[PATCH RFC 2/7] KVM: nVMX: modify vmcs12 fields to match Hyper-V enlightened VMCS

From: Vitaly Kuznetsov
Date: Mon Dec 18 2017 - 12:20:35 EST


From: Ladi Prosek <lprosek@xxxxxxxxxx>

Reorders existing fields and adds fields specific to Hyper-V. The layout
now matches Hyper-V TLFS 5.0b 16.11.2 Enlightened VMCS.

Fields used by KVM but missing from Hyper-V are placed in the second half
of the VMCS page to minimize the chances they will clash with future
enlightened VMCS versions.

Signed-off-by: Ladi Prosek <lprosek@xxxxxxxxxx>
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
[Vitaly]: Update VMCS12_REVISION to some new arbitrary number.
---
arch/x86/kvm/vmx.c | 321 +++++++++++++++++++++++++++++++----------------------
1 file changed, 187 insertions(+), 134 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 8eba631c4dbd..cd5f29a57880 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -239,159 +239,212 @@ struct __packed vmcs12 {
u32 revision_id;
u32 abort;

+ union {
+ u64 hv_vmcs[255];
+ struct {
+ u16 host_es_selector;
+ u16 host_cs_selector;
+ u16 host_ss_selector;
+ u16 host_ds_selector;
+ u16 host_fs_selector;
+ u16 host_gs_selector;
+ u16 host_tr_selector;
+
+ u64 host_ia32_pat;
+ u64 host_ia32_efer;
+
+ /*
+ * To allow migration of L1 (complete with its L2
+ * guests) between machines of different natural widths
+ * (32 or 64 bit), we cannot have unsigned long fields
+ * with no explicit size. We use u64 (aliased
+ * natural_width) instead. Luckily, x86 is
+ * little-endian.
+ */
+ natural_width host_cr0;
+ natural_width host_cr3;
+ natural_width host_cr4;
+
+ natural_width host_ia32_sysenter_esp;
+ natural_width host_ia32_sysenter_eip;
+ natural_width host_rip;
+ u32 host_ia32_sysenter_cs;
+
+ u32 pin_based_vm_exec_control;
+ u32 vm_exit_controls;
+ u32 secondary_vm_exec_control;
+
+ u64 io_bitmap_a;
+ u64 io_bitmap_b;
+ u64 msr_bitmap;
+
+ u16 guest_es_selector;
+ u16 guest_cs_selector;
+ u16 guest_ss_selector;
+ u16 guest_ds_selector;
+ u16 guest_fs_selector;
+ u16 guest_gs_selector;
+ u16 guest_ldtr_selector;
+ u16 guest_tr_selector;
+
+ u32 guest_es_limit;
+ u32 guest_cs_limit;
+ u32 guest_ss_limit;
+ u32 guest_ds_limit;
+ u32 guest_fs_limit;
+ u32 guest_gs_limit;
+ u32 guest_ldtr_limit;
+ u32 guest_tr_limit;
+ u32 guest_gdtr_limit;
+ u32 guest_idtr_limit;
+
+ u32 guest_es_ar_bytes;
+ u32 guest_cs_ar_bytes;
+ u32 guest_ss_ar_bytes;
+ u32 guest_ds_ar_bytes;
+ u32 guest_fs_ar_bytes;
+ u32 guest_gs_ar_bytes;
+ u32 guest_ldtr_ar_bytes;
+ u32 guest_tr_ar_bytes;
+
+ natural_width guest_es_base;
+ natural_width guest_cs_base;
+ natural_width guest_ss_base;
+ natural_width guest_ds_base;
+ natural_width guest_fs_base;
