| Message ID | 20191216213901.106941-7-bgardon@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Create a userfaultfd demand paging test | expand |
On Mon, Dec 16, 2019 at 01:38:59PM -0800, Ben Gardon wrote: > 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> > --- > .../selftests/kvm/demand_paging_test.c | 199 ++++++++++++------ > 1 file changed, 136 insertions(+), 63 deletions(-) > > diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c > index 8ede26e088ab6..2b80f614dd537 100644 > --- a/tools/testing/selftests/kvm/demand_paging_test.c > +++ b/tools/testing/selftests/kvm/demand_paging_test.c > @@ -24,8 +24,6 @@ > #include "kvm_util.h" > #include "processor.h" > > -#define VCPU_ID 1 > - > /* The memory slot index demand page */ > #define TEST_MEM_SLOT_INDEX 1 > > @@ -34,6 +32,12 @@ > > #define DEFAULT_GUEST_TEST_MEM_SIZE (1 << 30) /* 1G */ > > +#ifdef PRINT_PER_VCPU_UPDATES > +#define PER_VCPU_DEBUG(...) DEBUG(__VA_ARGS__) > +#else > +#define PER_VCPU_DEBUG(...) > +#endif > + > /* > * Guest/Host shared variables. Ensure addr_gva2hva() and/or > * sync_global_to/from_guest() are used when accessing from > @@ -76,10 +80,6 @@ static void guest_code(uint64_t gva, uint64_t pages) > GUEST_SYNC(1); > } > > -/* Points to the test VM memory region on which we are doing demand paging */ > -static void *host_test_mem; > -static uint64_t host_num_pages; > - > struct vcpu_thread_args { > uint64_t gva; > uint64_t pages; > @@ -113,18 +113,32 @@ static void *vcpu_worker(void *data) > return NULL; > } > > -static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid, > - uint64_t extra_mem_pages, void *guest_code) > +#define PAGE_SHIFT_4K 12 > +#define PTES_PER_PT 512 > + > +static struct kvm_vm *create_vm(enum vm_guest_mode mode, int vcpus, > + uint64_t vcpu_wss) > { > struct kvm_vm *vm; > - uint64_t extra_pg_pages = extra_mem_pages / 512 * 2; > + uint64_t pages = DEFAULT_GUEST_PHY_PAGES; > > - vm = _vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, O_RDWR); > + /* Account for a few pages per-vCPU for stacks */ > + pages += DEFAULT_STACK_PGS * vcpus; > + > + /* > + * Reserve twice the ammount of memory needed to map the test region and > + * the page table / stacks region, at 4k, for page tables. Do the > + * calculation with 4K page size: the smallest of all archs. (e.g., 64K > + * page size guest will need even less memory for page tables). > + */ > + pages += (2 * pages) / PTES_PER_PT; > + pages += ((2 * vcpus * vcpu_wss) >> PAGE_SHIFT_4K) / PTES_PER_PT; > + > + vm = _vm_create(mode, pages, O_RDWR); > kvm_vm_elf_load(vm, program_invocation_name, 0, 0); > #ifdef __x86_64__ > vm_create_irqchip(vm); > #endif > - vm_vcpu_add_default(vm, vcpuid, guest_code); > return vm; > } > > @@ -232,15 +246,13 @@ static void *uffd_handler_thread_fn(void *arg) > > static int setup_demand_paging(struct kvm_vm *vm, > pthread_t *uffd_handler_thread, > - useconds_t uffd_delay) > + useconds_t uffd_delay, > + struct uffd_handler_args *uffd_args, > + void *hva, uint64_t len) > { > int uffd; > struct uffdio_api uffdio_api; > struct uffdio_register uffdio_register; > - struct uffd_handler_args uffd_args; > - > - guest_data_prototype = malloc(host_page_size); > - memset(guest_data_prototype, 0xAB, host_page_size); > > uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK); > if (uffd == -1) { > @@ -255,8 +267,8 @@ static int setup_demand_paging(struct kvm_vm *vm, > return -1; > } > > - uffdio_register.range.start = (uint64_t)host_test_mem; > - uffdio_register.range.len = host_num_pages * host_page_size; > + uffdio_register.range.start = (uint64_t)hva; > + uffdio_register.range.len = len; > uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING; > if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) == -1) { > DEBUG("ioctl uffdio_register failed\n"); > @@ -269,42 +281,37 @@ static int setup_demand_paging(struct kvm_vm *vm, > return -1; > } > > - uffd_args.uffd = uffd; > - uffd_args.delay = uffd_delay; > + uffd_args->uffd = uffd; > + uffd_args->delay = uffd_delay; > pthread_create(uffd_handler_thread, NULL, uffd_handler_thread_fn, > - &uffd_args); > + uffd_args); > + > + PER_VCPU_DEBUG("Created uffd thread for HVA range [%p, %p)\n", > + hva, hva + len); > > return 0; > } > > -#define PAGE_SHIFT_4K 12 > - > static void run_test(enum vm_guest_mode mode, bool use_uffd, > - useconds_t uffd_delay, uint64_t vcpu_wss) > + useconds_t uffd_delay, int vcpus, uint64_t vcpu_wss) > { > - pthread_t vcpu_thread; > - pthread_t uffd_handler_thread; > + pthread_t *vcpu_threads; > + pthread_t *uffd_handler_threads = NULL; > + struct uffd_handler_args *uffd_args = NULL; > struct kvm_vm *vm; > - struct vcpu_thread_args vcpu_args; > + struct vcpu_thread_args *vcpu_args; > uint64_t guest_num_pages; > + int vcpu_id; > int r; > > - /* > - * We reserve page table for twice the ammount of memory we intend > - * to use in the test region for demand paging. Here we do the > - * calculation with 4K page size which is the smallest so the page > - * number will be enough for all archs. (e.g., 64K page size guest > - * will need even less memory for page tables). > - */ > - vm = create_vm(mode, VCPU_ID, (2 * vcpu_wss) >> PAGE_SHIFT_4K, > - guest_code); > + vm = create_vm(mode, vcpus, vcpu_wss); > > guest_page_size = vm_get_page_size(vm); > > TEST_ASSERT(vcpu_wss % guest_page_size == 0, > "Guest memory size is not guest page size aligned."); > > - guest_num_pages = vcpu_wss / guest_page_size; > + guest_num_pages = (vcpus * vcpu_wss) / guest_page_size; > > #ifdef __s390x__ > /* Round up to multiple of 1M (segment size) */ > @@ -316,13 +323,12 @@ static void run_test(enum vm_guest_mode mode, bool use_uffd, > */ > TEST_ASSERT(guest_num_pages < vm_get_max_gfn(vm), > "Requested more guest memory than address space allows.\n" > - " guest pages: %lx max gfn: %lx\n", > - guest_num_pages, vm_get_max_gfn(vm)); > + " guest pages: %lx max gfn: %lx vcpus: %d wss: %lx]\n", > + guest_num_pages, vm_get_max_gfn(vm), vcpus, vcpu_wss); > > host_page_size = getpagesize(); > TEST_ASSERT(vcpu_wss % host_page_size == 0, > "Guest memory size is not host page size aligned."); > - host_num_pages = vcpu_wss / host_page_size; > > guest_test_phys_mem = (vm_get_max_gfn(vm) - guest_num_pages) * > guest_page_size; > @@ -347,43 +353,102 @@ static void run_test(enum vm_guest_mode mode, bool use_uffd, > virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, > guest_num_pages * guest_page_size, 0); > > - /* Cache the HVA pointer of the region */ > - host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem); > + /* Export the shared variables to the guest */ > + sync_global_to_guest(vm, host_page_size); > + sync_global_to_guest(vm, guest_page_size); > + > + guest_data_prototype = malloc(host_page_size); > + TEST_ASSERT(guest_data_prototype, "Memory allocation failed"); > + memset(guest_data_prototype, 0xAB, host_page_size); > + > + vcpu_threads = malloc(vcpus * sizeof(*vcpu_threads)); > + TEST_ASSERT(vcpu_threads, "Memory allocation failed"); > > if (use_uffd) { > - /* Set up user fault fd to handle demand paging requests. */ > quit_uffd_thread = false; > - r = setup_demand_paging(vm, &uffd_handler_thread, > - uffd_delay); > - if (r < 0) > - exit(-r); > + > + uffd_handler_threads = > + malloc(vcpus * sizeof(*uffd_handler_threads)); > + TEST_ASSERT(uffd_handler_threads, "Memory allocation failed"); > + > + uffd_args = malloc(vcpus * sizeof(*uffd_args)); > + TEST_ASSERT(uffd_args, "Memory allocation failed"); > } > > + vcpu_args = malloc(vcpus * sizeof(*vcpu_args)); > + TEST_ASSERT(vcpu_args, "Memory allocation failed"); > + > + for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) { > + vm_paddr_t vcpu_gpa; > + void *vcpu_hva; > + > + vm_vcpu_add_default(vm, vcpu_id, guest_code); > + > + vcpu_gpa = guest_test_phys_mem + (vcpu_id * vcpu_wss); > + PER_VCPU_DEBUG("Added VCPU %d with test mem gpa [%lx, %lx)\n", > + vcpu_id, vcpu_gpa, vcpu_gpa + vcpu_wss); > + > + /* Cache the HVA pointer of the region */ > + vcpu_hva = addr_gpa2hva(vm, vcpu_gpa); > + > + if (use_uffd) { > + /* > + * Set up user fault fd to handle demand paging > + * requests. > + */ > + r = setup_demand_paging(vm, > + &uffd_handler_threads[vcpu_id], > + uffd_delay, &uffd_args[vcpu_id], > + vcpu_hva, vcpu_wss); > + if (r < 0) > + exit(-r); > + } > + > #ifdef __x86_64__ > - vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid()); > + vcpu_set_cpuid(vm, vcpu_id, kvm_get_supported_cpuid()); > #endif > > - /* Export the shared variables to the guest */ > - sync_global_to_guest(vm, host_page_size); > - sync_global_to_guest(vm, guest_page_size); > + vcpu_args[vcpu_id].vm = vm; > + vcpu_args[vcpu_id].vcpu_id = vcpu_id; > + vcpu_args[vcpu_id].gva = guest_test_virt_mem + > + (vcpu_id * vcpu_wss); > + vcpu_args[vcpu_id].pages = vcpu_wss / guest_page_size; > + } > + > + DEBUG("Finished creating vCPUs and starting uffd threads\n"); > + > + for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) { > + pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker, > + &vcpu_args[vcpu_id]); > + } > + > + DEBUG("Started all vCPUs\n"); > > - vcpu_args.vm = vm; > - vcpu_args.vcpu_id = VCPU_ID; > - vcpu_args.gva = guest_test_virt_mem; > - vcpu_args.pages = guest_num_pages; > - pthread_create(&vcpu_thread, NULL, vcpu_worker, &vcpu_args); > + /* Wait for the vcpu threads to quit */ > + for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) { > + pthread_join(vcpu_threads[vcpu_id], NULL); > + PER_VCPU_DEBUG("Joined thread for vCPU %d\n", vcpu_id); > + } > > - /* Wait for the vcpu thread to quit */ > - pthread_join(vcpu_thread, NULL); > + DEBUG("All vCPU threads joined\n"); > > if (use_uffd) { > - /* Tell the user fault fd handler thread to quit */ > + /* Tell the user fault fd handler threads to quit */ > quit_uffd_thread = true; > - pthread_join(uffd_handler_thread, NULL); > + for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) > + pthread_join(uffd_handler_threads[vcpu_id], NULL); > } > > ucall_uninit(vm); > kvm_vm_free(vm); > + > + free(guest_data_prototype); > + free(vcpu_threads); > + if (use_uffd) { > + free(uffd_handler_threads); > + free(uffd_args); > + } > + free(vcpu_args); > } > > struct vm_guest_mode_params { > @@ -404,7 +469,7 @@ static void help(char *name) > > puts(""); > printf("usage: %s [-h] [-m mode] [-u] [-d uffd_delay_usec]\n" > - " [-b bytes test memory]\n", name); > + " [-b bytes test memory] [-v vcpus]\n", name); > printf(" -m: specify the guest mode ID to test\n" > " (default: test all supported modes)\n" > " This option may be used multiple times.\n" > @@ -419,6 +484,7 @@ static void help(char *name) > " FD handler to simulate demand paging\n" > " overheads. Ignored without -u.\n"); > printf(" -b: specify the working set size, in bytes for each vCPU.\n"); > + printf(" -v: specify the number of vCPUs to run.\n"); > puts(""); > exit(0); > } > @@ -427,6 +493,7 @@ int main(int argc, char *argv[]) > { > bool mode_selected = false; > uint64_t vcpu_wss = DEFAULT_GUEST_TEST_MEM_SIZE; > + int vcpus = 1; > unsigned int mode; > int opt, i; > bool use_uffd = false; > @@ -439,7 +506,7 @@ int main(int argc, char *argv[]) > vm_guest_mode_params_init(VM_MODE_P40V48_4K, true, true); > #endif > > - while ((opt = getopt(argc, argv, "hm:ud:b:")) != -1) { > + while ((opt = getopt(argc, argv, "hm:ud:b:v:")) != -1) { > switch (opt) { > case 'm': > if (!mode_selected) { > @@ -462,6 +529,12 @@ int main(int argc, char *argv[]) > break; > case 'b': > vcpu_wss = strtoull(optarg, NULL, 0); > + break; There's that missing break. It's good to test each patch to ensure bisectability. > + case 'v': > + vcpus = atoi(optarg); > + TEST_ASSERT(vcpus > 0, > + "Must have a positive number of vCPUs"); > + break; > case 'h': > default: > help(argv[0]); > @@ -475,7 +548,7 @@ int main(int argc, char *argv[]) > TEST_ASSERT(vm_guest_mode_params[i].supported, > "Guest mode ID %d (%s) not supported.", > i, vm_guest_mode_string(i)); > - run_test(i, use_uffd, uffd_delay, vcpu_wss); > + run_test(i, use_uffd, uffd_delay, vcpus, vcpu_wss); > } > > return 0; > -- > 2.24.1.735.g03f4e72817-goog > Thanks, drew
diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c index 8ede26e088ab6..2b80f614dd537 100644 --- a/tools/testing/selftests/kvm/demand_paging_test.c +++ b/tools/testing/selftests/kvm/demand_paging_test.c @@ -24,8 +24,6 @@ #include "kvm_util.h" #include "processor.h" -#define VCPU_ID 1 - /* The memory slot index demand page */ #define TEST_MEM_SLOT_INDEX 1 @@ -34,6 +32,12 @@ #define DEFAULT_GUEST_TEST_MEM_SIZE (1 << 30) /* 1G */ +#ifdef PRINT_PER_VCPU_UPDATES +#define PER_VCPU_DEBUG(...) DEBUG(__VA_ARGS__) +#else +#define PER_VCPU_DEBUG(...) +#endif + /* * Guest/Host shared variables. Ensure addr_gva2hva() and/or * sync_global_to/from_guest() are used when accessing from @@ -76,10 +80,6 @@ static void guest_code(uint64_t gva, uint64_t pages) GUEST_SYNC(1); } -/* Points to the test VM memory region on which we are doing demand paging */ -static void *host_test_mem; -static uint64_t host_num_pages; - struct vcpu_thread_args { uint64_t gva; uint64_t pages; @@ -113,18 +113,32 @@ static void *vcpu_worker(void *data) return NULL; } -static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid, - uint64_t