[PATCH 08/10] KVM: x86: Hoist x86.c's global msr_* variables up above kvm_do_msr_access()

From: Sean Christopherson
Date: Thu Apr 25 2024 - 14:17:20 EST


Move the definitions of the various MSR arrays above kvm_do_msr_access()
so that kvm_do_msr_access() can query the arrays when handling failures,
e.g. to squash errors if userspace tries to read an MSR that isn't fully
supported, but that KVM advertised as being an MSR-to-save.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 368 ++++++++++++++++++++++-----------------------
1 file changed, 184 insertions(+), 184 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a0506878d58e..04a5ae853774 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -319,6 +319,190 @@ u64 __read_mostly host_xcr0;

static struct kmem_cache *x86_emulator_cache;

+/*
+ * The three MSR lists(msrs_to_save, emulated_msrs, msr_based_features) track
+ * the set of MSRs that KVM exposes to userspace through KVM_GET_MSRS,
+ * KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST. msrs_to_save holds MSRs that
+ * require host support, i.e. should be probed via RDMSR. emulated_msrs holds
+ * MSRs that KVM emulates without strictly requiring host support.
+ * msr_based_features holds MSRs that enumerate features, i.e. are effectively
+ * CPUID leafs. Note, msr_based_features isn't mutually exclusive with
+ * msrs_to_save and emulated_msrs.
+ */
+
+static const u32 msrs_to_save_base[] = {
+ MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
+ MSR_STAR,
+#ifdef CONFIG_X86_64
+ MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
+#endif
+ MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA,
+ MSR_IA32_FEAT_CTL, MSR_IA32_BNDCFGS, MSR_TSC_AUX,
+ MSR_IA32_SPEC_CTRL, MSR_IA32_TSX_CTRL,
+ MSR_IA32_RTIT_CTL, MSR_IA32_RTIT_STATUS, MSR_IA32_RTIT_CR3_MATCH,
+ MSR_IA32_RTIT_OUTPUT_BASE, MSR_IA32_RTIT_OUTPUT_MASK,
+ MSR_IA32_RTIT_ADDR0_A, MSR_IA32_RTIT_ADDR0_B,
+ MSR_IA32_RTIT_ADDR1_A, MSR_IA32_RTIT_ADDR1_B,
+ MSR_IA32_RTIT_ADDR2_A, MSR_IA32_RTIT_ADDR2_B,
+ MSR_IA32_RTIT_ADDR3_A, MSR_IA32_RTIT_ADDR3_B,
+ MSR_IA32_UMWAIT_CONTROL,
+
+ MSR_IA32_XFD, MSR_IA32_XFD_ERR,
+};
+
+static const u32 msrs_to_save_pmu[] = {
+ MSR_ARCH_PERFMON_FIXED_CTR0, MSR_ARCH_PERFMON_FIXED_CTR1,
