[PATCH v7 02/30] KVM: selftests: Expose function that sets up sregs based on VM's mode

[Sagi Shahar <sagis@google.com>]

From: Ackerley Tng <ackerleytng@google.com>

This allows initializing sregs without setting vCPU registers in
KVM.

No functional change intended.

Signed-off-by: Ackerley Tng <ackerleytng@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
---
 .../selftests/kvm/include/x86/processor.h     |  1 +
 .../testing/selftests/kvm/lib/x86/processor.c | 45 ++++++++++---------
 2 files changed, 25 insertions(+), 21 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86/processor.h b/tools/testing/selftests/kvm/include/x86/processor.h
index b11b5a53ebd5..f2eb764cbd7c 100644
--- a/tools/testing/selftests/kvm/include/x86/processor.h
+++ b/tools/testing/selftests/kvm/include/x86/processor.h
@@ -1025,6 +1025,7 @@ static inline struct kvm_cpuid2 *allocate_kvm_cpuid2(int nr_entries)
 }
 
 void vcpu_init_cpuid(struct kvm_vcpu *vcpu, const struct kvm_cpuid2 *cpuid);
+void vcpu_setup_mode_sregs(struct kvm_vm *vm, struct kvm_sregs *sregs);
 
 static inline void vcpu_get_cpuid(struct kvm_vcpu *vcpu)
 {
diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
index a92dc1dad085..002303e2a572 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -488,34 +488,37 @@ static void kvm_seg_set_tss_64bit(vm_vaddr_t base, struct kvm_segment *segp)
 	segp->present = 1;
 }
 
-static void vcpu_init_sregs(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
+void vcpu_setup_mode_sregs(struct kvm_vm *vm, struct kvm_sregs *sregs)
 {
-	struct kvm_sregs sregs;
-
 	TEST_ASSERT_EQ(vm->mode, VM_MODE_PXXV48_4K);
 
-	/* Set mode specific system register values. */
-	vcpu_sregs_get(vcpu, &sregs);
-
-	sregs.idt.base = vm->arch.idt;
-	sregs.idt.limit = NUM_INTERRUPTS * sizeof(struct idt_entry) - 1;
-	sregs.gdt.base = vm->arch.gdt;
-	sregs.gdt.limit = getpagesize() - 1;
+	sregs->idt.base = vm->arch.idt;
+	sregs->idt.limit = NUM_INTERRUPTS * sizeof(struct idt_entry) - 1;
+	sregs->gdt.base = vm->arch.gdt;
+	sregs->gdt.limit = getpagesize() - 1;
 
-	sregs.cr0 = X86_CR0_PE | X86_CR0_NE | X86_CR0_PG;
-	sregs.cr4 |= X86_CR4_PAE | X86_CR4_OSFXSR;
+	sregs->cr0 = X86_CR0_PE | X86_CR0_NE | X86_CR0_PG;
+	sregs->cr4 |= X86_CR4_PAE | X86_CR4_OSFXSR;
 	if (kvm_cpu_has(X86_FEATURE_XSAVE))
-		sregs.cr4 |= X86_CR4_OSXSAVE;
-	sregs.efer |= (EFER_LME | EFER_LMA | EFER_NX);
+		sregs->cr4 |= X86_CR4_OSXSAVE;
+	sregs->efer |= (EFER_LME | EFER_LMA | EFER_NX);
+
+	kvm_seg_set_unusable(&sregs->ldt);
+	kvm_seg_set_kernel_code_64bit(&sregs->cs);
+	kvm_seg_set_kernel_data_64bit(&sregs->ds);
+	kvm_seg_set_kernel_data_64bit(&sregs->es);
+	kvm_seg_set_kernel_data_64bit(&sregs->gs);
+	kvm_seg_set_tss_64bit(vm->arch.tss, &sregs->tr);
 
-	kvm_seg_set_unusable(&sregs.ldt);
-	kvm_seg_set_kernel_code_64bit(&sregs.cs);
-	kvm_seg_set_kernel_data_64bit(&sregs.ds);
-	kvm_seg_set_kernel_data_64bit(&sregs.es);
-	kvm_seg_set_kernel_data_64bit(&sregs.gs);
-	kvm_seg_set_tss_64bit(vm->arch.tss, &sregs.tr);
+	sregs->cr3 = vm->pgd;
+}
+
+static void vcpu_init_sregs(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
+{
+	struct kvm_sregs sregs;
 
-	sregs.cr3 = vm->pgd;
+	vcpu_sregs_get(vcpu, &sregs);
+	vcpu_setup_mode_sregs(vm, &sregs);
 	vcpu_sregs_set(vcpu, &sregs);
 }
 
-- 
2.50.0.rc2.692.g299adb8693-goog