summaryrefslogtreecommitdiffstats
path: root/Documentation/virt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/virt')
-rw-r--r--Documentation/virt/kvm/api.rst50
1 files changed, 50 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 55efa82e37eb..07a45474abe9 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -7083,6 +7083,56 @@ resource that is controlled with the H_SET_MODE hypercall.
This capability allows a guest kernel to use a better-performance mode for
handling interrupts and system calls.
+7.31 KVM_CAP_DISABLE_QUIRKS2
+----------------------------
+
+:Capability: KVM_CAP_DISABLE_QUIRKS2
+:Parameters: args[0] - set of KVM quirks to disable
+:Architectures: x86
+:Type: vm
+
+This capability, if enabled, will cause KVM to disable some behavior
+quirks.
+
+Calling KVM_CHECK_EXTENSION for this capability returns a bitmask of
+quirks that can be disabled in KVM.
+
+The argument to KVM_ENABLE_CAP for this capability is a bitmask of
+quirks to disable, and must be a subset of the bitmask returned by
+KVM_CHECK_EXTENSION.
+
+The valid bits in cap.args[0] are:
+
+=================================== ============================================
+ KVM_X86_QUIRK_LINT0_REENABLED By default, the reset value for the LVT
+ LINT0 register is 0x700 (APIC_MODE_EXTINT).
+ When this quirk is disabled, the reset value
+ is 0x10000 (APIC_LVT_MASKED).
+
+ KVM_X86_QUIRK_CD_NW_CLEARED By default, KVM clears CR0.CD and CR0.NW.
+ When this quirk is disabled, KVM does not
+ change the value of CR0.CD and CR0.NW.
+
+ KVM_X86_QUIRK_LAPIC_MMIO_HOLE By default, the MMIO LAPIC interface is
+ available even when configured for x2APIC
+ mode. When this quirk is disabled, KVM
+ disables the MMIO LAPIC interface if the
+ LAPIC is in x2APIC mode.
+
+ KVM_X86_QUIRK_OUT_7E_INC_RIP By default, KVM pre-increments %rip before
+ exiting to userspace for an OUT instruction
+ to port 0x7e. When this quirk is disabled,
+ KVM does not pre-increment %rip before
+ exiting to userspace.
+
+ KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT When this quirk is disabled, KVM sets
+ CPUID.01H:ECX[bit 3] (MONITOR/MWAIT) if
+ IA32_MISC_ENABLE[bit 18] (MWAIT) is set.
+ Additionally, when this quirk is disabled,
+ KVM clears CPUID.01H:ECX[bit 3] if
+ IA32_MISC_ENABLE[bit 18] is cleared.
+=================================== ============================================
+
8. Other capabilities.
======================