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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/kvm/cpuid.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/kvm/cpuid.c')
-rw-r--r--arch/x86/kvm/cpuid.c1507
1 files changed, 1507 insertions, 0 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
new file mode 100644
index 000000000..c3ef1fc60
--- /dev/null
+++ b/arch/x86/kvm/cpuid.c
@@ -0,0 +1,1507 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Kernel-based Virtual Machine driver for Linux
+ * cpuid support routines
+ *
+ * derived from arch/x86/kvm/x86.c
+ *
+ * Copyright 2011 Red Hat, Inc. and/or its affiliates.
+ * Copyright IBM Corporation, 2008
+ */
+
+#include <linux/kvm_host.h>
+#include <linux/export.h>
+#include <linux/vmalloc.h>
+#include <linux/uaccess.h>
+#include <linux/sched/stat.h>
+
+#include <asm/processor.h>
+#include <asm/user.h>
+#include <asm/fpu/xstate.h>
+#include <asm/sgx.h>
+#include <asm/cpuid.h>
+#include "cpuid.h"
+#include "lapic.h"
+#include "mmu.h"
+#include "trace.h"
+#include "pmu.h"
+
+/*
+ * Unlike "struct cpuinfo_x86.x86_capability", kvm_cpu_caps doesn't need to be
+ * aligned to sizeof(unsigned long) because it's not accessed via bitops.
+ */
+u32 kvm_cpu_caps[NR_KVM_CPU_CAPS] __read_mostly;
+EXPORT_SYMBOL_GPL(kvm_cpu_caps);
+
+u32 xstate_required_size(u64 xstate_bv, bool compacted)
+{
+ int feature_bit = 0;
+ u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
+
+ xstate_bv &= XFEATURE_MASK_EXTEND;
+ while (xstate_bv) {
+ if (xstate_bv & 0x1) {
+ u32 eax, ebx, ecx, edx, offset;
+ cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
+ /* ECX[1]: 64B alignment in compacted form */
+ if (compacted)
+ offset = (ecx & 0x2) ? ALIGN(ret, 64) : ret;
+ else
+ offset = ebx;
+ ret = max(ret, offset + eax);
+ }
+
+ xstate_bv >>= 1;
+ feature_bit++;
+ }
+
+ return ret;
+}
+
+/*
+ * This one is tied to SSB in the user API, and not
+ * visible in /proc/cpuinfo.
+ */
+#define KVM_X86_FEATURE_PSFD (13*32+28) /* Predictive Store Forwarding Disable */
+
+#define F feature_bit
+#define SF(name) (boot_cpu_has(X86_FEATURE_##name) ? F(name) : 0)
+
+/*
+ * Magic value used by KVM when querying userspace-provided CPUID entries and
+ * doesn't care about the CPIUD index because the index of the function in
+ * question is not significant. Note, this magic value must have at least one
+ * bit set in bits[63:32] and must be consumed as a u64 by cpuid_entry2_find()
+ * to avoid false positives when processing guest CPUID input.
+ */
+#define KVM_CPUID_INDEX_NOT_SIGNIFICANT -1ull
+
+static inline struct kvm_cpuid_entry2 *cpuid_entry2_find(
+ struct kvm_cpuid_entry2 *entries, int nent, u32 function, u64 index)
+{
+ struct kvm_cpuid_entry2 *e;
+ int i;
+
+ for (i = 0; i < nent; i++) {
+ e = &entries[i];
+
+ if (e->function != function)
+ continue;
+
+ /*
+ * If the index isn't significant, use the first entry with a
+ * matching function. It's userspace's responsibilty to not
+ * provide "duplicate" entries in all cases.
+ */
+ if (!(e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) || e->index == index)
+ return e;
+
+
+ /*
+ * Similarly, use the first matching entry if KVM is doing a
+ * lookup (as opposed to emulating CPUID) for a function that's
+ * architecturally defined as not having a significant index.
+ */
+ if (index == KVM_CPUID_INDEX_NOT_SIGNIFICANT) {
+ /*
+ * Direct lookups from KVM should not diverge from what
+ * KVM defines internally (the architectural behavior).
+ */
+ WARN_ON_ONCE(cpuid_function_is_indexed(function));
+ return e;
+ }
+ }
+
+ return NULL;
+}
+
+static int kvm_check_cpuid(struct kvm_vcpu *vcpu,
+ struct kvm_cpuid_entry2 *entries,
+ int nent)
+{
+ struct kvm_cpuid_entry2 *best;
+ u64 xfeatures;
+
+ /*
+ * The existing code assumes virtual address is 48-bit or 57-bit in the
+ * canonical address checks; exit if it is ever changed.
+ */
+ best = cpuid_entry2_find(entries, nent, 0x80000008,
+ KVM_CPUID_INDEX_NOT_SIGNIFICANT);
+ if (best) {
+ int vaddr_bits = (best->eax & 0xff00) >> 8;
+
+ if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0)
+ return -EINVAL;
+ }
+
+ /*
+ * Exposing dynamic xfeatures to the guest requires additional
+ * enabling in the FPU, e.g. to expand the guest XSAVE state size.
+ */
+ best = cpuid_entry2_find(entries, nent, 0xd, 0);
+ if (!best)
+ return 0;
+
+ xfeatures = best->eax | ((u64)best->edx << 32);
+ xfeatures &= XFEATURE_MASK_USER_DYNAMIC;
+ if (!xfeatures)
+ return 0;
+
+ return fpu_enable_guest_xfd_features(&vcpu->arch.guest_fpu, xfeatures);
+}
+
+/* Check whether the supplied CPUID data is equal to what is already set for the vCPU. */
+static int kvm_cpuid_check_equal(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2,
+ int nent)
+{
+ struct kvm_cpuid_entry2 *orig;
+ int i;
+
+ if (nent != vcpu->arch.cpuid_nent)
+ return -EINVAL;
+
+ for (i = 0; i < nent; i++) {
+ orig = &vcpu->arch.cpuid_entries[i];
+ if (e2[i].function != orig->function ||
+ e2[i].index != orig->index ||
+ e2[i].flags != orig->flags ||
+ e2[i].eax != orig->eax || e2[i].ebx != orig->ebx ||
+ e2[i].ecx != orig->ecx || e2[i].edx != orig->edx)
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void kvm_update_kvm_cpuid_base(struct kvm_vcpu *vcpu)
+{
+ u32 function;
+ struct kvm_cpuid_entry2 *entry;
+
+ vcpu->arch.kvm_cpuid_base = 0;
+
+ for_each_possible_hypervisor_cpuid_base(function) {
+ entry = kvm_find_cpuid_entry(vcpu, function);
+
+ if (entry) {
+ u32 signature[3];
+
+ signature[0] = entry->ebx;
+ signature[1] = entry->ecx;
+ signature[2] = entry->edx;
+
+ BUILD_BUG_ON(sizeof(signature) > sizeof(KVM_SIGNATURE));
+ if (!memcmp(signature, KVM_SIGNATURE, sizeof(signature))) {
+ vcpu->arch.kvm_cpuid_base = function;
+ break;
+ }
+ }
+ }
+}
+
+static struct kvm_cpuid_entry2 *__kvm_find_kvm_cpuid_features(struct kvm_vcpu *vcpu,
+ struct kvm_cpuid_entry2 *entries, int nent)
+{
+ u32 base = vcpu->arch.kvm_cpuid_base;
+
+ if (!base)
+ return NULL;
+
+ return cpuid_entry2_find(entries, nent, base | KVM_CPUID_FEATURES,
+ KVM_CPUID_INDEX_NOT_SIGNIFICANT);
+}
+
+static struct kvm_cpuid_entry2 *kvm_find_kvm_cpuid_features(struct kvm_vcpu *vcpu)
+{
+ return __kvm_find_kvm_cpuid_features(vcpu, vcpu->arch.cpuid_entries,
+ vcpu->arch.cpuid_nent);
+}
+
+void kvm_update_pv_runtime(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpuid_entry2 *best = kvm_find_kvm_cpuid_features(vcpu);
+
+ /*
+ * save the feature bitmap to avoid cpuid lookup for every PV
+ * operation
+ */
+ if (best)
+ vcpu->arch.pv_cpuid.features = best->eax;
+}
+
+/*
+ * Calculate guest's supported XCR0 taking into account guest CPUID data and
+ * KVM's supported XCR0 (comprised of host's XCR0 and KVM_SUPPORTED_XCR0).
