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charset="utf-8" From: Jack Thomson Adding __gmem_abort and __user_mem_abort that preserve -EAGAIN results. These will be used by the pre-fault implementation which needs to retry on -EAGAIN. Also add an optional page_size output parameter to __user_mem_abort to return the VMA page size, which will be needed for pre-faulting. No functional changes are intended Signed-off-by: Jack Thomson --- arch/arm64/kvm/mmu.c | 36 +++++++++++++++++++++++++++++------- 1 file changed, 29 insertions(+), 7 deletions(-) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index a36426ccd9b5..082e7d8ae655 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1521,9 +1521,9 @@ static void adjust_nested_fault_perms(struct kvm_s2_t= rans *nested, =20 #define KVM_PGTABLE_WALK_MEMABORT_FLAGS (KVM_PGTABLE_WALK_HANDLE_FAULT | K= VM_PGTABLE_WALK_SHARED) =20 -static int gmem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, - struct kvm_s2_trans *nested, - struct kvm_memory_slot *memslot, bool is_perm) +static int __gmem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, + struct kvm_s2_trans *nested, + struct kvm_memory_slot *memslot, bool is_perm) { bool write_fault, exec_fault, writable; enum kvm_pgtable_walk_flags flags =3D KVM_PGTABLE_WALK_MEMABORT_FLAGS; @@ -1592,13 +1592,22 @@ static int gmem_abort(struct kvm_vcpu *vcpu, phys_a= ddr_t fault_ipa, if (writable && !ret) mark_page_dirty_in_slot(kvm, memslot, gfn); =20 + return ret; +} + +static int gmem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, + struct kvm_s2_trans *nested, + struct kvm_memory_slot *memslot, bool is_perm) +{ + int ret =3D __gmem_abort(vcpu, fault_ipa, nested, memslot, is_perm); return ret !=3D -EAGAIN ? ret : 0; } =20 -static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, - struct kvm_s2_trans *nested, - struct kvm_memory_slot *memslot, unsigned long hva, - bool fault_is_perm) +static int __user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, + struct kvm_s2_trans *nested, + struct kvm_memory_slot *memslot, + long *page_size, unsigned long hva, + bool fault_is_perm) { int ret =3D 0; bool topup_memcache; @@ -1871,10 +1880,23 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, ph= ys_addr_t fault_ipa, kvm_release_faultin_page(kvm, page, !!ret, writable); kvm_fault_unlock(kvm); =20 + if (page_size) + *page_size =3D vma_pagesize; + /* Mark the page dirty only if the fault is handled successfully */ if (writable && !ret) mark_page_dirty_in_slot(kvm, memslot, gfn); 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charset="utf-8" From: Jack Thomson Don't return -EAGAIN from stage2_map_walker_try_leaf during KVM_PRE_FAULT_MEMORY. During pre-faults, user_abort() is retried upon returning -EAGAIN, meaning the ioctl would get stuck in an infinite loop if userspace tries to pre-fault already existing mappings Signed-off-by: Jack Thomson --- arch/arm64/include/asm/kvm_pgtable.h | 3 +++ arch/arm64/kvm/hyp/pgtable.c | 6 +++++- 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/= kvm_pgtable.h index 2888b5d03757..0789671d1c4f 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -296,6 +296,8 @@ typedef bool (*kvm_pgtable_force_pte_cb_t)(u64 addr, u6= 4 end, * @KVM_PGTABLE_WALK_SKIP_CMO: Visit and update table entries * without Cache maintenance * operations required. + * @KVM_PGTABLE_WALK_PRE_FAULT Indicates the page-table walk was + * invoked from a pre-fault request. */ enum kvm_pgtable_walk_flags { KVM_PGTABLE_WALK_LEAF =3D BIT(0), @@ -305,6 +307,7 @@ enum kvm_pgtable_walk_flags { KVM_PGTABLE_WALK_HANDLE_FAULT =3D BIT(4), KVM_PGTABLE_WALK_SKIP_BBM_TLBI =3D BIT(5), KVM_PGTABLE_WALK_SKIP_CMO =3D BIT(6), + KVM_PGTABLE_WALK_PRE_FAULT =3D BIT(7), }; =20 struct kvm_pgtable_visit_ctx { diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index c351b4abd5db..140dccec2c5b 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -914,9 +914,13 @@ static int stage2_map_walker_try_leaf(const struct kvm= _pgtable_visit_ctx *ctx, * same mapping or only change the access permissions. 