/*-
* Copyright (c) 2011 NetApp, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/pcpu.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <machine/clock.h>
#include <machine/cpufunc.h>
#include <machine/md_var.h>
#include <machine/segments.h>
#include <machine/specialreg.h>
#include <machine/vmm.h>
#include "vmm_host.h"
#include "vmm_ktr.h"
#include "vmm_util.h"
#include "x86.h"
SYSCTL_DECL(_hw_vmm);
static SYSCTL_NODE(_hw_vmm, OID_AUTO, topology, CTLFLAG_RD, 0, NULL);
#define CPUID_VM_HIGH 0x40000000
static const char bhyve_id[12] = "bhyve bhyve ";
static uint64_t bhyve_xcpuids;
SYSCTL_ULONG(_hw_vmm, OID_AUTO, bhyve_xcpuids, CTLFLAG_RW, &bhyve_xcpuids, 0,
"Number of times an unknown cpuid leaf was accessed");
/*
* The default CPU topology is a single thread per package.
*/
static u_int threads_per_core = 1;
SYSCTL_UINT(_hw_vmm_topology, OID_AUTO, threads_per_core, CTLFLAG_RDTUN,
&threads_per_core, 0, NULL);
static u_int cores_per_package = 1;
SYSCTL_UINT(_hw_vmm_topology, OID_AUTO, cores_per_package, CTLFLAG_RDTUN,
&cores_per_package, 0, NULL);
static int cpuid_leaf_b = 1;
SYSCTL_INT(_hw_vmm_topology, OID_AUTO, cpuid_leaf_b, CTLFLAG_RDTUN,
&cpuid_leaf_b, 0, NULL);
/*
* Round up to the next power of two, if necessary, and then take log2.
* Returns -1 if argument is zero.
*/
static __inline int
log2(u_int x)
{
return (fls(x << (1 - powerof2(x))) - 1);
}
int
x86_emulate_cpuid(struct vm *vm, int vcpu_id,
uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx)
{
const struct xsave_limits *limits;
uint64_t cr4;
int error, enable_invpcid, level, width, x2apic_id;
unsigned int func, regs[4], logical_cpus;
enum x2apic_state x2apic_state;
VCPU_CTR2(vm, vcpu_id, "cpuid %#x,%#x", *eax, *ecx);
/*
* Requests for invalid CPUID levels should map to the highest
* available level instead.
*/
if (cpu_exthigh != 0 && *eax >= 0x80000000) {
if (*eax > cpu_exthigh)
*eax = cpu_exthigh;
} else if (*eax >= 0x40000000) {
if (*eax > CPUID_VM_HIGH)
*eax = CPUID_VM_HIGH;
} else if (*eax > cpu_high) {
*eax = cpu_high;
}
func = *eax;
/*
* In general the approach used for CPU topology is to
* advertise a flat topology where all CPUs are packages with
* no multi-core or SMT.
*/
switch (func) {
/*
* Pass these through to the guest
*/
case CPUID_0000_0000:
case CPUID_0000_0002:
case CPUID_0000_0003:
case CPUID_8000_0000:
case CPUID_8000_0002:
case CPUID_8000_0003:
case CPUID_8000_0004:
case CPUID_8000_0006:
cpuid_count(*eax, *ecx, regs);
break;
case CPUID_8000_0008:
cpuid_count(*eax, *ecx, regs);
if (vmm_is_amd()) {
/*
* XXX this might appear silly because AMD
* cpus don't have threads.
*
* However this matches the logical cpus as
* advertised by leaf 0x1 and will work even
* if the 'threads_per_core' tunable is set
* incorrectly on an AMD host.
*/
logical_cpus = threads_per_core *
cores_per_package;
regs[2] = logical_cpus - 1;
}
break;
case CPUID_8000_0001:
cpuid_count(*eax, *ecx, regs);
/*
* Hide SVM and Topology Extension features from guest.
*/
regs[2] &= ~(AMDID2_SVM | AMDID2_TOPOLOGY);
/*
* Don't advertise extended performance counter MSRs
* to the guest.
*/
regs[2] &= ~AMDID2_PCXC;
regs[2] &= ~AMDID2_PNXC;
regs[2] &= ~AMDID2_PTSCEL2I;
/*
* Don't advertise Instruction Based Sampling feature.
*/
regs[2] &= ~AMDID2_IBS;
/* NodeID MSR not available */
regs[2] &= ~AMDID2_NODE_ID;
/* Don't advertise the OS visible workaround feature */
regs[2] &= ~AMDID2_OSVW;
/*
* Hide rdtscp/ia32_tsc_aux until we know how
* to deal with them.
