system/freebsd-src
system/freebsd-src
1
0
Fork 0
mirror of https://github.com/freebsd/freebsd-src synced 2024-09-20 00:33:57 +00:00
Code Issues Packages Projects Releases Wiki Activity

Detect VMware guest and set the TSC frequency as reported by the hypervisor.

Browse source 
VMware products virtualize TSC and it run at fixed frequency in so-called
"apparent time".  Although virtualized i8254 also runs in apparent time, TSC
calibration always gives slightly off frequency because of the complicated
timer emulation and lost-tick correction mechanism.
This commit is contained in:
Jung-uk Kim 2011-04-29 18:20:12 +00:00
parent e57539af23
commit 5da5812ba7
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=221214
1 changed files with 101 additions and 17 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

118
sys/x86/x86/tsc.c
View file

@ -32,6 +32,7 @@ __FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/limits.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
@ -90,6 +91,87 @@ static struct timecounter tsc_timecounter = {
800, /* quality (adjusted in code) */
};
#define VMW_HVMAGIC 0x564d5868
#define VMW_HVPORT 0x5658
#define VMW_HVCMD_GETVERSION 10
#define VMW_HVCMD_GETHZ 45
static __inline void
vmware_hvcall(u_int cmd, u_int *p)
{
__asm __volatile("inl (%%dx)"
: "=a" (p[0]), "=b" (p[1]), "=c" (p[2]), "=d" (p[3])
: "0" (VMW_HVMAGIC), "1" (UINT_MAX), "2" (cmd), "3" (VMW_HVPORT)
: "memory");
}
static int
tsc_freq_vmware(void)
{
char hv_sig[13];
u_int regs[4];
char *p;
u_int hv_high;
int i;
/*
* [RFC] CPUID usage for interaction between Hypervisors and Linux.
* http://lkml.org/lkml/2008/10/1/246
*
* KB1009458: Mechanisms to determine if software is running in
* a VMware virtual machine
* http://kb.vmware.com/kb/1009458
*/
hv_high = 0;
if ((cpu_feature2 & CPUID2_HV) != 0) {
do_cpuid(0x40000000, regs);
hv_high = regs[0];
for (i = 1, p = hv_sig; i < 4; i++, p += sizeof(regs) / 4)
memcpy(p, &regs[i], sizeof(regs[i]));
*p = '\0';
if (bootverbose) {
/*
* HV vendor ID string
* ------------+--------------
* KVM "KVMKVMKVM"
* Microsoft "Microsoft Hv"
* VMware "VMwareVMware"
* Xen "XenVMMXenVMM"
*/
printf("Hypervisor: Origin = \"%s\"\n", hv_sig);
}
if (strncmp(hv_sig, "VMwareVMware", 12) != 0)
return (0);
} else {
p = getenv("smbios.system.serial");
if (p == NULL)
return (0);
if (strncmp(p, "VMware-", 7) != 0 &&
strncmp(p, "VMW", 3) != 0) {
freeenv(p);
return (0);
}
freeenv(p);
vmware_hvcall(VMW_HVCMD_GETVERSION, regs);
if (regs[1] != VMW_HVMAGIC)
return (0);
}
if (hv_high >= 0x40000010) {
do_cpuid(0x40000010, regs);
tsc_freq = regs[0] * 1000;
} else {
vmware_hvcall(VMW_HVCMD_GETHZ, regs);
if (regs[1] != UINT_MAX)
tsc_freq = regs[0] | ((uint64_t)regs[1] << 32);
}
tsc_is_invariant = 1;
#ifdef SMP
smp_tsc = 1; /* XXX */
#endif
return (1);
}
static void
tsc_freq_intel(void)
{
@ -102,7 +184,6 @@ tsc_freq_intel(void)
/*
* Intel Processor Identification and the CPUID Instruction
* Application Note 485.
*
* http://www.intel.com/assets/pdf/appnote/241618.pdf
*/
if (cpu_exthigh >= 0x80000004) {
@ -156,6 +237,25 @@ probe_tsc_freq(void)
u_int regs[4];
uint64_t tsc1, tsc2;
if (cpu_high >= 6) {
do_cpuid(6, regs);
if ((regs[2] & CPUID_PERF_STAT) != 0) {
/*
* XXX Some emulators expose host CPUID without actual
* support for these MSRs. We must test whether they
* really work.
*/
wrmsr(MSR_MPERF, 0);
wrmsr(MSR_APERF, 0);
DELAY(10);
if (rdmsr(MSR_MPERF) > 0 && rdmsr(MSR_APERF) > 0)
tsc_perf_stat = 1;
}
}
if (tsc_freq_vmware())
return;
switch (cpu_vendor_id) {
case CPU_VENDOR_AMD:
if ((amd_pminfo & AMDPM_TSC_INVARIANT) != 0 ||
@ -181,22 +281,6 @@ probe_tsc_freq(void)
break;
}
if (cpu_high >= 6) {
do_cpuid(6, regs);
if ((regs[2] & CPUID_PERF_STAT) != 0) {
/*
* XXX Some emulators expose host CPUID without actual
* support for these MSRs. We must test whether they
* really work.
*/
wrmsr(MSR_MPERF, 0);
wrmsr(MSR_APERF, 0);
DELAY(10);
if (rdmsr(MSR_MPERF) > 0 && rdmsr(MSR_APERF) > 0)
tsc_perf_stat = 1;
}
}
if (tsc_skip_calibration) {
if (cpu_vendor_id == CPU_VENDOR_INTEL)
tsc_freq_intel();