Messages in this thread Patch in this message | | | Subject | Re: [PATCH 4/6] KVM: selftests: memslot_perf_test: Support variable guest page size | From | Gavin Shan <> | Date | Tue, 18 Oct 2022 08:51:50 +0800 |
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On 10/18/22 8:46 AM, Gavin Shan wrote: > On 10/18/22 5:31 AM, Maciej S. Szmigiero wrote: >> On 14.10.2022 09:19, Gavin Shan wrote: >>> The test case is obviously broken on aarch64 because non-4KB guest >>> page size is supported. The guest page size on aarch64 could be 4KB, >>> 16KB or 64KB. >>> >>> This supports variable guest page size, mostly for aarch64. >>> >>> - The host determines the guest page size when virtual machine is >>> created. The value is also passed to guest through the synchronization >>> area. >>> >>> - The number of guest pages are unknown until the virtual machine >>> is to be created. So all the related macros are dropped. Instead, >>> their values are dynamically calculated based on the guest page >>> size. >>> >>> - The static checks on memory sizes and pages becomes dependent >>> on guest page size, which is unknown until the virtual machine >>> is about to be created. So all the static checks are converted >>> to dynamic checks, done in check_memory_sizes(). >>> >>> - As the address passed to madvise() should be aligned to host page, >>> the size of page chunk is automatically selected, other than one >>> page. >>> >>> - All other changes included in this patch are almost mechanical >>> replacing '4096' with 'guest_page_size'. >>> >>> Signed-off-by: Gavin Shan <gshan@redhat.com> >>> --- >>> .../testing/selftests/kvm/memslot_perf_test.c | 191 +++++++++++------- >>> 1 file changed, 115 insertions(+), 76 deletions(-) >>> >>> diff --git a/tools/testing/selftests/kvm/memslot_perf_test.c b/tools/testing/selftests/kvm/memslot_perf_test.c >>> index d5aa9148f96f..d587bd952ff9 100644 >>> --- a/tools/testing/selftests/kvm/memslot_perf_test.c >>> +++ b/tools/testing/selftests/kvm/memslot_perf_test.c >>> @@ -26,14 +26,11 @@ >>> #include <processor.h> >>> #define MEM_SIZE ((512U << 20) + 4096) >>> -#define MEM_SIZE_PAGES (MEM_SIZE / 4096) >>> #define MEM_GPA 0x10000000UL >>> #define MEM_AUX_GPA MEM_GPA >>> #define MEM_SYNC_GPA MEM_AUX_GPA >>> #define MEM_TEST_GPA (MEM_AUX_GPA + 4096) >>> #define MEM_TEST_SIZE (MEM_SIZE - 4096) >>> -static_assert(MEM_SIZE % 4096 == 0, "invalid mem size"); >>> -static_assert(MEM_TEST_SIZE % 4096 == 0, "invalid mem test size"); >>> /* >>> * 32 MiB is max size that gets well over 100 iterations on 509 slots. >>> @@ -42,29 +39,16 @@ static_assert(MEM_TEST_SIZE % 4096 == 0, "invalid mem test size"); >>> * limited resolution). >>> */ >>> #define MEM_SIZE_MAP ((32U << 20) + 4096) >>> -#define MEM_SIZE_MAP_PAGES (MEM_SIZE_MAP / 4096) >>> #define MEM_TEST_MAP_SIZE (MEM_SIZE_MAP - 4096) >>> -#define MEM_TEST_MAP_SIZE_PAGES (MEM_TEST_MAP_SIZE / 4096) >>> -static_assert(MEM_SIZE_MAP % 4096 == 0, "invalid map test region size"); >>> -static_assert(MEM_TEST_MAP_SIZE % 4096 == 0, "invalid map test region size"); >>> -static_assert(MEM_TEST_MAP_SIZE_PAGES % 2 == 0, "invalid map test region size"); >>> -static_assert(MEM_TEST_MAP_SIZE_PAGES > 2, "invalid map test region size"); >>> /* >>> * 128 MiB is min size that fills 32k slots with at least one page in each >>> * while at the same time gets 100+ iterations in such test >>> + * >>> + * 2 MiB chunk size like a typical huge page >>> */ >>> #define MEM_TEST_UNMAP_SIZE (128U << 20) >>> -#define MEM_TEST_UNMAP_SIZE_PAGES (MEM_TEST_UNMAP_SIZE / 4096) >>> -/* 2 MiB chunk size like a typical huge page */ >>> -#define MEM_TEST_UNMAP_CHUNK_PAGES (2U << (20 - 12)) >>> -static_assert(MEM_TEST_UNMAP_SIZE <= MEM_TEST_SIZE, >>> - "invalid unmap test region size"); >>> -static_assert(MEM_TEST_UNMAP_SIZE % 4096 == 0, >>> - "invalid unmap test region size"); >>> -static_assert(MEM_TEST_UNMAP_SIZE_PAGES % >>> - (2 * MEM_TEST_UNMAP_CHUNK_PAGES) == 0, >>> - "invalid unmap test region size"); >>> +#define MEM_TEST_UNMAP_CHUNK_SIZE (2U << 20) >>> /* >>> * For the move active test the middle of the test area is placed on >>> @@ -77,8 +61,7 @@ static_assert(MEM_TEST_UNMAP_SIZE_PAGES % >>> * for the total size of 25 pages. >>> * Hence, the maximum size here is 50 pages. >>> */ >>> -#define