extra_mem_pages, void *guest_code) +#define PAGE_SHIFT_4K 12 +#define PTES_PER_PT 512 + +static struct kvm_vm *create_vm(enum vm_guest_mode mode, int vcpus, + uint64_t vcpu_wss) { struct kvm_vm *vm; - uint64_t extra_pg_pages = extra_mem_pages / 512 * 2; + uint64_t pages = DEFAULT_GUEST_PHY_PAGES; - vm = _vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, O_RDWR); + /* Account for a few pages per-vCPU for stacks */ + pages += DEFAULT_STACK_PGS * vcpus; + + /* + * Reserve twice the ammount of memory needed to map the test region and + * the page table / stacks region, at 4k, for page tables. Do the + * calculation with 4K page size: the smallest of all archs. (e.g., 64K + * page size guest will need even less memory for page tables). + */ + pages += (2 * pages) / PTES_PER_PT; + pages += ((2 * vcpus * vcpu_wss) >> PAGE_SHIFT_4K) / PTES_PER_PT; + + vm = _vm_create(mode, pages, O_RDWR); kvm_vm_elf_load(vm, program_invocation_name, 0, 0); #ifdef __x86_64__ vm_create_irqchip(vm); #endif - vm_vcpu_add_default(vm, vcpuid, guest_code); return vm; } @@ -232,15 +246,13 @@ static void *uffd_handler_thread_fn(void *arg) static int setup_demand_paging(struct kvm_vm *vm, pthread_t *uffd_handler_thread, - useconds_t uffd_delay) + useconds_t uffd_delay, + struct uffd_handler_args *uffd_args, + void *hva, uint64_t len) { int uffd; struct uffdio_api uffdio_api; struct uffdio_register uffdio_register; - struct uffd_handler_args uffd_args; - - guest_data_prototype = malloc(host_page_size); - memset(guest_data_prototype, 0xAB, host_page_size); uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK); if (uffd == -1) { @@ -255,8 +267,8 @@ static int setup_demand_paging(struct kvm_vm *vm, return -1; } - uffdio_register.range.start = (uint64_t)host_test_mem; - uffdio_register.range.len = host_num_pages * host_page_size; + uffdio_register.range.start = (uint64_t)hva; + uffdio_register.range.len = len; uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING; if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) == -1) { DEBUG("ioctl uffdio_register failed\n"); @@ -269,42 +281,37 @@ static int setup_demand_paging(struct kvm_vm *vm, return -1; } - uffd_args.uffd = uffd; - uffd_args.delay = uffd_delay; + uffd_args->uffd = uffd; + uffd_args->delay = uffd_delay; pthread_create(uffd_handler_thread, NULL, uffd_handler_thread_fn, - &uffd_args); + uffd_args); + + PER_VCPU_DEBUG("Created uffd thread for HVA range [%p, %p)\n", + hva, hva + len); return 0; } -#define PAGE_SHIFT_4K 12 - static void run_test(enum vm_guest_mode mode, bool use_uffd, - useconds_t uffd_delay, uint64_t vcpu_wss) + useconds_t uffd_delay, int vcpus, uint64_t vcpu_wss) { - pthread_t vcpu_thread; - pthread_t uffd_handler_thread; + pthread_t *vcpu_threads; + pthread_t *uffd_handler_threads = NULL; + struct uffd_handler_args *uffd_args = NULL; struct kvm_vm *vm; - struct vcpu_thread_args vcpu_args; + struct vcpu_thread_args *vcpu_args; uint64_t guest_num_pages; + int vcpu_id; int r; - /* - * We reserve page table for twice the ammount of memory we intend - * to use in the test region for demand paging. Here we do the - * calculation with 4K page size which is the smallest so the page - * number will be enough for all archs. (e.g., 64K page size guest - * will need even less memory for