Split prefix page tracking into prefix.c/h with conditional compilation via prefix-stubs.c for KVM for non-s390 guests. Enables gmap reuse by other KVM implementations that don't use prefix pages. The prefix tracking is conditional on the Makefile variable KVM_MANAGES_S390_GUEST. No functional changes. Signed-off-by: Steffen Eiden --- arch/s390/kvm/gmap/Makefile | 4 +- arch/s390/kvm/gmap/dat.c | 48 ------------------- arch/s390/kvm/gmap/gmap.c | 23 --------- arch/s390/kvm/gmap/gmap.h | 11 +---- arch/s390/kvm/gmap/prefix-stubs.c | 21 ++++++++ arch/s390/kvm/gmap/prefix.c | 80 +++++++++++++++++++++++++++++++ arch/s390/kvm/gmap/prefix.h | 68 ++++++++++++++++++++++++++ 7 files changed, 173 insertions(+), 82 deletions(-) create mode 100644 arch/s390/kvm/gmap/prefix-stubs.c create mode 100644 arch/s390/kvm/gmap/prefix.c create mode 100644 arch/s390/kvm/gmap/prefix.h diff --git a/arch/s390/kvm/gmap/Makefile b/arch/s390/kvm/gmap/Makefile index a49c7e36b71c..4ca7635d1d0e 100644 --- a/arch/s390/kvm/gmap/Makefile +++ b/arch/s390/kvm/gmap/Makefile @@ -4,7 +4,9 @@ GMAP ?= ../gmap # Enable s390-specific guest management features (storage keys and CMMA) KVM_MANAGES_S390_GUEST ?= y +USE_PREFIX_STUB := $(if $(filter y,$(KVM_MANAGES_S390_GUEST)),n,y) kvm-y += $(GMAP)/dat.o $(GMAP)/gmap.o $(GMAP)/faultin.o $(GMAP)/mmu.o -kvm-$(KVM_MANAGES_S390_GUEST) += $(GMAP)/sk.o $(GMAP)/cmma.o +kvm-$(KVM_MANAGES_S390_GUEST) += $(GMAP)/sk.o $(GMAP)/cmma.o $(GMAP)/prefix.o +kvm-$(USE_PREFIX_STUB) += $(GMAP)/prefix-stubs.o diff --git a/arch/s390/kvm/gmap/dat.c b/arch/s390/kvm/gmap/dat.c index 6114ff442837..4a9847139534 100644 --- a/arch/s390/kvm/gmap/dat.c +++ b/arch/s390/kvm/gmap/dat.c @@ -777,51 +777,3 @@ bool dat_test_age_gfn(union asce asce, gfn_t start, gfn_t end) { return _dat_walk_gfn_range(start, end, asce, &test_age_ops, 0, NULL) > 0; } - -static long dat_set_pn_crste(union crste *crstep, gfn_t gfn, gfn_t next, struct dat_walk *walk) -{ - union crste newcrste, oldcrste; - int *n = walk->priv; - - do { - oldcrste = READ_ONCE(*crstep); - if (!oldcrste.h.fc || oldcrste.h.i || oldcrste.h.p) - return 0; - if (oldcrste.s.fc1.prefix_notif) - break; - newcrste = oldcrste; - newcrste.s.fc1.prefix_notif = 1; - } while (!dat_crstep_xchg_atomic(crstep, oldcrste, newcrste, gfn, walk->asce)); - *n = 2; - return 0; -} - -static long dat_set_pn_pte(union pte *ptep, gfn_t gfn, gfn_t next, struct dat_walk *walk) -{ - int *n = walk->priv; - union pgste pgste; - - pgste = pgste_get_lock(ptep); - if (!ptep->h.i && !ptep->h.p) { - pgste.prefix_notif = 1; - *n += 1; - } - pgste_set_unlock(ptep, pgste); - return 0; -} - -int dat_set_prefix_notif_bit(union asce asce, gfn_t gfn) -{ - static const struct dat_walk_ops ops = { - .pte_entry = dat_set_pn_pte, - .pmd_entry = dat_set_pn_crste, - .pud_entry = dat_set_pn_crste, - }; - - int n = 0; - - _dat_walk_gfn_range(gfn, gfn + 2, asce, &ops, DAT_WALK_IGN_HOLES, &n); - if (n != 2) - return -EAGAIN; - return 0; -} diff --git a/arch/s390/kvm/gmap/gmap.c b/arch/s390/kvm/gmap/gmap.c index 4ade7794e990..3dcd1d4c6a29 100644 --- a/arch/s390/kvm/gmap/gmap.c +++ b/arch/s390/kvm/gmap/gmap.c @@ -254,29 +254,6 @@ int s390_replace_asce(struct gmap *gmap) return 