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support vdso which borrows clocksource from linux

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This commit is contained in:
NAKAMURA Gou
2016-03-28 14:42:49 +09:00
parent a587c8f5e5
commit 41bb2ab5e6
17 changed files with 689 additions and 18 deletions
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94
arch/x86/kernel/cpu.c
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@ -29,6 +29,7 @@
#include <process.h>
#include <cls.h>
#include <prctl.h>
#include <page.h>
#define LAPIC_ID 0x020
#define LAPIC_TIMER 0x320
@ -63,8 +64,10 @@
#ifdef DEBUG_PRINT_CPU
#define dkprintf kprintf
#define ekprintf kprintf
#else
#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
#define ekprintf kprintf
#endif
static void *lapic_vp;
@ -144,6 +147,12 @@ extern char debug_exception[], int3_exception[];
uint64_t boot_pat_state = 0;
int no_turbo = 0; /* May be updated by early parsing of kargs */
extern int num_processors; /* kernel/ap.c */
struct pvclock_vcpu_time_info *pvti = NULL;
int pvti_npages;
static long pvti_msr = -1;
static void init_idt(void)
{
int i;
@ -1581,3 +1590,88 @@ void sync_tick(void)
dkprintf("sync_tick():\n");
return;
}
static int is_pvclock_available(void)
{
uint32_t eax;
uint32_t ebx;
uint32_t ecx;
uint32_t edx;
dkprintf("is_pvclock_available()\n");
#define KVM_CPUID_SIGNATURE 0x40000000
asm ("cpuid" : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx)
: "a" (KVM_CPUID_SIGNATURE));
if ((eax && (eax < 0x40000001))
|| (ebx != 0x4b4d564b)
|| (ecx != 0x564b4d56)
|| (edx != 0x0000004d)) {
dkprintf("is_pvclock_available(): false (not kvm)\n");
return 0;
}
#define KVM_CPUID_FEATURES 0x40000001
asm ("cpuid" : "=a"(eax)
: "a"(KVM_CPUID_FEATURES)
: "%ebx", "%ecx", "%edx");
#define KVM_FEATURE_CLOCKSOURCE2 3
if (eax & (1 << KVM_FEATURE_CLOCKSOURCE2)) {
#define MSR_KVM_SYSTEM_TIME_NEW 0x4b564d01
pvti_msr = MSR_KVM_SYSTEM_TIME_NEW;
dkprintf("is_pvclock_available(): true (new)\n");
return 1;
}
#define KVM_FEATURE_CLOCKSOURCE 0
else if (eax & (1 << KVM_FEATURE_CLOCKSOURCE)) {
#define MSR_KVM_SYSTEM_TIME 0x12
pvti_msr = MSR_KVM_SYSTEM_TIME;
dkprintf("is_pvclock_available(): true (old)\n");
return 1;
}
dkprintf("is_pvclock_available(): false (not supported)\n");
return 0;
} /* is_pvclock_available() */
int arch_setup_pvclock(void)
{
size_t size;
int npages;
dkprintf("arch_setup_pvclock()\n");
if (!is_pvclock_available()) {
dkprintf("arch_setup_pvclock(): not supported\n");
return 0;
}
size = num_processors * sizeof(*pvti);
npages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
pvti_npages = npages;
pvti = allocate_pages(npages, IHK_MC_AP_NOWAIT);
if (!pvti) {
ekprintf("arch_setup_pvclock: allocate_pages failed.\n");
return -ENOMEM;
}
dkprintf("arch_setup_pvclock(): ok\n");
return 0;
} /* arch_setup_pvclock() */
void arch_start_pvclock(void)
{
int cpu;
dkprintf("arch_start_pvclock()\n");
if (!pvti) {
dkprintf("arch_start_pvclock(): not supported\n");
return;
}
cpu = ihk_mc_get_processor_id();
wrmsr(pvti_msr,(intptr_t)&pvti[cpu]);
dkprintf("arch_start_pvclock(): ok\n");
return;
} /* arch_start_pvclock() */
/*** end of file ***/