+ MSR_ARCH_PERFMON_FIXED_CTR0 + 2,
+ MSR_CORE_PERF_FIXED_CTR_CTRL, MSR_CORE_PERF_GLOBAL_STATUS,
+ MSR_CORE_PERF_GLOBAL_CTRL, MSR_CORE_PERF_GLOBAL_OVF_CTRL,
+ MSR_IA32_PEBS_ENABLE, MSR_IA32_DS_AREA, MSR_PEBS_DATA_CFG,
+
+ /* This part of MSRs should match KVM_INTEL_PMC_MAX_GENERIC. */
+ MSR_ARCH_PERFMON_PERFCTR0, MSR_ARCH_PERFMON_PERFCTR1,
+ MSR_ARCH_PERFMON_PERFCTR0 + 2, MSR_ARCH_PERFMON_PERFCTR0 + 3,
+ MSR_ARCH_PERFMON_PERFCTR0 + 4, MSR_ARCH_PERFMON_PERFCTR0 + 5,
+ MSR_ARCH_PERFMON_PERFCTR0 + 6, MSR_ARCH_PERFMON_PERFCTR0 + 7,
+ MSR_ARCH_PERFMON_EVENTSEL0, MSR_ARCH_PERFMON_EVENTSEL1,
+ MSR_ARCH_PERFMON_EVENTSEL0 + 2, MSR_ARCH_PERFMON_EVENTSEL0 + 3,
+ MSR_ARCH_PERFMON_EVENTSEL0 + 4, MSR_ARCH_PERFMON_EVENTSEL0 + 5,
+ MSR_ARCH_PERFMON_EVENTSEL0 + 6, MSR_ARCH_PERFMON_EVENTSEL0 + 7,
+
+ MSR_K7_EVNTSEL0, MSR_K7_EVNTSEL1, MSR_K7_EVNTSEL2, MSR_K7_EVNTSEL3,
+ MSR_K7_PERFCTR0, MSR_K7_PERFCTR1, MSR_K7_PERFCTR2, MSR_K7_PERFCTR3,
+
+ /* This part of MSRs should match KVM_AMD_PMC_MAX_GENERIC. */
+ MSR_F15H_PERF_CTL0, MSR_F15H_PERF_CTL1, MSR_F15H_PERF_CTL2,
+ MSR_F15H_PERF_CTL3, MSR_F15H_PERF_CTL4, MSR_F15H_PERF_CTL5,
+ MSR_F15H_PERF_CTR0, MSR_F15H_PERF_CTR1, MSR_F15H_PERF_CTR2,
+ MSR_F15H_PERF_CTR3, MSR_F15H_PERF_CTR4, MSR_F15H_PERF_CTR5,
+
+ MSR_AMD64_PERF_CNTR_GLOBAL_CTL,
+ MSR_AMD64_PERF_CNTR_GLOBAL_STATUS,
+ MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR,
+};
+
+static u32 msrs_to_save[ARRAY_SIZE(msrs_to_save_base) +
+ ARRAY_SIZE(msrs_to_save_pmu)];
+static unsigned num_msrs_to_save;
+
+static const u32 emulated_msrs_all[] = {
+ MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,
+ MSR_KVM_SYSTEM_TIME_NEW, MSR_KVM_WALL_CLOCK_NEW,
+
+#ifdef CONFIG_KVM_HYPERV
+ HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL,
+ HV_X64_MSR_TIME_REF_COUNT, HV_X64_MSR_REFERENCE_TSC,
+ HV_X64_MSR_TSC_FREQUENCY, HV_X64_MSR_APIC_FREQUENCY,
+ HV_X64_MSR_CRASH_P0, HV_X64_MSR_CRASH_P1, HV_X64_MSR_CRASH_P2,
+ HV_X64_MSR_CRASH_P3, HV_X64_MSR_CRASH_P4, HV_X64_MSR_CRASH_CTL,
+ HV_X64_MSR_RESET,
+ HV_X64_MSR_VP_INDEX,
+ HV_X64_MSR_VP_RUNTIME,
+ HV_X64_MSR_SCONTROL,
+ HV_X64_MSR_STIMER0_CONFIG,
+ HV_X64_MSR_VP_ASSIST_PAGE,
+ HV_X64_MSR_REENLIGHTENMENT_CONTROL, HV_X64_MSR_TSC_EMULATION_CONTROL,
+ HV_X64_MSR_TSC_EMULATION_STATUS, HV_X64_MSR_TSC_INVARIANT_CONTROL,