+ */
+static u64 cpuid_get_supported_xcr0(struct kvm_cpuid_entry2 *entries, int nent)
+{
+ struct kvm_cpuid_entry2 *best;
+
+ best = cpuid_entry2_find(entries, nent, 0xd, 0);
+ if (!best)
+ return 0;
+
+ return (best->eax | ((u64)best->edx << 32)) & kvm_caps.supported_xcr0;
+}
+
+static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *entries,
+ int nent)
+{
+ struct kvm_cpuid_entry2 *best;
+ u64 guest_supported_xcr0 = cpuid_get_supported_xcr0(entries, nent);
+
+ best = cpuid_entry2_find(entries, nent, 1, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
+ if (best) {
+ /* Update OSXSAVE bit */
+ if (boot_cpu_has(X86_FEATURE_XSAVE))
+ cpuid_entry_change(best, X86_FEATURE_OSXSAVE,
+ kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE));
+
+ cpuid_entry_change(best, X86_FEATURE_APIC,
+ vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE);
+ }
+
+ best = cpuid_entry2_find(entries, nent, 7, 0);
+ if (best && boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7)
+ cpuid_entry_change(best, X86_FEATURE_OSPKE,
+ kvm_read_cr4_bits(vcpu, X86_CR4_PKE));
+
+ best = cpuid_entry2_find(entries, nent, 0xD, 0);
+ if (best)
+ best->ebx = xstate_required_size(vcpu->arch.xcr0, false);
+
+ best = cpuid_entry2_find(entries, nent, 0xD, 1);
+ if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) ||
+ cpuid_entry_has(best, X86_FEATURE_XSAVEC)))
+ best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
+
+ best = __kvm_find_kvm_cpuid_features(vcpu, entries, nent);
+ if (kvm_hlt_in_guest(vcpu->kvm) && best &&
+ (best->eax & (1 << KVM_FEATURE_PV_UNHALT)))
+ best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT);
+
+ if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT)) {
+ best = cpuid_entry2_find(entries, nent, 0x1, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
+ if (best)
+ cpuid_entry_change(best, X86_FEATURE_MWAIT,
+ vcpu->arch.ia32_misc_enable_msr &
+ MSR_IA32_MISC_ENABLE_MWAIT);
+ }
+
+ /*
+ * Bits 127:0 of the allowed SECS.ATTRIBUTES (CPUID.0x12.0x1) enumerate
+ * the supported XSAVE Feature Request Mask (XFRM), i.e. the enclave's
+ * requested XCR0 value. The enclave's XFRM must be a subset of XCRO
+ * at the time of EENTER, thus adjust the allowed XFRM by the guest's
+ * supported XCR0. Similar to XCR0 handling, FP and SSE are forced to
+ * '1' even on CPUs that don't support XSAVE.
+ */
+ best = cpuid_entry2_find(entries, nent, 0x12, 0x1);
+ if (best) {
+ best->ecx &= guest_supported_xcr0 & 0xffffffff;
+ best->edx &= guest_supported_xcr0 >> 32;
+ best->ecx |= XFEATURE_MASK_FPSSE;
+ }
+}
+
+void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu)
+{
+ __kvm_update_cpuid_runtime(vcpu, vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent);
+}
+EXPORT_SYMBOL_GPL(kvm_update_cpuid_runtime);
+
+static bool kvm_cpuid_has_hyperv(struct kvm_cpuid_entry2 *entries, int nent)
+{
+ struct kvm_cpuid_entry2 *entry;
+
+ entry = cpuid_entry2_find(entries, nent, HYPERV_CPUID_INTERFACE,
+ KVM_CPUID_INDEX_NOT_SIGNIFICANT);
+ return entry && entry->eax == HYPERV_CPUID_SIGNATURE_EAX;
+}
+
+static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
+{
+ struct kvm_lapic *apic = vcpu->arch.apic;
+ struct kvm_cpuid_entry2 *best;
+
+ best = kvm_find_cpuid_entry(vcpu, 1);
+ if (best && apic) {
+ if (cpuid_entry_has(best, X86_FEATURE_TSC_DEADLINE_TIMER))
+ apic->lapic_timer.timer_mode_mask = 3 << 17;
+ else
+ apic->lapic_timer.timer_mode_mask = 1 << 17;
+
+ kvm_apic_set_version(vcpu);
+ }
+
+ vcpu->arch.guest_supported_xcr0 =
+ cpuid_get_supported_xcr0(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent);
+
+ kvm_update_pv_runtime(vcpu);
+
+ vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
+ vcpu->arch.reserved_gpa_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu);
+
+ kvm_pmu_refresh(vcpu);
+ vcpu->arch.cr4_guest_rsvd_bits =
+ __cr4_reserved_bits(guest_cpuid_has, vcpu);
+
+ kvm_hv_set_cpuid(vcpu, kvm_cpuid_has_hyperv(vcpu->arch.cpuid_entries,
+ vcpu->arch.cpuid_nent));
+
+ /* Invoke the vendor callback only after the above state is updated. */
+ static_call(kvm_x86_vcpu_after_set_cpuid)(vcpu);
+
+ /*
+ * Except for the MMU, which needs to do its thing any vendor specific
+ * adjustments to the reserved GPA bits.
+ */
+ kvm_mmu_after_set_cpuid(vcpu);
+}
+
+int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpuid_entry2 *best;
+
+ best = kvm_find_cpuid_entry(vcpu, 0x80000000);
+ if (!best || best->eax < 0x80000008)
+ goto not_found;
+ best = kvm_find_cpuid_entry(vcpu, 0x80000008);
+ if (best)
+ return best->eax & 0xff;
+not_found:
+ return 36;
+}
+
+/*
+ * This "raw" version returns the reserved GPA bits without any adjustments for
+ * encryption technologies that usurp bits. The raw mask should be used if and
+ * only if hardware does _not_ strip the usurped bits, e.g. in virtual MTRRs.
+ */
+u64 kvm_vcpu_reserved_gpa_bits_raw(struct kvm_vcpu *vcpu)
+{
+ return rsvd_bits(cpuid_maxphyaddr(vcpu), 63);
+}
+
+static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2,
+ int nent)
+{
+ int r;
+
+ __kvm_update_cpuid_runtime(vcpu, e2, nent);
+
+ /*
+ * KVM does not correctly handle changing guest CPUID after KVM_RUN, as
+ * MAXPHYADDR, GBPAGES support, AMD reserved bit behavior, etc.. aren't
+ * tracked in kvm_mmu_page_role. As a result, KVM may miss guest page
+ * faults due to reusing SPs/SPTEs. In practice no sane VMM mucks with
+ * the core vCPU model on the fly. It would've been better to forbid any
+ * KVM_SET_CPUID{,2} calls after KVM_RUN altogether but unfortunately
+ * some VMMs (e.g. QEMU) reuse vCPU fds for CPU hotplug/unplug and do
+ * KVM_SET_CPUID{,2} again. To support this legacy behavior, check
+ * whether the supplied CPUID data is equal to what's already set.
+ */
+ if (vcpu->arch.last_vmentry_cpu != -1) {
+ r = kvm_cpuid_check_equal(vcpu, e2, nent);
+ if (r)
+ return r;
+
+ kvfree(e2);
+ return 0;
+ }
+
+ if (kvm_cpuid_has_hyperv(e2, nent)) {
+ r = kvm_hv_vcpu_init(vcpu);
+ if (r)
+ return r;
+ }
+
+ r = kvm_check_cpuid(vcpu, e2, nent);
+ if (r)
+ return r;
+
+ kvfree(vcpu->arch.cpuid_entries);
+ vcpu->arch.cpuid_entries = e2;
+ vcpu->arch.cpuid_nent = nent;
+
+ kvm_update_kvm_cpuid_base(vcpu);
+ kvm_vcpu_after_set_cpuid(vcpu);
+
+ return 0;
+}
+
+/* when an old userspace process fills a new kernel module */
+int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
+ struct kvm_cpuid *cpuid,
+ struct kvm_cpuid_entry __user *entries)
+{
+ int r, i;
+ struct kvm_cpuid_entry *e = NULL;
+ struct kvm_cpuid_entry2 *e2 = NULL;
+
+ if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
+ return -E2BIG;
+
+ if (cpuid->nent) {
+ e = vmemdup_user(entries, array_size(sizeof(*e), cpuid->nent));
+ if (IS_ERR(e))
+ return PTR_ERR(e);
+
+ e2 = kvmalloc_array(cpuid->nent, sizeof(*e2), GFP_KERNEL_ACCOUNT);
+ if (!e2) {
+ r = -ENOMEM;
+ goto out_free_cpuid;
+ }
+ }
+ for (i = 0; i < cpuid->nent; i++) {
+ e2[i].function = e[i].function;
+ e2[i].eax = e[i].eax;
+ e2[i].ebx = e[i].ebx;
+ e2[i].ecx = e[i].ecx;
+ e2[i].edx = e[i].edx;
+ e2[i].index = 0;
+ e2[i].flags = 0;
+ e2[i].padding[0] = 0;
+ e2[i].padding[1] = 0;
+ e2[i].padding[2] = 0;
+ }
+
+ r = kvm_set_cpuid(vcpu, e2, cpuid->nent);
+ if (r)
+ kvfree(e2);
+
+out_free_cpuid:
+ kvfree(e);
+
+ return r;
+}
+
+int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
+ struct kvm_cpuid2 *cpuid,
+ struct kvm_cpuid_entry2 __user *entries)
+{
+ struct kvm_cpuid_entry2 *e2 = NULL;
+ int r;
+
+ if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
+ return -E2BIG;
+
+ if (cpuid->nent) {
+ e2 = vmemdup_user(entries, array_size(sizeof(*e2), cpuid->nent));
+ if (IS_ERR(e2))
+ return PTR_ERR(e2);
+ }
+
+ r = kvm_set_cpuid(vcpu, e2, cpuid->nent);
+ if (r)
+ kvfree(e2);
+
+ return r;
+}
+
+int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
+ struct kvm_cpuid2 *cpuid,
+ struct kvm_cpuid_entry2 __user *entries)
+{
+ int r;
+
+ r = -E2BIG;
+ if (cpuid->nent < vcpu->arch.cpuid_nent)
+ goto out;
+ r = -EFAULT;
+ if (copy_to_user(entries, vcpu->arch.cpuid_entries,
+ vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
+ goto out;
+ return 0;
+
+out:
+ cpuid->nent = vcpu->arch.cpuid_nent;
+ return r;
+}
+
+/* Mask kvm_cpu_caps for @leaf with the raw CPUID capabilities of this CPU. */
+static __always_inline void __kvm_cpu_cap_mask(unsigned int leaf)
+{
+ const struct cpuid_reg cpuid = x86_feature_cpuid(leaf * 32);
+ struct kvm_cpuid_entry2 entry;
+
+ reverse_cpuid_check(leaf);
+
+ cpuid_count(cpuid.function, cpuid.index,
+ &entry.eax, &entry.ebx, &entry.ecx, &entry.edx);
+
+ kvm_cpu_caps[leaf] &= *__cpuid_entry_get_reg(&entry, cpuid.reg);
+}
+
+static __always_inline
+void kvm_cpu_cap_init_scattered(enum kvm_only_cpuid_leafs leaf, u32 mask)
+{
+ /* Use kvm_cpu_cap_mask for non-scattered leafs. */
+ BUILD_BUG_ON(leaf < NCAPINTS);
+
+ kvm_cpu_caps[leaf] = mask;
+
+ __kvm_cpu_cap_mask(leaf);
+}
+
+static __always_inline void kvm_cpu_cap_mask(enum cpuid_leafs leaf, u32 mask)
+{
+ /* Use kvm_cpu_cap_init_scattered for scattered leafs. */
+ BUILD_BUG_ON(leaf >= NCAPINTS);
+
+ kvm_cpu_caps[leaf] &= mask;
+
+ __kvm_cpu_cap_mask(leaf);
+}
+
+void kvm_set_cpu_caps(void)
+{
+#ifdef CONFIG_X86_64
+ unsigned int f_gbpages = F(GBPAGES);
+ unsigned int f_lm = F(LM);
+ unsigned int f_xfd = F(XFD);
+#else
+ unsigned int f_gbpages = 0;
+ unsigned int f_lm = 0;
+ unsigned int f_xfd = 0;
+#endif
+ memset(kvm_cpu_caps, 0, sizeof(kvm_cpu_caps));
+
+ BUILD_BUG_ON(sizeof(kvm_cpu_caps) - (NKVMCAPINTS * sizeof(*kvm_cpu_caps)) >
+ sizeof(boot_cpu_data.x86_capability));
+
+ memcpy(&kvm_cpu_caps, &boot_cpu_data.x86_capability,
+ sizeof(kvm_cpu_caps) - (NKVMCAPINTS * sizeof(*kvm_cpu_caps)));
+
+ kvm_cpu_cap_mask(CPUID_1_ECX,
+ /*
+ * NOTE: MONITOR (and MWAIT) are emulated as NOP, but *not*
+ * advertised to guests via CPUID!