*/
regs[3] &= ~AMDID_RDTSCP;
break;
case CPUID_8000_0007:
/*
* AMD uses this leaf to advertise the processor's
* power monitoring and RAS capabilities. These
* features are hardware-specific and exposing
* them to a guest doesn't make a lot of sense.
*
* Intel uses this leaf only to advertise the
* "Invariant TSC" feature with all other bits
* being reserved (set to zero).
*/
regs[0] = 0;
regs[1] = 0;
regs[2] = 0;
regs[3] = 0;
/*
* "Invariant TSC" can be advertised to the guest if:
* - host TSC frequency is invariant
* - host TSCs are synchronized across physical cpus
*
* XXX This still falls short because the vcpu
* can observe the TSC moving backwards as it
* migrates across physical cpus. But at least
* it should discourage the guest from using the
* TSC to keep track of time.
*/
if (tsc_is_invariant && smp_tsc)
regs[3] |= AMDPM_TSC_INVARIANT;
break;
case CPUID_0000_0001:
do_cpuid(1, regs);
error = vm_get_x2apic_state(vm, vcpu_id, &x2apic_state);
if (error) {
panic("x86_emulate_cpuid: error %d "
"fetching x2apic state", error);
}
/*
* Override the APIC ID only in ebx
*/
regs[1] &= ~(CPUID_LOCAL_APIC_ID);
regs[1] |= (vcpu_id << CPUID_0000_0001_APICID_SHIFT);
/*
* Don't expose VMX, SpeedStep, TME or SMX capability.
* Advertise x2APIC capability and Hypervisor guest.
*/
regs[2] &= ~(CPUID2_VMX | CPUID2_EST | CPUID2_TM2);
regs[2] &= ~(CPUID2_SMX);
regs[2] |= CPUID2_HV;
if (x2apic_state != X2APIC_DISABLED)
regs[2] |= CPUID2_X2APIC;
else
regs[2] &= ~CPUID2_X2APIC;
/*
* Only advertise CPUID2_XSAVE in the guest if
* the host is using XSAVE.
*/
if (!(regs[2] & CPUID2_OSXSAVE))
regs[2] &= ~CPUID2_XSAVE;
/*
* If CPUID2_XSAVE is being advertised and the
* guest has set CR4_XSAVE, set
* CPUID2_OSXSAVE.
*/
regs[2] &= ~CPUID2_OSXSAVE;
if (regs[2] & CPUID2_XSAVE) {
error = vm_get_register(vm, vcpu_id,
VM_REG_GUEST_CR4, &cr4);
if (error)
panic("x86_emulate_cpuid: error %d "
"fetching %%cr4", error);
if (cr4 & CR4_XSAVE)
regs[2] |= CPUID2_OSXSAVE;
}
/*
* Hide monitor/mwait until we know how to deal with
* these instructions.
*/
regs[2] &= ~CPUID2_MON;
/*
* Hide the performance and debug features.
*/
regs[2] &= ~CPUID2_PDCM;
/*
* No TSC deadline support in the APIC yet
*/
regs[2] &= ~CPUID2_TSCDLT;
/*
* Hide thermal monitoring
*/
regs[3] &= ~(CPUID_ACPI | CPUID_TM);
/*
* Hide the debug store capability.
*/
regs[3] &= ~CPUID_DS;
/*
* Advertise the Machine Check and MTRR capability.
*
* Some guest OSes (e.g. Windows) will not boot if
* these features are absent.
*/
regs[3] |= (CPUID_MCA | CPUID_MCE | CPUID_MTRR);
logical_cpus = threads_per_core * cores_per_package;
regs[1] &= ~CPUID_HTT_CORES;
regs[1] |= (logical_cpus & 0xff) << 16;
regs[3] |= CPUID_HTT;
break;
case CPUID_0000_0004:
cpuid_count(*eax, *ecx, regs);
if (regs[0] || regs[1] || regs[2] || regs[3]) {
regs[0] &= 0x3ff;
regs[0] |= (cores_per_package - 1) << 26;
/*
* Cache topology:
* - L1 and L2 are shared only by the logical
* processors in a single core.
* - L3 and above are shared by all logical
* processors in the package.
*/
logical_cpus = threads_per_core;
level = (regs[0] >> 5) & 0x7;
if (level >= 3)
logical_cpus *= cores_per_package;
regs[0] |= (logical_cpus - 1) << 14;
}
break;
case CPUID_0000_0007:
regs[0] = 0;
regs[1] = 0;
regs[2] = 0;
regs[3] = 0;
/* leaf 0 */
if (*ecx == 0) {
cpuid_count(*eax, *ecx, regs);
/* Only leaf 0 is supported */
regs[0] = 0;
/*
* Expose known-safe features.
