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authorAbel Gordon <abelg@il.ibm.com>2013-04-18 14:37:25 +0300
committerGleb Natapov <gleb@redhat.com>2013-04-22 10:52:10 +0300
commit8de48833708a7834f1ba65a80944b1045082553a (patch)
tree0e2afad141c35ca6d1f1a5d65034ce7761c82ddb /arch/x86
parent145c28dd19a2a05aa798e77bd7e679847fe8bee3 (diff)
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: Abel Gordon <abelg@il.ibm.com> Reviewed-by: Orit Wasserman <owasserm@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/vmx.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 1cdfb5d7580a..7b27af9a14d8 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -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)
skip_emulated_instruction(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 */
+ vmcs_clear(shadow_vmcs);
+ vmx->nested.current_shadow_vmcs = shadow_vmcs;
+ }
INIT_LIST_HEAD(&(vmx->nested.vmcs02_pool));
vmx->nested.vmcs02_num = 0;