+ */
+ F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
+ 0 /* DS-CPL, VMX, SMX, EST */ |
+ 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
+ F(FMA) | F(CX16) | 0 /* xTPR Update */ | F(PDCM) |
+ F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
+ F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
+ 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
+ F(F16C) | F(RDRAND)
+ );
+ /* KVM emulates x2apic in software irrespective of host support. */
+ kvm_cpu_cap_set(X86_FEATURE_X2APIC);
+
+ kvm_cpu_cap_mask(CPUID_1_EDX,
+ F(FPU) | F(VME) | F(DE) | F(PSE) |
+ F(TSC) | F(MSR) | F(PAE) | F(MCE) |
+ F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
+ F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
+ F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
+ 0 /* Reserved, DS, ACPI */ | F(MMX) |
+ F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
+ 0 /* HTT, TM, Reserved, PBE */
+ );
+
+ kvm_cpu_cap_mask(CPUID_7_0_EBX,
+ F(FSGSBASE) | F(SGX) | F(BMI1) | F(HLE) | F(AVX2) |
+ F(FDP_EXCPTN_ONLY) | F(SMEP) | F(BMI2) | F(ERMS) | F(INVPCID) |
+ F(RTM) | F(ZERO_FCS_FDS) | 0 /*MPX*/ | F(AVX512F) |
+ F(AVX512DQ) | F(RDSEED) | F(ADX) | F(SMAP) | F(AVX512IFMA) |
+ F(CLFLUSHOPT) | F(CLWB) | 0 /*INTEL_PT*/ | F(AVX512PF) |
+ F(AVX512ER) | F(AVX512CD) | F(SHA_NI) | F(AVX512BW) |
+ F(AVX512VL));
+
+ kvm_cpu_cap_mask(CPUID_7_ECX,
+ F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ | F(RDPID) |
+ F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) |
+ F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG) |
+ F(CLDEMOTE) | F(MOVDIRI) | F(MOVDIR64B) | 0 /*WAITPKG*/ |
+ F(SGX_LC) | F(BUS_LOCK_DETECT)
+ );
+ /* Set LA57 based on hardware capability. */
+ if (cpuid_ecx(7) & F(LA57))
+ kvm_cpu_cap_set(X86_FEATURE_LA57);
+
+ /*
+ * PKU not yet implemented for shadow paging and requires OSPKE
+ * to be set on the host. Clear it if that is not the case
+ */
+ if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
+ kvm_cpu_cap_clear(X86_FEATURE_PKU);
+
+ kvm_cpu_cap_mask(CPUID_7_EDX,
+ F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
+ F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP) |
+ F(MD_CLEAR) | F(AVX512_VP2INTERSECT) | F(FSRM) |
+ F(SERIALIZE) | F(TSXLDTRK) | F(AVX512_FP16) |
+ F(AMX_TILE) | F(AMX_INT8) | F(AMX_BF16)
+ );
+
+ /* TSC_ADJUST and ARCH_CAPABILITIES are emulated in software. */
+ kvm_cpu_cap_set(X86_FEATURE_TSC_ADJUST);
+ kvm_cpu_cap_set(X86_FEATURE_ARCH_CAPABILITIES);
+
+ if (boot_cpu_has(X86_FEATURE_IBPB) && boot_cpu_has(X86_FEATURE_IBRS))
+ kvm_cpu_cap_set(X86_FEATURE_SPEC_CTRL);
+ if (boot_cpu_has(X86_FEATURE_STIBP))
+ kvm_cpu_cap_set(X86_FEATURE_INTEL_STIBP);
+ if (boot_cpu_has(X86_FEATURE_AMD_SSBD))
+ kvm_cpu_cap_set(X86_FEATURE_SPEC_CTRL_SSBD);
+
+ kvm_cpu_cap_mask(CPUID_7_1_EAX,
+ F(AVX_VNNI) | F(AVX512_BF16)
+ );
+
+ kvm_cpu_cap_mask(CPUID_D_1_EAX,
+ F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | F(XSAVES) | f_xfd
+ );
+
+ kvm_cpu_cap_init_scattered(CPUID_12_EAX,
+ SF(SGX1) | SF(SGX2)
+ );
+
+ kvm_cpu_cap_mask(CPUID_8000_0001_ECX,
+ F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
+ F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
+ F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
+ 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM) |
+ F(TOPOEXT) | 0 /* PERFCTR_CORE */
+ );
+
+ kvm_cpu_cap_mask(CPUID_8000_0001_EDX,
+ F(FPU) | F(VME) | F(DE) | F(PSE) |
+ F(TSC) | F(MSR) | F(PAE) | F(MCE) |
+ F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
+ F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
+ F(PAT) | F(PSE36) | 0 /* Reserved */ |
+ F(NX) | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
+ F(FXSR) | F(FXSR_OPT) | f_gbpages | F(RDTSCP) |
+ 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW)
+ );
+
+ if (!tdp_enabled && IS_ENABLED(CONFIG_X86_64))
+ kvm_cpu_cap_set(X86_FEATURE_GBPAGES);
+
+ kvm_cpu_cap_mask(CPUID_8000_0008_EBX,
+ F(CLZERO) | F(XSAVEERPTR) |
+ F(WBNOINVD) | F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) |
+ F(AMD_SSB_NO) | F(AMD_STIBP) | F(AMD_STIBP_ALWAYS_ON) |
+ __feature_bit(KVM_X86_FEATURE_PSFD)
+ );
+
+ /*
+ * AMD has separate bits for each SPEC_CTRL bit.
+ * arch/x86/kernel/cpu/bugs.c is kind enough to
+ * record that in cpufeatures so use them.
+ */
+ if (boot_cpu_has(X86_FEATURE_IBPB))
+ kvm_cpu_cap_set(X86_FEATURE_AMD_IBPB);
+ if (boot_cpu_has(X86_FEATURE_IBRS))
+ kvm_cpu_cap_set(X86_FEATURE_AMD_IBRS);
+ if (boot_cpu_has(X86_FEATURE_STIBP))
+ kvm_cpu_cap_set(X86_FEATURE_AMD_STIBP);
+ if (boot_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD))
+ kvm_cpu_cap_set(X86_FEATURE_AMD_SSBD);
+ if (!boot_cpu_has_bug(X86_BUG_SPEC_STORE_BYPASS))
+ kvm_cpu_cap_set(X86_FEATURE_AMD_SSB_NO);
+ /*
+ * The preference is to use SPEC CTRL MSR instead of the
+ * VIRT_SPEC MSR.
+ */
+ if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) &&
+ !boot_cpu_has(X86_FEATURE_AMD_SSBD))
+ kvm_cpu_cap_set(X86_FEATURE_VIRT_SSBD);
+
+ /*
+ * Hide all SVM features by default, SVM will set the cap bits for
+ * features it emulates and/or exposes for L1.
