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kvm__setup_cpuid: use KVM_GET_SUPPORTED_CPUID to simplify cpuid setup

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Let kernel setup "struct kvm_cpuid2" for us!

https://kerneltrap.org/mailarchive/linux-kernel/2010/4/27/4563640
Avi Kivity:
'''
No.  KVM_GET_CPUID2 reads what was set by KVM_SET_CPUID, as modified by
the guest executing the cpuid instruction.  KVM_GET_SUPPORTED_CPUID
tells userspace which bits are supported by the host cpu and kvm.

The API for KVM_GET_SUPPORTED_CPUID returns all cpuid leaves supported
in one go, IIRC.
'''
Signed-off-by: Asias He <asias.hejun@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
This commit is contained in:
Asias He
2010-07-12 20:52:23 +08:00
committed by Will Deacon
parent 192a99d1d7
commit bb988cf5b9
1 changed files with 5 additions and 235 deletions
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cpuid.c
+5 -235
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@@ -1,254 +1,24 @@
#include "kvm/kvm.h"
#include "kvm/cpufeature.h"
#include "kvm/util.h"
#include <sys/ioctl.h>
#include <stdlib.h>
#include <assert.h>
static struct kvm_cpuid2 *kvm_cpuid__new(unsigned long nent)
{
struct kvm_cpuid2 *self;
self = calloc(1, sizeof(*self) + (sizeof(struct kvm_cpuid_entry2) * nent));
if (!self)
die("out of memory");
return self;
}
static void kvm_cpuid__delete(struct kvm_cpuid2 *self)
{
free(self);
}
#define MAX_KVM_CPUID_ENTRIES 100
enum {
CPUID_GET_VENDOR_ID = 0x00,
CPUID_GET_HIGHEST_EXT_FUNCTION = 0x80000000,
};
static uint32_t cpuid_highest_ext_func(void)
{
struct cpuid_regs regs;
regs = (struct cpuid_regs) {
.eax = CPUID_GET_HIGHEST_EXT_FUNCTION,
};
host_cpuid(&regs);
return regs.eax;
}
static uint32_t cpuid_highest_func(void)
{
struct cpuid_regs regs;
regs = (struct cpuid_regs) {
.eax = CPUID_GET_VENDOR_ID,
};
host_cpuid(&regs);
return regs.eax;
}
void kvm__setup_cpuid(struct kvm *self)
{
struct kvm_cpuid2 *kvm_cpuid;
uint32_t highest_ext;
uint32_t function;
uint32_t highest;
uint32_t ndx = 0;
kvm_cpuid = kvm_cpuid__new(MAX_KVM_CPUID_ENTRIES);
highest = cpuid_highest_func();
kvm_cpuid = calloc(1, sizeof(*kvm_cpuid) + MAX_KVM_CPUID_ENTRIES * sizeof(*kvm_cpuid->entries));
for (function = 0; function <= highest; function++) {
/*
* NOTE NOTE NOTE! Functions 0x0b and 0x0d seem to need special
* treatment as per qemu sources but we treat them as regular
* CPUID functions here because they are fairly exotic and the
* Linux kernel is not interested in them during boot up.
*/
switch (function) {
case 0x00: { /* Vendor-ID and Largest Standard Function */
kvm_cpuid->entries[ndx++] = (struct kvm_cpuid_entry2) {
.function = 0,
.index = 0,
.flags = 0,
.eax = 4,
.ebx = CPUID_VENDOR_INTEL_1,
.ecx = CPUID_VENDOR_INTEL_3,
.edx = CPUID_VENDOR_INTEL_2,
};
break;
}
case 0x01: { /* Feature Information */
struct cpuid_regs regs;
regs = (struct cpuid_regs) {
.eax = function,
};
host_cpuid(&regs);
kvm_cpuid->entries[ndx++] = (struct kvm_cpuid_entry2) {
.function = function,
.index = 0,
.flags = 0,
.eax = regs.eax,
.ebx = regs.ebx,
.ecx =
