On 9/4/2025 2:54 PM, Sagi Shahar wrote:
TDX can't set sregs values directly using KVM_SET_SREGS. Expose the default values of certain sregs used by TDX VMs so they can be set manually.
Signed-off-by: Sagi Shahar sagis@google.com
Reviewed-by: Binbin Wu binbin.wu@linux.intel.com
One suggestion: It's better to add change history so that reviewers can know the change quickly without comparing b/t versions.
.../selftests/kvm/include/x86/processor.h | 33 +++++++++++++++++++ .../testing/selftests/kvm/lib/x86/processor.c | 12 +++---- 2 files changed, 38 insertions(+), 7 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/x86/processor.h b/tools/testing/selftests/kvm/include/x86/processor.h index 2efb05c2f2fb..f610c09cadf4 100644 --- a/tools/testing/selftests/kvm/include/x86/processor.h +++ b/tools/testing/selftests/kvm/include/x86/processor.h @@ -27,6 +27,10 @@ extern uint64_t guest_tsc_khz; #define MAX_NR_CPUID_ENTRIES 100 #endif +#ifndef NUM_INTERRUPTS +#define NUM_INTERRUPTS 256 +#endif
- #define NONCANONICAL 0xaaaaaaaaaaaaaaaaull
/* Forced emulation prefix, used to invoke the emulator unconditionally. */ @@ -1456,4 +1460,33 @@ void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, bool sys_clocksource_is_based_on_tsc(void); +static inline uint16_t kvm_get_default_idt_limit(void) +{
- return NUM_INTERRUPTS * sizeof(struct idt_entry) - 1;
+}
+static inline uint16_t kvm_get_default_gdt_limit(void) +{
- return getpagesize() - 1;
+}
+static inline uint64_t kvm_get_default_cr0(void) +{
- return X86_CR0_PE | X86_CR0_NE | X86_CR0_PG;
+}
+static inline uint64_t kvm_get_default_cr4(void) +{
- uint64_t cr4 = X86_CR4_PAE | X86_CR4_OSFXSR;
- if (kvm_cpu_has(X86_FEATURE_XSAVE))
cr4 |= X86_CR4_OSXSAVE;- return cr4;
+}
+static inline uint64_t kvm_get_default_efer(void) +{
- return EFER_LME | EFER_LMA | EFER_NX;
+}
- #endif /* SELFTEST_KVM_PROCESSOR_H */
diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c index d4c19ac885a9..83efcf48faad 100644 --- a/tools/testing/selftests/kvm/lib/x86/processor.c +++ b/tools/testing/selftests/kvm/lib/x86/processor.c @@ -498,15 +498,13 @@ static void vcpu_init_sregs(struct kvm_vm *vm, struct kvm_vcpu *vcpu) vcpu_sregs_get(vcpu, &sregs); sregs.idt.base = vm->arch.idt;
- sregs.idt.limit = NUM_INTERRUPTS * sizeof(struct idt_entry) - 1;
- sregs.idt.limit = kvm_get_default_idt_limit(); sregs.gdt.base = vm->arch.gdt;
- sregs.gdt.limit = getpagesize() - 1;
- sregs.gdt.limit = kvm_get_default_gdt_limit();
- 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.cr0 = kvm_get_default_cr0();
- sregs.cr4 |= kvm_get_default_cr4();
- sregs.efer |= kvm_get_default_efer();
kvm_seg_set_unusable(&sregs.ldt); kvm_seg_set_kernel_code_64bit(&sregs.cs);