+ */
+ kvm_cpu_cap_mask(CPUID_8000_000A_EDX, 0);
+
+ kvm_cpu_cap_mask(CPUID_8000_001F_EAX,
+ 0 /* SME */ | F(SEV) | 0 /* VM_PAGE_FLUSH */ | F(SEV_ES) |
+ F(SME_COHERENT));
+
+ kvm_cpu_cap_mask(CPUID_C000_0001_EDX,
+ F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
+ F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
+ F(PMM) | F(PMM_EN)
+ );
+
+ if (cpu_feature_enabled(X86_FEATURE_SRSO_NO))
+ kvm_cpu_cap_set(X86_FEATURE_SRSO_NO);
+
+ /*
+ * Hide RDTSCP and RDPID if either feature is reported as supported but
+ * probing MSR_TSC_AUX failed. This is purely a sanity check and
+ * should never happen, but the guest will likely crash if RDTSCP or
+ * RDPID is misreported, and KVM has botched MSR_TSC_AUX emulation in
+ * the past. For example, the sanity check may fire if this instance of
+ * KVM is running as L1 on top of an older, broken KVM.
+ */
+ if (WARN_ON((kvm_cpu_cap_has(X86_FEATURE_RDTSCP) ||
+ kvm_cpu_cap_has(X86_FEATURE_RDPID)) &&
+ !kvm_is_supported_user_return_msr(MSR_TSC_AUX))) {
+ kvm_cpu_cap_clear(X86_FEATURE_RDTSCP);
+ kvm_cpu_cap_clear(X86_FEATURE_RDPID);
+ }
+}
+EXPORT_SYMBOL_GPL(kvm_set_cpu_caps);
+
+struct kvm_cpuid_array {
+ struct kvm_cpuid_entry2 *entries;
+ int maxnent;
+ int nent;
+};
+
+static struct kvm_cpuid_entry2 *get_next_cpuid(struct kvm_cpuid_array *array)
+{
+ if (array->nent >= array->maxnent)
+ return NULL;
+
+ return &array->entries[array->nent++];
+}
+
+static struct kvm_cpuid_entry2 *do_host_cpuid(struct kvm_cpuid_array *array,
+ u32 function, u32 index)
+{
+ struct kvm_cpuid_entry2 *entry = get_next_cpuid(array);
+
+ if (!entry)
+ return NULL;
+
+ memset(entry, 0, sizeof(*entry));
+ entry->function = function;
+ entry->index = index;
+ switch (function & 0xC0000000) {
+ case 0x40000000:
+ /* Hypervisor leaves are always synthesized by __do_cpuid_func. */
+ return entry;
+
+ case 0x80000000:
+ /*
+ * 0x80000021 is sometimes synthesized by __do_cpuid_func, which
+ * would result in out-of-bounds calls to do_host_cpuid.
+ */
+ {
+ static int max_cpuid_80000000;
+ if (!READ_ONCE(max_cpuid_80000000))
+ WRITE_ONCE(max_cpuid_80000000, cpuid_eax(0x80000000));
+ if (function > READ_ONCE(max_cpuid_80000000))
+ return entry;
+ }
+ break;
+
+ default:
+ break;
+ }
+
+ cpuid_count(entry->function, entry->index,
+ &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
+
+ if (cpuid_function_is_indexed(function))
+ entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
+
+ return entry;
+}
+
+static int __do_cpuid_func_emulated(struct kvm_cpuid_array *array, u32 func)
+{
+ struct kvm_cpuid_entry2 *entry;
+
+ if (array->nent >= array->maxnent)
+ return -E2BIG;
+
+ entry = &array->entries[array->nent];
+ entry->function = func;
+ entry->index = 0;
+ entry->flags = 0;
+
+ switch (func) {
+ case 0:
+ entry->eax = 7;
+ ++array->nent;
+ break;
+ case 1:
+ entry->ecx = F(MOVBE);
+ ++array->nent;
+ break;
+ case 7:
+ entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
+ entry->eax = 0;
+ if (kvm_cpu_cap_has(X86_FEATURE_RDTSCP))
+ entry->ecx = F(RDPID);
+ ++array->nent;
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
+{
+ struct kvm_cpuid_entry2 *entry;
+ int r, i, max_idx;
+
+ /* all calls to cpuid_count() should be made on the same cpu */
+ get_cpu();
+
+ r = -E2BIG;
+
+ entry = do_host_cpuid(array, function, 0);
+ if (!entry)
+ goto out;
+
+ switch (function) {
+ case 0:
+ /* Limited to the highest leaf implemented in KVM. */
+ entry->eax = min(entry->eax, 0x1fU);
+ break;
+ case 1:
+ cpuid_entry_override(entry, CPUID_1_EDX);
+ cpuid_entry_override(entry, CPUID_1_ECX);
+ break;
+ case 2:
+ /*
+ * On ancient CPUs, function 2 entries are STATEFUL. That is,
+ * CPUID(function=2, index=0) may return different results each
+ * time, with the least-significant byte in EAX enumerating the
+ * number of times software should do CPUID(2, 0).
+ *
+ * Modern CPUs, i.e. every CPU KVM has *ever* run on are less
+ * idiotic. Intel's SDM states that EAX & 0xff "will always
+ * return 01H. Software should ignore this value and not
+ * interpret it as an informational descriptor", while AMD's
+ * APM states that CPUID(2) is reserved.
+ *
+ * WARN if a frankenstein CPU that supports virtualization and
+ * a stateful CPUID.0x2 is encountered.
+ */
+ WARN_ON_ONCE((entry->eax & 0xff) > 1);
+ break;
+ /* functions 4 and 0x8000001d have additional index. */
+ case 4:
+ case 0x8000001d:
+ /*
+ * Read entries until the cache type in the previous entry is
+ * zero, i.e. indicates an invalid entry.
+ */
+ for (i = 1; entry->eax & 0x1f; ++i) {
+ entry = do_host_cpuid(array, function, i);
+ if (!entry)
+ goto out;
+ }
+ break;
+ case 6: /* Thermal management */
+ entry->eax = 0x4; /* allow ARAT */
+ entry->ebx = 0;
+ entry->ecx = 0;
+ entry->edx = 0;
+ break;
+ /* function 7 has additional index. */
+ case 7:
+ entry->eax = min(entry->eax, 1u);
+ cpuid_entry_override(entry, CPUID_7_0_EBX);
+ cpuid_entry_override(entry, CPUID_7_ECX);
+ cpuid_entry_override(entry, CPUID_7_EDX);
+
+ /* KVM only supports 0x7.0 and 0x7.1, capped above via min(). */
+ if (entry->eax == 1) {
+ entry = do_host_cpuid(array, function, 1);
+ if (!entry)
+ goto out;
+
+ cpuid_entry_override(entry, CPUID_7_1_EAX);
+ entry->ebx = 0;
+ entry->ecx = 0;
+ entry->edx = 0;
+ }
+ break;
+ case 0xa: { /* Architectural Performance Monitoring */
+ union cpuid10_eax eax;
+ union cpuid10_edx edx;
+
+ if (!static_cpu_has(X86_FEATURE_ARCH_PERFMON)) {
+ entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
+ break;
+ }
+
+ eax.split.version_id = kvm_pmu_cap.version;
+ eax.split.num_counters = kvm_pmu_cap.num_counters_gp;
+ eax.split.bit_width = kvm_pmu_cap.bit_width_gp;
+ eax.split.mask_length = kvm_pmu_cap.events_mask_len;
+ edx.split.num_counters_fixed = kvm_pmu_cap.num_counters_fixed;
+ edx.split.bit_width_fixed = kvm_pmu_cap.bit_width_fixed;
+
+ if (kvm_pmu_cap.version)
+ edx.split.anythread_deprecated = 1;
+ edx.split.reserved1 = 0;
+ edx.split.reserved2 = 0;
+
+ entry->eax = eax.full;
+ entry->ebx = kvm_pmu_cap.events_mask;
+ entry->ecx = 0;
+ entry->edx = edx.full;
+ break;
+ }
+ case 0x1f:
+ case 0xb:
+ /*
+ * No topology; a valid topology is indicated by the presence
+ * of subleaf 1.