page tables). - */ - vm = create_vm(mode, VCPU_ID, (2 * vcpu_wss) >> PAGE_SHIFT_4K, - guest_code); + vm = create_vm(mode, vcpus, vcpu_wss); guest_page_size = vm_get_page_size(vm); TEST_ASSERT(vcpu_wss % guest_page_size == 0, "Guest memory size is not guest page size aligned."); - guest_num_pages = vcpu_wss / guest_page_size; + guest_num_pages = (vcpus * vcpu_wss) / guest_page_size; #ifdef __s390x__ /* Round up to multiple of 1M (segment size) */ @@ -316,13 +323,12 @@ static void run_test(enum vm_guest_mode mode, bool use_uffd, */ TEST_ASSERT(guest_num_pages < vm_get_max_gfn(vm), "Requested more guest memory than address space allows.\n" - " guest pages: %lx max gfn: %lx\n", - guest_num_pages, vm_get_max_gfn(vm)); + " guest pages: %lx max gfn: %lx vcpus: %d wss: %lx]\n", + guest_num_pages, vm_get_max_gfn(vm), vcpus, vcpu_wss); host_page_size = getpagesize(); TEST_ASSERT(vcpu_wss % host_page_size == 0, "Guest memory size is not host page size aligned."); - host_num_pages = vcpu_wss / host_page_size; guest_test_phys_mem = (vm_get_max_gfn(vm) - guest_num_pages) * guest_page_size; @@ -347,43 +353,102 @@ static void run_test(enum vm_guest_mode mode, bool use_uffd, virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages * guest_page_size, 0); - /* Cache the HVA pointer of the region */ - host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem); + /* Export the shared variables to the guest */ + sync_global_to_guest(vm, host_page_size); + sync_global_to_guest(vm, guest_page_size); + + guest_data_prototype = malloc(host_page_size); + TEST_ASSERT(guest_data_prototype, "Memory allocation failed"); + memset(guest_data_prototype, 0xAB, host_page_size); + + vcpu_threads = malloc(vcpus * sizeof(*vcpu_threads)); + TEST_ASSERT(vcpu_threads, "Memory allocation failed"); if (use_uffd) { - /* Set up user fault fd to handle demand paging requests. */ quit_uffd_thread = false; - r = setup_demand_paging(vm, &uffd_handler_thread, - uffd_delay); - if (r < 0) - exit(-r); + + uffd_handler_threads = + malloc(vcpus * sizeof(*uffd_handler_threads)); + TEST_ASSERT(uffd_handler_threads, "Memory allocation failed"); + + uffd_args = malloc(vcpus * sizeof(*uffd_args)); + TEST_ASSERT(uffd_args, "Memory allocation failed"); } + vcpu_args = malloc(vcpus * sizeof(*vcpu_args)); + TEST_ASSERT(vcpu_args, "Memory allocation failed"); + + for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) { + vm_paddr_t vcpu_gpa; + void *vcpu_hva; + + vm_vcpu_add_default(vm, vcpu_id, guest_code); + + vcpu_gpa = guest_test_phys_mem + (vcpu_id * vcpu_wss); + PER_VCPU_DEBUG("Added VCPU %d with test mem gpa [%lx, %lx)\n", + vcpu_id, vcpu_gpa, vcpu_gpa + vcpu_wss); + + /* Cache the HVA pointer of the region */ + vcpu_hva = addr_gpa2hva(vm, vcpu_gpa); + + if (use_uffd) { + /* + * Set up user fault fd to handle demand paging + * requests. + */ + r = setup_demand_paging(vm, + &uffd_handler_threads[vcpu_id], + uffd_delay, &uffd_args[vcpu_id], + vcpu_hva, vcpu_wss); + if (r < 0) + exit(-r); + } + #ifdef __x86_64__ - vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid()); + vcpu_set_cpuid(vm, vcpu_id, kvm_get_supported_cpuid()); #endif - /* Export the shared variables to the guest */ - sync_global_to_guest(vm, host_page_size); - sync_global_to_guest(vm, guest_page_size); + vcpu_args[vcpu_id].vm = vm; + vcpu_args[vcpu_id].vcpu_id = vcpu_id; + vcpu_args[vcpu_id].gva = guest_test_virt_mem + + (vcpu_id * vcpu_wss); + vcpu_args[vcpu_id].pages = vcpu_wss / guest_page_size; + } + + DEBUG("Finished creating vCPUs and starting uffd threads\n"); + + for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) { + pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker, + &vcpu_args[vcpu_id]); + } + + DEBUG("Started all vCPUs\n"); - vcpu_args.vm = vm; - vcpu_args.vcpu_id = VCPU_ID; - vcpu_args.gva = guest_test_virt_mem; - vcpu_args.pages = guest_num_pages; - pthread_create(&vcpu_thread, NULL, vcpu_worker, &vcpu_args); + /* Wait for the vcpu threads to quit */ + for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) { + pthread_join(vcpu_threads[vcpu_id], NULL); + PER_VCPU_DEBUG("Joined thread for vCPU %d\n", vcpu_id); + } - /* Wait for the vcpu thread to quit */ - pthread_join(vcpu_thread, NULL); + DEBUG("All vCPU threads joined\n"); if (use_uffd) { - /* Tell the user fault fd handler thread to quit */ + /* Tell the user fault fd handler threads to quit */ quit_uffd_thread = true; - pthread_join(uffd_handler_thread, NULL); + for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) + pthread_join(uffd_handler_threads[vcpu_id], NULL); } ucall_uninit(vm); kvm_vm_free(vm); + + free(guest_data_prototype); + free(vcpu_threads); + if (use_uffd) { + free(uffd_handler_threads); + free(uffd_args); + } + free(vcpu_args); } struct vm_guest_mode_params { @@ -404,7 +469,7 @@ static void help(char *name) puts(""); printf("usage: %s [-h] [-m mode] [-u] [-d uffd_delay_usec]\n" - " [-b bytes test memory]\n", name); + " [-b bytes test memory] [-v vcpus]\n", name); printf(" -m: specify the guest mode ID to test\n" " (default: test all supported modes)\n" " This option may be used multiple times.\n" @@ -419,6 +484,7 @@ static void help(char *name) " FD handler to simulate demand paging\n" " overheads. Ignored without -u.\n"); printf(" -b: specify the working set size, in bytes for each vCPU.\n"); + printf(" -v: specify the number of vCPUs to run.\n"); puts(""); exit(0); } @@ -427,6 +493,7 @@ int main(int argc, char *argv[]) { bool mode_selected = false; uint64_t vcpu_wss = DEFAULT_GUEST_TEST_MEM_SIZE; + int vcpus = 1; unsigned int mode; int opt, i; bool use_uffd = false; @@ -439,7 +506,7 @@ int main(int argc, char *argv[]) vm_guest_mode_params_init(VM_MODE_P40V48_4K, true, true); #endif - while ((opt = getopt(argc, argv, "hm:ud:b:")) != -1) { + while ((opt = getopt(argc, argv, "hm:ud:b:v:")) != -1) { switch (opt) { case 'm': if (!mode_selected) { @@ -462,6 +529,12 @@ int main(int argc, char *argv[]) break; case 'b': vcpu_wss = strtoull(optarg, NULL, 0); + break; + case 'v': + vcpus = atoi(optarg); + TEST_ASSERT(vcpus > 0, + "Must have a positive number of vCPUs"); + break; case 'h': default: help(argv[0]); @@ -475,7 +548,7 @@ int main(int argc, char *argv[]) TEST_ASSERT(vm_guest_mode_params[i].supported, "Guest mode ID %d (%s) not supported.", i, vm_guest_mode_string(i)); - run_test(i, use_uffd, uffd_delay, vcpu_wss); + run_test(i, use_uffd, uffd_delay, vcpus, vcpu_wss); } return 0;
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> --- .../selftests/kvm/demand_paging_test.c | 199 ++++++++++++------ 1 file changed, 136 insertions(+), 63 deletions(-)