[PATCH 4/5] KVM: nVMX: Enable nested virtual interrupt delivery.

[Wincy Van]

With virtual interrupt delivery, the hardware prevent KVM from
the low efficiency interrupt inject way. In nested vmx, it is
a important feature, we can reduce much more nested-vmexit,
especially in high throughput scenes.

Signed-off-by: Wincy Van <fanwenyi0529@xxxxxxxxx>
---
 arch/x86/kvm/vmx.c |   49 +++++++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 47 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 99e19bb..ea56e9f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -216,6 +216,10 @@ struct __packed vmcs12 {
        u64 virtual_apic_page_addr;
        u64 apic_access_addr;
        u64 ept_pointer;
+       u64 eoi_exit_bitmap0;
+       u64 eoi_exit_bitmap1;
+       u64 eoi_exit_bitmap2;
+       u64 eoi_exit_bitmap3;
        u64 xss_exit_bitmap;
        u64 guest_physical_address;
        u64 vmcs_link_pointer;
@@ -338,6 +342,7 @@ struct __packed vmcs12 {
        u16 guest_gs_selector;
        u16 guest_ldtr_selector;
        u16 guest_tr_selector;
+       u16 guest_intr_status;
        u16 host_es_selector;
        u16 host_cs_selector;
        u16 host_ss_selector;
@@ -624,6 +629,7 @@ static const unsigned short vmcs_field_to_offset_table[] = {
        FIELD(GUEST_GS_SELECTOR, guest_gs_selector),
        FIELD(GUEST_LDTR_SELECTOR, guest_ldtr_selector),
        FIELD(GUEST_TR_SELECTOR, guest_tr_selector),
+       FIELD(GUEST_INTR_STATUS, guest_intr_status),
        FIELD(HOST_ES_SELECTOR, host_es_selector),
        FIELD(HOST_CS_SELECTOR, host_cs_selector),
        FIELD(HOST_SS_SELECTOR, host_ss_selector),
@@ -641,6 +647,10 @@ 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(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(XSS_EXIT_BITMAP, xss_exit_bitmap),
        FIELD64(GUEST_PHYSICAL_ADDRESS, guest_physical_address),
        FIELD64(VMCS_LINK_POINTER, vmcs_link_pointer),
@@ -1144,6 +1154,11 @@ static inline bool
nested_cpu_has_apic_reg_virt(struct vmcs12 *vmcs12)
        return nested_cpu_has2(vmcs12, SECONDARY_EXEC_APIC_REGISTER_VIRT);
 }

+static inline bool nested_cpu_has_vid(struct vmcs12 *vmcs12)
+{
+       return nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY);
+}
+
 static inline bool is_exception(u32 intr_info)
 {
        return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VALID_MASK))
@@ -2438,6 +2453,7 @@ static void nested_vmx_setup_ctls_msrs(struct
vcpu_vmx *vmx)
                SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
                SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE |
                SECONDARY_EXEC_APIC_REGISTER_VIRT |
+               SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY |
                SECONDARY_EXEC_WBINVD_EXITING |
                SECONDARY_EXEC_XSAVES;

@@ -7346,7 +7362,8 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
                return nested_cpu_has2(vmcs12,
                        SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES);
        case EXIT_REASON_APIC_WRITE:
-               /* apic_write should exit unconditionally. */
+       case EXIT_REASON_EOI_INDUCED:
+               /* apic_write and eoi_induced should exit unconditionally. */
                return 1;
        case EXIT_REASON_EPT_VIOLATION:
                /*
@@ -8379,17 +8396,29 @@ static inline int
nested_vmx_check_virt_x2apic(struct kvm_vcpu *vcpu,
        return 0;
 }

+static inline int nested_vmx_check_vid(struct kvm_vcpu *vcpu,
+                                      struct vmcs12 *vmcs12)
+{
+       if (!nested_exit_on_intr(vcpu))
+               return -EINVAL;
+       return 0;
+}
+
 static int nested_vmx_check_apicv_controls(struct kvm_vcpu *vcpu,
                                           struct vmcs12 *vmcs12)
 {
        int r;

        if (!nested_cpu_has_virt_x2apic_mode(vmcs12) &&
-           !nested_cpu_has_apic_reg_virt(vmcs12))
+           !nested_cpu_has_apic_reg_virt(vmcs12) &&
+           !nested_cpu_has_vid(vmcs12))
                return 0;

        if (nested_cpu_has_virt_x2apic_mode(vmcs12))
                r = nested_vmx_check_virt_x2apic(vcpu, vmcs12);
+       if (nested_cpu_has_vid(vmcs12))
+               r |= nested_vmx_check_vid(vcpu, vmcs12);
+
        if (r)
                goto fail;

@@ -8705,6 +8734,19 @@ static void prepare_vmcs02(struct kvm_vcpu
*vcpu, struct vmcs12 *vmcs12)
                        kvm_vcpu_reload_apic_access_page(vcpu);
                }

+               if (exec_control & SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY) {
+                       vmcs_write64(EOI_EXIT_BITMAP0,
+                               vmcs12->eoi_exit_bitmap0);
+                       vmcs_write64(EOI_EXIT_BITMAP1,
+                               vmcs12->eoi_exit_bitmap1);
+                       vmcs_write64(EOI_EXIT_BITMAP2,
+                               vmcs12->eoi_exit_bitmap2);
+                       vmcs_write64(EOI_EXIT_BITMAP3,
+                               vmcs12->eoi_exit_bitmap3);
+                       vmcs_write16(GUEST_INTR_STATUS,
+                               vmcs12->guest_intr_status);
+               }
+
                vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control);
        }

@@ -9272,6 +9314,9 @@ static void prepare_vmcs12(struct kvm_vcpu
*vcpu, struct vmcs12 *vmcs12,
                vmcs12->guest_pdptr3 = vmcs_read64(GUEST_PDPTR3);
        }

+       if (nested_cpu_has_vid(vmcs12))
+               vmcs12->guest_intr_status = vmcs_read16(GUEST_INTR_STATUS);
+
        vmcs12->vm_entry_controls =
                (vmcs12->vm_entry_controls & ~VM_ENTRY_IA32E_MODE) |
                (vm_entry_controls_get(to_vmx(vcpu)) & VM_ENTRY_IA32E_MODE);
--
1.7.1
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