diff mbox series

[13/18] KVM: selftests: Drop superfluous switch() on vm->mode in vcpu_init_sregs()

Message ID 20240314232637.2538648-14-seanjc@google.com (mailing list archive)
State New, archived
Headers show
Series KVM: selftests: Clean up x86's DT initialization | expand

Commit Message

Sean Christopherson March 14, 2024, 11:26 p.m. UTC
Replace the switch statement on vm->mode in x86's vcpu_init_sregs()'s with
a simple assert that the VM has a 48-bit virtual address space.  A switch
statement is both overkill and misleading, as the existing code incorrectly
implies that VMs with LA57 would need different to configuration for the
LDT, TSS, and flat segments.  In all likelihood, the only difference that
would be needed for selftests is CR4.LA57 itself.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 .../selftests/kvm/lib/x86_64/processor.c      | 25 ++++++++-----------
 1 file changed, 10 insertions(+), 15 deletions(-)

Comments

Ackerley Tng March 28, 2024, 2:28 a.m. UTC | #1
Sean Christopherson <seanjc@google.com> writes:

> Replace the switch statement on vm->mode in x86's vcpu_init_sregs()'s with
> a simple assert that the VM has a 48-bit virtual address space.  A switch
> statement is both overkill and misleading, as the existing code incorrectly
> implies that VMs with LA57 would need different to configuration for the
> LDT, TSS, and flat segments.  In all likelihood, the only difference that
> would be needed for selftests is CR4.LA57 itself.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
>  .../selftests/kvm/lib/x86_64/processor.c      | 25 ++++++++-----------
>  1 file changed, 10 insertions(+), 15 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> index 8547833ffa26..561c0aa93608 100644
> --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
> +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> @@ -555,6 +555,8 @@ static void vcpu_init_sregs(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
>  {
>  	struct kvm_sregs sregs;
>  
> +	TEST_ASSERT_EQ(vm->mode, VM_MODE_PXXV48_4K);
> +
>  	/* Set mode specific system register values. */
>  	vcpu_sregs_get(vcpu, &sregs);
>  
> @@ -562,22 +564,15 @@ static void vcpu_init_sregs(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
>  
>  	kvm_setup_gdt(vm, &sregs.gdt);
>  
> -	switch (vm->mode) {
> -	case VM_MODE_PXXV48_4K:
> -		sregs.cr0 = X86_CR0_PE | X86_CR0_NE | X86_CR0_PG;
> -		sregs.cr4 |= X86_CR4_PAE | X86_CR4_OSFXSR;
> -		sregs.efer |= (EFER_LME | EFER_LMA | EFER_NX);
> +	sregs.cr0 = X86_CR0_PE | X86_CR0_NE | X86_CR0_PG;
> +	sregs.cr4 |= X86_CR4_PAE | X86_CR4_OSFXSR;
> +	sregs.efer |= (EFER_LME | EFER_LMA | EFER_NX);
>  
> -		kvm_seg_set_unusable(&sregs.ldt);
> -		kvm_seg_set_kernel_code_64bit(vm, DEFAULT_CODE_SELECTOR, &sregs.cs);
> -		kvm_seg_set_kernel_data_64bit(vm, DEFAULT_DATA_SELECTOR, &sregs.ds);
> -		kvm_seg_set_kernel_data_64bit(vm, DEFAULT_DATA_SELECTOR, &sregs.es);
> -		kvm_setup_tss_64bit(vm, &sregs.tr, 0x18);
> -		break;
> -
> -	default:
> -		TEST_FAIL("Unknown guest mode, mode: 0x%x", vm->mode);
> -	}
> +	kvm_seg_set_unusable(&sregs.ldt);
> +	kvm_seg_set_kernel_code_64bit(vm, DEFAULT_CODE_SELECTOR, &sregs.cs);
> +	kvm_seg_set_kernel_data_64bit(vm, DEFAULT_DATA_SELECTOR, &sregs.ds);
> +	kvm_seg_set_kernel_data_64bit(vm, DEFAULT_DATA_SELECTOR, &sregs.es);
> +	kvm_setup_tss_64bit(vm, &sregs.tr, 0x18);
>  
>  	sregs.cr3 = vm->pgd;
>  	vcpu_sregs_set(vcpu, &sregs);
> -- 
> 2.44.0.291.gc1ea87d7ee-goog

Reviewed-by: Ackerley Tng <ackerleytng@google.com>
diff mbox series

Patch

diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index 8547833ffa26..561c0aa93608 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -555,6 +555,8 @@  static void vcpu_init_sregs(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
 {
 	struct kvm_sregs sregs;
 
+	TEST_ASSERT_EQ(vm->mode, VM_MODE_PXXV48_4K);
+
 	/* Set mode specific system register values. */
 	vcpu_sregs_get(vcpu, &sregs);
 
@@ -562,22 +564,15 @@  static void vcpu_init_sregs(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
 
 	kvm_setup_gdt(vm, &sregs.gdt);
 
-	switch (vm->mode) {
-	case VM_MODE_PXXV48_4K:
-		sregs.cr0 = X86_CR0_PE | X86_CR0_NE | X86_CR0_PG;
-		sregs.cr4 |= X86_CR4_PAE | X86_CR4_OSFXSR;
-		sregs.efer |= (EFER_LME | EFER_LMA | EFER_NX);
+	sregs.cr0 = X86_CR0_PE | X86_CR0_NE | X86_CR0_PG;
+	sregs.cr4 |= X86_CR4_PAE | X86_CR4_OSFXSR;
+	sregs.efer |= (EFER_LME | EFER_LMA | EFER_NX);
 
-		kvm_seg_set_unusable(&sregs.ldt);
-		kvm_seg_set_kernel_code_64bit(vm, DEFAULT_CODE_SELECTOR, &sregs.cs);
-		kvm_seg_set_kernel_data_64bit(vm, DEFAULT_DATA_SELECTOR, &sregs.ds);
-		kvm_seg_set_kernel_data_64bit(vm, DEFAULT_DATA_SELECTOR, &sregs.es);
-		kvm_setup_tss_64bit(vm, &sregs.tr, 0x18);
-		break;
-
-	default:
-		TEST_FAIL("Unknown guest mode, mode: 0x%x", vm->mode);
-	}
+	kvm_seg_set_unusable(&sregs.ldt);
+	kvm_seg_set_kernel_code_64bit(vm, DEFAULT_CODE_SELECTOR, &sregs.cs);
+	kvm_seg_set_kernel_data_64bit(vm, DEFAULT_DATA_SELECTOR, &sregs.ds);
+	kvm_seg_set_kernel_data_64bit(vm, DEFAULT_DATA_SELECTOR, &sregs.es);
+	kvm_setup_tss_64bit(vm, &sregs.tr, 0x18);
 
 	sregs.cr3 = vm->pgd;
 	vcpu_sregs_set(vcpu, &sregs);