*/
#define KVM_MAX_NR_USER_RETURN_MSRS 16
-struct kvm_user_return_msrs_global {
- int nr;
- u32 msrs[KVM_MAX_NR_USER_RETURN_MSRS];
-};
-
struct kvm_user_return_msrs {
struct user_return_notifier urn;
bool registered;
} values[KVM_MAX_NR_USER_RETURN_MSRS];
};
-static struct kvm_user_return_msrs_global __read_mostly user_return_msrs_global;
+u32 __read_mostly kvm_nr_uret_msrs;
+EXPORT_SYMBOL_GPL(kvm_nr_uret_msrs);
+static u32 __read_mostly kvm_uret_msrs_list[KVM_MAX_NR_USER_RETURN_MSRS];
static struct kvm_user_return_msrs __percpu *user_return_msrs;
#define KVM_SUPPORTED_XCR0 (XFEATURE_MASK_FP | XFEATURE_MASK_SSE \
user_return_notifier_unregister(urn);
}
local_irq_restore(flags);
- for (slot = 0; slot < user_return_msrs_global.nr; ++slot) {
+ for (slot = 0; slot < kvm_nr_uret_msrs; ++slot) {
values = &msrs->values[slot];
if (values->host != values->curr) {
- wrmsrl(user_return_msrs_global.msrs[slot], values->host);
+ wrmsrl(kvm_uret_msrs_list[slot], values->host);
values->curr = values->host;
}
}
}
-void kvm_define_user_return_msr(unsigned slot, u32 msr)
+static int kvm_probe_user_return_msr(u32 msr)
+{
+ u64 val;
+ int ret;
+
+ preempt_disable();
+ ret = rdmsrl_safe(msr, &val);
+ if (ret)
+ goto out;
+ ret = wrmsrl_safe(msr, val);
+out:
+ preempt_enable();
+ return ret;
+}
+
+int kvm_add_user_return_msr(u32 msr)
{
- BUG_ON(slot >= KVM_MAX_NR_USER_RETURN_MSRS);
- user_return_msrs_global.msrs[slot] = msr;
- if (slot >= user_return_msrs_global.nr)
- user_return_msrs_global.nr = slot + 1;
+ BUG_ON(kvm_nr_uret_msrs >= KVM_MAX_NR_USER_RETURN_MSRS);
+
+ if (kvm_probe_user_return_msr(msr))
+ return -1;
+
+ kvm_uret_msrs_list[kvm_nr_uret_msrs] = msr;
+ return kvm_nr_uret_msrs++;
}
-EXPORT_SYMBOL_GPL(kvm_define_user_return_msr);
+EXPORT_SYMBOL_GPL(kvm_add_user_return_msr);
+
+int kvm_find_user_return_msr(u32 msr)
+{
+ int i;
+
+ for (i = 0; i < kvm_nr_uret_msrs; ++i) {
+ if (kvm_uret_msrs_list[i] == msr)
+ return i;
+ }
+ return -1;
+}
+EXPORT_SYMBOL_GPL(kvm_find_user_return_msr);
static void kvm_user_return_msr_cpu_online(void)
{
u64 value;
int i;
- for (i = 0; i < user_return_msrs_global.nr; ++i) {
- rdmsrl_safe(user_return_msrs_global.msrs[i], &value);
+ for (i = 0; i < kvm_nr_uret_msrs; ++i) {
+ rdmsrl_safe(kvm_uret_msrs_list[i], &value);
msrs->values[i].host = value;
msrs->values[i].curr = value;
}
value = (value & mask) | (msrs->values[slot].host & ~mask);
if (value == msrs->values[slot].curr)
return 0;
- err = wrmsrl_safe(user_return_msrs_global.msrs[slot], value);
+ err = wrmsrl_safe(kvm_uret_msrs_list[slot], value);
if (err)
return 1;
if (!guest_cpuid_has(vcpu, X86_FEATURE_RTM))
fixed |= DR6_RTM;
+
+ if (!guest_cpuid_has(vcpu, X86_FEATURE_BUS_LOCK_DETECT))
+ fixed |= DR6_BUS_LOCK;
return fixed;
}
* invokes 64-bit SYSENTER.
*/
data = get_canonical(data, vcpu_virt_addr_bits(vcpu));
+ break;
+ case MSR_TSC_AUX:
+ if (!kvm_is_supported_user_return_msr(MSR_TSC_AUX))
+ return 1;
+
+ if (!host_initiated &&
+ !guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP) &&
+ !guest_cpuid_has(vcpu, X86_FEATURE_RDPID))
+ return 1;
+
+ /*
+ * Per Intel's SDM, bits 63:32 are reserved, but AMD's APM has
+ * incomplete and conflicting architectural behavior. Current
+ * AMD CPUs completely ignore bits 63:32, i.e. they aren't
+ * reserved and always read as zeros. Enforce Intel's reserved
+ * bits check if and only if the guest CPU is Intel, and clear
+ * the bits in all other cases. This ensures cross-vendor
+ * migration will provide consistent behavior for the guest.
