From: Claudio Imbrenda <imbrenda@linux.ibm.com>
To: Sean Christopherson <seanjc@google.com>
Cc: Marc Zyngier <maz@kernel.org>, Oliver Upton <oupton@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Tianrui Zhao <zhaotianrui@loongson.cn>,
Bibo Mao <maobibo@loongson.cn>,
Huacai Chen <chenhuacai@kernel.org>,
Anup Patel <anup@brainfault.org>, Paul Walmsley <pjw@kernel.org>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Janosch Frank <frankja@linux.ibm.com>,
Fuad Tabba <fuad.tabba@linux.dev>,
Joey Gouly <joey.gouly@arm.com>,
Steffen Eiden <seiden@linux.ibm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
Atish Patra <atish.patra@linux.dev>,
Alexandre Ghiti <alex@ghiti.fr>,
David Hildenbrand <david@kernel.org>,
linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
kvm@vger.kernel.org, loongarch@lists.linux.dev,
kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org,
linux-kernel@vger.kernel.org,
Itaru Kitayama <itaru.kitayama@fujitsu.com>,
Nicholas Piggin <npiggin@gmail.com>,
Ritesh Harjani <ritesh.list@gmail.com>
Subject: Re: [PATCH v2 12/20] KVM: selftests: Add APIs to override memory region types with custom memslots
Date: Thu, 10 Sep 2026 12:27:56 +0200 [thread overview]
Message-ID: <20260910122756.0d5e221c@p-imbrenda> (raw)
In-Reply-To: <20260902164123.2546762-13-seanjc@google.com>
On Wed, 2 Sep 2026 09:41:15 -0700
Sean Christopherson <seanjc@google.com> wrote:
> Add and use APIs to override memory region types instead of open coding the
> logic in tests, partly to dedup test code, but mostly to add some amount of
> protection against conflicting overrides. This will allow converting more
> tests to override memory regions without taking on too much risk of bugs in
> the long term, e.g. due to silently overriding a region multiple times.
>
> Deliberately "unroll" the loops in __vm_create() and the CMMA test's
> create_main_memslot() to avoid filling all memslots in anticipation of
> adding an "extra" memslot that is for test use and *only* test use, i.e.
> shouldn't be configured by core library code.
>
> Converting tests to overriding memory regions will allow taking the region
> type instead of the raw memslot in the physical page allocator APIs.
>
> Tested-by: Itaru Kitayama <itaru.kitayama@fujitsu.com>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
> .../selftests/kvm/arm64/page_fault_test.c | 18 +++++------
> .../testing/selftests/kvm/include/kvm_util.h | 30 +++++++++++++++++++
> tools/testing/selftests/kvm/lib/kvm_util.c | 8 +++--
> tools/testing/selftests/kvm/s390/cmma_test.c | 19 ++++--------
> 4 files changed, 49 insertions(+), 26 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/arm64/page_fault_test.c b/tools/testing/selftests/kvm/arm64/page_fault_test.c
> index 6bb3d82906b2..b0e3fc8cd76a 100644
> --- a/tools/testing/selftests/kvm/arm64/page_fault_test.c
> +++ b/tools/testing/selftests/kvm/arm64/page_fault_test.c
> @@ -597,18 +597,16 @@ static void setup_memslots(struct kvm_vm *vm, struct test_params *p)
>
> vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0,
> CODE_AND_DATA_MEMSLOT, code_npages, 0);
> - vm->memslots[MEM_REGION_CODE] = CODE_AND_DATA_MEMSLOT;
> - vm->memslots[MEM_REGION_DATA] = CODE_AND_DATA_MEMSLOT;
> + ____vm_override_mem_region(vm, MEM_REGION_CODE, CODE_AND_DATA_MEMSLOT);
> + ____vm_override_mem_region(vm, MEM_REGION_DATA, CODE_AND_DATA_MEMSLOT);
>
> - vm_userspace_mem_region_add(vm, p->src_type, data_gpa - pt_size,
> - PAGE_TABLE_MEMSLOT, pt_size / guest_page_size,
> - p->test_desc->pt_memslot_flags);
> - vm->memslots[MEM_REGION_PT] = PAGE_TABLE_MEMSLOT;
> + __vm_override_mem_region(vm, MEM_REGION_PT, p->src_type, data_gpa - pt_size,
> + PAGE_TABLE_MEMSLOT, pt_size / guest_page_size,
> + p->test_desc->pt_memslot_flags);
>
> - vm_userspace_mem_region_add(vm, p->src_type, data_gpa, TEST_DATA_MEMSLOT,
> - data_size / guest_page_size,
> - p->test_desc->data_memslot_flags);