MEM_TEST_MOVE_SIZE_PAGES (50) >>> -#define MEM_TEST_MOVE_SIZE (MEM_TEST_MOVE_SIZE_PAGES * 4096) >>> +#define MEM_TEST_MOVE_SIZE 0x32000 >> >> The above number seems less readable than an explicit value of 50 pages. >> >> In addition to that, it's 50 pages only with 4k page size, so at least >> the comment above needs to be updated to reflect this fact. >> > > Yeah, I will change the comments like below in next revision. > > /* > * When running this test with 32k memslots, actually 32763 excluding > * the reserved memory slot 0, the memory for each slot is 0x4000 bytes. > * The last slot contains 0x19000 bytes memory. Hence, the maximum size > * here is 0x32000 bytes. > */ >
I will replace those numbers with readable ones like below :)
/* * When running this test with 32k memslots, actually 32763 excluding * the reserved memory slot 0, the memory for each slot is 16KB. The * last slot contains 100KB memory with the remaining 84KB. Hence, * the maximum size is double of that (200KB) */
>>> #define MEM_TEST_MOVE_GPA_DEST (MEM_GPA + MEM_SIZE) >>> static_assert(MEM_TEST_MOVE_SIZE <= MEM_TEST_SIZE, >>> "invalid move test region size"); >> (...) >>> @@ -242,33 +229,34 @@ static struct vm_data *alloc_vm(void) >>> } >>> static bool prepare_vm(struct vm_data *data, int nslots, uint64_t *maxslots, >>> - void *guest_code, uint64_t mempages, >>> + void *guest_code, uint64_t mem_size, >>> struct timespec *slot_runtime) >>> { >>> - uint64_t rempages; >>> + uint64_t mempages, rempages; >>> uint64_t guest_addr; >>> - uint32_t slot; >>> + uint32_t slot, guest_page_size; >>> struct timespec tstart; >>> struct sync_area *sync; >>> - TEST_ASSERT(mempages > 1, >>> - "Can't test without any memory"); >>> + guest_page_size = vm_guest_mode_params[VM_MODE_DEFAULT].page_size; >>> + mempages = mem_size / guest_page_size; >>> + >>> + data->vm = __vm_create_with_one_vcpu(&data->vcpu, mempages, guest_code); >>> + ucall_init(data->vm, NULL); >>> >> >> TEST_ASSERT(data->vm->page_size == guest_page_size, "Invalid VM page size") >> here would catch the case if someone accidentally modifies >> __vm_create_with_one_vcpu() to use other page size than specified for >> VM_MODE_DEFAULT. >> > > Sure, it's not harmful at least. > >>> data->npages = mempages; >>> + TEST_ASSERT(data->npages > 1, "Can't test without any memory"); >>> data->nslots = nslots; >>> - data->pages_per_slot = mempages / data->nslots; >>> + data->pages_per_slot = data->npages / data->nslots; >>> if (!data->pages_per_slot) { >>> - *maxslots = mempages + 1; >>> + *maxslots = data->npages + 1; >>> return false; >>> } >>> - rempages = mempages % data->nslots; >>> + rempages = data->npages % data->nslots; >>> data->hva_slots = malloc(sizeof(*data->hva_slots) * data->nslots); >>> TEST_ASSERT(data->hva_slots, "malloc() fail"); >>> - data->vm = __vm_create_with_one_vcpu(&data->vcpu, mempages, guest_code); >>> - ucall_init(data->vm, NULL); >>> - >>> pr_info_v("Adding slots 1..%i, each slot with %"PRIu64" pages + %"PRIu64" extra pages last\n", >>> data->nslots, data->pages_per_slot, rempages); >> (...) >>> @@ -856,6 +863,35 @@ static void help(char *name, struct test_args *targs) >>> pr_info("%d: %s\n", ctr, tests[ctr].name); >>> } >>> +static bool check_memory_sizes(void) >>> +{ >>> + uint32_t guest_page_size = vm_guest_mode_params[VM_MODE_DEFAULT].page_size; >>> + >>> + if (MEM_SIZE % guest_page_size || >>> + MEM_TEST_SIZE % guest_page_size) { >>> + pr_info("invalid MEM_SIZE or MEM_TEST_SIZE\n"); >>> + return false; >>> + } >>> + >>> + if (MEM_SIZE_MAP % guest_page_size || >>> + MEM_TEST_MAP_SIZE % guest_page_size || >>> + (MEM_TEST_MAP_SIZE / guest_page_size) <= 2 || >>> + (MEM_TEST_MAP_SIZE / guest_page_size) % 2) { >>> + pr_info("invalid MEM_SIZE_MAP or MEM_TEST_MAP_SIZE\n"); >>> + return false; >>> + } >>> + >>> + if (MEM_TEST_UNMAP_SIZE > MEM_TEST_SIZE || >>> + MEM_TEST_UNMAP_SIZE % guest_page_size || >>> + (MEM_TEST_UNMAP_SIZE / guest_page_size) % >>> + (MEM_TEST_UNMAP_CHUNK_SIZE / guest_page_size)) { >> >> This should be (MEM_TEST_UNMAP_SIZE / guest_page_size) % (2 * MEM_TEST_UNMAP_CHUNK_SIZE / guest_page_size)) >> to match the old static_assert(). >> > > Nice catch! I will fix it up in next revision :) >
Thanks, Gavin
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