+ */
+ if (guest_cpuid_is_intel(vcpu) && (data >> 32) != 0)
+ return 1;
+
+ data = (u32)data;
+ break;
}
msr.data = data;
if (!host_initiated && !kvm_msr_allowed(vcpu, index, KVM_MSR_FILTER_READ))
return KVM_MSR_RET_FILTERED;
+ switch (index) {
+ case MSR_TSC_AUX:
+ if (!kvm_is_supported_user_return_msr(MSR_TSC_AUX))
+ return 1;
+
+ if (!host_initiated &&
+ !guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP) &&
+ !guest_cpuid_has(vcpu, X86_FEATURE_RDPID))
+ return 1;
+ break;
+ }
+
msr.index = index;
msr.host_initiated = host_initiated;
static int kvm_add_msr_filter(struct kvm_x86_msr_filter *msr_filter,
struct kvm_msr_filter_range *user_range)
{
- struct msr_bitmap_range range;
unsigned long *bitmap = NULL;
size_t bitmap_size;
- int r;
if (!user_range->nmsrs)
return 0;
+ if (user_range->flags & ~(KVM_MSR_FILTER_READ | KVM_MSR_FILTER_WRITE))
+ return -EINVAL;
+
+ if (!user_range->flags)
+ return -EINVAL;
+
bitmap_size = BITS_TO_LONGS(user_range->nmsrs) * sizeof(long);
if (!bitmap_size || bitmap_size > KVM_MSR_FILTER_MAX_BITMAP_SIZE)
return -EINVAL;
if (IS_ERR(bitmap))
return PTR_ERR(bitmap);
- range = (struct msr_bitmap_range) {
+ msr_filter->ranges[msr_filter->count] = (struct msr_bitmap_range) {
.flags = user_range->flags,
.base = user_range->base,
.nmsrs = user_range->nmsrs,
.bitmap = bitmap,
};
- if (range.flags & ~(KVM_MSR_FILTER_READ | KVM_MSR_FILTER_WRITE)) {
- r = -EINVAL;
- goto err;
- }
-
- if (!range.flags) {
- r = -EINVAL;
- goto err;
- }
-
- /* Everything ok, add this range identifier. */
- msr_filter->ranges[msr_filter->count] = range;
msr_filter->count++;
-
return 0;
-err:
- kfree(bitmap);
- return r;
}
static int kvm_vm_ioctl_set_msr_filter(struct kvm *kvm, void __user *argp)
continue;
break;
case MSR_TSC_AUX:
- if (!kvm_cpu_cap_has(X86_FEATURE_RDTSCP))
+ if (!kvm_cpu_cap_has(X86_FEATURE_RDTSCP) &&
+ !kvm_cpu_cap_has(X86_FEATURE_RDPID))
continue;
break;
case MSR_IA32_UMWAIT_CONTROL:
static DECLARE_WORK(pvclock_gtod_work, pvclock_gtod_update_fn);
+/*
+ * Indirection to move queue_work() out of the tk_core.seq write held
+ * region to prevent possible deadlocks against time accessors which
+ * are invoked with work related locks held.
+ */
+static void pvclock_irq_work_fn(struct irq_work *w)
+{
+ queue_work(system_long_wq, &pvclock_gtod_work);
+}
+
+static DEFINE_IRQ_WORK(pvclock_irq_work, pvclock_irq_work_fn);
+
/*
* Notification about pvclock gtod data update.
*/
update_pvclock_gtod(tk);
- /* disable master clock if host does not trust, or does not
- * use, TSC based clocksource.
+ /*
+ * Disable master clock if host does not trust, or does not use,
+ * TSC based clocksource. Delegate queue_work() to irq_work as
+ * this is invoked with tk_core.seq write held.
*/
if (!gtod_is_based_on_tsc(gtod->clock.vclock_mode) &&
atomic_read(&kvm_guest_has_master_clock) != 0)
- queue_work(system_long_wq, &pvclock_gtod_work);
-
+ irq_work_queue(&pvclock_irq_work);
return 0;
}
printk(KERN_ERR "kvm: failed to allocate percpu kvm_user_return_msrs\n");
goto out_free_x86_emulator_cache;
}
+ kvm_nr_uret_msrs = 0;
r = kvm_mmu_module_init();
if (r)
cpuhp_remove_state_nocalls(CPUHP_AP_X86_KVM_CLK_ONLINE);
#ifdef CONFIG_X86_64
pvclock_gtod_unregister_notifier(&pvclock_gtod_notifier);
+ irq_work_sync(&pvclock_irq_work);
+ cancel_work_sync(&pvclock_gtod_work);
#endif
kvm_x86_ops.hardware_enable = NULL;
kvm_mmu_module_exit();