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Thu, 11 Sep 2025 06:49:47 -0700 (PDT) Received: from f4d4888f22f2.ant.amazon.com.com ([15.248.2.27]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3e760778915sm2608361f8f.12.2025.09.11.06.49.46 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Thu, 11 Sep 2025 06:49:47 -0700 (PDT) From: Jack Thomson To: maz@kernel.org, oliver.upton@linux.dev, pbonzini@redhat.com Cc: joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, shuah@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, isaku.yamahata@intel.com, roypat@amazon.co.uk, kalyazin@amazon.co.uk, jackabt@amazon.com Subject: [PATCH 3/6] KVM: arm64: Add pre_fault_memory implementation Date: Thu, 11 Sep 2025 14:46:45 +0100 Message-Id: <20250911134648.58945-4-jackabt.amazon@gmail.com> X-Mailer: git-send-email 2.39.5 (Apple Git-154) In-Reply-To: <20250911134648.58945-1-jackabt.amazon@gmail.com> References: <20250911134648.58945-1-jackabt.amazon@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Jack Thomson Add kvm_arch_vcpu_pre_fault_memory() for arm64. The implementation hands off the stage-2 faulting logic to either gmem_abort() or user_mem_abort(). Update __gmem_abort() and __user_mem_abort() to take the pre_fault parameter. When passed, the paths to determine write or exec faults are short circuited to false, as when pre-faulting, it should be treated as a read fault. This closely follows the implementation on x86. Signed-off-by: Jack Thomson --- arch/arm64/kvm/Kconfig | 1 + arch/arm64/kvm/arm.c | 1 + arch/arm64/kvm/mmu.c | 71 ++++++++++++++++++++++++++++++++++++------ 3 files changed, 64 insertions(+), 9 deletions(-) diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index bff62e75d681..1ac0605f86cb 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -25,6 +25,7 @@ menuconfig KVM select HAVE_KVM_CPU_RELAX_INTERCEPT select KVM_MMIO select KVM_GENERIC_DIRTYLOG_READ_PROTECT + select KVM_GENERIC_PRE_FAULT_MEMORY select KVM_XFER_TO_GUEST_WORK select KVM_VFIO select HAVE_KVM_DIRTY_RING_ACQ_REL diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 888f7c7abf54..65654a742864 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -322,6 +322,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long = ext) case KVM_CAP_IRQFD_RESAMPLE: case KVM_CAP_COUNTER_OFFSET: case KVM_CAP_ARM_WRITABLE_IMP_ID_REGS: + case KVM_CAP_PRE_FAULT_MEMORY: r =3D 1; break; case KVM_CAP_SET_GUEST_DEBUG2: diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 082e7d8ae655..002f564c6ac7 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1523,7 +1523,8 @@ static void adjust_nested_fault_perms(struct kvm_s2_t= rans *nested, =20 static int __gmem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, struct kvm_s2_trans *nested, - struct kvm_memory_slot *memslot, bool is_perm) + struct kvm_memory_slot *memslot, bool is_perm, + bool pre_fault) { bool write_fault, exec_fault, writable; enum kvm_pgtable_walk_flags flags =3D KVM_PGTABLE_WALK_MEMABORT_FLAGS; @@ -1537,6 +1538,9 @@ static int __gmem_abort(struct kvm_vcpu *vcpu, phys_a= ddr_t fault_ipa, gfn_t gfn; int ret; =20 + if (pre_fault) + flags |=3D KVM_PGTABLE_WALK_PRE_FAULT; + ret =3D prepare_mmu_memcache(vcpu, true, &memcache); if (ret) return ret; @@ -1546,8 +1550,8 @@ static int __gmem_abort(struct kvm_vcpu *vcpu, phys_a= ddr_t fault_ipa, else gfn =3D fault_ipa >> PAGE_SHIFT; =20 - write_fault =3D kvm_is_write_fault(vcpu); - exec_fault =3D kvm_vcpu_trap_is_exec_fault(vcpu); + write_fault =3D !pre_fault && kvm_is_write_fault(vcpu); + exec_fault =3D !pre_fault && kvm_vcpu_trap_is_exec_fault(vcpu); =20 VM_WARN_ON_ONCE(write_fault && exec_fault); =20 @@ -1599,7 +1603,7 @@ static int gmem_abort(struct kvm_vcpu *vcpu, phys_add= r_t fault_ipa, struct kvm_s2_trans *nested, struct kvm_memory_slot *memslot, bool is_perm) { - int ret =3D __gmem_abort(vcpu, fault_ipa, nested, memslot, is_perm); + int ret =3D __gmem_abort(vcpu, fault_ipa, nested, memslot, is_perm, false= ); return ret !