| /* |
| * Async PF test. For the test to actually do anything it needs to be started |
| * in memory cgroup with 512M of memory and with more than 1G memory provided |
| * to the guest. |
| * |
| * To identify the cgroup version on Linux: |
| * stat -fc %T /sys/fs/cgroup/ |
| * |
| * If the output is tmpfs, your system is using cgroup v1: |
| * To create cgroup do as root: |
| * mkdir /dev/cgroup |
| * mount -t cgroup none -omemory /dev/cgroup |
| * chmod a+rxw /dev/cgroup/ |
| * |
| * From a shell you will start qemu from: |
| * mkdir /dev/cgroup/1 |
| * echo $$ > /dev/cgroup/1/tasks |
| * echo 512M > /dev/cgroup/1/memory.limit_in_bytes |
| * |
| * If the output is cgroup2fs, your system is using cgroup v2: |
| * mkdir /sys/fs/cgroup/cg1 |
| * echo $$ > /sys/fs/cgroup/cg1/cgroup.procs |
| * echo 512M > /sys/fs/cgroup/cg1/memory.max |
| * |
| */ |
| #include "x86/processor.h" |
| #include "x86/apic.h" |
| #include "x86/isr.h" |
| #include "x86/vm.h" |
| #include "alloc.h" |
| #include "vmalloc.h" |
| |
| #define KVM_PV_REASON_PAGE_NOT_PRESENT 1 |
| |
| #define MSR_KVM_ASYNC_PF_EN 0x4b564d02 |
| #define MSR_KVM_ASYNC_PF_INT 0x4b564d06 |
| #define MSR_KVM_ASYNC_PF_ACK 0x4b564d07 |
| |
| #define KVM_ASYNC_PF_ENABLED (1 << 0) |
| #define KVM_ASYNC_PF_SEND_ALWAYS (1 << 1) |
| #define KVM_ASYNC_PF_DELIVERY_AS_INT (1 << 3) |
| |
| #define HYPERVISOR_CALLBACK_VECTOR 0xf3 |
| |
| struct kvm_vcpu_pv_apf_data { |
| /* Used for 'page not present' events delivered via #PF */ |
| uint32_t flags; |
| |
| /* Used for 'page ready' events delivered via interrupt notification */ |
| uint32_t token; |
| |
| uint8_t pad[56]; |
| uint32_t enabled; |
| } apf_reason __attribute__((aligned(64))); |
| |
| char *buf; |
| void* virt; |
| volatile uint64_t i; |
| volatile uint64_t phys; |
| volatile uint32_t saved_token; |
| volatile uint32_t asyncpf_num; |
| |
| static inline uint32_t get_and_clear_apf_reason(void) |
| { |
| uint32_t r = apf_reason.flags; |
| apf_reason.flags = 0; |
| return r; |
| } |
| |
| static void handle_interrupt(isr_regs_t *regs) |
| { |
| uint32_t apf_token = apf_reason.token; |
| |
| apf_reason.token = 0; |
| wrmsr(MSR_KVM_ASYNC_PF_ACK, 1); |
| |
| if (apf_token == 0xffffffff) { |
| report_pass("Wakeup all, got token 0x%x", apf_token); |
| } else if (apf_token == saved_token) { |
| asyncpf_num++; |
| install_pte(phys_to_virt(read_cr3()), 1, virt, phys | PT_PRESENT_MASK | PT_WRITABLE_MASK, 0); |
| phys = 0; |
| } else { |
| report_fail("unexpected async pf int token 0x%x", apf_token); |
| } |
| |
| eoi(); |
| } |
| |
| static void handle_pf(struct ex_regs *r) |
| { |
| virt = (void*)((ulong)(buf+i) & ~(PAGE_SIZE-1)); |
| uint32_t reason = get_and_clear_apf_reason(); |
| switch (reason) { |
| case 0: |
| report_fail("unexpected #PF at %#lx", read_cr2()); |
| exit(report_summary()); |
| case KVM_PV_REASON_PAGE_NOT_PRESENT: |
| phys = virt_to_pte_phys(phys_to_virt(read_cr3()), virt); |
| install_pte(phys_to_virt(read_cr3()), 1, virt, phys, 0); |
| write_cr3(read_cr3()); |
| saved_token = read_cr2(); |
| while (phys) { |
| safe_halt(); /* enables irq */ |
| } |
| break; |
| default: |
| report_fail("unexpected async pf with reason 0x%x", reason); |
| exit(report_summary()); |
| } |
| } |
| |
| #define MEM (1ull*1024*1024*1024) |
| |
| int main(int ac, char **av) |
| { |
| if (!this_cpu_has(KVM_FEATURE_ASYNC_PF)) { |
| report_skip("KVM_FEATURE_ASYNC_PF is not supported\n"); |
| return report_summary(); |
| } |
| |
| if (!this_cpu_has(KVM_FEATURE_ASYNC_PF_INT)) { |
| report_skip("KVM_FEATURE_ASYNC_PF_INT is not supported\n"); |
| return report_summary(); |
| } |
| |
| setup_vm(); |
| |
| handle_exception(PF_VECTOR, handle_pf); |
| handle_irq(HYPERVISOR_CALLBACK_VECTOR, handle_interrupt); |
| memset(&apf_reason, 0, sizeof(apf_reason)); |
| |
| wrmsr(MSR_KVM_ASYNC_PF_INT, HYPERVISOR_CALLBACK_VECTOR); |
| wrmsr(MSR_KVM_ASYNC_PF_EN, virt_to_phys((void*)&apf_reason) | |
| KVM_ASYNC_PF_SEND_ALWAYS | KVM_ASYNC_PF_ENABLED | KVM_ASYNC_PF_DELIVERY_AS_INT); |
| |
| buf = malloc(MEM); |
| sti(); |
| |
| /* access a lot of memory to make host swap it out */ |
| for (i = 0; i < MEM; i += 4096) |
| buf[i] = 1; |
| |
| cli(); |
| if (!asyncpf_num) |
| report_skip("No async page fault events, cgroup configuration likely needed"); |
| else |
| report_pass("Serviced %d async page faults events (!PRESENT #PF + READY IRQ)", |
| asyncpf_num); |
| return report_summary(); |
| } |