Implement the VMLAUNCH and VMRESUME instructions, allowing a guest
hypervisor to run its own guests.
This patch does not include some of the necessary validity checks on
vmcs12 fields before the entry. These will appear in a separate patch
below.
Signed-off-by: Nadav Har'El <nyh@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 65 +++++++++++++++++++++++++++++++++++++++++--
1 file changed, 63 insertions(+), 2 deletions(-)
--- .before/arch/x86/kvm/vmx.c 2011-05-25 22:41:03.000000000 +0300
+++ .after/arch/x86/kvm/vmx.c 2011-05-25 22:41:03.000000000 +0300
@@ -4942,6 +4942,21 @@ static int handle_vmclear(struct kvm_vcp
return 1;
}
+static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch);
+
+/* Emulate the VMLAUNCH instruction */
+static int handle_vmlaunch(struct kvm_vcpu *vcpu)
+{
+ return nested_vmx_run(vcpu, true);
+}
+
+/* Emulate the VMRESUME instruction */
+static int handle_vmresume(struct kvm_vcpu *vcpu)
+{
+
+ return nested_vmx_run(vcpu, false);
+}
+
enum vmcs_field_type {
VMCS_FIELD_TYPE_U16 = 0,
VMCS_FIELD_TYPE_U64 = 1,
@@ -5239,11 +5254,11 @@ static int (*kvm_vmx_exit_handlers[])(st
[EXIT_REASON_INVLPG] = handle_invlpg,
[EXIT_REASON_VMCALL] = handle_vmcall,
[EXIT_REASON_VMCLEAR] = handle_vmclear,
- [EXIT_REASON_VMLAUNCH] = handle_vmx_insn,
+ [EXIT_REASON_VMLAUNCH] = handle_vmlaunch,
[EXIT_REASON_VMPTRLD] = handle_vmptrld,
[EXIT_REASON_VMPTRST] = handle_vmptrst,
[EXIT_REASON_VMREAD] = handle_vmread,
- [EXIT_REASON_VMRESUME] = handle_vmx_insn,
+ [EXIT_REASON_VMRESUME] = handle_vmresume,
[EXIT_REASON_VMWRITE] = handle_vmwrite,
[EXIT_REASON_VMOFF] = handle_vmoff,
[EXIT_REASON_VMON] = handle_vmon,
@@ -6088,6 +6103,52 @@ static void prepare_vmcs02(struct kvm_vc
kvm_register_write(vcpu, VCPU_REGS_RIP, vmcs12->guest_rip);
}
+/*
+ * nested_vmx_run() handles a nested entry, i.e., a VMLAUNCH or VMRESUME on L1
+ * for running an L2 nested guest.
+ */
+static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
+{
+ struct vmcs12 *vmcs12;
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+ int cpu;
+ struct loaded_vmcs *vmcs02;
+
+ if (!nested_vmx_check_permission(vcpu) ||
+ !nested_vmx_check_vmcs12(vcpu))
+ return 1;
+
+ skip_emulated_instruction(vcpu);
+ vmcs12 = get_vmcs12(vcpu);
+
+ vmcs02 = nested_get_current_vmcs02(vmx);
+ if (!vmcs02)
+ return -ENOMEM;
+
+ enter_guest_mode(vcpu);
+
+ vmx->nested.vmcs01_tsc_offset = vmcs_read64(TSC_OFFSET);
+
+ cpu = get_cpu();
+ vmx->loaded_vmcs = vmcs02;
+ vmx_vcpu_put(vcpu);
+ vmx_vcpu_load(vcpu, cpu);
+ vcpu->cpu = cpu;
+ put_cpu();
+
+ vmcs12->launch_state = 1;
+
+ prepare_vmcs02(vcpu, vmcs12);
+
+ /*
+ * Note no nested_vmx_succeed or nested_vmx_fail here. At this point
+ * we are no longer running L1, and VMLAUNCH/VMRESUME has not yet
+ * returned as far as L1 is concerned. It will only return (and set
+ * the success flag) when L2 exits (see nested_vmx_vmexit()).
+ */
+ return 1;
+}
+
static int vmx_check_intercept(struct kvm_vcpu *vcpu,
struct x86_instruction_info *info,
enum x86_intercept_stage stage)
--
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