KVM: selftests: Support multiple vCPUs in demand paging test
Most VMs have multiple vCPUs, the concurrent execution of which has a substantial impact on demand paging performance. Add an option to create multiple vCPUs to each access disjoint regions of memory. Signed-off-by: Ben Gardon <bgardon@google.com> [guest_code() can't return, use GUEST_ASSERT(). Ensure the number of guests pages is compatible with the host.] Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Ben Gardon
Paolo Bonzini
parent
9bbf24744e
commit
018494e6d8
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@ -26,7 +26,6 @@
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#include "processor.h"
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#ifdef __NR_userfaultfd
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#define VCPU_ID 1
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/* The memory slot index demand page */
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#define TEST_MEM_SLOT_INDEX 1
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@ -36,6 +35,14 @@
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#define DEFAULT_GUEST_TEST_MEM_SIZE (1 << 30) /* 1G */
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#ifdef PRINT_PER_VCPU_UPDATES
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#define PER_VCPU_DEBUG(...) DEBUG(__VA_ARGS__)
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#else
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#define PER_VCPU_DEBUG(...)
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#endif
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#define MAX_VCPUS 512
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/*
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* Guest/Host shared variables. Ensure addr_gva2hva() and/or
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* sync_global_to/from_guest() are used when accessing from
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@ -69,18 +76,24 @@ struct vcpu_args {
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struct kvm_vm *vm;
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};
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static struct vcpu_args vcpu_args;
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static struct vcpu_args vcpu_args[MAX_VCPUS];
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/*
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* Continuously write to the first 8 bytes of each page in the demand paging
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* memory region.
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*/
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static void guest_code(void)
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static void guest_code(uint32_t vcpu_id)
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{
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uint64_t gva = vcpu_args.gva;
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uint64_t pages = vcpu_args.pages;
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uint64_t gva;
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uint64_t pages;
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int i;
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/* Make sure vCPU args data structure is not corrupt. */
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GUEST_ASSERT(vcpu_args[vcpu_id].vcpu_id == vcpu_id);
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gva = vcpu_args[vcpu_id].gva;
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pages = vcpu_args[vcpu_id].pages;
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for (i = 0; i < pages; i++) {
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uint64_t addr = gva + (i * guest_page_size);
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@ -91,17 +104,15 @@ static void guest_code(void)
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GUEST_SYNC(1);
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}
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/* Points to the test VM memory region on which we are doing demand paging */
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static void *host_test_mem;
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static uint64_t host_num_pages;
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static void *vcpu_worker(void *data)
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{
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int ret;
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struct kvm_vm *vm = vcpu_args.vm;
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int vcpu_id = vcpu_args.vcpu_id;
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struct vcpu_args *args = (struct vcpu_args *)data;
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struct kvm_vm *vm = args->vm;
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int vcpu_id = args->vcpu_id;
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struct kvm_run *run;
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vcpu_args_set(vm, vcpu_id, 1, vcpu_id);
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run = vcpu_state(vm, vcpu_id);
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/* Let the guest access its memory */
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@ -116,18 +127,34 @@ static void *vcpu_worker(void *data)
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return NULL;
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}
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static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid,
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uint64_t extra_mem_pages, void *guest_code)
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#define PAGE_SHIFT_4K 12
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#define PTES_PER_4K_PT 512
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static struct kvm_vm *create_vm(enum vm_guest_mode mode, int vcpus,
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uint64_t vcpu_memory_bytes)
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{
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struct kvm_vm *vm;
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uint64_t extra_pg_pages = extra_mem_pages / 512 * 2;
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uint64_t pages = DEFAULT_GUEST_PHY_PAGES;
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vm = _vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, O_RDWR);
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/* Account for a few pages per-vCPU for stacks */
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pages += DEFAULT_STACK_PGS * vcpus;
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/*
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* Reserve twice the ammount of memory needed to map the test region and
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* the page table / stacks region, at 4k, for page tables. Do the
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* calculation with 4K page size: the smallest of all archs. (e.g., 64K
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* page size guest will need even less memory for page tables).