+ HV_X64_MSR_SYNDBG_OPTIONS,
+ HV_X64_MSR_SYNDBG_CONTROL, HV_X64_MSR_SYNDBG_STATUS,
+ HV_X64_MSR_SYNDBG_SEND_BUFFER, HV_X64_MSR_SYNDBG_RECV_BUFFER,
+ HV_X64_MSR_SYNDBG_PENDING_BUFFER,
+#endif
+
+ MSR_KVM_ASYNC_PF_EN, MSR_KVM_STEAL_TIME,
+ MSR_KVM_PV_EOI_EN, MSR_KVM_ASYNC_PF_INT, MSR_KVM_ASYNC_PF_ACK,
+
+ MSR_IA32_TSC_ADJUST,
+ MSR_IA32_TSC_DEADLINE,
+ MSR_IA32_ARCH_CAPABILITIES,
+ MSR_IA32_PERF_CAPABILITIES,
+ MSR_IA32_MISC_ENABLE,
+ MSR_IA32_MCG_STATUS,
+ MSR_IA32_MCG_CTL,
+ MSR_IA32_MCG_EXT_CTL,
+ MSR_IA32_SMBASE,
+ MSR_SMI_COUNT,
+ MSR_PLATFORM_INFO,
+ MSR_MISC_FEATURES_ENABLES,
+ MSR_AMD64_VIRT_SPEC_CTRL,
+ MSR_AMD64_TSC_RATIO,
+ MSR_IA32_POWER_CTL,
+ MSR_IA32_UCODE_REV,
+
+ /*
+ * KVM always supports the "true" VMX control MSRs, even if the host
+ * does not. The VMX MSRs as a whole are considered "emulated" as KVM
+ * doesn't strictly require them to exist in the host (ignoring that
+ * KVM would refuse to load in the first place if the core set of MSRs
+ * aren't supported).
+ */
+ MSR_IA32_VMX_BASIC,
+ MSR_IA32_VMX_TRUE_PINBASED_CTLS,
+ MSR_IA32_VMX_TRUE_PROCBASED_CTLS,
+ MSR_IA32_VMX_TRUE_EXIT_CTLS,
+ MSR_IA32_VMX_TRUE_ENTRY_CTLS,
+ MSR_IA32_VMX_MISC,
+ MSR_IA32_VMX_CR0_FIXED0,
+ MSR_IA32_VMX_CR4_FIXED0,
+ MSR_IA32_VMX_VMCS_ENUM,
+ MSR_IA32_VMX_PROCBASED_CTLS2,
+ MSR_IA32_VMX_EPT_VPID_CAP,
+ MSR_IA32_VMX_VMFUNC,
+
+ MSR_K7_HWCR,
+ MSR_KVM_POLL_CONTROL,
+};
+
+static u32 emulated_msrs[ARRAY_SIZE(emulated_msrs_all)];
+static unsigned num_emulated_msrs;
+
+/*
+ * List of MSRs that control the existence of MSR-based features, i.e. MSRs
+ * that are effectively CPUID leafs. VMX MSRs are also included in the set of
+ * feature MSRs, but are handled separately to allow expedited lookups.
+ */
+static const u32 msr_based_features_all_except_vmx[] = {
+ MSR_AMD64_DE_CFG,
+ MSR_IA32_UCODE_REV,
+ MSR_IA32_ARCH_CAPABILITIES,
+ MSR_IA32_PERF_CAPABILITIES,
+};
+
+static u32 msr_based_features[ARRAY_SIZE(msr_based_features_all_except_vmx) +
+ (KVM_LAST_EMULATED_VMX_MSR - KVM_FIRST_EMULATED_VMX_MSR + 1)];
+static unsigned int num_msr_based_features;
+
+/*
+ * All feature MSRs except uCode revID, which tracks the currently loaded uCode
+ * patch, are immutable once the vCPU model is defined.
