From 290c5b54012b7f05e9c51af32d557574bf69a654 Mon Sep 17 00:00:00 2001 From: Ricardo Koller Date: Mon, 17 Oct 2022 19:58:27 +0000 Subject: [PATCH] KVM: selftests: Add vm->memslots[] and enum kvm_mem_region_type The vm_create() helpers are hardcoded to place most page types (code, page-tables, stacks, etc) in the same memslot #0, and always backed with anonymous 4K. There are a couple of issues with that. First, tests willing to differ a bit, like placing page-tables in a different backing source type must replicate much of what's already done by the vm_create() functions. Second, the hardcoded assumption of memslot #0 holding most things is spread everywhere; this makes it very hard to change. Fix the above issues by having selftests specify how they want memory to be laid out. Start by changing ____vm_create() to not create memslot #0; a test (to come) will specify all memslots used by the VM. Then, add the vm->memslots[] array to specify the right memslot for different memory allocators, e.g.,: lib/elf should use the vm->[MEM_REGION_CODE] memslot. This will be used as a way to specify the page-tables memslots (to be backed by huge pages for example). There is no functional change intended. The current commit lays out memory exactly as before. A future commit will change the allocators to get the region they should be using, e.g.,: like the page table allocators using the pt memslot. Cc: Sean Christopherson Cc: Andrew Jones Signed-off-by: Ricardo Koller Reviewed-by: Andrew Jones Reviewed-by: Sean Christopherson Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20221017195834.2295901-8-ricarkol@google.com --- .../testing/selftests/kvm/include/kvm_util_base.h | 26 ++++++++++++++++++++-- tools/testing/selftests/kvm/lib/kvm_util.c | 18 ++++++++------- 2 files changed, 34 insertions(+), 10 deletions(-) diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h index a9264ed..6442aa9 100644 --- a/tools/testing/selftests/kvm/include/kvm_util_base.h +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h @@ -65,6 +65,14 @@ struct userspace_mem_regions { DECLARE_HASHTABLE(slot_hash, 9); }; +enum kvm_mem_region_type { + MEM_REGION_CODE, + MEM_REGION_DATA, + MEM_REGION_PT, + MEM_REGION_TEST_DATA, + NR_MEM_REGIONS, +}; + struct kvm_vm { int mode; unsigned long type; @@ -93,6 +101,13 @@ struct kvm_vm { int stats_fd; struct kvm_stats_header stats_header; struct kvm_stats_desc *stats_desc; + + /* + * KVM region slots. These are the default memslots used by page + * allocators, e.g., lib/elf uses the memslots[MEM_REGION_CODE] + * memslot. + */ + uint32_t memslots[NR_MEM_REGIONS]; }; @@ -105,6 +120,13 @@ struct kvm_vm { struct userspace_mem_region * memslot2region(struct kvm_vm *vm, uint32_t memslot); +static inline struct userspace_mem_region *vm_get_mem_region(struct kvm_vm *vm, + enum kvm_mem_region_type type) +{ + assert(type < NR_MEM_REGIONS); + return memslot2region(vm, vm->memslots[type]); +} + /* Minimum allocated guest virtual and physical addresses */ #define KVM_UTIL_MIN_VADDR 0x2000 #define KVM_GUEST_PAGE_TABLE_MIN_PADDR 0x180000 @@ -647,13 +669,13 @@ vm_paddr_t vm_alloc_page_table(struct kvm_vm *vm); * __vm_create() does NOT create vCPUs, @nr_runnable_vcpus is used purely to * calculate the amount of memory needed for per-vCPU data, e.g. stacks. */ -struct kvm_vm *____vm_create(enum vm_guest_mode mode, uint64_t nr_pages); +struct kvm_vm *____vm_create(enum vm_guest_mode mode); struct kvm_vm *__vm_create(enum vm_guest_mode mode, uint32_t nr_runnable_vcpus, uint64_t nr_extra_pages); static inline struct kvm_vm *vm_create_barebones(void) { - return ____vm_create(VM_MODE_DEFAULT, 0); + return ____vm_create(VM_MODE_DEFAULT); } static inline struct kvm_vm *vm_create(uint32_t nr_runnable_vcpus) diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 6affce4..f3dfa4e 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -185,13 +185,10 @@ const struct vm_guest_mode_params vm_guest_mode_params[] = { _Static_assert(sizeof(vm_guest_mode_params)/sizeof(struct vm_guest_mode_params) == NUM_VM_MODES, "Missing new mode params?"); -struct kvm_vm *____vm_create(enum vm_guest_mode mode, uint64_t nr_pages) +struct kvm_vm *____vm_create(enum vm_guest_mode mode) { struct kvm_vm *vm; - pr_debug("%s: mode='%s' pages='%ld'\n", __func__, - vm_guest_mode_string(mode), nr_pages); - vm = calloc(1, sizeof(*vm)); TEST_ASSERT(vm != NULL, "Insufficient Memory"); @@ -287,9 +284,6 @@ struct kvm_vm *____vm_create(enum vm_guest_mode mode, uint64_t nr_pages) /* Allocate and setup memory for guest. */ vm->vpages_mapped = sparsebit_alloc(); - if (nr_pages != 0) - vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, - 0, 0, nr_pages, 0); return vm; } @@ -335,8 +329,16 @@ struct kvm_vm *__vm_create(enum vm_guest_mode mode, uint32_t nr_runnable_vcpus, uint64_t nr_pages = vm_nr_pages_required(mode, nr_runnable_vcpus, nr_extra_pages); struct kvm_vm *vm; + int i; + + pr_debug("%s: mode='%s' pages='%ld'\n", __func__, + vm_guest_mode_string(mode), nr_pages); + + vm = ____vm_create(mode); - vm = ____vm_create(mode, nr_pages); + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0, 0, nr_pages, 0); + for (i = 0; i < NR_MEM_REGIONS; i++) + vm->memslots[i] = 0; kvm_vm_elf_load(vm, program_invocation_name); -- 2.7.4