Spaces:
Runtime error
Runtime error
File size: 2,685 Bytes
8df6da4 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 |
/*
* 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 "libcflat.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("unexpected #PF at %#lx", false, read_cr2());
break;
case KVM_PV_REASON_PAGE_NOT_PRESENT:
phys = virt_to_phys_cr3(virt);
install_pte(phys_to_virt(read_cr3()), 1, virt, phys, 0);
write_cr3(read_cr3());
report("Got not present #PF token %lx virt addr %p phys addr %#" PRIx64,
true, read_cr2(), virt, phys);
while(phys) {
safe_halt(); /* enables irq */
irq_disable();
}
break;
case KVM_PV_REASON_PAGE_READY:
report("Got present #PF token %lx", true, 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("unexpected async pf reason %d", false, reason);
break;
}
}
#define MEM 1ull*1024*1024*1024
int main(int ac, char **av)
{
int loop = 2;
setup_vm();
setup_idt();
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 = vmalloc(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();
}
|