+ natural_width guest_gs_base;
+ natural_width guest_ldtr_base;
+ natural_width guest_tr_base;
+ natural_width guest_gdtr_base;
+ natural_width guest_idtr_base;
+
+ u64 padding64_1[3];
+
+ u64 vm_exit_msr_store_addr;
+ u64 vm_exit_msr_load_addr;
+ u64 vm_entry_msr_load_addr;
+
+ natural_width cr3_target_value0;
+ natural_width cr3_target_value1;
+ natural_width cr3_target_value2;
+ natural_width cr3_target_value3;
+
+ u32 page_fault_error_code_mask;
+ u32 page_fault_error_code_match;
+
+ u32 cr3_target_count;
+ u32 vm_exit_msr_store_count;
+ u32 vm_exit_msr_load_count;
+ u32 vm_entry_msr_load_count;
+
+ u64 tsc_offset;
+ u64 virtual_apic_page_addr;
+ u64 vmcs_link_pointer;
+
+ u64 guest_ia32_debugctl;
+ u64 guest_ia32_pat;
+ u64 guest_ia32_efer;
+
+ u64 guest_pdptr0;
+ u64 guest_pdptr1;
+ u64 guest_pdptr2;
+ u64 guest_pdptr3;
+
+ natural_width guest_pending_dbg_exceptions;
+ natural_width guest_sysenter_esp;
+ natural_width guest_sysenter_eip;
+
+ u32 guest_activity_state;
+ u32 guest_sysenter_cs;
+
+ natural_width cr0_guest_host_mask;
+ natural_width cr4_guest_host_mask;
+ natural_width cr0_read_shadow;
+ natural_width cr4_read_shadow;
+ natural_width guest_cr0;
+ natural_width guest_cr3;
+ natural_width guest_cr4;
+ natural_width guest_dr7;
+
+ natural_width host_fs_base;
+ natural_width host_gs_base;
+ natural_width host_tr_base;
+ natural_width host_gdtr_base;
+ natural_width host_idtr_base;
+ natural_width host_rsp;
+
+ u64 ept_pointer;
+
+ u16 virtual_processor_id;
+ u16 padding16[3];
+
+ u64 padding64_2[5];
+ u64 guest_physical_address;
+
+ u32 vm_instruction_error;
+ u32 vm_exit_reason;
+ u32 vm_exit_intr_info;
+ u32 vm_exit_intr_error_code;
+ u32 idt_vectoring_info_field;
+ u32 idt_vectoring_error_code;
+ u32 vm_exit_instruction_len;
+ u32 vmx_instruction_info;
+
+ natural_width exit_qualification;
+ natural_width padding64_3[4];
+
+ natural_width guest_linear_address;
+ natural_width guest_rsp;
+ natural_width guest_rflags;
+
+ u32 guest_interruptibility_info;
+ u32 cpu_based_vm_exec_control;
+ u32 exception_bitmap;
+ u32 vm_entry_controls;
+ u32 vm_entry_intr_info_field;
+ u32 vm_entry_exception_error_code;
+ u32 vm_entry_instruction_len;
+ u32 tpr_threshold;
+
+ natural_width guest_rip;
+
+ u32 hv_clean_fields;
+ u32 hv_padding_32;
+ u32 hv_synthetic_controls;
+ u32 hv_enlightenments_control;
+ u32 hv_vp_id;
+
+ u64 hv_vm_id;
+ u64 partition_assist_page;
+ u64 padding64_4[4];
+ u64 guest_bndcfgs;
+ u64 padding64_5[7];
+ u64 xss_exit_bitmap;
+ u64 padding64_6[7];
+ };
+ };
+
+ /* Synthetic and KVM-specific fields: */
u32 launch_state; /* set to 0 by VMCLEAR, to 1 by VMLAUNCH */
u32 padding[7]; /* room for future expansion */

