aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--Documentation/virtual/kvm/api.txt40
-rw-r--r--arch/x86/include/asm/kvm_host.h3
-rw-r--r--arch/x86/kvm/lapic.c10
-rw-r--r--arch/x86/kvm/svm.c44
-rw-r--r--arch/x86/kvm/vmx.c7
-rw-r--r--arch/x86/kvm/x86.c102
-rw-r--r--include/uapi/linux/kvm.h2
7 files changed, 179 insertions, 29 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 792fa8717d13..d6b3ff51a14f 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -123,14 +123,15 @@ memory layout to fit in user mode), check KVM_CAP_MIPS_VZ and use the
flag KVM_VM_MIPS_VZ.
-4.3 KVM_GET_MSR_INDEX_LIST
+4.3 KVM_GET_MSR_INDEX_LIST, KVM_GET_MSR_FEATURE_INDEX_LIST
-Capability: basic
+Capability: basic, KVM_CAP_GET_MSR_FEATURES for KVM_GET_MSR_FEATURE_INDEX_LIST
Architectures: x86
-Type: system
+Type: system ioctl
Parameters: struct kvm_msr_list (in/out)
Returns: 0 on success; -1 on error
Errors:
+ EFAULT: the msr index list cannot be read from or written to
E2BIG: the msr index list is to be to fit in the array specified by
the user.
@@ -139,16 +140,23 @@ struct kvm_msr_list {
__u32 indices[0];
};
-This ioctl returns the guest msrs that are supported. The list varies
-by kvm version and host processor, but does not change otherwise. The
-user fills in the size of the indices array in nmsrs, and in return
-kvm adjusts nmsrs to reflect the actual number of msrs and fills in
-the indices array with their numbers.
+The user fills in the size of the indices array in nmsrs, and in return
+kvm adjusts nmsrs to reflect the actual number of msrs and fills in the
+indices array with their numbers.
+
+KVM_GET_MSR_INDEX_LIST returns the guest msrs that are supported. The list
+varies by kvm version and host processor, but does not change otherwise.
Note: if kvm indicates supports MCE (KVM_CAP_MCE), then the MCE bank MSRs are
not returned in the MSR list, as different vcpus can have a different number
of banks, as set via the KVM_X86_SETUP_MCE ioctl.
+KVM_GET_MSR_FEATURE_INDEX_LIST returns the list of MSRs that can be passed
+to the KVM_GET_MSRS system ioctl. This lets userspace probe host capabilities
+and processor features that are exposed via MSRs (e.g., VMX capabilities).
+This list also varies by kvm version and host processor, but does not change
+otherwise.
+
4.4 KVM_CHECK_EXTENSION
@@ -475,14 +483,22 @@ Support for this has been removed. Use KVM_SET_GUEST_DEBUG instead.
4.18 KVM_GET_MSRS
-Capability: basic
+Capability: basic (vcpu), KVM_CAP_GET_MSR_FEATURES (system)
Architectures: x86
-Type: vcpu ioctl
+Type: system ioctl, vcpu ioctl
Parameters: struct kvm_msrs (in/out)
-Returns: 0 on success, -1 on error
+Returns: number of msrs successfully returned;
+ -1 on error
+
+When used as a system ioctl:
+Reads the values of MSR-based features that are available for the VM. This
+is similar to KVM_GET_SUPPORTED_CPUID, but it returns MSR indices and values.
+The list of msr-based features can be obtained using KVM_GET_MSR_FEATURE_INDEX_LIST
+in a system ioctl.
+When used as a vcpu ioctl:
Reads model-specific registers from the vcpu. Supported msr indices can
-be obtained using KVM_GET_MSR_INDEX_LIST.
