| /* |
| * 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 then 1G memory provided |
| * to the guest. |
| * |
| * 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 |
| * |
| */ |
| #include "x86/msr.h" |
| #include "x86/processor.h" |
| #include "x86/apic-defs.h" |
| #include "x86/apic.h" |
| #include "x86/desc.h" |
| #include "x86/isr.h" |
| #include "x86/vm.h" |
| |
| #include "asm/page.h" |
| #include "alloc.h" |
| #include "libcflat.h" |
| #include "vmalloc.h" |
| #include <stdint.h> |
| |
| #define KVM_PV_REASON_PAGE_NOT_PRESENT 1 |
| #define KVM_PV_REASON_PAGE_READY 2 |
| |
| #define MSR_KVM_ASYNC_PF_EN 0x4b564d02 |
| |
| #define KVM_ASYNC_PF_ENABLED (1 << 0) |
| #define KVM_ASYNC_PF_SEND_ALWAYS (1 << 1) |
| |
| volatile uint32_t apf_reason __attribute__((aligned(64))); |
| char *buf; |
| volatile uint64_t i; |
| volatile uint64_t phys; |
| |
| static inline uint32_t get_apf_reason(void) |
| { |
| uint32_t r = apf_reason; |
| apf_reason = 0; |
| return r; |
| } |
| |
| static void pf_isr(struct ex_regs *r) |
| { |
| void* virt = (void*)((ulong)(buf+i) & ~(PAGE_SIZE-1)); |
| uint32_t reason = get_apf_reason(); |
| |
| switch (reason) { |
| case 0: |
| report(false, "unexpected #PF at %#lx", read_cr2()); |
| break; |
| 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()); |
| report(true, |
| "Got not present #PF token %lx virt addr %p phys addr %#" PRIx64, |
| read_cr2(), virt, phys); |
| while(phys) { |
| safe_halt(); /* enables irq */ |
| irq_disable(); |
| } |
| break; |
| case KVM_PV_REASON_PAGE_READY: |
| report(true, "Got present #PF token %lx", read_cr2()); |
| if ((uint32_t)read_cr2() == ~0) |
| break; |
| install_pte(phys_to_virt(read_cr3()), 1, virt, phys | PT_PRESENT_MASK | PT_WRITABLE_MASK, 0); |
| write_cr3(read_cr3()); |
| phys = 0; |
| break; |
| default: |
| report(false, "unexpected async pf reason %" PRId32, reason); |
| break; |
| } |
| } |
| |
| #define MEM 1ull*1024*1024*1024 |
| |
| int main(int ac, char **av) |
| { |
| int loop = 2; |
| |
| setup_vm(); |
| printf("install handler\n"); |
| handle_exception(14, pf_isr); |
| apf_reason = 0; |
| printf("enable async pf\n"); |
| wrmsr(MSR_KVM_ASYNC_PF_EN, virt_to_phys((void*)&apf_reason) | |
| KVM_ASYNC_PF_SEND_ALWAYS | KVM_ASYNC_PF_ENABLED); |
| printf("alloc memory\n"); |
| buf = malloc(MEM); |
| irq_enable(); |
| while(loop--) { |
| printf("start loop\n"); |
| /* access a lot of memory to make host swap it out */ |
| for (i=0; i < MEM; i+=4096) |
| buf[i] = 1; |
| printf("end loop\n"); |
| } |
| irq_disable(); |
| |
| return report_summary(); |
| } |