=3D -EAGAIN ? ret : 0; } =20 @@ -1607,7 +1611,7 @@ static int __user_mem_abort(struct kvm_vcpu *vcpu, ph= ys_addr_t fault_ipa, struct kvm_s2_trans *nested, struct kvm_memory_slot *memslot, long *page_size, unsigned long hva, - bool fault_is_perm) + bool fault_is_perm, bool pre_fault) { int ret =3D 0; bool topup_memcache; @@ -1631,10 +1635,13 @@ static int __user_mem_abort(struct kvm_vcpu *vcpu, = phys_addr_t fault_ipa, vm_flags_t vm_flags; enum kvm_pgtable_walk_flags flags =3D KVM_PGTABLE_WALK_MEMABORT_FLAGS; =20 + if (pre_fault) + flags |=3D KVM_PGTABLE_WALK_PRE_FAULT; + if (fault_is_perm) fault_granule =3D kvm_vcpu_trap_get_perm_fault_granule(vcpu); - write_fault =3D kvm_is_write_fault(vcpu); - exec_fault =3D kvm_vcpu_trap_is_exec_fault(vcpu); + write_fault =3D !pre_fault && kvm_is_write_fault(vcpu); + exec_fault =3D !pre_fault && kvm_vcpu_trap_is_exec_fault(vcpu); VM_WARN_ON_ONCE(write_fault && exec_fault); =20 /* @@ -1895,8 +1902,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys= _addr_t fault_ipa, struct kvm_memory_slot *memslot, unsigned long hva, bool fault_is_perm) { - int ret =3D __user_mem_abort(vcpu, fault_ipa, nested, memslot, NULL, - hva, fault_is_perm); + int ret =3D __user_mem_abort(vcpu, fault_ipa, nested, memslot, NULL, hva, + fault_is_perm, false); return ret !=3D -EAGAIN ? ret : 0; } =20 @@ -2468,3 +2475,49 @@ void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool wa= s_enabled) =20 trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled); } + +long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu, + struct kvm_pre_fault_memory *range) +{ + int r; + hva_t hva; + phys_addr_t end; + long page_size; + struct kvm_memory_slot *memslot; + phys_addr_t ipa =3D range->gpa; + gfn_t gfn =3D gpa_to_gfn(range->gpa); + + while (true) { + page_size =3D PAGE_SIZE; + memslot =3D gfn_to_memslot(vcpu->kvm, gfn); + if (!memslot) + return -ENOENT; + + if (kvm_slot_has_gmem(memslot)) { + r =3D __gmem_abort(vcpu, ipa, NULL, memslot, false, true); + } else { + hva =3D gfn_to_hva_memslot_prot(memslot, gfn, NULL); + if (kvm_is_error_hva(hva)) + return -EFAULT; + r =3D __user_mem_abort(vcpu, ipa, NULL, memslot, &page_size, hva, false, + true); + } + + if (r !=3D -EAGAIN) + break; 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charset="utf-8" From: Jack Thomson When creating a VM using mmap with huge pages, and the memory amount does not align with the underlying page size. The stored mmap_size value does not account for the fact that mmap will automatically align the length to a multiple of the underlying page size. During the teardown of the test, munmap is used. However, munmap requires the length to be a multiple of the underlying page size. Update the vm_mem_add method to ensure the mmap_size is aligned to the underlying page size. Signed-off-by: Jack Thomson --- tools/testing/selftests/kvm/lib/kvm_util.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/sel= ftests/kvm/lib/kvm_util.c index c3f5142b0a54..b106fbed999c 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -1051,7 +1051,6 @@ void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backin= g_src_type src_type, /* Allocate and initialize new mem region structure. */ region =3D calloc(1, sizeof(*region)); TEST_ASSERT(region !