Commit 8de48833 authored by Abel Gordon's avatar Abel Gordon Committed by Gleb Natapov
Browse files

KVM: nVMX: Allocate shadow vmcs

Allocate a shadow vmcs used by the processor to shadow part of the fields
stored in the software defined VMCS12 (let L1 access fields without causing
exits). Note we keep a shadow vmcs only for the current vmcs12.  Once a vmcs12
becomes non-current, its shadow vmcs is released.
Signed-off-by: default avatarAbel Gordon <>
Reviewed-by: default avatarOrit Wasserman <>
Signed-off-by: default avatarGleb Natapov <>
parent 145c28dd
......@@ -355,6 +355,7 @@ struct nested_vmx {
/* The host-usable pointer to the above */
struct page *current_vmcs12_page;
struct vmcs12 *current_vmcs12;
struct vmcs *current_shadow_vmcs;
/* vmcs02_list cache of VMCSs recently used to run L2 guests */
struct list_head vmcs02_pool;
......@@ -5527,6 +5528,7 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
struct kvm_segment cs;
struct vcpu_vmx *vmx = to_vmx(vcpu);
struct vmcs *shadow_vmcs;
/* The Intel VMX Instruction Reference lists a bunch of bits that
* are prerequisite to running VMXON, most notably cr4.VMXE must be
......@@ -5555,6 +5557,16 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
return 1;
if (enable_shadow_vmcs) {
shadow_vmcs = alloc_vmcs();
if (!shadow_vmcs)
return -ENOMEM;
/* mark vmcs as shadow */
shadow_vmcs->revision_id |= (1u << 31);
/* init shadow vmcs */
vmx->nested.current_shadow_vmcs = shadow_vmcs;
vmx->nested.vmcs02_num = 0;
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment