KVM: VMX: Support Unrestricted Guest feature

"Unrestricted Guest" feature is added in the VMX specification.
Intel Westmere and onwards processors will support this feature.

    It allows kvm guests to run real mode and unpaged mode
code natively in the VMX mode when EPT is turned on. With the
unrestricted guest there is no need to emulate the guest real mode code
in the vm86 container or in the emulator. Also the guest big real mode
code works like native.

  The attached patch enhances KVM to use the unrestricted guest feature
if available on the processor. It also adds a new kernel/module
parameter to disable the unrestricted guest feature at the boot time.

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Nitin A Kamble
2009-06-08 11:34:16 -07:00
committed by Avi Kivity
parent fa40a8214b
commit 3a624e29c7
3 changed files with 62 additions and 11 deletions

View File

@ -37,12 +37,14 @@
#define CR3_L_MODE_RESERVED_BITS (CR3_NONPAE_RESERVED_BITS | \
0xFFFFFF0000000000ULL)
#define KVM_GUEST_CR0_MASK \
(X86_CR0_PG | X86_CR0_PE | X86_CR0_WP | X86_CR0_NE \
| X86_CR0_NW | X86_CR0_CD)
#define KVM_GUEST_CR0_MASK_UNRESTRICTED_GUEST \
(X86_CR0_WP | X86_CR0_NE | X86_CR0_NW | X86_CR0_CD)
#define KVM_GUEST_CR0_MASK \
(KVM_GUEST_CR0_MASK_UNRESTRICTED_GUEST | X86_CR0_PG | X86_CR0_PE)
#define KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST \
(X86_CR0_WP | X86_CR0_NE | X86_CR0_TS | X86_CR0_MP)
#define KVM_VM_CR0_ALWAYS_ON \
(X86_CR0_PG | X86_CR0_PE | X86_CR0_WP | X86_CR0_NE | X86_CR0_TS \
| X86_CR0_MP)
(KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST | X86_CR0_PG | X86_CR0_PE)
#define KVM_GUEST_CR4_MASK \
(X86_CR4_VME | X86_CR4_PSE | X86_CR4_PAE | X86_CR4_PGE | X86_CR4_VMXE)
#define KVM_PMODE_VM_CR4_ALWAYS_ON (X86_CR4_PAE | X86_CR4_VMXE)