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Instead of individual conditional statements to look for each hypervisor

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type, use a table to make it easier to add more in the future, if needed.

Add VirtualBox detection to the table ("VBoxVBoxVBox" is the hypervisor
vendor string to look for.) Also add VM_GUEST_VBOX to the VM_GUEST
enumeration to indicate VirtualBox.

Save the CPUID base for the hypervisor entry that we detected. Driver code
may need to know about it in order to obtain additional CPUID features.

Approved by:	bryanv, jhb
Differential Revision:	https://reviews.freebsd.org/D16305
This commit is contained in:
Stephen J. Kiernan 2019-05-17 17:21:32 +00:00
parent 8f7f38457f
commit 949f834a61
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=347932
4 changed files with 70 additions and 23 deletions
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1
sys/kern/subr_param.c
View File

@ -153,6 +153,7 @@ static const char *const vm_guest_sysctl_names[] = {
"vmware",
"kvm",
"bhyve",
"vbox",
NULL
};
CTASSERT(nitems(vm_guest_sysctl_names) - 1 == VM_LAST);

3
sys/sys/systm.h
View File

@ -78,7 +78,8 @@ extern int vm_guest; /* Running as virtual machine guest? */
* Keep in sync with vm_guest_sysctl_names[].
*/
enum VM_GUEST { VM_GUEST_NO = 0, VM_GUEST_VM, VM_GUEST_XEN, VM_GUEST_HV,
VM_GUEST_VMWARE, VM_GUEST_KVM, VM_GUEST_BHYVE, VM_LAST };
VM_GUEST_VMWARE, VM_GUEST_KVM, VM_GUEST_BHYVE, VM_GUEST_VBOX,
VM_LAST };
/*
* These functions need to be declared before the KASSERT macro is invoked in

1
sys/x86/include/x86_var.h
View File

@ -68,6 +68,7 @@ extern u_int cpu_mon_min_size;
extern u_int cpu_mon_max_size;
extern u_int cpu_maxphyaddr;
extern char ctx_switch_xsave[];
extern u_int hv_base;
extern u_int hv_high;
extern char hv_vendor[];
extern char kstack[];

88
sys/x86/x86/identcpu.c
View File

@ -164,6 +164,7 @@ static int hw_clockrate;
SYSCTL_INT(_hw, OID_AUTO, clockrate, CTLFLAG_RD,
&hw_clockrate, 0, "CPU instruction clock rate");
u_int hv_base;
u_int hv_high;
char hv_vendor[16];
SYSCTL_STRING(_hw, OID_AUTO, hv_vendor, CTLFLAG_RD | CTLFLAG_MPSAFE, hv_vendor,
@ -1323,11 +1324,22 @@ static const char *const vm_pnames[] = {
NULL
};
void
identify_hypervisor(void)
static struct {
const char *vm_cpuid;
int vm_guest;
} vm_cpuids[] = {
{ "XENXENXEN", VM_GUEST_XEN }, /* XEN */
{ "Microsoft Hv", VM_GUEST_HV }, /* Microsoft Hyper-V */
{ "VMwareVMware", VM_GUEST_VMWARE }, /* VMware VM */
{ "KVMKVMKVM", VM_GUEST_KVM }, /* KVM */
{ "bhyve bhyve ", VM_GUEST_BHYVE }, /* bhyve */
{ "VBoxVBoxVBox", VM_GUEST_VBOX }, /* VirtualBox */
};
static void
identify_hypervisor_cpuid_base(void)
{
u_int regs[4];
char *p;
u_int leaf, regs[4];
int i;
/*
@ -1337,10 +1349,13 @@ identify_hypervisor(void)
* KB1009458: Mechanisms to determine if software is running in
* a VMware virtual machine
* http://kb.vmware.com/kb/1009458
*
* Search for a hypervisor that we recognize. If we cannot find
* a specific hypervisor, return the first information about the
* hypervisor that we found, as others may be able to use.
*/
if (cpu_feature2 & CPUID2_HV) {
vm_guest = VM_GUEST_VM;
do_cpuid(0x40000000, regs);
for (leaf = 0x40000000; leaf < 0x40010000; leaf += 0x100) {
do_cpuid(leaf, regs);
/*
* KVM from Linux kernels prior to commit
@ -1351,23 +1366,52 @@ identify_hypervisor(void)
*/
if (regs[0] == 0 && regs[1] == 0x4b4d564b &&
regs[2] == 0x564b4d56 && regs[3] == 0x0000004d)
regs[0] = 0x40000001;
regs[0] = leaf + 1;
if (regs[0] >= 0x40000000) {
hv_high = regs[0];
((u_int *)&hv_vendor)[0] = regs[1];
((u_int *)&hv_vendor)[1] = regs[2];
((u_int *)&hv_vendor)[2] = regs[3];
hv_vendor[12] = '\0';
if (strcmp(hv_vendor, "VMwareVMware") == 0)
vm_guest = VM_GUEST_VMWARE;
else if (strcmp(hv_vendor, "Microsoft Hv") == 0)
vm_guest = VM_GUEST_HV;
else if (strcmp(hv_vendor, "KVMKVMKVM") == 0)
vm_guest = VM_GUEST_KVM;
else if (strcmp(hv_vendor, "bhyve bhyve ") == 0)
vm_guest = VM_GUEST_BHYVE;
if (regs[0] >= leaf) {
for (i = 0; i < nitems(vm_cpuids); i++)
if (strncmp((const char *)&regs[1],
vm_cpuids[i].vm_cpuid, 12) == 0) {
vm_guest = vm_cpuids[i].vm_guest;
break;
}
/*
* If this is the first entry or we found a
* specific hypervisor, record the base, high value,
* and vendor identifier.
*/
if (vm_guest != VM_GUEST_VM || leaf == 0x40000000) {
hv_high = leaf;
((u_int *)&hv_vendor)[0] = regs[1];
((u_int *)&hv_vendor)[1] = regs[2];
((u_int *)&hv_vendor)[2] = regs[3];
hv_vendor[12] = '\0';
/*
* If we found a specific hypervisor, then
* we are finished.
*/
if (vm_guest != VM_GUEST_VM)
return;
}
}
}
}
void
identify_hypervisor(void)
{
u_int regs[4];
char *p;
int i;
/*
* If CPUID2_HV is set, we are running in a hypervisor environment.
*/
if (cpu_feature2 & CPUID2_HV) {
vm_guest = VM_GUEST_VM;
identify_hypervisor_cpuid_base();
return;
}