diff options
| -rw-r--r-- | tools/testing/selftests/kvm/include/x86_64/processor.h | 5 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/include/x86_64/svm_util.h | 14 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/include/x86_64/vmx.h | 15 |
3 files changed, 24 insertions, 10 deletions
diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index a10f39affa45..5d310abe6c3f 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -677,11 +677,6 @@ static inline void cpu_relax(void) asm volatile("rep; nop" ::: "memory"); } -#define vmmcall() \ - __asm__ __volatile__( \ - "vmmcall\n" \ - ) - #define ud2() \ __asm__ __volatile__( \ "ud2\n" \ diff --git a/tools/testing/selftests/kvm/include/x86_64/svm_util.h b/tools/testing/selftests/kvm/include/x86_64/svm_util.h index 7aee6244ab6a..044f0f872ba9 100644 --- a/tools/testing/selftests/kvm/include/x86_64/svm_util.h +++ b/tools/testing/selftests/kvm/include/x86_64/svm_util.h @@ -32,6 +32,20 @@ struct svm_test_data { uint64_t msr_gpa; }; +static inline void vmmcall(void) +{ + /* + * Stuff RAX and RCX with "safe" values to make sure L0 doesn't handle + * it as a valid hypercall (e.g. Hyper-V L2 TLB flush) as the intended + * use of this function is to exit to L1 from L2. Clobber all other + * GPRs as L1 doesn't correctly preserve them during vmexits. + */ + __asm__ __volatile__("push %%rbp; vmmcall; pop %%rbp" + : : "a"(0xdeadbeef), "c"(0xbeefdead) + : "rbx", "rdx", "rsi", "rdi", "r8", "r9", + "r10", "r11", "r12", "r13", "r14", "r15"); +} + #define stgi() \ __asm__ __volatile__( \ "stgi\n" \ diff --git a/tools/testing/selftests/kvm/include/x86_64/vmx.h b/tools/testing/selftests/kvm/include/x86_64/vmx.h index ef784bd6dfc2..5f0c0a29c556 100644 --- a/tools/testing/selftests/kvm/include/x86_64/vmx.h +++ b/tools/testing/selftests/kvm/include/x86_64/vmx.h @@ -437,11 +437,16 @@ static inline int vmresume(void) static inline void vmcall(void) { - /* Currently, L1 destroys our GPRs during vmexits. */ - __asm__ __volatile__("push %%rbp; vmcall; pop %%rbp" : : : - "rax", "rbx", "rcx", "rdx", - "rsi", "rdi", "r8", "r9", "r10", "r11", "r12", - "r13", "r14", "r15"); + /* + * Stuff RAX and RCX with "safe" values to make sure L0 doesn't handle + * it as a valid hypercall (e.g. Hyper-V L2 TLB flush) as the intended + * use of this function is to exit to L1 from L2. Clobber all other + * GPRs as L1 doesn't correctly preserve them during vmexits. + */ + __asm__ __volatile__("push %%rbp; vmcall; pop %%rbp" + : : "a"(0xdeadbeef), "c"(0xbeefdead) + : "rbx", "rdx", "rsi", "rdi", "r8", "r9", + "r10", "r11", "r12", "r13", "r14", "r15"); } static inline int vmread(uint64_t encoding, uint64_t *value) |