KVM: Add helper functions for nested Intel VMX virtualization

mdoucha · pevik · commit 98da818fc4a8 · 2025-01-31T08:36:52.000+01:00
Link: https://lore.kernel.org/ltp/20250121164426.27977-7-mdoucha@suse.cz/ Acked-by: Petr Vorel <pvorel@suse.cz> Signed-off-by: Martin Doucha <mdoucha@suse.cz>
diff --git a/testcases/kernel/kvm/bootstrap_x86.S b/testcases/kernel/kvm/bootstrap_x86.S
@@ -11,6 +11,9 @@
 
 .set MSR_VM_HSAVE_PA, 0xc0010117
 
+.set VMX_VMCS_HOST_RSP, 0x6c14
+.set VMX_VMCS_HOST_RIP, 0x6c16
+
 /*
  * This section will be allocated at address 0x1000 and
  * jumped to from the reset stub provided by kvm_run.
@@ -451,6 +454,67 @@ kvm_svm_vmrun:
 	pop %edi
 	ret
 
+.global kvm_vmx_vmlaunch
+kvm_vmx_vmlaunch:
+	push %edi
+	mov 8(%esp), %edi
+	push %ebx
+	push %esi
+	push %ebp
+	push %edi
+
+	mov $VMX_VMCS_HOST_RSP, %eax
+	vmwrite %esp, %eax
+	jna vmx_vmwrite_error
+	mov $VMX_VMCS_HOST_RIP, %eax
+	lea vmx_vm_exit, %ebx
+	vmwrite %ebx, %eax
+	jna vmx_vmwrite_error
+
+	load_vcpu_regs
+	vmlaunch
+	jmp vmx_vm_exit
+
+.global kvm_vmx_vmresume
+kvm_vmx_vmresume:
+	push %edi
+	mov 8(%esp), %edi
+	push %ebx
+	push %esi
+	push %ebp
+	push %edi
+
+	mov $VMX_VMCS_HOST_RSP, %eax
+	vmwrite %esp, %eax
+	jna vmx_vmwrite_error
+	mov $VMX_VMCS_HOST_RIP, %eax
+	lea vmx_vm_exit, %ebx
+	vmwrite %ebx, %eax
+	jna vmx_vmwrite_error
+
+	load_vcpu_regs
+	vmresume
+
+vmx_vm_exit:
+	jna vmx_vmentry_error
+	save_vcpu_regs
+	xorl %eax, %eax
+
+vmx_vm_ret:
+	pop %edi
+	pop %ebp
+	pop %esi
+	pop %ebx
+	pop %edi
+	ret
+
+vmx_vmwrite_error:
+	movl $2, %eax
+	jmp vmx_vm_ret
+
+vmx_vmentry_error:
+	movl $1, %eax
+	jmp vmx_vm_ret
 
 .section .bss.pgtables, "aw", @nobits
 .global kvm_pagetable
diff --git a/testcases/kernel/kvm/bootstrap_x86_64.S b/testcases/kernel/kvm/bootstrap_x86_64.S
@@ -12,6 +12,9 @@
 
 .set MSR_VM_HSAVE_PA, 0xc0010117
 
+.set VMX_VMCS_HOST_RSP, 0x6c14
+.set VMX_VMCS_HOST_RIP, 0x6c16
+
 /*
  * This section will be allocated at address 0x1000 and
  * jumped to from the reset stub provided by kvm_run.
@@ -587,6 +590,57 @@ kvm_svm_vmrun:
 	pop_local
 	retq
 