+be obtained using KVM_GET_MSR_INDEX_LIST in a system ioctl.
struct kvm_msrs {
__u32 nmsrs; /* number of msrs in entries */
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 0a9e330b34f0..b605a5b6a30c 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -507,6 +507,7 @@ struct kvm_vcpu_arch {
u64 smi_count;
bool tpr_access_reporting;
u64 ia32_xss;
+ u64 microcode_version;
/*
* Paging state of the vcpu
@@ -1095,6 +1096,8 @@ struct kvm_x86_ops {
int (*mem_enc_op)(struct kvm *kvm, void __user *argp);
int (*mem_enc_reg_region)(struct kvm *kvm, struct kvm_enc_region *argp);
int (*mem_enc_unreg_region)(struct kvm *kvm, struct kvm_enc_region *argp);
+
+ int (*get_msr_feature)(struct kvm_msr_entry *entry);
};
struct kvm_arch_async_pf {
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index cc5fe7a50dde..391dda8d43b7 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2002,14 +2002,13 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
{
- struct kvm_lapic *apic;
+ struct kvm_lapic *apic = vcpu->arch.apic;
int i;
- apic_debug("%s\n", __func__);
+ if (!apic)
+ return;
- ASSERT(vcpu);
- apic = vcpu->arch.apic;
- ASSERT(apic != NULL);
+ apic_debug("%s\n", __func__);
/* Stop the timer in case it's a reset to an active apic */
hrtimer_cancel(&apic->lapic_timer.timer);
@@ -2568,7 +2567,6 @@ void kvm_apic_accept_events(struct kvm_vcpu *vcpu)
pe = xchg(&apic->pending_events, 0);
if (test_bit(KVM_APIC_INIT, &pe)) {
- kvm_lapic_reset(vcpu, true);
kvm_vcpu_reset(vcpu, true);
if (kvm_vcpu_is_bsp(apic->vcpu))
vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index cbd7ab74952e..be9c839e2c89 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -179,6 +179,8 @@ struct vcpu_svm {
uint64_t sysenter_eip;
uint64_t tsc_aux;
+ u64 msr_decfg;
+
u64 next_rip;
u64 host_user_msrs[NR_HOST_SAVE_USER_MSRS];
@@ -1906,6 +1908,7 @@ static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
u32 dummy;
u32 eax = 1;
+ vcpu->arch.microcode_version = 0x01000065;
svm->spec_ctrl = 0;
if (!init_event) {
@@ -3870,6 +3873,22 @@ static int cr8_write_interception(struct vcpu_svm *svm)
return 0;
}
+static int svm_get_msr_feature(struct kvm_msr_entry *msr)
+{
+ msr->data = 0;
+
+ switch (msr->index) {
+ case MSR_F10H_DECFG:
+ if (boot_cpu_has(X86_FEATURE_LFENCE_RDTSC))
+ msr->data |= MSR_F10H_DECFG_LFENCE_SERIALIZE;
+ break;
+ default:
+ return 1;
+ }
+
+ return 0;
+}
+
static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
struct vcpu_svm *svm = to_svm(vcpu);
@@ -3945,9 +3964,6 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
msr_info->data = svm->spec_ctrl;
break;
- case MSR_IA32_UCODE_REV:
- msr_info->data = 0x01000065;
- break;
case MSR_F15H_IC_CFG: {
int family, model;
@@ -3965,6 +3981,9 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
msr_info->data = 0x1E;
}
break;
+ case MSR_F10H_DECFG:
+ msr_info->data = svm->msr_decfg;
+ break;
default:
return kvm_get_msr_common(vcpu, msr_info);
}
@@ -4143,6 +4162,24 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
case MSR_VM_IGNNE:
vcpu_unimpl(vcpu, "unimplemented wrmsr: 0x%x data 0x%llx\n", ecx, data);
break;
+ case MSR_F10H_DECFG: {
+ struct kvm_msr_entry msr_entry;
+
+ msr_entry.index = msr->index;
+ if (svm_get_msr_feature(&msr_entry))
+ return 1;
+
+ /* Check the supported bits */
+ if (data & ~msr_entry.data)
+ return 1;
+
+ /* Don't allow the guest to change a bit, #GP */
+ if (!msr->host_initiated && (data ^ msr_entry.data))
+ return 1;
+
+ svm->msr_decfg = data;
+ break;
+ }
case MSR_IA32_APICBASE:
if (kvm_vcpu_apicv_active(vcpu))
avic_update_vapic_bar(to_svm(vcpu), data);
@@ -6833,6 +6870,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
.vcpu_unblocking = svm_vcpu_unblocking,
.update_bp_intercept = update_bp_intercept,
+ .get_msr_feature = svm_get_msr_feature,
.get_msr = svm_get_msr,
.set_msr = svm_set_msr,
.get_segment_base = svm_get_segment_base,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index cab6ea1f8be5..051dab74e4e9 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3227,6 +3227,11 @@ static inline bool vmx_feature_control_msr_valid(struct kvm_vcpu *vcpu,
return !(val & ~valid_bits);
}
+static int vmx_get_msr_feature(struct kvm_msr_entry *msr)
+{
+ return 1;
+}
+
/*
* Reads an msr value (of 'msr_index') into 'pdata'.