=3D NULL, "Insufficient Memory"); - region->mmap_size =3D mem_size; =20 #ifdef __s390x__ /* On s390x, the host address must be aligned to 1M (due to PGSTEs) */ @@ -1060,6 +1059,11 @@ void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backi= ng_src_type src_type, alignment =3D 1; #endif =20 + alignment =3D max(backing_src_pagesz, alignment); + region->mmap_size =3D align_up(mem_size, alignment); + + TEST_ASSERT_EQ(guest_paddr, align_up(guest_paddr, backing_src_pagesz)); + /* * When using THP mmap is not guaranteed to returned a hugepage aligned * address so we have to pad the mmap. 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Thu, 11 Sep 2025 06:49:52 -0700 (PDT) Received: from f4d4888f22f2.ant.amazon.com.com ([15.248.2.27]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3e760778915sm2608361f8f.12.2025.09.11.06.49.51 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Thu, 11 Sep 2025 06:49:51 -0700 (PDT) From: Jack Thomson To: maz@kernel.org, oliver.upton@linux.dev, pbonzini@redhat.com Cc: joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, shuah@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, isaku.yamahata@intel.com, roypat@amazon.co.uk, kalyazin@amazon.co.uk, jackabt@amazon.com Subject: [PATCH 5/6] KVM: selftests: Enable pre_fault_memory_test for arm64 Date: Thu, 11 Sep 2025 14:46:47 +0100 Message-Id: <20250911134648.58945-6-jackabt.amazon@gmail.com> X-Mailer: git-send-email 2.39.5 (Apple Git-154) In-Reply-To: <20250911134648.58945-1-jackabt.amazon@gmail.com> References: <20250911134648.58945-1-jackabt.amazon@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Jack Thomson Enable the pre_fault_memory_test to run on arm64 by making it work with different guest page sizes and testing multiple guest configurations. Update the test_assert to compare against the UCALL_EXIT_REASON, for portability, as arm64 exits with KVM_EXIT_MMIO while x86 uses KVM_EXIT_IO. Signed-off-by: Jack Thomson --- tools/testing/selftests/kvm/Makefile.kvm | 1 + .../selftests/kvm/pre_fault_memory_test.c | 79 ++++++++++++++----- 2 files changed, 59 insertions(+), 21 deletions(-) diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selft= ests/kvm/Makefile.kvm index 90f03f00cb04..4db1737fad04 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -180,6 +180,7 @@ TEST_GEN_PROGS_arm64 +=3D memslot_perf_test TEST_GEN_PROGS_arm64 +=3D mmu_stress_test TEST_GEN_PROGS_arm64 +=3D rseq_test TEST_GEN_PROGS_arm64 +=3D steal_time +TEST_GEN_PROGS_arm64 +=3D pre_fault_memory_test =20 TEST_GEN_PROGS_s390 =3D $(TEST_GEN_PROGS_COMMON) TEST_GEN_PROGS_s390 +=3D s390/memop diff --git a/tools/testing/selftests/kvm/pre_fault_memory_test.c b/tools/te= sting/selftests/kvm/pre_fault_memory_test.c index 0350a8896a2f..ed9848a8af60 100644 --- a/tools/testing/selftests/kvm/pre_fault_memory_test.c +++ b/tools/testing/selftests/kvm/pre_fault_memory_test.c @@ -10,19 +10,29 @@ #include #include #include +#include =20 /* Arbitrarily chosen values */ -#define TEST_SIZE (SZ_2M + PAGE_SIZE) -#define TEST_NPAGES (TEST_SIZE / PAGE_SIZE) +#define TEST_BASE_SIZE SZ_2M #define TEST_SLOT 10 =20 +/* Storage of test info to share with guest code */ +struct test_config { + int page_size; + uint64_t test_size; + uint64_t test_num_pages; +}; + +struct test_config test_config; + static void guest_code(uint64_t base_gpa) { volatile uint64_t val __used; + struct test_config *config =3D &test_config; int i; =20 - for (i =3D 0; i < TEST_NPAGES; i++) { - uint64_t *src =3D (uint64_t *)(base_gpa + i * PAGE_SIZE); + for (i =3D 0; i < config->test_num_pages; i++) { + uint64_t *src =3D (uint64_t *)(base_gpa + i * config->page_size); =20 val =3D *src; } @@ -63,11 +73,17 @@ static void pre_fault_memory(struct kvm_vcpu *vcpu, u64= gpa, u64 size, "KVM_PRE_FAULT_MEMORY", ret, vcpu->vm); } =20 -static void __test_pre_fault_memory(unsigned long vm_type, bool private) +struct test_params { + unsigned long vm_type; + bool