- u64 io_bitmap_a;
- u64 io_bitmap_b;
- u64 msr_bitmap;
- u64 vm_exit_msr_store_addr;
- u64 vm_exit_msr_load_addr;
- u64 vm_entry_msr_load_addr;
- u64 tsc_offset;
- u64 virtual_apic_page_addr;
u64 apic_access_addr;
u64 posted_intr_desc_addr;
u64 vm_function_control;
- u64 ept_pointer;
u64 eoi_exit_bitmap0;
u64 eoi_exit_bitmap1;
u64 eoi_exit_bitmap2;
u64 eoi_exit_bitmap3;
u64 eptp_list_address;
- u64 xss_exit_bitmap;
- u64 guest_physical_address;
- u64 vmcs_link_pointer;
u64 pml_address;
- u64 guest_ia32_debugctl;
- u64 guest_ia32_pat;
- u64 guest_ia32_efer;
u64 guest_ia32_perf_global_ctrl;
- u64 guest_pdptr0;
- u64 guest_pdptr1;
- u64 guest_pdptr2;
- u64 guest_pdptr3;
- u64 guest_bndcfgs;
- u64 host_ia32_pat;
- u64 host_ia32_efer;
u64 host_ia32_perf_global_ctrl;
u64 padding64[8]; /* room for future expansion */
- /*
- * To allow migration of L1 (complete with its L2 guests) between
- * machines of different natural widths (32 or 64 bit), we cannot have
- * unsigned long fields with no explict size. We use u64 (aliased
- * natural_width) instead. Luckily, x86 is little-endian.
- */
- natural_width cr0_guest_host_mask;
- natural_width cr4_guest_host_mask;
- natural_width cr0_read_shadow;
- natural_width cr4_read_shadow;
- natural_width cr3_target_value0;
- natural_width cr3_target_value1;
- natural_width cr3_target_value2;
- natural_width cr3_target_value3;
- natural_width exit_qualification;
- natural_width guest_linear_address;
- natural_width guest_cr0;
- natural_width guest_cr3;
- natural_width guest_cr4;
- natural_width guest_es_base;
- natural_width guest_cs_base;
- natural_width guest_ss_base;
- natural_width guest_ds_base;
- natural_width guest_fs_base;
- natural_width guest_gs_base;
- natural_width guest_ldtr_base;
- natural_width guest_tr_base;
- natural_width guest_gdtr_base;
- natural_width guest_idtr_base;
- natural_width guest_dr7;
- natural_width guest_rsp;
- natural_width guest_rip;
- natural_width guest_rflags;
- natural_width guest_pending_dbg_exceptions;
- natural_width guest_sysenter_esp;
- natural_width guest_sysenter_eip;
- natural_width host_cr0;
- natural_width host_cr3;
- natural_width host_cr4;
- natural_width host_fs_base;
- natural_width host_gs_base;
- natural_width host_tr_base;
- natural_width host_gdtr_base;
- natural_width host_idtr_base;
- natural_width host_ia32_sysenter_esp;
- natural_width host_ia32_sysenter_eip;
- natural_width host_rsp;
- natural_width host_rip;
- natural_width paddingl[8]; /* room for future expansion */
- u32 pin_based_vm_exec_control;
- u32 cpu_based_vm_exec_control;
- u32 exception_bitmap;
- u32 page_fault_error_code_mask;
- u32 page_fault_error_code_match;
- u32 cr3_target_count;
- u32 vm_exit_controls;
- u32 vm_exit_msr_store_count;
- u32 vm_exit_msr_load_count;
- u32 vm_entry_controls;
- u32 vm_entry_msr_load_count;
- u32 vm_entry_intr_info_field;
- u32 vm_entry_exception_error_code;
- u32 vm_entry_instruction_len;
- u32 tpr_threshold;
- u32 secondary_vm_exec_control;
- u32 vm_instruction_error;
- u32 vm_exit_reason;
- u32 vm_exit_intr_info;
- u32 vm_exit_intr_error_code;
- u32 idt_vectoring_info_field;
- u32 idt_vectoring_error_code;
- u32 vm_exit_instruction_len;
- u32 vmx_instruction_info;
- u32 guest_es_limit;
- u32 guest_cs_limit;
- u32 guest_ss_limit;
- u32 guest_ds_limit;
- u32 guest_fs_limit;
- u32 guest_gs_limit;
- u32 guest_ldtr_limit;
- u32 guest_tr_limit;
- u32 guest_gdtr_limit;
- u32 guest_idtr_limit;
- u32 guest_es_ar_bytes;
- u32 guest_cs_ar_bytes;
- u32 guest_ss_ar_bytes;
- u32 guest_ds_ar_bytes;
- u32 guest_fs_ar_bytes;
- u32 guest_gs_ar_bytes;
- u32 guest_ldtr_ar_bytes;
- u32 guest_tr_ar_bytes;
- u32 guest_interruptibility_info;
- u32 guest_activity_state;
- u32 guest_sysenter_cs;
- u32 host_ia32_sysenter_cs;
u32 vmx_preemption_timer_value;
u32 padding32[7]; /* room for future expansion */
- u16 virtual_processor_id;
u16 posted_intr_nv;
- u16 guest_es_selector;
- u16 guest_cs_selector;
- u16 guest_ss_selector;
- u16 guest_ds_selector;
- u16 guest_fs_selector;
- u16 guest_gs_selector;
- u16 guest_ldtr_selector;
- u16 guest_tr_selector;
u16 guest_intr_status;
u16 guest_pml_index;
- u16 host_es_selector;
- u16 host_cs_selector;
- u16 host_ss_selector;
- u16 host_ds_selector;
- u16 host_fs_selector;
- u16 host_gs_selector;
- u16 host_tr_selector;
};

/*
@@ -399,7 +452,7 @@ struct __packed vmcs12 {
* layout of struct vmcs12 is changed. MSR_IA32_VMX_BASIC returns this id, and
* VMPTRLD verifies that the VMCS region that L1 is loading contains this id.
*/
-#define VMCS12_REVISION 0x11e57ed0
+#define VMCS12_REVISION 0x11e586b1

/*
* VMCS12_SIZE is the number of bytes L1 should allocate for the VMXON region
--
2.14.3