0; } -bool _gmap_unmap_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end, bool hint) -{ - struct kvm *kvm = gmap->kvm; - struct kvm_vcpu *vcpu; - gfn_t prefix_gfn; - unsigned long i; - - if (is_shadow(gmap)) - return false; - kvm_for_each_vcpu(i, vcpu, kvm) { - /* Match against both prefix pages */ - prefix_gfn = gpa_to_gfn(kvm_s390_get_prefix(vcpu)); - if (prefix_gfn < end && gfn <= prefix_gfn + 1) { - if (hint && kvm_s390_is_in_sie(vcpu)) - return false; - VCPU_EVENT(vcpu, 2, "gmap notifier for %llx-%llx", - gfn_to_gpa(gfn), gfn_to_gpa(end)); - kvm_s390_sync_request(KVM_REQ_REFRESH_GUEST_PREFIX, vcpu); - } - } - return true; -} - struct clear_young_pte_priv { struct gmap *gmap; bool young; diff --git a/arch/s390/kvm/gmap/gmap.h b/arch/s390/kvm/gmap/gmap.h index aa65fe724fdb..0500c8c6c9ca 100644 --- a/arch/s390/kvm/gmap/gmap.h +++ b/arch/s390/kvm/gmap/gmap.h @@ -13,6 +13,7 @@ #include #include "dat.h" +#include "prefix.h" /** * enum gmap_flags - Flags of a gmap. @@ -158,16 +159,6 @@ static inline void gmap_handle_vsie_unshadow_event(struct gmap *parent, gfn_t gf _gmap_handle_vsie_unshadow_event(parent, gfn); } -static inline bool gmap_mkold_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end) -{ - return _gmap_unmap_prefix(gmap, gfn, end, true); -} - -static inline bool gmap_unmap_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end) -{ - return _gmap_unmap_prefix(gmap, gfn, end, false); -} - /** * pte_needs_unshadow() -- Check if the pte operations triggers unshadowing. * @oldpte: the previous value for the guest pte. diff --git a/arch/s390/kvm/gmap/prefix-stubs.c b/arch/s390/kvm/gmap/prefix-stubs.c new file mode 100644 index 000000000000..d1d6286f454a --- /dev/null +++ b/arch/s390/kvm/gmap/prefix-stubs.c @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * These stubs are used when building gmap for non-s390 guests + * that don't need prefix page tracking. + */ + +#include +#include + +#include "dat.h" +#include "prefix.h" + +bool _gmap_unmap_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end, bool hint) +{ + return true; +} + +int dat_set_prefix_notif_bit(union asce asce, gfn_t gfn) +{ + return 0; +} diff --git a/arch/s390/kvm/gmap/prefix.c b/arch/s390/kvm/gmap/prefix.c new file mode 100644 index 000000000000..44caffed2da1 --- /dev/null +++ b/arch/s390/kvm/gmap/prefix.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +#include "gmap.h" +#include "dat.h" +#include "prefix.h" +#include "../s390/s390.h" + +bool _gmap_unmap_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end, bool hint) +{ + struct kvm *kvm = gmap->kvm; + struct kvm_vcpu *vcpu; + gfn_t prefix_gfn; + unsigned long i; + + if (is_shadow(gmap)) + return false; + kvm_for_each_vcpu(i, vcpu, kvm) { + /* Match against both prefix pages */ + prefix_gfn = gpa_to_gfn(kvm_s390_get_prefix(vcpu)); + if (prefix_gfn < end && gfn <= prefix_gfn + 1) { + if (hint && kvm_s390_is_in_sie(vcpu)) + return false; + VCPU_EVENT(vcpu, 2, "gmap notifier for %llx-%llx", + gfn_to_gpa(gfn), gfn_to_gpa(end)); + kvm_s390_sync_request(KVM_REQ_REFRESH_GUEST_PREFIX, vcpu); + } + } + return true; +} + +static long dat_set_pn_crste(union crste *crstep, gfn_t gfn, gfn_t