Diffstat (limited to 'Documentation/virtual/kvm/api.txt')
1 files changed, 16 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 7945b0bd35e..e2a4b528736 100644
@@ -1100,6 +1100,15 @@ emulate them efficiently. The fields in each entry are defined as follows:
eax, ebx, ecx, edx: the values returned by the cpuid instruction for
this function/index combination
+The TSC deadline timer feature (CPUID leaf 1, ecx) is always returned
+as false, since the feature depends on KVM_CREATE_IRQCHIP for local APIC
+support. Instead it is reported via
+ ioctl(KVM_CHECK_EXTENSION, KVM_CAP_TSC_DEADLINE_TIMER)
+if that returns true and you use KVM_CREATE_IRQCHIP, or if you emulate the
+feature in userspace, then you can enable the feature for KVM_SET_CPUID2.
@@ -1151,6 +1160,13 @@ following flags are specified:
/* Depends on KVM_CAP_IOMMU */
#define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0)
+The KVM_DEV_ASSIGN_ENABLE_IOMMU flag is a mandatory option to ensure
+isolation of the device. Usages not specifying this flag are deprecated.
+Only PCI header type 0 devices with PCI BAR resources are supported by
+device assignment. The user requesting this ioctl must have read/write
+access to the PCI sysfs resource files associated with the device.