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*/
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pages += (2 * pages) / PTES_PER_4K_PT;
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pages += ((2 * vcpus * vcpu_memory_bytes) >> PAGE_SHIFT_4K) /
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PTES_PER_4K_PT;
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pages = vm_adjust_num_guest_pages(mode, pages);
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vm = _vm_create(mode, pages, O_RDWR);
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kvm_vm_elf_load(vm, program_invocation_name, 0, 0);
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#ifdef __x86_64__
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vm_create_irqchip(vm);
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#endif
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vm_vcpu_add_default(vm, vcpuid, guest_code);
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return vm;
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}
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@ -242,17 +269,13 @@ static void *uffd_handler_thread_fn(void *arg)
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static int setup_demand_paging(struct kvm_vm *vm,
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pthread_t *uffd_handler_thread, int pipefd,
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useconds_t uffd_delay)
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useconds_t uffd_delay,
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struct uffd_handler_args *uffd_args,
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void *hva, uint64_t len)
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{
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int uffd;
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struct uffdio_api uffdio_api;
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struct uffdio_register uffdio_register;
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struct uffd_handler_args uffd_args;
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guest_data_prototype = malloc(host_page_size);
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TEST_ASSERT(guest_data_prototype,
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"Failed to allocate buffer for guest data pattern");
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memset(guest_data_prototype, 0xAB, host_page_size);
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uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
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if (uffd == -1) {
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@ -267,8 +290,8 @@ static int setup_demand_paging(struct kvm_vm *vm,
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return -1;
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}
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uffdio_register.range.start = (uint64_t)host_test_mem;
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uffdio_register.range.len = host_num_pages * host_page_size;
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uffdio_register.range.start = (uint64_t)hva;
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uffdio_register.range.len = len;
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uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING;
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if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) == -1) {
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DEBUG("ioctl uffdio_register failed\n");
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@ -281,44 +304,40 @@ static int setup_demand_paging(struct kvm_vm *vm,
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return -1;
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}
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uffd_args.uffd = uffd;
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uffd_args.pipefd = pipefd;
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uffd_args.delay = uffd_delay;
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uffd_args->uffd = uffd;
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uffd_args->pipefd = pipefd;
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uffd_args->delay = uffd_delay;
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pthread_create(uffd_handler_thread, NULL, uffd_handler_thread_fn,
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&uffd_args);
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uffd_args);
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PER_VCPU_DEBUG("Created uffd thread for HVA range [%p, %p)\n",
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hva, hva + len);
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return 0;
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}
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#define PAGE_SHIFT_4K 12
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static void run_test(enum vm_guest_mode mode, bool use_uffd,
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useconds_t uffd_delay, uint64_t guest_memory_bytes)
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useconds_t uffd_delay, int vcpus,
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uint64_t vcpu_memory_bytes)
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{
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pthread_t vcpu_thread;
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pthread_t uffd_handler_thread;
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int pipefd[2];
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pthread_t *vcpu_threads;
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pthread_t *uffd_handler_threads = NULL;
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struct uffd_handler_args *uffd_args = NULL;
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int *pipefds = NULL;
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struct kvm_vm *vm;
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uint64_t guest_num_pages;
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int vcpu_id;
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int r;
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/*
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* We reserve page table for twice the ammount of memory we intend
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* to use in the test region for demand paging. Here we do the
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* calculation with 4K page size which is the smallest so the page
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* number will be enough for all archs. (e.g., 64K page size guest
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* will need even less memory for page tables).
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*/
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vm = create_vm(mode, VCPU_ID,
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(2 * guest_memory_bytes) >> PAGE_SHIFT_4K,
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guest_code);
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vm = create_vm(mode, vcpus, vcpu_memory_bytes);
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guest_page_size = vm_get_page_size(vm);
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TEST_ASSERT(guest_memory_bytes % guest_page_size == 0,
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TEST_ASSERT(vcpu_memory_bytes % guest_page_size == 0,
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"Guest memory size is not guest page size aligned.");
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guest_num_pages = guest_memory_bytes / guest_page_size;
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guest_num_pages = (vcpus * vcpu_memory_bytes) / guest_page_size;
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guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
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#ifdef __s390x__
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/* Round up to multiple of 1M (segment size) */
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@ -330,13 +349,13 @@ static void run_test(enum vm_guest_mode mode, bool use_uffd,
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*/
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TEST_ASSERT(guest_num_pages < vm_get_max_gfn(vm),
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"Requested more guest memory than address space allows.\n"
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" guest pages: %lx max gfn: %lx\n",
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guest_num_pages, vm_get_max_gfn(vm));
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" guest pages: %lx max gfn: %lx vcpus: %d wss: %lx]\n",
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guest_num_pages, vm_get_max_gfn(vm), vcpus,
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vcpu_memory_bytes);
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host_page_size = getpagesize();
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TEST_ASSERT(guest_memory_bytes % host_page_size == 0,
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TEST_ASSERT(vcpu_memory_bytes % host_page_size == 0,
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"Guest memory size is not host page size aligned.");
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host_num_pages = guest_memory_bytes / host_page_size;
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guest_test_phys_mem = (vm_get_max_gfn(vm) - guest_num_pages) *
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guest_page_size;
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@ -361,55 +380,114 @@ static void run_test(enum vm_guest_mode mode, bool use_uffd,
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virt_map(vm, guest_test_virt_mem, guest_test_phys_mem,
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guest_num_pages * guest_page_size, 0);
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/* Cache the HVA pointer of the region */
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host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem);
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ucall_init(vm, NULL);
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guest_data_prototype = malloc(host_page_size);
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TEST_ASSERT(guest_data_prototype,
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"Failed to allocate buffer for guest data pattern");
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memset(guest_data_prototype, 0xAB, host_page_size);
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vcpu_threads = malloc(vcpus * sizeof(*vcpu_threads));
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TEST_ASSERT(vcpu_threads, "Memory allocation failed");
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if (use_uffd) {
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/* Set up user fault fd to handle demand paging requests. */
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r = pipe2(pipefd, O_CLOEXEC | O_NONBLOCK);
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TEST_ASSERT(!r, "Failed to set up pipefd");
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uffd_handler_threads =
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malloc(vcpus * sizeof(*uffd_handler_threads));
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TEST_ASSERT(uffd_handler_threads, "Memory allocation failed");
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r = setup_demand_paging(vm, &uffd_handler_thread, pipefd[0],
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uffd_delay);
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if (r < 0)
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exit(-r);
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uffd_args = malloc(vcpus * sizeof(*uffd_args));
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TEST_ASSERT(uffd_args, "Memory allocation failed");
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pipefds = malloc(sizeof(int) * vcpus * 2);
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TEST_ASSERT(pipefds, "Unable to allocate memory for pipefd");
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}
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for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) {
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vm_paddr_t vcpu_gpa;
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void *vcpu_hva;
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vm_vcpu_add_default(vm, vcpu_id, guest_code);
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vcpu_gpa = guest_test_phys_mem + (vcpu_id * vcpu_memory_bytes);
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PER_VCPU_DEBUG("Added VCPU %d with test mem gpa [%lx, %lx)\n",
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vcpu_id, vcpu_gpa, vcpu_gpa + vcpu_memory_bytes);
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/* Cache the HVA pointer of the region */
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vcpu_hva = addr_gpa2hva(vm, vcpu_gpa);
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if (use_uffd) {
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/*
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* Set up user fault fd to handle demand paging
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* requests.
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*/
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r = pipe2(&pipefds[vcpu_id * 2],
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O_CLOEXEC | O_NONBLOCK);
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TEST_ASSERT(!r, "Failed to set up pipefd");
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r = setup_demand_paging(vm,
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&uffd_handler_threads[vcpu_id],
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pipefds[vcpu_id * 2],
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uffd_delay, &uffd_args[vcpu_id],
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vcpu_hva, vcpu_memory_bytes);
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if (r < 0)
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exit(-r);
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}
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#ifdef __x86_64__
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vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
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#endif
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#ifdef __aarch64__
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ucall_init(vm, NULL);
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vcpu_set_cpuid(vm, vcpu_id, kvm_get_supported_cpuid());
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#endif
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vcpu_args[vcpu_id].vm = vm;
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vcpu_args[vcpu_id].vcpu_id = vcpu_id;
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vcpu_args[vcpu_id].gva = guest_test_virt_mem +
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(vcpu_id * vcpu_memory_bytes);
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vcpu_args[vcpu_id].pages = vcpu_memory_bytes / guest_page_size;
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}
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/* Export the shared variables to the guest */
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sync_global_to_guest(vm, host_page_size);
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sync_global_to_guest(vm, guest_page_size);
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vcpu_args.vm = vm;
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vcpu_args.vcpu_id = VCPU_ID;
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vcpu_args.gva = guest_test_virt_mem;
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vcpu_args.pages = guest_num_pages;
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sync_global_to_guest(vm, vcpu_args);
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pthread_create(&vcpu_thread, NULL, vcpu_worker, &vcpu_args);
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/* Wait for the vcpu thread to quit */
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pthread_join(vcpu_thread, NULL);
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DEBUG("Finished creating vCPUs and starting uffd threads\n");
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for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) {
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pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker,
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&vcpu_args[vcpu_id]);
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}
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DEBUG("Started all vCPUs\n");
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/* Wait for the vcpu threads to quit */
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for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) {
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pthread_join(vcpu_threads[vcpu_id], NULL);
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PER_VCPU_DEBUG("Joined thread for vCPU %d\n", vcpu_id);
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}
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DEBUG("All vCPU threads joined\n");
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if (use_uffd) {
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char c;
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/* Tell the user fault fd handler thread to quit */
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r = write(pipefd[1], &c, 1);
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TEST_ASSERT(r == 1, "Unable to write to pipefd");
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/* Tell the user fault fd handler threads to quit */
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for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) {
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r = write(pipefds[vcpu_id * 2 + 1], &c, 1);
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TEST_ASSERT(r == 1, "Unable to write to pipefd");
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pthread_join(uffd_handler_thread, NULL);
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pthread_join(uffd_handler_threads[vcpu_id], NULL);
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}
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}
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ucall_uninit(vm);
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kvm_vm_free(vm);
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free(guest_data_prototype);
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free(vcpu_threads);
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if (use_uffd) {
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free(uffd_handler_threads);
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free(uffd_args);
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free(pipefds);
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}
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}
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struct guest_mode {
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@ -428,7 +506,7 @@ static void help(char *name)
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puts("");
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printf("usage: %s [-h] [-m mode] [-u] [-d uffd_delay_usec]\n"
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" [-b memory]\n", name);
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" [-b memory] [-v vcpus]\n", name);
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printf(" -m: specify the guest mode ID to test\n"
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" (default: test all supported modes)\n"
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" This option may be used multiple times.\n"
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@ -443,7 +521,9 @@ static void help(char *name)
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" FD handler to simulate demand paging\n"
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" overheads. Ignored without -u.\n");
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printf(" -b: specify the size of the memory region which should be\n"
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" demand paged. e.g. 10M or 3G. Default: 1G\n");
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" demand paged by each vCPU. e.g. 10M or 3G.\n"
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" Default: 1G\n");
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printf(" -v: specify the number of vCPUs to run.\n");
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puts("");
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exit(0);
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}
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@ -451,7 +531,8 @@ static void help(char *name)
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int main(int argc, char *argv[])
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{
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bool mode_selected = false;
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uint64_t guest_memory_bytes = DEFAULT_GUEST_TEST_MEM_SIZE;
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uint64_t vcpu_memory_bytes = DEFAULT_GUEST_TEST_MEM_SIZE;
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int vcpus = 1;
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unsigned int mode;
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int opt, i;
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bool use_uffd = false;
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@ -478,7 +559,7 @@ int main(int argc, char *argv[])
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guest_mode_init(VM_MODE_P40V48_4K, true, true);
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#endif
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while ((opt = getopt(argc, argv, "hm:ud:b:")) != -1) {
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while ((opt = getopt(argc, argv, "hm:ud:b:v:")) != -1) {
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switch (opt) {
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case 'm':
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if (!mode_selected) {
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@ -500,7 +581,15 @@ int main(int argc, char *argv[])
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"A negative UFFD delay is not supported.");
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break;
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case 'b':
|
||||
guest_memory_bytes = parse_size(optarg);
|
||||
vcpu_memory_bytes = parse_size(optarg);
|
||||
break;
|
||||
case 'v':
|
||||
vcpus = atoi(optarg);
|
||||
TEST_ASSERT(vcpus > 0,
|
||||
"Must have a positive number of vCPUs");
|
||||
TEST_ASSERT(vcpus <= MAX_VCPUS,
|
||||
"This test does not currently support\n"
|
||||
"more than %d vCPUs.", MAX_VCPUS);
|
||||
break;
|
||||
case 'h':
|
||||
default:
|
||||
|
|
@ -515,7 +604,7 @@ int main(int argc, char *argv[])
|
|||
TEST_ASSERT(guest_modes[i].supported,
|
||||
"Guest mode ID %d (%s) not supported.",
|
||||
i, vm_guest_mode_string(i));
|
||||
run_test(i, use_uffd, uffd_delay, guest_memory_bytes);
|
||||
run_test(i, use_uffd, uffd_delay, vcpus, vcpu_memory_bytes);
|
||||
}
|
||||
|
||||
return 0;
|
||||
|
|
|
|||
Loading…
Reference in New Issue