next, struct dat_walk *walk) +{ + union crste newcrste, oldcrste; + int *n = walk->priv; + + do { + oldcrste = READ_ONCE(*crstep); + if (!oldcrste.h.fc || oldcrste.h.i || oldcrste.h.p) + return 0; + if (oldcrste.s.fc1.prefix_notif) + break; + newcrste = oldcrste; + newcrste.s.fc1.prefix_notif = 1; + } while (!dat_crstep_xchg_atomic(crstep, oldcrste, newcrste, gfn, walk->asce)); + *n = 2; + return 0; +} + +static long dat_set_pn_pte(union pte *ptep, gfn_t gfn, gfn_t next, struct dat_walk *walk) +{ + int *n = walk->priv; + union pgste pgste; + + pgste = pgste_get_lock(ptep); + if (!ptep->h.i && !ptep->h.p) { + pgste.prefix_notif = 1; + *n += 1; + } + pgste_set_unlock(ptep, pgste); + return 0; +} + +int dat_set_prefix_notif_bit(union asce asce, gfn_t gfn) +{ + static const struct dat_walk_ops ops = { + .pte_entry = dat_set_pn_pte, + .pmd_entry = dat_set_pn_crste, + .pud_entry = dat_set_pn_crste, + }; + + int n = 0; + + _dat_walk_gfn_range(gfn, gfn + 2, asce, &ops, DAT_WALK_IGN_HOLES, &n); + if (n != 2) + return -EAGAIN; + return 0; +} diff --git a/arch/s390/kvm/gmap/prefix.h b/arch/s390/kvm/gmap/prefix.h new file mode 100644 index 000000000000..f1f3ace24f03 --- /dev/null +++ b/arch/s390/kvm/gmap/prefix.h @@ -0,0 +1,68 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef ARCH_KVM_GMAP_PREFIX_H +#define ARCH_KVM_GMAP_PREFIX_H + +#include +#include + +struct gmap; +union asce; + +/** + * _gmap_unmap_prefix() - Notify vCPUs if prefix pages are affected + * @gmap: The gmap + * @gfn: Start of the range + * @end: End of the range (exclusive) + * @hint: If true, skip notification if vCPU is in SIE + * + * Check if any vCPU's prefix pages fall within the given range and + * request prefix refresh if needed. + * + * Return: false if notification was skipped due to hint, true otherwise + */ +bool _gmap_unmap_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end, bool hint); + +/** + * dat_set_prefix_notif_bit() - Set prefix notification bits + * @asce: The address space control element + * @gfn: Guest frame number of the prefix area + * + * Set the prefix notification bit in the page table entries for the + * two prefix pages starting at @gfn. + * + * Return: 0 on success, -EAGAIN if not all bits could be set + */ +int dat_set_prefix_notif_bit(union asce asce, gfn_t gfn); + +/** + * gmap_mkold_prefix() - Mark prefix pages as old + * @gmap: The gmap + * @gfn: Start of the range + * @end: End of the range (exclusive) + * + * Inline wrapper that calls _gmap_unmap_prefix with hint=true. + * + * Return: Result from _gmap_unmap_prefix + */ +static inline bool gmap_mkold_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end) +{ + return _gmap_unmap_prefix(gmap, gfn, end, true); +} + +/** + * gmap_unmap_prefix() - Unconditionally notify about prefix pages + * @gmap: The gmap + * @gfn: Start of the range + * @end: End of the range (exclusive) + * + * Inline wrapper that calls _gmap_unmap_prefix with hint=false. + * + * Return: Result from _gmap_unmap_prefix + */ +static inline bool gmap_unmap_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end) +{ + return _gmap_unmap_prefix(gmap, gfn, end, false); +} + +#endif /* ARCH_KVM_GMAP_PREFIX_H */ -- 2.53.0