+ */
+static bool kvm_is_immutable_feature_msr(u32 msr)
+{
+ int i;
+
+ if (msr >= KVM_FIRST_EMULATED_VMX_MSR && msr <= KVM_LAST_EMULATED_VMX_MSR)
+ return true;
+
+ for (i = 0; i < ARRAY_SIZE(msr_based_features_all_except_vmx); i++) {
+ if (msr == msr_based_features_all_except_vmx[i])
+ return msr != MSR_IA32_UCODE_REV;
+ }
+
+ return false;
+}
+
+static bool kvm_is_msr_to_save(u32 msr_index)
+{
+ unsigned int i;
+
+ for (i = 0; i < num_msrs_to_save; i++) {
+ if (msrs_to_save[i] == msr_index)
+ return true;
+ }
+
+ return false;
+}
+
typedef int (*msr_access_t)(struct kvm_vcpu *vcpu, u32 index, u64 *data,
bool host_initiated);

@@ -1448,178 +1632,6 @@ int kvm_emulate_rdpmc(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(kvm_emulate_rdpmc);

-/*
- * The three MSR lists(msrs_to_save, emulated_msrs, msr_based_features) track
- * the set of MSRs that KVM exposes to userspace through KVM_GET_MSRS,
- * KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST. msrs_to_save holds MSRs that
- * require host support, i.e. should be probed via RDMSR. emulated_msrs holds
- * MSRs that KVM emulates without strictly requiring host support.
- * msr_based_features holds MSRs that enumerate features, i.e. are effectively
- * CPUID leafs. Note, msr_based_features isn't mutually exclusive with
- * msrs_to_save and emulated_msrs.
- */
-
-static const u32 msrs_to_save_base[] = {
- MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
- MSR_STAR,
-#ifdef CONFIG_X86_64
- MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
-#endif
- MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA,
- MSR_IA32_FEAT_CTL, MSR_IA32_BNDCFGS, MSR_TSC_AUX,
- MSR_IA32_SPEC_CTRL, MSR_IA32_TSX_CTRL,
- MSR_IA32_RTIT_CTL, MSR_IA32_RTIT_STATUS, MSR_IA32_RTIT_CR3_MATCH,
- MSR_IA32_RTIT_OUTPUT_BASE, MSR_IA32_RTIT_OUTPUT_MASK,
- MSR_IA32_RTIT_ADDR0_A, MSR_IA32_RTIT_ADDR0_B,
- MSR_IA32_RTIT_ADDR1_A, MSR_IA32_RTIT_ADDR1_B,
- MSR_IA32_RTIT_ADDR2_A, MSR_IA32_RTIT_ADDR2_B,
- MSR_IA32_RTIT_ADDR3_A, MSR_IA32_RTIT_ADDR3_B,
- MSR_IA32_UMWAIT_CONTROL,
-
- MSR_IA32_XFD, MSR_IA32_XFD_ERR,
-};
-
-static const u32 msrs_to_save_pmu[] = {
- MSR_ARCH_PERFMON_FIXED_CTR0, MSR_ARCH_PERFMON_FIXED_CTR1,
- MSR_ARCH_PERFMON_FIXED_CTR0 + 2,
- MSR_CORE_PERF_FIXED_CTR_CTRL, MSR_CORE_PERF_GLOBAL_STATUS,
- MSR_CORE_PERF_GLOBAL_CTRL, MSR_CORE_PERF_GLOBAL_OVF_CTRL,
- MSR_IA32_PEBS_ENABLE, MSR_IA32_DS_AREA, MSR_PEBS_DATA_CFG,
-
- /* This part of MSRs should match KVM_INTEL_PMC_MAX_GENERIC. */
- MSR_ARCH_PERFMON_PERFCTR0, MSR_ARCH_PERFMON_PERFCTR1,
- MSR_ARCH_PERFMON_PERFCTR0 + 2, MSR_ARCH_PERFMON_PERFCTR0 + 3,
- MSR_ARCH_PERFMON_PERFCTR0 + 4, MSR_ARCH_PERFMON_PERFCTR0 + 5,
- MSR_ARCH_PERFMON_PERFCTR0 + 6, MSR_ARCH_PERFMON_PERFCTR0 + 7,
