[PATCH v4 08/21] KVM: VMX: Refactor VMX instruction information access
From: Chang S. Bae
Date: Mon May 11 2026 - 21:47:00 EST
Introduce a helper that returns the instruction information as 64-bit
value and adjust existing sites to prepare for a wider field.
The VMX instruction information field is currently 32 bits. Future
extensions may expand this field to support extended register IDs,
requiring a wider width. The change provides a single access point for
the transition.
No functional change intended.
Signed-off-by: Chang S. Bae <chang.seok.bae@xxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 22 +++++++++++-----------
arch/x86/kvm/vmx/nested.h | 2 +-
arch/x86/kvm/vmx/vmx.c | 4 ++--
arch/x86/kvm/vmx/vmx.h | 10 ++++++++--
4 files changed, 22 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 4690a4d23709..06c1d83a8082 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5229,7 +5229,7 @@ static void nested_vmx_triple_fault(struct kvm_vcpu *vcpu)
* #UD, #GP, or #SS.
*/
int get_vmx_mem_address(struct kvm_vcpu *vcpu, unsigned long exit_qualification,
- u32 vmx_instruction_info, bool wr, int len, gva_t *ret)
+ u64 vmx_instruction_info, bool wr, int len, gva_t *ret)
{
gva_t off;
bool exn;
@@ -5361,7 +5361,7 @@ static int nested_vmx_get_vmptr(struct kvm_vcpu *vcpu, gpa_t *vmpointer,
int r;
if (get_vmx_mem_address(vcpu, vmx_get_exit_qual(vcpu),
- vmcs_read32(VMX_INSTRUCTION_INFO), false,
+ vmx_get_instr_info(), false,
sizeof(*vmpointer), &gva)) {
*ret = 1;
return -EINVAL;
@@ -5646,7 +5646,7 @@ static int handle_vmread(struct kvm_vcpu *vcpu)
struct vmcs12 *vmcs12 = is_guest_mode(vcpu) ? get_shadow_vmcs12(vcpu)
: get_vmcs12(vcpu);
unsigned long exit_qualification = vmx_get_exit_qual(vcpu);
- u32 instr_info = vmcs_read32(VMX_INSTRUCTION_INFO);
+ u64 instr_info = vmx_get_instr_info();
struct vcpu_vmx *vmx = to_vmx(vcpu);
struct x86_exception e;
unsigned long field;
@@ -5752,7 +5752,7 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu)
struct vmcs12 *vmcs12 = is_guest_mode(vcpu) ? get_shadow_vmcs12(vcpu)
: get_vmcs12(vcpu);
unsigned long exit_qualification = vmx_get_exit_qual(vcpu);
- u32 instr_info = vmcs_read32(VMX_INSTRUCTION_INFO);
+ u64 instr_info = vmx_get_instr_info();
struct vcpu_vmx *vmx = to_vmx(vcpu);
struct x86_exception e;
unsigned long field;
@@ -5941,7 +5941,7 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu)
static int handle_vmptrst(struct kvm_vcpu *vcpu)
{
unsigned long exit_qual = vmx_get_exit_qual(vcpu);
- u32 instr_info = vmcs_read32(VMX_INSTRUCTION_INFO);
+ u64 instr_info = vmx_get_instr_info();
gpa_t current_vmptr = to_vmx(vcpu)->nested.current_vmptr;
struct x86_exception e;
gva_t gva;
@@ -5969,7 +5969,7 @@ static int handle_vmptrst(struct kvm_vcpu *vcpu)
static int handle_invept(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
- u32 vmx_instruction_info, types;
+ u64 vmx_instruction_info, types;
unsigned long type, roots_to_free;
struct kvm_mmu *mmu;
gva_t gva;
@@ -5989,7 +5989,7 @@ static int handle_invept(struct kvm_vcpu *vcpu)
if (!nested_vmx_check_permission(vcpu))
return 1;
- vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
+ vmx_instruction_info = vmx_get_instr_info();
gpr_index = vmx_get_instr_info_reg2(vmx_instruction_info);
type = kvm_register_read(vcpu, gpr_index);
@@ -6049,7 +6049,7 @@ static int handle_invept(struct kvm_vcpu *vcpu)