+.global kvm_vmx_vmlaunch
+kvm_vmx_vmlaunch:
+	push_local
+	pushq %rdi
+
+	mov $VMX_VMCS_HOST_RSP, %rax
+	vmwrite %rsp, %rax
+	jna vmx_vmwrite_error
+	mov $VMX_VMCS_HOST_RIP, %rax
+	lea vmx_vm_exit, %rbx
+	vmwrite %rbx, %rax
+	jna vmx_vmwrite_error
+
+	load_vcpu_regs
+	vmlaunch
+	jmp vmx_vm_exit
+
+.global kvm_vmx_vmresume
+kvm_vmx_vmresume:
+	push_local
+	pushq %rdi
+
+	movq $VMX_VMCS_HOST_RSP, %rax
+	vmwrite %rsp, %rax
+	jna vmx_vmwrite_error
+	movq $VMX_VMCS_HOST_RIP, %rax
+	lea vmx_vm_exit, %rbx
+	vmwrite %rbx, %rax
+	jna vmx_vmwrite_error
+
+	load_vcpu_regs
+	vmresume
+
+vmx_vm_exit:
+	jna vmx_vmentry_error
+	save_vcpu_regs
+	xorq %rax, %rax
+
+vmx_vm_ret:
+	popq %rdi
+	pop_local
+	retq
+
+vmx_vmwrite_error:
+	movq $2, %rax
+	jmp vmx_vm_ret
+
+vmx_vmentry_error:
+	movq $1, %rax
+	jmp vmx_vm_ret
+
 .section .bss.pgtables, "aw", @nobits
 .global kvm_pagetable
 kvm_pagetable:
diff --git a/testcases/kernel/kvm/include/kvm_x86_vmx.h b/testcases/kernel/kvm/include/kvm_x86_vmx.h
@@ -0,0 +1,201 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2024 SUSE LLC <mdoucha@suse.cz>
+ *
+ * x86-specific KVM helper functions and structures for Intel VMX
+ */
+
+#ifndef KVM_X86_VMX_H_
+#define KVM_X86_VMX_H_
+
+#include "kvm_x86.h"
+
+/* CPUID_GET_MODEL_INFO flags returned in ECX */
+#define CPUID_MODEL_VMX (1 << 5)
+#define CPUID_MODEL_SMX (1 << 6)
+
+#define MSR_IA32_VMX_BASIC 0x480
+#define MSR_IA32_VMX_PINX_MASK 0x481
+#define MSR_IA32_VMX_EXECCTL_MASK 0x482
+#define MSR_IA32_VMX_EXITCTL_MASK 0x483
+#define MSR_IA32_VMX_ENTRYCTL_MASK 0x484
+#define MSR_IA32_VMX_CR0_FIXED0 0x486
+#define MSR_IA32_VMX_CR0_FIXED1 0x487
+#define MSR_IA32_VMX_CR4_FIXED0 0x488
+#define MSR_IA32_VMX_CR4_FIXED1 0x489
+#define MSR_IA32_VMX_EXECCTL2_MASK 0x48b
+#define MSR_IA32_VMX_PINX_MASK2 0x48d
+#define MSR_IA32_VMX_EXECCTL_MASK2 0x48e
+#define MSR_IA32_VMX_EXITCTL_MASK2 0x48f
+#define MSR_IA32_VMX_ENTRYCTL_MASK2 0x490
+
+#define IA32FC_LOCK (1 << 0)
+#define IA32FC_VMXON_SMX (1 << 1)
+#define IA32FC_VMXON_NORMAL (1 << 2)
+
+#define IA32_VMXBASIC_USELESS_CTL_MASKS (1ULL << 55)
+
+#define VMX_VMCS_GUEST_ES	0x800
+#define VMX_VMCS_GUEST_CS	0x802
+#define VMX_VMCS_GUEST_SS	0x804
+#define VMX_VMCS_GUEST_DS	0x806
+#define VMX_VMCS_GUEST_FS	0x808
+#define VMX_VMCS_GUEST_GS	0x80a
+#define VMX_VMCS_GUEST_LDTR	0x80c
+#define VMX_VMCS_GUEST_TR	0x80e
+#define VMX_VMCS_GUEST_INTR	0x810
+#define VMX_VMCS_HOST_ES	0xc00
+#define VMX_VMCS_HOST_CS	0xc02
+#define VMX_VMCS_HOST_SS	0xc04
+#define VMX_VMCS_HOST_DS	0xc06
+#define VMX_VMCS_HOST_FS	0xc08
+#define VMX_VMCS_HOST_GS	0xc0a
+#define VMX_VMCS_HOST_TR	0xc0c
