOJrBMB3ORXdZ75BSl4++rpskGJC 4OMu74XSEcHYXmG3w+toDvhiYEs6kxIQhrPqYUr6ekCmJq6RATekdXGITcn0wEq09YvFWsLnHN4 PTVzLrhR6uDhcASchGw== X-Proofpoint-GUID: _zcMZEaWR1ccVvGANlvtJbHz7sxLxAu2 X-Proofpoint-ORIG-GUID: _zcMZEaWR1ccVvGANlvtJbHz7sxLxAu2 X-Authority-Analysis: v=2.4 cv=LesxKzfi c=1 sm=1 tr=0 ts=69835fad cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=HzLeVaNsDn8A:10 a=VkNPw1HP01LnGYTKEx00:22 a=VnNF1IyMAAAA:8 a=20KFwNOVAAAA:8 a=ciOewYurfqE_QU1RCzEA:9 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-02-04_04,2026-02-04_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 impostorscore=0 spamscore=0 lowpriorityscore=0 clxscore=1015 adultscore=0 suspectscore=0 priorityscore=1501 phishscore=0 malwarescore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2601150000 definitions=main-2602040113 Add page table management functions to be used for KVM guest (gmap) page tables. This patch adds the boilerplate and functions for the allocation and deallocation of DAT tables. Signed-off-by: Claudio Imbrenda --- arch/s390/kvm/Makefile | 1 + arch/s390/kvm/dat.c | 103 +++++++++++++++++++++++++++++++++++++ arch/s390/kvm/dat.h | 77 +++++++++++++++++++++++++++ arch/s390/mm/page-states.c | 1 + 4 files changed, 182 insertions(+) create mode 100644 arch/s390/kvm/dat.c diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile index 9a723c48b05a..84315d2f75fb 100644 --- a/arch/s390/kvm/Makefile +++ b/arch/s390/kvm/Makefile @@ -9,6 +9,7 @@ ccflags-y := -Ivirt/kvm -Iarch/s390/kvm kvm-y += kvm-s390.o intercept.o interrupt.o priv.o sigp.o kvm-y += diag.o gaccess.o guestdbg.o vsie.o pv.o gmap-vsie.o +kvm-y += dat.o kvm-$(CONFIG_VFIO_PCI_ZDEV_KVM) += pci.o obj-$(CONFIG_KVM) += kvm.o diff --git a/arch/s390/kvm/dat.c b/arch/s390/kvm/dat.c new file mode 100644 index 000000000000..c324a27f379f --- /dev/null +++ b/arch/s390/kvm/dat.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KVM guest address space mapping code + * + * Copyright IBM Corp. 2007, 2020, 2024 + * Author(s): Claudio Imbrenda + * Martin Schwidefsky + * David Hildenbrand + * Janosch Frank + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include "dat.h" + +int kvm_s390_mmu_cache_topup(struct kvm_s390_mmu_cache *mc) +{ + void *o; + + for ( ; mc->n_crsts < KVM_S390_MMU_CACHE_N_CRSTS; mc->n_crsts++) { + o = (void *)__get_free_pages(GFP_KERNEL_ACCOUNT | __GFP_COMP, CRST_ALLOC_ORDER); + if (!o) + return -ENOMEM; + mc->crsts[mc->n_crsts] = o; + } + for ( ; mc->n_pts < KVM_S390_MMU_CACHE_N_PTS; mc->n_pts++) { + o = (void *)__get_free_page(GFP_KERNEL_ACCOUNT); + if (!o) + return -ENOMEM; + mc->pts[mc->n_pts] = o; + } + for ( ; mc->n_rmaps < KVM_S390_MMU_CACHE_N_RMAPS; mc->n_rmaps++) { + o = kzalloc(sizeof(*mc->rmaps[0]), GFP_KERNEL_ACCOUNT); + if (!o) + return -ENOMEM; + mc->rmaps[mc->n_rmaps] = o; + } + return 0; +} + +static inline struct page_table *dat_alloc_pt_noinit(struct kvm_s390_mmu_cache *mc) +{ + struct page_table *res; + + res = kvm_s390_mmu_cache_alloc_pt(mc); + if (res) + __arch_set_page_dat(res, 1); + return res; +} + +static inline struct crst_table *dat_alloc_crst_noinit(struct kvm_s390_mmu_cache *mc) +{ + struct crst_table *res; + + res = kvm_s390_mmu_cache_alloc_crst(mc); + if (res) + __arch_set_page_dat(res, 1UL << CRST_ALLOC_ORDER); + return res; +} + +struct crst_table *dat_alloc_crst_sleepable(unsigned long init) +{ + struct page *page; + void *virt; + + page = alloc_pages(GFP_KERNEL_ACCOUNT | __GFP_COMP, CRST_ALLOC_ORDER); + if (!page) + return NULL; + virt = page_to_virt(page); + __arch_set_page_dat(virt, 1UL << CRST_ALLOC_ORDER); + crst_table_init(virt, init); + return virt; +} + +void dat_free_level(struct crst_table *table, bool owns_ptes) +{ + unsigned int i; + + for (i = 0; i < _CRST_ENTRIES; i++) { + if (table->crstes[i].h.fc || table->crstes[i].h.i) + continue; + if (!is_pmd(table->crstes[i])) + dat_free_level(dereference_crste(table->crstes[i]), owns_ptes); + else if (owns_ptes) + dat_free_pt(dereference_pmd(table->crstes[i].pmd)); + } + dat_free_crst(table); +} diff --git a/arch/s390/kvm/dat.h b/arch/s390/kvm/dat.h index d5e1a45813bc..a053f0d49bae 100644 --- a/arch/s390/kvm/dat.h +++ b/arch/s390/kvm/dat.h @@ -418,6 +418,46 @@ struct vsie_rmap { static_assert(sizeof(struct vsie_rmap) == 2 * sizeof(long)); +#define KVM_S390_MMU_CACHE_N_CRSTS 6 +#define KVM_S390_MMU_CACHE_N_PTS 2 +#define KVM_S390_MMU_CACHE_N_RMAPS 16 +struct kvm_s390_mmu_cache { + void *crsts[KVM_S390_MMU_CACHE_N_CRSTS]; + void *pts[KVM_S390_MMU_CACHE_N_PTS]; + void *rmaps[KVM_S390_MMU_CACHE_N_RMAPS]; + short int n_crsts; + short int n_pts; + short int n_rmaps; +}; + +void dat_free_level(struct crst_table *table, bool owns_ptes); +struct crst_table *dat_alloc_crst_sleepable(unsigned long init); + +int kvm_s390_mmu_cache_topup(struct kvm_s390_mmu_cache *mc); + +#define GFP_KVM_S390_MMU_CACHE (GFP_ATOMIC | __GFP_ACCOUNT | __GFP_NOWARN) + +static inline struct page_table *kvm_s390_mmu_cache_alloc_pt(struct kvm_s390_mmu_cache *mc) +{ + if (mc->n_pts) + return mc->pts[--mc->n_pts]; + return (void *)__get_free_page(GFP_KVM_S390_MMU_CACHE); +} + +static inline struct crst_table *kvm_s390_mmu_cache_alloc_crst(struct kvm_s390_mmu_cache *mc) +{ + if (mc->n_crsts) + return mc->crsts[--mc->n_crsts]; + return (void *)__get_free_pages(GFP_KVM_S390_MMU_CACHE | __GFP_COMP, CRST_ALLOC_ORDER); +} + +static inline struct vsie_rmap *kvm_s390_mmu_cache_alloc_rmap(struct kvm_s390_mmu_cache *mc) +{ + if (mc->n_rmaps) + return mc->rmaps[--mc->n_rmaps]; + return kzalloc(sizeof(struct vsie_rmap), GFP_KVM_S390_MMU_CACHE); +} + static inline struct crst_table *crste_table_start(union crste *crstep) { return (struct crst_table *)ALIGN_DOWN((unsigned long)crstep, _CRST_TABLE_SIZE); @@ -717,4 +757,41 @@ static inline void pgste_set_unlock(union pte *ptep, union pgste pgste) WRITE_ONCE(*pgste_of(ptep), pgste); } +static inline void dat_free_pt(struct page_table *pt) +{ + free_page((unsigned long)pt); +} + +static inline void _dat_free_crst(struct crst_table *table) +{ + free_pages((unsigned long)table, CRST_ALLOC_ORDER); +} + +#define dat_free_crst(x) _dat_free_crst(_CRSTP(x)) + +static inline void kvm_s390_free_mmu_cache(struct kvm_s390_mmu_cache *mc) +{ + if (!mc) + return; + while (mc->n_pts) + dat_free_pt(mc->pts[--mc->n_pts]); + while (mc->n_crsts) + _dat_free_crst(mc->crsts[--mc->n_crsts]); + while (mc->n_rmaps) + kfree(mc->rmaps[--mc->n_rmaps]); + kfree(mc); +} + +DEFINE_FREE(kvm_s390_mmu_cache, struct kvm_s390_mmu_cache *, if (_T) kvm_s390_free_mmu_cache(_T)) + +static inline struct kvm_s390_mmu_cache *kvm_s390_new_mmu_cache(void) +{ + struct kvm_s390_mmu_cache *mc __free(kvm_s390_mmu_cache) = NULL; + + mc = kzalloc(sizeof(*mc), GFP_KERNEL_ACCOUNT); + if (mc && !kvm_s390_mmu_cache_topup(mc)) + return_ptr(mc); + return NULL; +} + #endif /* __KVM_S390_DAT_H */ diff --git a/arch/s390/mm/page-states.c b/arch/s390/mm/page-states.c index 01f9b39e65f5..5bee173db72e 100644 --- a/arch/s390/mm/page-states.c +++ b/arch/s390/mm/page-states.c @@ -13,6 +13,7 @@ #include int __bootdata_preserved(cmma_flag); +EXPORT_SYMBOL(cmma_flag); void arch_free_page(struct page *page, int order) { -- 2.52.0