Introduce the struct vsie_sca to hold the SSCA and required management data along with alloc and free methods to use with the struct. On this basis we can also add methods {,un}pin_sca() to simplify the pinning SCAs in g1. Signed-off-by: Christoph Schlameuss --- arch/s390/include/asm/kvm_host_types.h | 1 + arch/s390/kvm/vsie.c | 97 +++++++++++++++++++++++++++++++++- 2 files changed, 97 insertions(+), 1 deletion(-) diff --git a/arch/s390/include/asm/kvm_host_types.h b/arch/s390/include/asm/kvm_host_types.h index 6540146b4b00..d6025b34a66d 100644 --- a/arch/s390/include/asm/kvm_host_types.h +++ b/arch/s390/include/asm/kvm_host_types.h @@ -7,6 +7,7 @@ #include #define KVM_S390_MAX_VSIE_VCPUS 256 +#define KVM_S390_MAX_SCA_PAGES 5 #define KVM_S390_BSCA_CPU_SLOTS 64 #define KVM_S390_ESCA_CPU_SLOTS 248 diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index 442e7997ee51..e63231122200 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -65,7 +65,8 @@ struct vsie_page { gpa_t scb_gpa; /* 0x0258 */ /* the shadow gmap in use by the vsie_page */ struct gmap_cache gmap_cache; /* 0x0260 */ - __u8 reserved[0x06f8 - 0x0278]; /* 0x0278 */ + struct vsie_sca *vsie_sca; /* 0x0278 */ + __u8 reserved[0x06f8 - 0x0280]; /* 0x0280 */ struct kvm_s390_crypto_cb crycb; /* 0x06f8 */ __u8 fac[8 + S390_ARCH_FAC_LIST_SIZE_BYTE];/* 0x07f8 */ }; @@ -77,6 +78,32 @@ struct kvm_address_pair { hpa_t hpa; }; +enum vsie_sca_flags { + VSIE_SCA_ESCA = 0, + VSIE_SCA_SCA_PINNED = 1, +}; + +struct vsie_sca { + struct ssca_block ssca; + struct {} start_no_clear_fields; + struct vsie_page *pages[KVM_S390_MAX_VSIE_VCPUS]; + /* The mutex is used to synchronize access to the pages[] */ + struct mutex mutex; + atomic_t ref_count; + struct {} end_no_clear_fields; + gpa_t sca_gpa; + unsigned long flags; + u64 mcn[4]; + unsigned int sca_o_nr_pages; + struct kvm_address_pair sca_o_pages[KVM_S390_MAX_SCA_PAGES]; +}; + +/* + * SSCA needs to be 32-byte aligned and members before the cpu field need to be on the same page. + * Forcing it to offset 0 will always fulfill the requirements. + */ +static_assert(!(offsetof(struct vsie_sca, ssca))); + static inline bool sie_uses_esca(struct kvm_s390_sie_block *scb) { return (scb->ecb2 & ECB2_ESCA); @@ -845,6 +872,74 @@ static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) return 0; } +/* + * Unpin g2 original sca in g1 memory. + * + * Called with vsie_sca_lock held. + */ +static void unpin_sca(struct kvm *kvm, struct vsie_sca *vsie_sca) +{ + if (!test_bit(VSIE_SCA_SCA_PINNED, &vsie_sca->flags)) + return; + + unpin_guest_pages(kvm, vsie_sca->sca_o_pages, vsie_sca->sca_o_nr_pages); + vsie_sca->sca_o_nr_pages = 0; + + __clear_bit(VSIE_SCA_SCA_PINNED, &vsie_sca->flags); +} + +/* + * Pin g2 original sca in g1 memory. + * + * Called with vsie_sca_lock held. + */ +static int pin_sca(struct kvm *kvm, struct vsie_sca *vsie_sca) +{ + bool is_esca = test_bit(VSIE_SCA_ESCA, &vsie_sca->flags); + gpa_t offset = vsie_sca->sca_gpa & ~PAGE_MASK; + int nr_pages; + + if (test_bit(VSIE_SCA_SCA_PINNED, &vsie_sca->flags)) + return 0; + + if (is_esca) { + nr_pages = 4; + if (offset + sizeof(struct esca_block) > 4 * PAGE_SIZE) + nr_pages = 5; + } else { + nr_pages = 1; + if (offset + sizeof(struct bsca_block) > PAGE_SIZE) + nr_pages = 2; + } + + vsie_sca->sca_o_nr_pages = pin_guest_pages(kvm, vsie_sca->sca_gpa, nr_pages, + vsie_sca->sca_o_pages); + if (WARN_ON_ONCE(vsie_sca->sca_o_nr_pages != nr_pages)) + return -EIO; + __set_bit(VSIE_SCA_SCA_PINNED, &vsie_sca->flags); + + return 0; +} + +static void free_vsie_sca(struct kvm *kvm, struct vsie_sca *vsie_sca) +{ + free_pages_exact(vsie_sca, sizeof(*vsie_sca)); +} + +static struct vsie_sca *alloc_vsie_sca(void) +{ + struct vsie_sca *vsie_sca; + + vsie_sca = alloc_pages_exact(sizeof(*vsie_sca), GFP_KERNEL_ACCOUNT | __GFP_ZERO); + if (!vsie_sca) + return NULL; + + mutex_init(&vsie_sca->mutex); + atomic_set(&vsie_sca->ref_count, 0); + + return vsie_sca; +} + void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, gpa_t start, gpa_t end) { struct vsie_page *cur, *next; -- 2.55.0