static int handle_invvpid(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
- u32 vmx_instruction_info;
+ u64 vmx_instruction_info;
unsigned long type, types;
gva_t gva;
struct x86_exception e;
@@ -6070,7 +6070,7 @@ static int handle_invvpid(struct kvm_vcpu *vcpu)
if (!nested_vmx_check_permission(vcpu))
return 1;
- vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
+ vmx_instruction_info = vmx_get_instr_info();
gpr_index = vmx_get_instr_info_reg2(vmx_instruction_info);
type = kvm_register_read(vcpu, gpr_index);
@@ -6423,7 +6423,7 @@ static bool nested_vmx_exit_handled_encls(struct kvm_vcpu *vcpu,
static bool nested_vmx_exit_handled_vmcs_access(struct kvm_vcpu *vcpu,
struct vmcs12 *vmcs12, gpa_t bitmap)
{
- u32 vmx_instruction_info;
+ u64 vmx_instruction_info;
unsigned long field;
u8 b;
@@ -6431,7 +6431,7 @@ static bool nested_vmx_exit_handled_vmcs_access(struct kvm_vcpu *vcpu,
return true;
/* Decode instruction info and find the field to access */
- vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
+ vmx_instruction_info = vmx_get_instr_info();
field = kvm_register_read(vcpu, (((vmx_instruction_info) >> 28) & 0xf));
/* Out-of-range fields always cause a VM exit from L2 to L1 */
diff --git a/arch/x86/kvm/vmx/nested.h b/arch/x86/kvm/vmx/nested.h
index 213a448104af..ff1ea771d1fb 100644
--- a/arch/x86/kvm/vmx/nested.h
+++ b/arch/x86/kvm/vmx/nested.h
@@ -51,7 +51,7 @@ void nested_sync_vmcs12_to_shadow(struct kvm_vcpu *vcpu);
int vmx_set_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data);
int vmx_get_vmx_msr(struct nested_vmx_msrs *msrs, u32 msr_index, u64 *pdata);
int get_vmx_mem_address(struct kvm_vcpu *vcpu, unsigned long exit_qualification,
- u32 vmx_instruction_info, bool wr, int len, gva_t *ret);
+ u64 vmx_instruction_info, bool wr, int len, gva_t *ret);
bool nested_vmx_check_io_bitmaps(struct kvm_vcpu *vcpu, unsigned int port,
int size);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index e8dd5d5b33ad..6bf3b79c69f3 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6136,7 +6136,7 @@ static int handle_monitor_trap(struct kvm_vcpu *vcpu)
static int handle_invpcid(struct kvm_vcpu *vcpu)
{
- u32 vmx_instruction_info;
+ u64 vmx_instruction_info;
unsigned long type;
gva_t gva;
struct {
@@ -6150,7 +6150,7 @@ static int handle_invpcid(struct kvm_vcpu *vcpu)
return 1;
}
- vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
+ vmx_instruction_info = vmx_get_instr_info();
gpr_index = vmx_get_instr_info_reg2(vmx_instruction_info);
type = kvm_register_read(vcpu, gpr_index);
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index daedf663c0a9..aa4190620e82 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -702,12 +702,18 @@ static inline bool vmx_guest_state_valid(struct kvm_vcpu *vcpu)
void dump_vmcs(struct kvm_vcpu *vcpu);
-static inline int vmx_get_instr_info_reg(u32 vmx_instr_info)
+/* A placeholder to smoothen 64-bit extension */
+static inline u64 vmx_get_instr_info(void)
+{
+ return vmcs_read32(VMX_INSTRUCTION_INFO);
+}
+
+static inline int vmx_get_instr_info_reg(u64 vmx_instr_info)
{
return (vmx_instr_info >> 3) & 0xf;
}
-static inline int vmx_get_instr_info_reg2(u32 vmx_instr_info)
+static inline int vmx_get_instr_info_reg2(u64 vmx_instr_info)
{
return (vmx_instr_info >> 28) & 0xf;
}
--
2.51.0