cpu_feature_disable(regs.ecx, KVM__X86_FEATURE_XSAVE) &
cpu_feature_disable(regs.ecx, KVM__X86_FEATURE_VMX),
.edx = regs.edx,
};
break;
}
case 0x02: { /* Processor configuration descriptor */
struct cpuid_regs regs;
uint32_t times;
regs = (struct cpuid_regs) {
.eax = function,
};
host_cpuid(&regs);
kvm_cpuid->entries[ndx++] = (struct kvm_cpuid_entry2) {
.function = function,
.index = 0,
.flags = KVM_CPUID_FLAG_STATEFUL_FUNC | KVM_CPUID_FLAG_STATE_READ_NEXT,
.eax = regs.eax,
.ebx = regs.ebx,
.ecx = regs.ecx,
.edx = regs.edx,
};
times = regs.eax & 0xff; /* AL */
while (times-- > 0) {
regs = (struct cpuid_regs) {
.eax = function,
};
host_cpuid(&regs);
kvm_cpuid->entries[ndx++] = (struct kvm_cpuid_entry2) {
.function = function,
.index = 0,
.flags = KVM_CPUID_FLAG_STATEFUL_FUNC,
.eax = regs.eax,
.ebx = regs.ebx,
.ecx = regs.ecx,
.edx = regs.edx,
};
}
break;
}
case 0x04: { /* Deterministic Cache Parameters */
uint32_t eax;
/*
* eax for n cores
* eax = (n - 1) << 26
* eax for k threads
* eax = (k - 1) << 14
* they could be OR'ified
*/
eax = 0;
/* L1 dcache info */
kvm_cpuid->entries[ndx++] = (struct kvm_cpuid_entry2) {
.function = function,
.index = 0,
.flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX | KVM_CPUID_FLAG_STATE_READ_NEXT,
.eax = eax | 0x0000121,
.ebx = 0x1c0003f,
.ecx = 0x000003f,
.edx = 0x0000001,
};
/* L1 icache info */
kvm_cpuid->entries[ndx++] = (struct kvm_cpuid_entry2) {
.function = function,
.index = 1,
.flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX | KVM_CPUID_FLAG_STATE_READ_NEXT,
.eax = eax | 0x0000122,
.ebx = 0x1c0003f,
.ecx = 0x000003f,
.edx = 0x0000001,
};
/* L2 cache info */
kvm_cpuid->entries[ndx++] = (struct kvm_cpuid_entry2) {
.function = function,
.index = 2,
.flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX | KVM_CPUID_FLAG_STATE_READ_NEXT,
.eax = eax | 0x0000143,
.ebx = 0x3c0003f,
.ecx = 0x0000fff,
.edx = 0x0000001,
};
/* End of list */
kvm_cpuid->entries[ndx++] = (struct kvm_cpuid_entry2) {
.function = function,
.index = 3,
.flags = 0,
.eax = 0,
.ebx = 0,
.ecx = 0,
.edx = 0,
};
break;
}
default: {
struct cpuid_regs regs;
regs = (struct cpuid_regs) {
.eax = function,
};
host_cpuid(&regs);
kvm_cpuid->entries[ndx++] = (struct kvm_cpuid_entry2) {
.function = function,
.index = 0,
.flags = 0,
.eax = regs.eax,
.ebx = regs.ebx,
.ecx = regs.ecx,
.edx = regs.edx,
};
break;
}};
}
highest_ext = cpuid_highest_ext_func();
for (function = CPUID_GET_HIGHEST_EXT_FUNCTION; function <= highest_ext; function++) {
struct cpuid_regs regs;
regs = (struct cpuid_regs) {
.eax = function,
};
host_cpuid(&regs);
kvm_cpuid->entries[ndx++] = (struct kvm_cpuid_entry2) {
.function = function,
.index = 0,
.flags = 0,
.eax = regs.eax,
.ebx = regs.ebx,
.ecx = regs.ecx,
.edx = regs.edx,
};
}
assert(ndx < MAX_KVM_CPUID_ENTRIES);
kvm_cpuid->nent = ndx;
kvm_cpuid->nent = MAX_KVM_CPUID_ENTRIES;
if (ioctl(self->sys_fd, KVM_GET_SUPPORTED_CPUID, kvm_cpuid) < 0)
die_perror("KVM_GET_SUPPORTED_CPUID failed");
if (ioctl(self->vcpu_fd, KVM_SET_CPUID2, kvm_cpuid) < 0)
die_perror("KVM_SET_CPUID2 failed");
kvm_cpuid__delete(kvm_cpuid);
free(kvm_cpuid);
}