[PATCH 2/2] KVM: nVMX: Advertise VMFUNC to L1 hypervisor

[Bandan Das]

Advertise VMFUNC and EPTP switching function to the L1
hypervisor. Change nested_vmx_exit_handled() to return false
for VMFUNC so L0 can handle it.

Signed-off-by: Bandan Das <bsd@xxxxxxxxxx>
---
 arch/x86/include/asm/vmx.h |  4 ++++
 arch/x86/kvm/vmx.c         | 18 ++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index e06783e..5f63a2e 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -192,6 +192,8 @@ enum vmcs_field {
 	APIC_ACCESS_ADDR_HIGH		= 0x00002015,
 	POSTED_INTR_DESC_ADDR           = 0x00002016,
 	POSTED_INTR_DESC_ADDR_HIGH      = 0x00002017,
+	VM_FUNCTION_CONTROL             = 0x00002018,
+	VM_FUNCTION_CONTROL_HIGH        = 0x00002019,
 	EPT_POINTER                     = 0x0000201a,
 	EPT_POINTER_HIGH                = 0x0000201b,
 	EOI_EXIT_BITMAP0                = 0x0000201c,
@@ -202,6 +204,8 @@ enum vmcs_field {
 	EOI_EXIT_BITMAP2_HIGH           = 0x00002021,
 	EOI_EXIT_BITMAP3                = 0x00002022,
 	EOI_EXIT_BITMAP3_HIGH           = 0x00002023,
+	EPTP_LIST_ADDRESS               = 0x00002024,
+	EPTP_LIST_ADDRESS_HIGH          = 0x00002025,
 	VMREAD_BITMAP                   = 0x00002026,
 	VMWRITE_BITMAP                  = 0x00002028,
 	XSS_EXIT_BITMAP                 = 0x0000202C,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 75049c0..bf06bef 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -767,11 +767,13 @@ static const unsigned short vmcs_field_to_offset_table[] = {
 	FIELD64(VIRTUAL_APIC_PAGE_ADDR, virtual_apic_page_addr),
 	FIELD64(APIC_ACCESS_ADDR, apic_access_addr),
 	FIELD64(POSTED_INTR_DESC_ADDR, posted_intr_desc_addr),
+	FIELD64(VM_FUNCTION_CONTROL, vm_function_control),
 	FIELD64(EPT_POINTER, ept_pointer),
 	FIELD64(EOI_EXIT_BITMAP0, eoi_exit_bitmap0),
 	FIELD64(EOI_EXIT_BITMAP1, eoi_exit_bitmap1),
 	FIELD64(EOI_EXIT_BITMAP2, eoi_exit_bitmap2),
 	FIELD64(EOI_EXIT_BITMAP3, eoi_exit_bitmap3),
+	FIELD64(EPTP_LIST_ADDRESS, eptp_list_address),
 	FIELD64(XSS_EXIT_BITMAP, xss_exit_bitmap),
 	FIELD64(GUEST_PHYSICAL_ADDRESS, guest_physical_address),
 	FIELD64(VMCS_LINK_POINTER, vmcs_link_pointer),
@@ -2806,6 +2808,13 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx)
 	} else
 		vmx->nested.nested_vmx_ept_caps = 0;
 
+	if (cpu_has_vmx_vmfunc()) {
+		vmx->nested.nested_vmx_secondary_ctls_high |=
+			SECONDARY_EXEC_ENABLE_VMFUNC;
+		vmx->nested.nested_vmx_vmfunc_controls =
+			vmx_vmfunc_controls() & 1;
+	}
+
 	/*
 	 * Old versions of KVM use the single-context version without
 	 * checking for support, so declare that it is supported even
@@ -8215,6 +8224,8 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
 	case EXIT_REASON_PML_FULL:
 		/* We emulate PML support to L1. */
 		return false;
+	case EXIT_REASON_VMFUNC:
+		return false;
 	default:
 		return true;
 	}
@@ -10309,6 +10320,13 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
 		vmx_flush_tlb_ept_only(vcpu);
 	}
 
+	if (nested_cpu_has_eptp_switching(vmcs12)) {
+		vmcs_write64(VM_FUNCTION_CONTROL,
+			     vmcs12->vm_function_control & 1);
+		vmcs_write64(EPTP_LIST_ADDRESS,
+			     page_to_phys(vmx->nested.shadow_eptp_list));
+	}
+
 	/*
 	 * This sets GUEST_CR0 to vmcs12->guest_cr0, possibly modifying those
 	 * bits which we consider mandatory enabled.
-- 
2.9.4