private; +}; + +static void __test_pre_fault_memory(enum vm_guest_mode guest_mode, void *a= rg) { + struct test_params *p =3D arg; const struct vm_shape shape =3D { - .mode =3D VM_MODE_DEFAULT, - .type =3D vm_type, + .mode =3D guest_mode, + .type =3D p->vm_type, }; struct kvm_vcpu *vcpu; struct kvm_run *run; @@ -78,10 +94,17 @@ static void __test_pre_fault_memory(unsigned long vm_ty= pe, bool private) uint64_t guest_test_virt_mem; uint64_t alignment, guest_page_size; =20 + pr_info("Testing guest mode: %s\n", vm_guest_mode_string(guest_mode)); + vm =3D vm_create_shape_with_one_vcpu(shape, &vcpu, guest_code); =20 - alignment =3D guest_page_size =3D vm_guest_mode_params[VM_MODE_DEFAULT].p= age_size; - guest_test_phys_mem =3D (vm->max_gfn - TEST_NPAGES) * guest_page_size; + guest_page_size =3D vm_guest_mode_params[guest_mode].page_size; + + test_config.page_size =3D guest_page_size; + test_config.test_size =3D TEST_BASE_SIZE + test_config.page_size; + test_config.test_num_pages =3D vm_calc_num_guest_pages(vm->mode, test_con= fig.test_size); + + guest_test_phys_mem =3D (vm->max_gfn - test_config.test_num_pages) * test= _config.page_size; #ifdef __s390x__ alignment =3D max(0x100000UL, guest_page_size); #else @@ -91,22 +114,31 @@ static void __test_pre_fault_memory(unsigned long vm_t= ype, bool private) guest_test_virt_mem =3D guest_test_phys_mem & ((1ULL << (vm->va_bits - 1)= ) - 1); =20 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, - guest_test_phys_mem, TEST_SLOT, TEST_NPAGES, - private ? KVM_MEM_GUEST_MEMFD : 0); - virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, TEST_NPAGES); - - if (private) - vm_mem_set_private(vm, guest_test_phys_mem, TEST_SIZE); - pre_fault_memory(vcpu, guest_test_phys_mem, SZ_2M, 0); - pre_fault_memory(vcpu, guest_test_phys_mem + SZ_2M, PAGE_SIZE * 2, PAGE_S= IZE); - pre_fault_memory(vcpu, guest_test_phys_mem + TEST_SIZE, PAGE_SIZE, PAGE_S= IZE); + guest_test_phys_mem, TEST_SLOT, test_config.test_num_pages, + p->private ? KVM_MEM_GUEST_MEMFD : 0); + virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, test_config.test_n= um_pages); + + if (p->private) + vm_mem_set_private(vm, guest_test_phys_mem, test_config.test_size); + pre_fault_memory(vcpu, guest_test_phys_mem, TEST_BASE_SIZE, 0); + /* Test pre-faulting over an already faulted range */ + pre_fault_memory(vcpu, guest_test_phys_mem, TEST_BASE_SIZE, 0); + pre_fault_memory(vcpu, guest_test_phys_mem + TEST_BASE_SIZE, + test_config.page_size * 2, test_config.page_size); + pre_fault_memory(vcpu, guest_test_phys_mem + test_config.test_size, + test_config.page_size, test_config.page_size); =20 vcpu_args_set(vcpu, 1, guest_test_virt_mem); + + /* Export the shared variables to the guest. */ + sync_global_to_guest(vm, test_config); + vcpu_run(vcpu); =20 run =3D vcpu->run; - TEST_ASSERT(run->exit_reason =3D=3D KVM_EXIT_IO, - "Wanted KVM_EXIT_IO, got exit reason: %u (%s)", + TEST_ASSERT(run->exit_reason =3D=3D UCALL_EXIT_REASON, + "Wanted %s, got exit reason: %u (%s)", + exit_reason_str(UCALL_EXIT_REASON), run->exit_reason, exit_reason_str(run->exit_reason)); 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Thu, 11 Sep 2025 06:49:54 -0700 (PDT) Received: from f4d4888f22f2.ant.amazon.com.com ([15.248.2.27]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3e760778915sm2608361f8f.12.2025.09.11.06.49.53 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Thu, 11 Sep 2025 06:49:54 -0700 (PDT) From: Jack Thomson To: maz@kernel.org, oliver.upton@linux.dev, pbonzini@redhat.com Cc: joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, shuah@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, isaku.yamahata@intel.com, roypat@amazon.co.uk, kalyazin@amazon.co.uk, jackabt@amazon.com Subject: [PATCH 6/6] KVM: selftests: Add option for different backing in pre-fault