+ */
+ entry->eax = entry->ebx = entry->ecx = 0;
+ break;
+ case 0xd: {
+ u64 permitted_xcr0 = kvm_caps.supported_xcr0 & xstate_get_guest_group_perm();
+ u64 permitted_xss = kvm_caps.supported_xss;
+
+ entry->eax &= permitted_xcr0;
+ entry->ebx = xstate_required_size(permitted_xcr0, false);
+ entry->ecx = entry->ebx;
+ entry->edx &= permitted_xcr0 >> 32;
+ if (!permitted_xcr0)
+ break;
+
+ entry = do_host_cpuid(array, function, 1);
+ if (!entry)
+ goto out;
+
+ cpuid_entry_override(entry, CPUID_D_1_EAX);
+ if (entry->eax & (F(XSAVES)|F(XSAVEC)))
+ entry->ebx = xstate_required_size(permitted_xcr0 | permitted_xss,
+ true);
+ else {
+ WARN_ON_ONCE(permitted_xss != 0);
+ entry->ebx = 0;
+ }
+ entry->ecx &= permitted_xss;
+ entry->edx &= permitted_xss >> 32;
+
+ for (i = 2; i < 64; ++i) {
+ bool s_state;
+ if (permitted_xcr0 & BIT_ULL(i))
+ s_state = false;
+ else if (permitted_xss & BIT_ULL(i))
+ s_state = true;
+ else
+ continue;
+
+ entry = do_host_cpuid(array, function, i);
+ if (!entry)
+ goto out;
+
+ /*
+ * The supported check above should have filtered out
+ * invalid sub-leafs. Only valid sub-leafs should
+ * reach this point, and they should have a non-zero
+ * save state size. Furthermore, check whether the
+ * processor agrees with permitted_xcr0/permitted_xss
+ * on whether this is an XCR0- or IA32_XSS-managed area.
+ */
+ if (WARN_ON_ONCE(!entry->eax || (entry->ecx & 0x1) != s_state)) {
+ --array->nent;
+ continue;
+ }
+
+ if (!kvm_cpu_cap_has(X86_FEATURE_XFD))
+ entry->ecx &= ~BIT_ULL(2);
+ entry->edx = 0;
+ }
+ break;
+ }
+ case 0x12:
+ /* Intel SGX */
+ if (!kvm_cpu_cap_has(X86_FEATURE_SGX)) {
+ entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
+ break;
+ }
+
+ /*
+ * Index 0: Sub-features, MISCSELECT (a.k.a extended features)
+ * and max enclave sizes. The SGX sub-features and MISCSELECT
+ * are restricted by kernel and KVM capabilities (like most
+ * feature flags), while enclave size is unrestricted.
+ */
+ cpuid_entry_override(entry, CPUID_12_EAX);
+ entry->ebx &= SGX_MISC_EXINFO;
+
+ entry = do_host_cpuid(array, function, 1);
+ if (!entry)
+ goto out;
+
+ /*
+ * Index 1: SECS.ATTRIBUTES. ATTRIBUTES are restricted a la
+ * feature flags. Advertise all supported flags, including
+ * privileged attributes that require explicit opt-in from
+ * userspace. ATTRIBUTES.XFRM is not adjusted as userspace is
+ * expected to derive it from supported XCR0.
+ */
+ entry->eax &= SGX_ATTR_DEBUG | SGX_ATTR_MODE64BIT |
+ SGX_ATTR_PROVISIONKEY | SGX_ATTR_EINITTOKENKEY |
+ SGX_ATTR_KSS;
+ entry->ebx &= 0;
+ break;
+ /* Intel PT */
+ case 0x14:
+ if (!kvm_cpu_cap_has(X86_FEATURE_INTEL_PT)) {
+ entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
+ break;
+ }
+
+ for (i = 1, max_idx = entry->eax; i <= max_idx; ++i) {
+ if (!do_host_cpuid(array, function, i))
+ goto out;
+ }
+ break;
+ /* Intel AMX TILE */
+ case 0x1d:
+ if (!kvm_cpu_cap_has(X86_FEATURE_AMX_TILE)) {
+ entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
+ break;
+ }
+
+ for (i = 1, max_idx = entry->eax; i <= max_idx; ++i) {
+ if (!do_host_cpuid(array, function, i))
+ goto out;
+ }
+ break;
+ case 0x1e: /* TMUL information */
+ if (!kvm_cpu_cap_has(X86_FEATURE_AMX_TILE)) {
+ entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
+ break;
+ }
+ break;
+ case KVM_CPUID_SIGNATURE: {
+ const u32 *sigptr = (const u32 *)KVM_SIGNATURE;
+ entry->eax = KVM_CPUID_FEATURES;
+ entry->ebx = sigptr[0];
+ entry->ecx = sigptr[1];
+ entry->edx = sigptr[2];
+ break;
+ }
+ case KVM_CPUID_FEATURES:
+ entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
+ (1 << KVM_FEATURE_NOP_IO_DELAY) |
+ (1 << KVM_FEATURE_CLOCKSOURCE2) |
+ (1 << KVM_FEATURE_ASYNC_PF) |
+ (1 << KVM_FEATURE_PV_EOI) |
+ (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
+ (1 << KVM_FEATURE_PV_UNHALT) |
+ (1 << KVM_FEATURE_PV_TLB_FLUSH) |
+ (1 << KVM_FEATURE_ASYNC_PF_VMEXIT) |
+ (1 << KVM_FEATURE_PV_SEND_IPI) |
+ (1 << KVM_FEATURE_POLL_CONTROL) |
+ (1 << KVM_FEATURE_PV_SCHED_YIELD) |
+ (1 << KVM_FEATURE_ASYNC_PF_INT);
+
+ if (sched_info_on())
+ entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
+
+ entry->ebx = 0;
+ entry->ecx = 0;
+ entry->edx = 0;
+ break;
+ case 0x80000000:
+ entry->eax = min(entry->eax, 0x80000021);
+ /*
+ * Serializing LFENCE is reported in a multitude of ways, and
+ * NullSegClearsBase is not reported in CPUID on Zen2; help
+ * userspace by providing the CPUID leaf ourselves.
+ *
+ * However, only do it if the host has CPUID leaf 0x8000001d.
+ * QEMU thinks that it can query the host blindly for that
+ * CPUID leaf if KVM reports that it supports 0x8000001d or
+ * above. The processor merrily returns values from the
+ * highest Intel leaf which QEMU tries to use as the guest's
+ * 0x8000001d. Even worse, this can result in an infinite
+ * loop if said highest leaf has no subleaves indexed by ECX.
