Re: [RFC PATCH v5 02/29] KVM: selftests: Expose function that sets up sregs based on VM's mode

On 12/13/2023 4:46 AM, Sagi Shahar wrote:

From: Ackerley Tng ackerleytng@google.com

This allows initializing sregs without setting vCPU registers in KVM.

No functional change intended.

Reviewed-by: Binbin Wu binbin.wu@linux.intel.com

Signed-off-by: Ackerley Tng ackerleytng@google.com Signed-off-by: Ryan Afranji afranji@google.com Signed-off-by: Sagi Shahar sagis@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 35fcf4d78dfa..0b8855d68744 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -958,6 +958,8 @@ 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_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 aef1c021c4bb..f130f78a4974 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -543,36 +543,39 @@ 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_SEV: 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); }