*/
regs[1] &= (CPUID_STDEXT_FSGSBASE |
CPUID_STDEXT_BMI1 | CPUID_STDEXT_HLE |
CPUID_STDEXT_AVX2 | CPUID_STDEXT_BMI2 |
CPUID_STDEXT_ERMS | CPUID_STDEXT_RTM |
CPUID_STDEXT_AVX512F |
CPUID_STDEXT_AVX512PF |
CPUID_STDEXT_AVX512ER |
CPUID_STDEXT_AVX512CD);
regs[2] = 0;
regs[3] = 0;
/* Advertise INVPCID if it is enabled. */
error = vm_get_capability(vm, vcpu_id,
VM_CAP_ENABLE_INVPCID, &enable_invpcid);
if (error == 0 && enable_invpcid)
regs[1] |= CPUID_STDEXT_INVPCID;
}
break;
case CPUID_0000_0006:
regs[0] = CPUTPM1_ARAT;
regs[1] = 0;
regs[2] = 0;
regs[3] = 0;
break;
case CPUID_0000_000A:
/*
* Handle the access, but report 0 for
* all options
*/
regs[0] = 0;
regs[1] = 0;
regs[2] = 0;
regs[3] = 0;
break;
case CPUID_0000_000B:
/*
* Processor topology enumeration
*/
if (*ecx == 0) {
logical_cpus = threads_per_core;
width = log2(logical_cpus);
level = CPUID_TYPE_SMT;
x2apic_id = vcpu_id;
}
if (*ecx == 1) {
logical_cpus = threads_per_core *
cores_per_package;
width = log2(logical_cpus);
level = CPUID_TYPE_CORE;
x2apic_id = vcpu_id;
}
if (!cpuid_leaf_b || *ecx >= 2) {
width = 0;
logical_cpus = 0;
level = 0;
x2apic_id = 0;
}
regs[0] = width & 0x1f;
regs[1] = logical_cpus & 0xffff;
regs[2] = (level << 8) | (*ecx & 0xff);
regs[3] = x2apic_id;
break;
case CPUID_0000_000D:
limits = vmm_get_xsave_limits();
if (!limits->xsave_enabled) {
regs[0] = 0;
regs[1] = 0;
regs[2] = 0;
regs[3] = 0;
break;
}
cpuid_count(*eax, *ecx, regs);
switch (*ecx) {
case 0:
/*
* Only permit the guest to use bits
* that are active in the host in
* %xcr0. Also, claim that the
* maximum save area size is
* equivalent to the host's current
* save area size. Since this runs
* "inside" of vmrun(), it runs with
* the guest's xcr0, so the current
* save area size is correct as-is.
*/
regs[0] &= limits->xcr0_allowed;
regs[2] = limits->xsave_max_size;
regs[3] &= (limits->xcr0_allowed >> 32);
break;
case 1:
/* Only permit XSAVEOPT. */
regs[0] &= CPUID_EXTSTATE_XSAVEOPT;
regs[1] = 0;
regs[2] = 0;
regs[3] = 0;
break;
default:
/*
* If the leaf is for a permitted feature,
* pass through as-is, otherwise return
* all zeroes.
*/
if (!(limits->xcr0_allowed & (1ul << *ecx))) {
regs[0] = 0;
regs[1] = 0;
regs[2] = 0;
regs[3] = 0;
}
break;
}
break;
case 0x40000000:
regs[0] = CPUID_VM_HIGH;
bcopy(bhyve_id, ®s[1], 4);
bcopy(bhyve_id + 4, ®s[2], 4);
bcopy(bhyve_id + 8, ®s[3], 4);
break;
default:
/*
* The leaf value has already been clamped so
* simply pass this through, keeping count of
* how many unhandled leaf values have been seen.
*/
atomic_add_long(&bhyve_xcpuids, 1);
cpuid_count(*eax, *ecx, regs);
break;
}
*eax = regs[0];
*ebx = regs[1];
*ecx = regs[2];
*edx = regs[3];
return (1);
}
bool
vm_cpuid_capability(struct vm *vm, int vcpuid, enum vm_cpuid_capability cap)
{
bool rv;
KASSERT(cap > 0 && cap < VCC_LAST, ("%s: invalid vm_cpu_capability %d",
__func__, cap));
/*
* Simply passthrough the capabilities of the host cpu for now.
*/
rv = false;
switch (cap) {
case VCC_NO_EXECUTE:
if (amd_feature & AMDID_NX)
rv = true;
break;
case VCC_FFXSR:
if (amd_feature & AMDID_FFXSR)
rv = true;
break;
case VCC_TCE:
if (amd_feature2 & AMDID2_TCE)
rv = true;
break;
default:
panic("%s: unknown vm_cpu_capability %d", __func__, cap);
}
return (rv);
}