+ */
+ if (entry->eax >= 0x8000001d &&
+ (static_cpu_has(X86_FEATURE_LFENCE_RDTSC)
+ || !static_cpu_has_bug(X86_BUG_NULL_SEG)))
+ entry->eax = max(entry->eax, 0x80000021);
+ break;
+ case 0x80000001:
+ entry->ebx &= ~GENMASK(27, 16);
+ cpuid_entry_override(entry, CPUID_8000_0001_EDX);
+ cpuid_entry_override(entry, CPUID_8000_0001_ECX);
+ break;
+ case 0x80000006:
+ /* Drop reserved bits, pass host L2 cache and TLB info. */
+ entry->edx &= ~GENMASK(17, 16);
+ break;
+ case 0x80000007: /* Advanced power management */
+ /* invariant TSC is CPUID.80000007H:EDX[8] */
+ entry->edx &= (1 << 8);
+ /* mask against host */
+ entry->edx &= boot_cpu_data.x86_power;
+ entry->eax = entry->ebx = entry->ecx = 0;
+ break;
+ case 0x80000008: {
+ unsigned g_phys_as = (entry->eax >> 16) & 0xff;
+ unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
+ unsigned phys_as = entry->eax & 0xff;
+
+ /*
+ * If TDP (NPT) is disabled use the adjusted host MAXPHYADDR as
+ * the guest operates in the same PA space as the host, i.e.
+ * reductions in MAXPHYADDR for memory encryption affect shadow
+ * paging, too.
+ *
+ * If TDP is enabled but an explicit guest MAXPHYADDR is not
+ * provided, use the raw bare metal MAXPHYADDR as reductions to
+ * the HPAs do not affect GPAs.
+ */
+ if (!tdp_enabled)
+ g_phys_as = boot_cpu_data.x86_phys_bits;
+ else if (!g_phys_as)
+ g_phys_as = phys_as;
+
+ entry->eax = g_phys_as | (virt_as << 8);
+ entry->ecx &= ~(GENMASK(31, 16) | GENMASK(11, 8));
+ entry->edx = 0;
+ cpuid_entry_override(entry, CPUID_8000_0008_EBX);
+ break;
+ }
+ case 0x8000000A:
+ if (!kvm_cpu_cap_has(X86_FEATURE_SVM)) {
+ entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
+ break;
+ }
+ entry->eax = 1; /* SVM revision 1 */
+ entry->ebx = 8; /* Lets support 8 ASIDs in case we add proper
+ ASID emulation to nested SVM */
+ entry->ecx = 0; /* Reserved */
+ cpuid_entry_override(entry, CPUID_8000_000A_EDX);
+ break;
+ case 0x80000019:
+ entry->ecx = entry->edx = 0;
+ break;
+ case 0x8000001a:
+ entry->eax &= GENMASK(2, 0);
+ entry->ebx = entry->ecx = entry->edx = 0;
+ break;
+ case 0x8000001e:
+ /* Do not return host topology information. */
+ entry->eax = entry->ebx = entry->ecx = 0;
+ entry->edx = 0; /* reserved */
+ break;
+ case 0x8000001F:
+ if (!kvm_cpu_cap_has(X86_FEATURE_SEV)) {
+ entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
+ } else {
+ cpuid_entry_override(entry, CPUID_8000_001F_EAX);
+ /* Clear NumVMPL since KVM does not support VMPL. */
+ entry->ebx &= ~GENMASK(31, 12);
+ /*
+ * Enumerate '0' for "PA bits reduction", the adjusted
+ * MAXPHYADDR is enumerated directly (see 0x80000008).
+ */
+ entry->ebx &= ~GENMASK(11, 6);
+ }
+ break;
+ case 0x80000020:
+ entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
+ break;
+ case 0x80000021:
+ entry->ebx = entry->ecx = entry->edx = 0;
+ /*
+ * Pass down these bits:
+ * EAX 0 NNDBP, Processor ignores nested data breakpoints
+ * EAX 2 LAS, LFENCE always serializing
+ * EAX 6 NSCB, Null selector clear base
+ *
+ * Other defined bits are for MSRs that KVM does not expose:
+ * EAX 3 SPCL, SMM page configuration lock
+ * EAX 13 PCMSR, Prefetch control MSR
+ */
+ entry->eax &= BIT(0) | BIT(2) | BIT(6);
+ if (static_cpu_has(X86_FEATURE_LFENCE_RDTSC))
+ entry->eax |= BIT(2);
+ if (!static_cpu_has_bug(X86_BUG_NULL_SEG))
+ entry->eax |= BIT(6);
+ break;
+ /*Add support for Centaur's CPUID instruction*/
+ case 0xC0000000:
+ /*Just support up to 0xC0000004 now*/
+ entry->eax = min(entry->eax, 0xC0000004);
+ break;
+ case 0xC0000001:
+ cpuid_entry_override(entry, CPUID_C000_0001_EDX);
+ break;
+ case 3: /* Processor serial number */
+ case 5: /* MONITOR/MWAIT */
+ case 0xC0000002:
+ case 0xC0000003:
+ case 0xC0000004:
+ default:
+ entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
+ break;
+ }
+
+ r = 0;
+
+out:
+ put_cpu();
+
+ return r;
+}
+
+static int do_cpuid_func(struct kvm_cpuid_array *array, u32 func,
+ unsigned int type)
+{
+ if (type == KVM_GET_EMULATED_CPUID)
+ return __do_cpuid_func_emulated(array, func);
+
+ return __do_cpuid_func(array, func);
+}
+
+#define CENTAUR_CPUID_SIGNATURE 0xC0000000
+
+static int get_cpuid_func(struct kvm_cpuid_array *array, u32 func,
+ unsigned int type)
+{
+ u32 limit;
+ int r;
+
+ if (func == CENTAUR_CPUID_SIGNATURE &&
+ boot_cpu_data.x86_vendor != X86_VENDOR_CENTAUR)
+ return 0;
+
+ r = do_cpuid_func(array, func, type);
+ if (r)
+ return r;
+
+ limit = array->entries[array->nent - 1].eax;
+ for (func = func + 1; func <= limit; ++func) {
+ r = do_cpuid_func(array, func, type);
+ if (r)
+ break;
+ }
+
+ return r;
+}
+
+static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
+ __u32 num_entries, unsigned int ioctl_type)
+{
+ int i;
+ __u32 pad[3];
+
+ if (ioctl_type != KVM_GET_EMULATED_CPUID)
+ return false;
+
+ /*
+ * We want to make sure that ->padding is being passed clean from
+ * userspace in case we want to use it for something in the future.
+ *
+ * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
+ * have to give ourselves satisfied only with the emulated side. /me
+ * sheds a tear.