* Returns 0 on success, non-0 otherwise.
@@ -5767,6 +5772,7 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
vmx->rmode.vm86_active = 0;
vmx->spec_ctrl = 0;
+ vcpu->arch.microcode_version = 0x100000000ULL;
vmx->vcpu.arch.regs[VCPU_REGS_RDX] = get_rdx_init_val();
kvm_set_cr8(vcpu, 0);
@@ -12297,6 +12303,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
.vcpu_put = vmx_vcpu_put,
.update_bp_intercept = update_exception_bitmap,
+ .get_msr_feature = vmx_get_msr_feature,
.get_msr = vmx_get_msr,
.set_msr = vmx_set_msr,
.get_segment_base = vmx_get_segment_base,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 96edda878dbf..18b5ca7a3197 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1049,6 +1049,45 @@ static u32 emulated_msrs[] = {
static unsigned num_emulated_msrs;
+/*
+ * List of msr numbers which are used to expose MSR-based features that
+ * can be used by a hypervisor to validate requested CPU features.
+ */
+static u32 msr_based_features[] = {
+ MSR_F10H_DECFG,
+ MSR_IA32_UCODE_REV,
+};
+
+static unsigned int num_msr_based_features;
+
+static int kvm_get_msr_feature(struct kvm_msr_entry *msr)
+{
+ switch (msr->index) {
+ case MSR_IA32_UCODE_REV:
+ rdmsrl(msr->index, msr->data);
+ break;
+ default:
+ if (kvm_x86_ops->get_msr_feature(msr))
+ return 1;
+ }
+ return 0;
+}
+
+static int do_get_msr_feature(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
+{
+ struct kvm_msr_entry msr;
+ int r;
+
+ msr.index = index;
+ r = kvm_get_msr_feature(&msr);
+ if (r)
+ return r;
+
+ *data = msr.data;
+
+ return 0;
+}
+
bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer)
{
if (efer & efer_reserved_bits)
@@ -2222,7 +2261,6 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
switch (msr) {
case MSR_AMD64_NB_CFG:
- case MSR_IA32_UCODE_REV:
case MSR_IA32_UCODE_WRITE:
case MSR_VM_HSAVE_PA:
case MSR_AMD64_PATCH_LOADER:
@@ -2230,6 +2268,10 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
case MSR_AMD64_DC_CFG:
break;
+ case MSR_IA32_UCODE_REV:
+ if (msr_info->host_initiated)
+ vcpu->arch.microcode_version = data;
+ break;
case MSR_EFER:
return set_efer(vcpu, data);
case MSR_K7_HWCR:
@@ -2525,7 +2567,7 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
msr_info->data = 0;
break;
case MSR_IA32_UCODE_REV:
- msr_info->data = 0x100000000ULL;
+ msr_info->data = vcpu->arch.microcode_version;
break;
case MSR_MTRRcap:
case 0x200 ... 0x2ff:
@@ -2680,13 +2722,11 @@ static int __msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs *msrs,
int (*do_msr)(struct kvm_vcpu *vcpu,
unsigned index, u64 *data))
{
- int i, idx;
+ int i;
- idx = srcu_read_lock(&vcpu->kvm->srcu);
for (i = 0; i < msrs->nmsrs; ++i)
if (do_msr(vcpu, entries[i].index, &entries[i].data))
break;
- srcu_read_unlock(&vcpu->kvm->srcu, idx);
return i;
}
@@ -2785,6 +2825,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_SET_BOOT_CPU_ID:
case KVM_CAP_SPLIT_IRQCHIP:
case KVM_CAP_IMMEDIATE_EXIT:
+ case KVM_CAP_GET_MSR_FEATURES:
r = 1;
break;
case KVM_CAP_ADJUST_CLOCK:
@@ -2899,6 +2940,31 @@ long kvm_arch_dev_ioctl(struct file *filp,
goto out;
r = 0;
break;
+ case KVM_GET_MSR_FEATURE_INDEX_LIST: {
+ struct kvm_msr_list __user *user_msr_list = argp;
+ struct kvm_msr_list msr_list;
+ unsigned int n;
+
+ r = -EFAULT;
+ if (copy_from_user(&msr_list, user_msr_list, sizeof(msr_list)))
+ goto out;
+ n = msr_list.nmsrs;
+ msr_list.nmsrs = num_msr_based_features;
+ if (copy_to_user(user_msr_list, &msr_list, sizeof(msr_list)))
+ goto out;
+ r = -E2BIG;
+ if (n < msr_list.nmsrs)
+ goto out;
+ r = -EFAULT;
+ if (copy_to_user(user_msr_list->indices, &msr_based_features,
+ num_msr_based_features * sizeof(u32)))
+ goto out;
+ r = 0;
+ break;
+ }
+ case KVM_GET_MSRS:
+ r = msr_io(NULL, argp, do_get_msr_feature, 1);
+ break;
}
default:
r = -EINVAL;
@@ -3636,12 +3702,18 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
r = 0;
break;
}
- case KVM_GET_MSRS:
+ case KVM_GET_MSRS: {
+ int idx = srcu_read_lock(&vcpu->kvm->srcu);
r = msr_io(vcpu, argp, do_get_msr, 1);
+ srcu_read_unlock(&vcpu->kvm->srcu, idx);
break;
- case KVM_SET_MSRS:
+ }
+ case KVM_SET_MSRS: {
+ int idx = srcu_read_lock(&vcpu->kvm->srcu);
r = msr_io(vcpu, argp, do_set_msr, 0);
+ srcu_read_unlock(&vcpu->kvm->srcu, idx);
break;
+ }
case KVM_TPR_ACCESS_REPORTING: {
struct kvm_tpr_access_ctl tac;
@@ -4464,6 +4536,19 @@ static void kvm_init_msr_list(void)
j++;
}
num_emulated_msrs = j;
+
+ for (i = j = 0; i < ARRAY_SIZE(msr_based_features); i++) {
+ struct kvm_msr_entry msr;
+
+ msr.index = msr_based_features[i];
+ if (kvm_get_msr_feature(&msr))
+ continue;
+
+ if (j < i)
+ msr_based_features[j] = msr_based_features[i];
+ j++;
+ }
+ num_msr_based_features = j;
}
static int vcpu_mmio_write(struct kvm_vcpu *vcpu, gpa_t addr, int len,
@@ -7975,7 +8060,6 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
kvm_vcpu_mtrr_init(vcpu);
vcpu_load(vcpu);
kvm_vcpu_reset(vcpu, false);
- kvm_lapic_reset(vcpu, false);
kvm_mmu_setup(vcpu);
vcpu_put(vcpu);
return 0;
@@ -8018,6 +8102,8 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
{
+ kvm_lapic_reset(vcpu, init_event);
+
vcpu->arch.hflags = 0;
vcpu->arch.smi_pending = 0;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 0fb5ef939732..7b26d4b0b052 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -761,6 +761,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_TRACE_PAUSE __KVM_DEPRECATED_MAIN_0x07
#define KVM_TRACE_DISABLE __KVM_DEPRECATED_MAIN_0x08
#define KVM_GET_EMULATED_CPUID _IOWR(KVMIO, 0x09, struct kvm_cpuid2)
+#define KVM_GET_MSR_FEATURE_INDEX_LIST _IOWR(KVMIO, 0x0a, struct kvm_msr_list)
/*
* Extension capability list.
@@ -934,6 +935,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_S390_AIS_MIGRATION 150
#define KVM_CAP_PPC_GET_CPU_CHAR 151
#define KVM_CAP_S390_BPB 152
+#define KVM_CAP_GET_MSR_FEATURES 153
#ifdef KVM_CAP_IRQ_ROUTING
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.