> - vm->memslots[MEM_REGION_TEST_DATA] = TEST_DATA_MEMSLOT;
> + __vm_override_mem_region(vm, MEM_REGION_TEST_DATA, p->src_type, data_gpa,
> + TEST_DATA_MEMSLOT, data_size / guest_page_size,
> + p->test_desc->data_memslot_flags);
> }
>
> static void setup_ucall(struct kvm_vm *vm)
> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
> index 304ef6af3268..c8faa8a02b93 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> @@ -704,6 +704,36 @@ void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backing_src_type src_type,
> gpa_t gpa, u32 slot, u64 npages, u32 flags,
> int guest_memfd_fd, u64 guest_memfd_offset);
>
> +
> +static inline void ____vm_override_mem_region(struct kvm_vm *vm,
> + enum kvm_mem_region_type type,
> + u32 slot)
> +{
> + TEST_ASSERT(vm->memslots[type] == KVM_INVALID_MEMSLOT,
> + "Memory region type '%u' was already overridden with slot=%u",
> + type, vm->memslots[type]);
> +
> + vm->memslots[type] = slot;
> +}
> +
> +static inline void __vm_override_mem_region(struct kvm_vm *vm,
> + enum kvm_mem_region_type type,
> + enum vm_mem_backing_src_type src_type,
> + gpa_t gpa, u32 slot, u64 npages,
> + u32 flags)
> +{
> + ____vm_override_mem_region(vm, type, slot);
> + vm_userspace_mem_region_add(vm, src_type, gpa, slot, npages, flags);
> +}
> +
> +static inline void vm_override_mem_region(struct kvm_vm *vm,
> + enum kvm_mem_region_type type,
> + enum vm_mem_backing_src_type src_type,
> + gpa_t gpa, u32 slot, u64 npages)
> +{
> + __vm_override_mem_region(vm, type, src_type, gpa, slot, npages, 0);
> +}
> +
> #ifndef vm_arch_has_protected_memory
> static inline bool vm_arch_has_protected_memory(struct kvm_vm *vm)
> {
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index 56df5b1d9c79..781af2928d04 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -495,7 +495,7 @@ struct kvm_vm *__vm_create(struct vm_shape shape, u32 nr_runnable_vcpus,
> nr_extra_pages);
> struct userspace_mem_region *slot0;
> struct kvm_vm *vm;
> - int i, flags;
> + int flags;
>
> kvm_set_files_rlimit(nr_runnable_vcpus);
>
> @@ -513,8 +513,10 @@ struct kvm_vm *__vm_create(struct vm_shape shape, u32 nr_runnable_vcpus,
> flags |= KVM_MEM_GUEST_MEMFD;
>
> vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0, 0, nr_pages, flags);
> - for (i = 0; i < NR_MEM_REGIONS; i++)
> - vm->memslots[i] = 0;
> + ____vm_override_mem_region(vm, MEM_REGION_CODE, 0);
> + ____vm_override_mem_region(vm, MEM_REGION_PT, 0);
> + ____vm_override_mem_region(vm, MEM_REGION_DATA, 0);
> + ____vm_override_mem_region(vm, MEM_REGION_TEST_DATA, 0);
>
> kvm_vm_elf_load(vm, program_invocation_name);
>
> diff --git a/tools/testing/selftests/kvm/s390/cmma_test.c b/tools/testing/selftests/kvm/s390/cmma_test.c
> index 15d81b2ed7ad..73387cc3bca7 100644
> --- a/tools/testing/selftests/kvm/s390/cmma_test.c
> +++ b/tools/testing/selftests/kvm/s390/cmma_test.c
> @@ -102,24 +102,17 @@ static void guest_dirty_test_data(void)
>
> static void create_main_memslot(struct kvm_vm *vm)
> {
> - int i;
> -
> vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0, 0, MAIN_PAGE_COUNT, 0);
> - /* set the array of memslots to zero like __vm_create does */
> - for (i = 0; i < NR_MEM_REGIONS; i++)
> - vm->memslots[i] = 0;
> + ____vm_override_mem_region(vm, MEM_REGION_CODE, 0);
> + ____vm_override_mem_region(vm, MEM_REGION_PT, 0);
> + ____vm_override_mem_region(vm, MEM_REGION_DATA, 0);
> }
>
> static void create_test_memslot(struct kvm_vm *vm)
> {
> - vm_userspace_mem_region_add(vm,
> - VM_MEM_SRC_ANONYMOUS,
> - TEST_DATA_START_GFN << vm->page_shift,
> - TEST_DATA_MEMSLOT,
> - TEST_DATA_PAGE_COUNT,
> - 0
> - );
> - vm->memslots[MEM_REGION_TEST_DATA] = TEST_DATA_MEMSLOT;
> + vm_override_mem_region(vm, MEM_REGION_TEST_DATA, VM_MEM_SRC_ANONYMOUS,
> + TEST_DATA_START_GFN << vm->page_shift,
> + TEST_DATA_MEMSLOT, TEST_DATA_PAGE_COUNT);
> }
>
> static void create_memslots(struct kvm_vm *vm)
