[RFC PATCH v3 03/31] KVM: selftests: Expose function that sets up sregs based on VM's mode

Ackerley Tng
2023-01-21T00:16:42Z

This allows initializing sregs without setting vCPU registers in
KVM.

No functional change intended.

Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
.../selftests/kvm/include/x86_64/processor.h | 2 +
.../selftests/kvm/lib/x86_64/processor.c | 39 ++++++++++---------
2 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index e8ca0d8a6a7e0..74e0d3698f30c 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -644,6 +644,8 @@ const struct kvm_cpuid_entry2 *get_cpuid_entry(const struct kvm_cpuid2 *cpuid,
void vcpu_init_cpuid(struct kvm_vcpu *vcpu, const struct kvm_cpuid2 *cpuid);
void vcpu_set_hv_cpuid(struct kvm_vcpu *vcpu);

+void vcpu_setup_mode_sregs(struct kvm_vm *vm, struct kvm_sregs *sregs);
+
static inline struct kvm_cpuid_entry2 *__vcpu_get_cpuid_entry(struct kvm_vcpu *vcpu,
uint32_t function,
uint32_t index)
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index ed811181320de..1bb07d3c025b0 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -589,35 +589,38 @@ static void kvm_setup_tss_64bit(struct kvm_vm *vm, struct kvm_segment *segp,
kvm_seg_fill_gdt_64bit(vm, segp);
}

-static void vcpu_setup(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;
-
- /* Set mode specific system register values. */
- vcpu_sregs_get(vcpu, &sregs);
-
- sregs.idt.limit = 0;
+ sregs->idt.limit = 0;

- kvm_setup_gdt(vm, &sregs.gdt);
+ 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);
-
- 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->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);
}

- sregs.cr3 = vm->pgd;
+ sregs->cr3 = vm->pgd;
+}
+
+static void vcpu_setup(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
+{
+ struct kvm_sregs sregs;
+
+ vcpu_sregs_get(vcpu, &sregs);
+ vcpu_setup_mode_sregs(vm, &sregs);
vcpu_sregs_set(vcpu, &sregs);
}

--
2.39.0.246.g2a6d74b583-goog