+
+#define VMX_VMCS_LINK_POINTER	0x2800
+
+#define VMX_VMCS_GUEST_ES_LIMIT		0x4800
+#define VMX_VMCS_GUEST_CS_LIMIT		0x4802
+#define VMX_VMCS_GUEST_SS_LIMIT		0x4804
+#define VMX_VMCS_GUEST_DS_LIMIT		0x4806
+#define VMX_VMCS_GUEST_FS_LIMIT		0x4808
+#define VMX_VMCS_GUEST_GS_LIMIT		0x480a
+#define VMX_VMCS_GUEST_LDTR_LIMIT	0x480c
+#define VMX_VMCS_GUEST_TR_LIMIT		0x480e
+#define VMX_VMCS_GUEST_GDTR_LIMIT	0x4810
+#define VMX_VMCS_GUEST_IDTR_LIMIT	0x4812
+#define VMX_VMCS_GUEST_ES_ACCESS	0x4814
+#define VMX_VMCS_GUEST_CS_ACCESS	0x4816
+#define VMX_VMCS_GUEST_SS_ACCESS	0x4818
+#define VMX_VMCS_GUEST_DS_ACCESS	0x481a
+#define VMX_VMCS_GUEST_FS_ACCESS	0x481c
+#define VMX_VMCS_GUEST_GS_ACCESS	0x481e
+#define VMX_VMCS_GUEST_LDTR_ACCESS	0x4820
+#define VMX_VMCS_GUEST_TR_ACCESS	0x4822
+#define VMX_VMCS_GUEST_INTR_STATE	0x4824
+#define VMX_VMCS_GUEST_ACT_STATE	0x4826
+#define VMX_VMCS_GUEST_SMBASE		0x4828
+#define VMX_VMCS_GUEST_SYSENTER_CS	0x482a
+#define VMX_VMCS_HOST_SYSENTER_CS	0x4c00
+
+#define VMX_VMCS_GUEST_CR0		0x6800
+#define VMX_VMCS_GUEST_CR3		0x6802
+#define VMX_VMCS_GUEST_CR4		0x6804
+#define VMX_VMCS_GUEST_ES_BASE		0x6806
+#define VMX_VMCS_GUEST_CS_BASE		0x6808
+#define VMX_VMCS_GUEST_SS_BASE		0x680a
+#define VMX_VMCS_GUEST_DS_BASE		0x680c
+#define VMX_VMCS_GUEST_FS_BASE		0x680e
+#define VMX_VMCS_GUEST_GS_BASE		0x6810
+#define VMX_VMCS_GUEST_LDTR_BASE	0x6812
+#define VMX_VMCS_GUEST_TR_BASE		0x6814
+#define VMX_VMCS_GUEST_GDTR_BASE	0x6816
+#define VMX_VMCS_GUEST_IDTR_BASE	0x6818
+#define VMX_VMCS_GUEST_DR7		0x681a
+#define VMX_VMCS_GUEST_RSP		0x681c
+#define VMX_VMCS_GUEST_RIP		0x681e
+#define VMX_VMCS_GUEST_RFLAGS		0x6820
+#define VMX_VMCS_GUEST_DEBUG_EXC	0x6822
+#define VMX_VMCS_GUEST_SYSENTER_ESP	0x6824
+#define VMX_VMCS_GUEST_SYSENTER_EIP	0x6826
+#define VMX_VMCS_HOST_CR0		0x6c00
+#define VMX_VMCS_HOST_CR3		0x6c02
+#define VMX_VMCS_HOST_CR4		0x6c04
+#define VMX_VMCS_HOST_FS_BASE		0x6c06
+#define VMX_VMCS_HOST_GS_BASE		0x6c08
+#define VMX_VMCS_HOST_TR_BASE		0x6c0a
+#define VMX_VMCS_HOST_GDTR_BASE		0x6c0c
+#define VMX_VMCS_HOST_IDTR_BASE		0x6c0e
+#define VMX_VMCS_HOST_SYSENTER_ESP	0x6c10
+#define VMX_VMCS_HOST_SYSENTER_EIP	0x6c12
+#define VMX_VMCS_HOST_RSP		0x6c14
+#define VMX_VMCS_HOST_RIP		0x6c16
+
+#define VMX_VMCS_VMPINX_CTL		0x4000
+#define VMX_VMCS_VMEXEC_CTL		0x4002
+#define VMX_VMCS_VMEXIT_CTL		0x400c
+#define VMX_VMCS_VMEXIT_MSR_STORE	0x400e
+#define VMX_VMCS_VMEXIT_MSR_LOAD	0x4010
+#define VMX_VMCS_VMENTRY_CTL		0x4012
+#define VMX_VMCS_VMENTRY_MSR_LOAD	0x4014
+#define VMX_VMCS_VMENTRY_INTR		0x4016
+#define VMX_VMCS_VMENTRY_EXC		0x4018