tests Date: Thu, 11 Sep 2025 14:46:48 +0100 Message-Id: <20250911134648.58945-7-jackabt.amazon@gmail.com> X-Mailer: git-send-email 2.39.5 (Apple Git-154) In-Reply-To: <20250911134648.58945-1-jackabt.amazon@gmail.com> References: <20250911134648.58945-1-jackabt.amazon@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Jack Thomson Add a -m option to specify different memory backing types for the pre-fault tests (e.g., anonymous, hugetlb), allowing testing of the pre-fault functionality across different memory configurations. Signed-off-by: Jack Thomson --- .../selftests/kvm/pre_fault_memory_test.c | 31 ++++++++++++++++--- 1 file changed, 26 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/kvm/pre_fault_memory_test.c b/tools/te= sting/selftests/kvm/pre_fault_memory_test.c index ed9848a8af60..22e2e53945d9 100644 --- a/tools/testing/selftests/kvm/pre_fault_memory_test.c +++ b/tools/testing/selftests/kvm/pre_fault_memory_test.c @@ -76,6 +76,7 @@ static void pre_fault_memory(struct kvm_vcpu *vcpu, u64 g= pa, u64 size, struct test_params { unsigned long vm_type; bool private; + enum vm_mem_backing_src_type mem_backing_src; }; =20 static void __test_pre_fault_memory(enum vm_guest_mode guest_mode, void *a= rg) @@ -94,7 +95,11 @@ static void __test_pre_fault_memory(enum vm_guest_mode g= uest_mode, void *arg) uint64_t guest_test_virt_mem; uint64_t alignment, guest_page_size; =20 + size_t backing_src_pagesz =3D get_backing_src_pagesz(p->mem_backing_src); + pr_info("Testing guest mode: %s\n", vm_guest_mode_string(guest_mode)); + pr_info("Testing memory backing src type: %s\n", + vm_mem_backing_src_alias(p->mem_backing_src)->name); =20 vm =3D vm_create_shape_with_one_vcpu(shape, &vcpu, guest_code); =20 @@ -110,10 +115,11 @@ static void __test_pre_fault_memory(enum vm_guest_mod= e guest_mode, void *arg) #else alignment =3D SZ_2M; #endif + alignment =3D max(alignment, backing_src_pagesz); guest_test_phys_mem =3D align_down(guest_test_phys_mem, alignment); guest_test_virt_mem =3D guest_test_phys_mem & ((1ULL << (vm->va_bits - 1)= ) - 1); =20 - vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, + vm_userspace_mem_region_add(vm, p->mem_backing_src, guest_test_phys_mem, TEST_SLOT, test_config.test_num_pages, p->private ? KVM_MEM_GUEST_MEMFD : 0); virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, test_config.test_n= um_pages); @@ -155,7 +161,8 @@ static void __test_pre_fault_memory(enum vm_guest_mode = guest_mode, void *arg) kvm_vm_free(vm); } =20 -static void test_pre_fault_memory(unsigned long vm_type, bool private) +static void test_pre_fault_memory(unsigned long vm_type, enum vm_mem_backi= ng_src_type backing_src, + bool private) { if (vm_type && !(kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(vm_type))) { pr_info("Skipping tests for vm_type 0x%lx\n", vm_type); @@ -165,6 +172,7 @@ static void test_pre_fault_memory(unsigned long vm_type= , bool private) struct test_params p =3D { .vm_type =3D vm_type, .private =3D private, + .mem_backing_src =3D backing_src, }; =20 for_each_guest_mode(__test_pre_fault_memory, &p); @@ -174,10 +182,23 @@ int main(int argc, char *argv[]) { TEST_REQUIRE(kvm_check_cap(KVM_CAP_PRE_FAULT_MEMORY)); =20 - test_pre_fault_memory(0, false); + int opt; + enum vm_mem_backing_src_type backing =3D VM_MEM_SRC_ANONYMOUS; + + while ((opt =3D getopt(argc, argv, "m:")) !=3D -1) { + switch (opt) { + case 'm': + backing =3D parse_backing_src_type(optarg); + break; + default: + break; + } + } + + test_pre_fault_memory(0, backing, false); #ifdef __x86_64__ - test_pre_fault_memory(KVM_X86_SW_PROTECTED_VM, false); - test_pre_fault_memory(KVM_X86_SW_PROTECTED_VM, true); + test_pre_fault_memory(KVM_X86_SW_PROTECTED_VM, backing, false); + test_pre_fault_memory(KVM_X86_SW_PROTECTED_VM, backing, true); #endif return 0; } --=20 2.43.0