- MSR_ARCH_PERFMON_EVENTSEL0, MSR_ARCH_PERFMON_EVENTSEL1,
- MSR_ARCH_PERFMON_EVENTSEL0 + 2, MSR_ARCH_PERFMON_EVENTSEL0 + 3,
- MSR_ARCH_PERFMON_EVENTSEL0 + 4, MSR_ARCH_PERFMON_EVENTSEL0 + 5,
- MSR_ARCH_PERFMON_EVENTSEL0 + 6, MSR_ARCH_PERFMON_EVENTSEL0 + 7,
-
- MSR_K7_EVNTSEL0, MSR_K7_EVNTSEL1, MSR_K7_EVNTSEL2, MSR_K7_EVNTSEL3,
- MSR_K7_PERFCTR0, MSR_K7_PERFCTR1, MSR_K7_PERFCTR2, MSR_K7_PERFCTR3,
-
- /* This part of MSRs should match KVM_AMD_PMC_MAX_GENERIC. */
- MSR_F15H_PERF_CTL0, MSR_F15H_PERF_CTL1, MSR_F15H_PERF_CTL2,
- MSR_F15H_PERF_CTL3, MSR_F15H_PERF_CTL4, MSR_F15H_PERF_CTL5,
- MSR_F15H_PERF_CTR0, MSR_F15H_PERF_CTR1, MSR_F15H_PERF_CTR2,
- MSR_F15H_PERF_CTR3, MSR_F15H_PERF_CTR4, MSR_F15H_PERF_CTR5,
-
- MSR_AMD64_PERF_CNTR_GLOBAL_CTL,
- MSR_AMD64_PERF_CNTR_GLOBAL_STATUS,
- MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR,
-};
-
-static u32 msrs_to_save[ARRAY_SIZE(msrs_to_save_base) +
- ARRAY_SIZE(msrs_to_save_pmu)];
-static unsigned num_msrs_to_save;
-
-static const u32 emulated_msrs_all[] = {
- MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,
- MSR_KVM_SYSTEM_TIME_NEW, MSR_KVM_WALL_CLOCK_NEW,
-
-#ifdef CONFIG_KVM_HYPERV
- HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL,
- HV_X64_MSR_TIME_REF_COUNT, HV_X64_MSR_REFERENCE_TSC,
- HV_X64_MSR_TSC_FREQUENCY, HV_X64_MSR_APIC_FREQUENCY,
- HV_X64_MSR_CRASH_P0, HV_X64_MSR_CRASH_P1, HV_X64_MSR_CRASH_P2,
- HV_X64_MSR_CRASH_P3, HV_X64_MSR_CRASH_P4, HV_X64_MSR_CRASH_CTL,
- HV_X64_MSR_RESET,
- HV_X64_MSR_VP_INDEX,
- HV_X64_MSR_VP_RUNTIME,
- HV_X64_MSR_SCONTROL,
- HV_X64_MSR_STIMER0_CONFIG,
- HV_X64_MSR_VP_ASSIST_PAGE,
- HV_X64_MSR_REENLIGHTENMENT_CONTROL, HV_X64_MSR_TSC_EMULATION_CONTROL,
- HV_X64_MSR_TSC_EMULATION_STATUS, HV_X64_MSR_TSC_INVARIANT_CONTROL,
- HV_X64_MSR_SYNDBG_OPTIONS,
- HV_X64_MSR_SYNDBG_CONTROL, HV_X64_MSR_SYNDBG_STATUS,
- HV_X64_MSR_SYNDBG_SEND_BUFFER, HV_X64_MSR_SYNDBG_RECV_BUFFER,
- HV_X64_MSR_SYNDBG_PENDING_BUFFER,
-#endif
-
- MSR_KVM_ASYNC_PF_EN, MSR_KVM_STEAL_TIME,
- MSR_KVM_PV_EOI_EN, MSR_KVM_ASYNC_PF_INT, MSR_KVM_ASYNC_PF_ACK,
-
- MSR_IA32_TSC_ADJUST,
- MSR_IA32_TSC_DEADLINE,
- MSR_IA32_ARCH_CAPABILITIES,
- MSR_IA32_PERF_CAPABILITIES,
- MSR_IA32_MISC_ENABLE,
- MSR_IA32_MCG_STATUS,
- MSR_IA32_MCG_CTL,
- MSR_IA32_MCG_EXT_CTL,
- MSR_IA32_SMBASE,
- MSR_SMI_COUNT,
- MSR_PLATFORM_INFO,
- MSR_MISC_FEATURES_ENABLES,
- MSR_AMD64_VIRT_SPEC_CTRL,
- MSR_AMD64_TSC_RATIO,
- MSR_IA32_POWER_CTL,
- MSR_IA32_UCODE_REV,
-
- /*
- * KVM always supports the "true" VMX control MSRs, even if the host
- * does not. The VMX MSRs as a whole are considered "emulated" as KVM
- * doesn't strictly require them to exist in the host (ignoring that
- * KVM would refuse to load in the first place if the core set of MSRs
- * aren't supported).