+#define VMX_VMCS_VMENTRY_INST_LEN	0x401a
+#define VMX_VMCS_VMEXEC_CTL2		0x401e
+
+#define VMX_VMCS_VMINST_ERROR		0x4400
+#define VMX_VMCS_EXIT_REASON		0x4402
+#define VMX_VMCS_VMEXIT_INTR_INFO	0x4404
+#define VMX_VMCS_VMEXIT_INTR_ERRNO	0x4406
+#define VMX_VMCS_IDTVEC_INFO		0x4408
+#define VMX_VMCS_IDTVEC_ERRNO		0x440a
+#define VMX_VMCS_VMEXIT_INST_LEN	0x440c
+#define VMX_VMCS_VMEXIT_INST_INFO	0x440e
+#define VMX_VMCS_EXIT_QUALIFICATION	0x6400
+
+#define VMX_INTERCEPT_HLT (1 << 7)
+#define VMX_EXECCTL_ENABLE_CTL2 (1 << 31)
+
+#define VMX_EXECCTL2_SHADOW_VMCS (1 << 14)
+
+#define VMX_EXITCTL_SAVE_DR (1 << 2)
+#define VMX_EXITCTL_X64 (1 << 9)
+
+#define VMX_ENTRYCTL_LOAD_DR (1 << 2)
+#define VMX_ENTRYCTL_X64 (1 << 9)
+
+#define VMX_SHADOW_VMCS 0x80000000
+#define VMX_VMCSFIELD_64BIT 0x2000
+#define VMX_VMCSFIELD_SIZE_MASK 0x6000
+
+#define VMX_INVALID_VMCS 0xffffffffffffffffULL
+
+#define VMX_EXIT_HLT 12
+#define VMX_EXIT_FAILED_ENTRY 0x80000000
+
+struct kvm_vmcs {
+	uint32_t version;
+	uint32_t abort;
+	uint8_t data[4088];
+};
+
+struct kvm_vmx_vcpu {
+	struct kvm_vmcs *vmcs;
+	struct kvm_regs64 regs;
+	int launched;
+};
+
+/* Intel VMX virtualization helper functions */
+int kvm_is_vmx_supported(void);
+void kvm_set_vmx_state(int enabled);
+struct kvm_vmcs *kvm_alloc_vmcs(void);
+
+/* Copy GDT entry to given fields of the current VMCS */
+void kvm_vmcs_copy_gdt_descriptor(unsigned int gdt_id,
+	unsigned long vmcs_selector, unsigned long vmcs_flags,
+	unsigned long vmcs_limit, unsigned long vmcs_baseaddr);
+void kvm_init_vmx_vcpu(struct kvm_vmx_vcpu *cpu, uint16_t ss, void *rsp,
+	int (*guest_main)(void));
+struct kvm_vmx_vcpu *kvm_create_vmx_vcpu(int (*guest_main)(void),
+	int alloc_stack);
+
+/* Set the VMCS as current and update the host state fields */
+void kvm_vmx_activate_vcpu(struct kvm_vmx_vcpu *cpu);
+void kvm_vmx_vmrun(struct kvm_vmx_vcpu *cpu);
+
+void kvm_vmx_vmclear(struct kvm_vmcs *buf);
+void kvm_vmx_vmptrld(struct kvm_vmcs *buf);
+uint64_t kvm_vmx_vmptrst(void);
+uint64_t kvm_vmx_vmread(unsigned long var_id);
+void kvm_vmx_vmwrite(unsigned long var_id, uint64_t value);
+int kvm_vmx_vmlaunch(struct kvm_vmx_vcpu *buf);
+int kvm_vmx_vmresume(struct kvm_vmx_vcpu *buf);
+
+/* Read last VMX instruction error from current VMCS */
+int kvm_vmx_inst_errno(void);
+/* Get VMX instruction error description */
+const char *kvm_vmx_inst_strerr(int vmx_errno);
+/* Get description of last VMX instruction error in current VMCS */
+const char *kvm_vmx_inst_err(void);
+
+#endif /* KVM_X86_VMX_H_ */
diff --git a/testcases/kernel/kvm/lib_x86.c b/testcases/kernel/kvm/lib_x86.c