next prev parent reply other threads:[~2026-09-10 10:29 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-02 16:41 [PATCH v2 00/20] KVM: selftests: PPC pre-enabling Sean Christopherson
2026-09-02 16:41 ` [PATCH v2 01/20] KVM: selftests: Use MEM_REGION_PT memslot instead of '0' for s390 regions/segments Sean Christopherson
2026-09-02 16:50 ` sashiko-bot
2026-09-10 10:24 ` Claudio Imbrenda
2026-09-02 16:41 ` [PATCH v2 02/20] KVM: selftests: Use the common minimum GPA for page tables on LoongArch Sean Christopherson
2026-09-03 1:01 ` Bibo Mao
2026-09-02 16:41 ` [PATCH v2 03/20] KVM: selftests: Use vm_alloc_page_table() to allocate LoongArch page tables Sean Christopherson
2026-09-02 16:41 ` [PATCH v2 04/20] KVM: selftests: Rename "num" param to "nr_pages" for physical page allocators Sean Christopherson
2026-09-02 16:50 ` sashiko-bot
2026-09-04 13:30 ` Ritesh Harjani
2026-09-02 16:41 ` [PATCH v2 05/20] KVM: selftests: Use goto instead of do-while to retry finding unused physical pages Sean Christopherson
2026-09-04 11:40 ` Gautam Menghani
2026-09-02 16:41 ` [PATCH v2 06/20] KVM: selftests: Extend page allocator to support naturally aligned allocations Sean Christopherson
2026-09-02 16:49 ` sashiko-bot
2026-09-10 5:27 ` Ritesh Harjani
2026-09-02 16:41 ` [PATCH v2 07/20] KVM: selftests: Make the single-page allocator APIs static inline Sean Christopherson
2026-09-10 6:36 ` Ritesh Harjani
2026-09-02 16:41 ` [PATCH v2 08/20] KVM: selftests: Use the innermost page allocator API in the memslot perf test Sean Christopherson
2026-09-10 10:55 ` Ritesh Harjani
2026-09-10 11:00 ` Ritesh Harjani
2026-09-02 16:41 ` [PATCH v2 09/20] KVM: selftests: Use the innermost page allocator API in s390's IRQ routing test Sean Christopherson
2026-09-07 11:21 ` Janosch Frank
2026-09-10 10:25 ` Claudio Imbrenda
2026-09-02 16:41 ` [PATCH v2 10/20] KVM: selftests: Add a wrapper API to allocate multiple page table pages Sean Christopherson
2026-09-04 11:41 ` Gautam Menghani
2026-09-07 8:23 ` Anup Patel
2026-09-10 10:23 ` Claudio Imbrenda
2026-09-10 11:04 ` Ritesh Harjani
2026-09-02 16:41 ` [PATCH v2 11/20] KVM: selftests: Initialize vm->memslots[] with invalid memslots during creation Sean Christopherson
2026-09-04 11:42 ` Gautam Menghani
2026-09-10 11:09 ` Ritesh Harjani
2026-09-02 16:41 ` [PATCH v2 12/20] KVM: selftests: Add APIs to override memory region types with custom memslots Sean Christopherson
2026-09-10 10:27 ` Claudio Imbrenda [this message]
2026-09-10 11:18 ` Ritesh Harjani
2026-09-10 16:24 ` Sean Christopherson
2026-09-02 16:41 ` [PATCH v2 13/20] KVM: selftests: Add TEST_EXTRA memory region type for "special" memslots Sean Christopherson
2026-09-02 16:53 ` sashiko-bot
2026-09-02 16:41 ` [PATCH v2 14/20] KVM: selftests: Use TEST_EXTRA region in arm64's vGIC LPI stress test Sean Christopherson
2026-09-02 16:41 ` [PATCH v2 15/20] KVM: selftests: Use TEST_EXTRA region in x86's smaller MAXPHYADDR test Sean Christopherson
2026-09-02 16:41 ` [PATCH v2 16/20] KVM: selftests: Use TEST_EXTRA region in set memory region test Sean Christopherson
2026-09-02 16:41 ` [PATCH v2 17/20] KVM: selftests: Take the memory region type, not memslot, in page allocators Sean Christopherson
2026-09-10 11:40 ` Ritesh Harjani
2026-09-02 16:41 ` [PATCH v2 18/20] KVM: selftests: Use TEST_ASSERT(), not assert(), in vm_get_mem_region() Sean Christopherson
2026-09-10 11:27 ` Ritesh Harjani
2026-09-02 16:41 ` [PATCH v2 19/20] KVM: selftests: Automatically pick min_gpa for allocations based on region type Sean Christopherson
2026-09-02 16:41 ` [PATCH v2 20/20] KVM: selftests: Add arch hook to force page tables to be naturally aligned Sean Christopherson
2026-09-02 16:59 ` sashiko-bot
2026-09-10 11:57 ` Ritesh Harjani
2026-09-02 23:06 ` [PATCH v2 00/20] KVM: selftests: PPC pre-enabling Itaru Kitayama
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