- */
- MSR_IA32_VMX_BASIC,
- MSR_IA32_VMX_TRUE_PINBASED_CTLS,
- MSR_IA32_VMX_TRUE_PROCBASED_CTLS,
- MSR_IA32_VMX_TRUE_EXIT_CTLS,
- MSR_IA32_VMX_TRUE_ENTRY_CTLS,
- MSR_IA32_VMX_MISC,
- MSR_IA32_VMX_CR0_FIXED0,
- MSR_IA32_VMX_CR4_FIXED0,
- MSR_IA32_VMX_VMCS_ENUM,
- MSR_IA32_VMX_PROCBASED_CTLS2,
- MSR_IA32_VMX_EPT_VPID_CAP,
- MSR_IA32_VMX_VMFUNC,
-
- MSR_K7_HWCR,
- MSR_KVM_POLL_CONTROL,
-};
-
-static u32 emulated_msrs[ARRAY_SIZE(emulated_msrs_all)];
-static unsigned num_emulated_msrs;
-
-/*
- * List of MSRs that control the existence of MSR-based features, i.e. MSRs
- * that are effectively CPUID leafs. VMX MSRs are also included in the set of
- * feature MSRs, but are handled separately to allow expedited lookups.
- */
-static const u32 msr_based_features_all_except_vmx[] = {
- MSR_AMD64_DE_CFG,
- MSR_IA32_UCODE_REV,
- MSR_IA32_ARCH_CAPABILITIES,
- MSR_IA32_PERF_CAPABILITIES,
-};
-
-static u32 msr_based_features[ARRAY_SIZE(msr_based_features_all_except_vmx) +
- (KVM_LAST_EMULATED_VMX_MSR - KVM_FIRST_EMULATED_VMX_MSR + 1)];
-static unsigned int num_msr_based_features;
-
-/*
- * All feature MSRs except uCode revID, which tracks the currently loaded uCode
- * patch, are immutable once the vCPU model is defined.
- */
-static bool kvm_is_immutable_feature_msr(u32 msr)
-{
- int i;
-
- if (msr >= KVM_FIRST_EMULATED_VMX_MSR && msr <= KVM_LAST_EMULATED_VMX_MSR)
- return true;
-
- for (i = 0; i < ARRAY_SIZE(msr_based_features_all_except_vmx); i++) {
- if (msr == msr_based_features_all_except_vmx[i])
- return msr != MSR_IA32_UCODE_REV;
- }
-
- return false;
-}
-
/*
* Some IA32_ARCH_CAPABILITIES bits have dependencies on MSRs that KVM
* does not yet virtualize. These include:
@@ -3770,18 +3782,6 @@ static void record_steal_time(struct kvm_vcpu *vcpu)
mark_page_dirty_in_slot(vcpu->kvm, ghc->memslot, gpa_to_gfn(ghc->gpa));
}

-static bool kvm_is_msr_to_save(u32 msr_index)
-{
- unsigned int i;
-
- for (i = 0; i < num_msrs_to_save; i++) {
- if (msrs_to_save[i] == msr_index)
- return true;
- }
-
- return false;
-}
-
int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
u32 msr = msr_info->index;
--
2.44.0.769.g3c40516874-goog