+ */
+ for (i = 0; i < num_entries; i++) {
+ if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
+ return true;
+
+ if (pad[0] || pad[1] || pad[2])
+ return true;
+ }
+ return false;
+}
+
+int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
+ struct kvm_cpuid_entry2 __user *entries,
+ unsigned int type)
+{
+ static const u32 funcs[] = {
+ 0, 0x80000000, CENTAUR_CPUID_SIGNATURE, KVM_CPUID_SIGNATURE,
+ };
+
+ struct kvm_cpuid_array array = {
+ .nent = 0,
+ };
+ int r, i;
+
+ if (cpuid->nent < 1)
+ return -E2BIG;
+ if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
+ cpuid->nent = KVM_MAX_CPUID_ENTRIES;
+
+ if (sanity_check_entries(entries, cpuid->nent, type))
+ return -EINVAL;
+
+ array.entries = kvcalloc(cpuid->nent, sizeof(struct kvm_cpuid_entry2), GFP_KERNEL);
+ if (!array.entries)
+ return -ENOMEM;
+
+ array.maxnent = cpuid->nent;
+
+ for (i = 0; i < ARRAY_SIZE(funcs); i++) {
+ r = get_cpuid_func(&array, funcs[i], type);
+ if (r)
+ goto out_free;
+ }
+ cpuid->nent = array.nent;
+
+ if (copy_to_user(entries, array.entries,
+ array.nent * sizeof(struct kvm_cpuid_entry2)))
+ r = -EFAULT;
+
+out_free:
+ kvfree(array.entries);
+ return r;
+}
+
+struct kvm_cpuid_entry2 *kvm_find_cpuid_entry_index(struct kvm_vcpu *vcpu,
+ u32 function, u32 index)
+{
+ return cpuid_entry2_find(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent,
+ function, index);
+}
+EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry_index);
+
+struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
+ u32 function)
+{
+ return cpuid_entry2_find(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent,
+ function, KVM_CPUID_INDEX_NOT_SIGNIFICANT);
+}
+EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
+
+/*
+ * Intel CPUID semantics treats any query for an out-of-range leaf as if the
+ * highest basic leaf (i.e. CPUID.0H:EAX) were requested. AMD CPUID semantics
+ * returns all zeroes for any undefined leaf, whether or not the leaf is in
+ * range. Centaur/VIA follows Intel semantics.
+ *
+ * A leaf is considered out-of-range if its function is higher than the maximum
+ * supported leaf of its associated class or if its associated class does not
+ * exist.
+ *
+ * There are three primary classes to be considered, with their respective
+ * ranges described as "<base> - <top>[,<base2> - <top2>] inclusive. A primary
+ * class exists if a guest CPUID entry for its <base> leaf exists. For a given
+ * class, CPUID.<base>.EAX contains the max supported leaf for the class.
+ *
+ * - Basic: 0x00000000 - 0x3fffffff, 0x50000000 - 0x7fffffff
+ * - Hypervisor: 0x40000000 - 0x4fffffff
+ * - Extended: 0x80000000 - 0xbfffffff
+ * - Centaur: 0xc0000000 - 0xcfffffff
+ *
+ * The Hypervisor class is further subdivided into sub-classes that each act as
+ * their own independent class associated with a 0x100 byte range. E.g. if Qemu
+ * is advertising support for both HyperV and KVM, the resulting Hypervisor
+ * CPUID sub-classes are:
+ *
+ * - HyperV: 0x40000000 - 0x400000ff
+ * - KVM: 0x40000100 - 0x400001ff
+ */
+static struct kvm_cpuid_entry2 *
+get_out_of_range_cpuid_entry(struct kvm_vcpu *vcpu, u32 *fn_ptr, u32 index)
+{
+ struct kvm_cpuid_entry2 *basic, *class;
+ u32 function = *fn_ptr;
+
+ basic = kvm_find_cpuid_entry(vcpu, 0);
+ if (!basic)
+ return NULL;
+
+ if (is_guest_vendor_amd(basic->ebx, basic->ecx, basic->edx) ||
+ is_guest_vendor_hygon(basic->ebx, basic->ecx, basic->edx))
+ return NULL;
+
+ if (function >= 0x40000000 && function <= 0x4fffffff)
+ class = kvm_find_cpuid_entry(vcpu, function & 0xffffff00);
+ else if (function >= 0xc0000000)
+ class = kvm_find_cpuid_entry(vcpu, 0xc0000000);
+ else
+ class = kvm_find_cpuid_entry(vcpu, function & 0x80000000);
+
+ if (class && function <= class->eax)
+ return NULL;
+
+ /*
+ * Leaf specific adjustments are also applied when redirecting to the
+ * max basic entry, e.g. if the max basic leaf is 0xb but there is no
+ * entry for CPUID.0xb.index (see below), then the output value for EDX
+ * needs to be pulled from CPUID.0xb.1.
+ */
+ *fn_ptr = basic->eax;
+
+ /*
+ * The class does not exist or the requested function is out of range;
+ * the effective CPUID entry is the max basic leaf. Note, the index of
+ * the original requested leaf is observed!
+ */
+ return kvm_find_cpuid_entry_index(vcpu, basic->eax, index);
+}
+
+bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
+ u32 *ecx, u32 *edx, bool exact_only)
+{
+ u32 orig_function = *eax, function = *eax, index = *ecx;
+ struct kvm_cpuid_entry2 *entry;
+ bool exact, used_max_basic = false;
+
+ entry = kvm_find_cpuid_entry_index(vcpu, function, index);
+ exact = !!entry;
+
+ if (!entry && !exact_only) {
+ entry = get_out_of_range_cpuid_entry(vcpu, &function, index);
+ used_max_basic = !!entry;
+ }
+
+ if (entry) {
+ *eax = entry->eax;
+ *ebx = entry->ebx;
+ *ecx = entry->ecx;
+ *edx = entry->edx;
+ if (function == 7 && index == 0) {
+ u64 data;
+ if (!__kvm_get_msr(vcpu, MSR_IA32_TSX_CTRL, &data, true) &&
+ (data & TSX_CTRL_CPUID_CLEAR))
+ *ebx &= ~(F(RTM) | F(HLE));
+ }
+ } else {
+ *eax = *ebx = *ecx = *edx = 0;
+ /*
+ * When leaf 0BH or 1FH is defined, CL is pass-through
+ * and EDX is always the x2APIC ID, even for undefined
+ * subleaves. Index 1 will exist iff the leaf is
+ * implemented, so we pass through CL iff leaf 1
+ * exists. EDX can be copied from any existing index.
+ */
+ if (function == 0xb || function == 0x1f) {
+ entry = kvm_find_cpuid_entry_index(vcpu, function, 1);
+ if (entry) {
+ *ecx = index & 0xff;
+ *edx = entry->edx;
+ }
+ }
+ }
+ trace_kvm_cpuid(orig_function, index, *eax, *ebx, *ecx, *edx, exact,
+ used_max_basic);
+ return exact;
+}
+EXPORT_SYMBOL_GPL(kvm_cpuid);
+
+int kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
+{
+ u32 eax, ebx, ecx, edx;
+
+ if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0))
+ return 1;
+
+ eax = kvm_rax_read(vcpu);
+ ecx = kvm_rcx_read(vcpu);
+ kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, false);
+ kvm_rax_write(vcpu, eax);
+ kvm_rbx_write(vcpu, ebx);
+ kvm_rcx_write(vcpu, ecx);
+ kvm_rdx_write(vcpu, edx);
+ return kvm_skip_emulated_instruction(vcpu);
+}
+EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);