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authorVitaly Kuznetsov <vkuznets@redhat.com>2022-11-01 15:54:23 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2022-11-21 06:42:39 -0500
commit75ee7505feae16bbfbed62115e04f762047c4765 (patch)
tree4c9736db3fe72e9034784ac4544bc944502de587
parent8fda37cf3d41f1dfb0667c4b10e3dd01d17735b8 (diff)
KVM: selftests: Introduce rdmsr_from_l2() and use it for MSR-Bitmap tests
Hyper-V MSR-Bitmap tests do RDMSR from L2 to exit to L1. While 'evmcs_test' correctly clobbers all GPRs (which are not preserved), 'hyperv_svm_test' does not. Introduce a more generic rdmsr_from_l2() to avoid code duplication and remove hardcoding of MSRs. Do not put it in common code because it is really just a selftests bug rather than a processor feature that requires it. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20221101145426.251680-46-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--tools/testing/selftests/kvm/x86_64/evmcs_test.c27
-rw-r--r--tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c17
2 files changed, 23 insertions, 21 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/evmcs_test.c b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
index 74f076ba574b..58fa98512c24 100644
--- a/tools/testing/selftests/kvm/x86_64/evmcs_test.c
+++ b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
@@ -30,22 +30,15 @@ static void guest_nmi_handler(struct ex_regs *regs)
{
}
-/* Exits to L1 destroy GRPs! */
-static inline void rdmsr_fs_base(void)
+static inline void rdmsr_from_l2(uint32_t msr)
{
- __asm__ __volatile__ ("mov $0xc0000100, %%rcx; rdmsr" : : :
- "rax", "rbx", "rcx", "rdx",
- "rsi", "rdi", "r8", "r9", "r10", "r11", "r12",
- "r13", "r14", "r15");
-}
-static inline void rdmsr_gs_base(void)
-{
- __asm__ __volatile__ ("mov $0xc0000101, %%rcx; rdmsr" : : :
- "rax", "rbx", "rcx", "rdx",
- "rsi", "rdi", "r8", "r9", "r10", "r11", "r12",
- "r13", "r14", "r15");
+ /* Currently, L1 doesn't preserve GPRs during vmexits. */
+ __asm__ __volatile__ ("rdmsr" : : "c"(msr) :
+ "rax", "rbx", "rdx", "rsi", "rdi", "r8", "r9",
+ "r10", "r11", "r12", "r13", "r14", "r15");
}
+/* Exit to L1 from L2 with RDMSR instruction */
void l2_guest_code(void)
{
GUEST_SYNC(7);
@@ -58,11 +51,11 @@ void l2_guest_code(void)
vmcall();
/* MSR-Bitmap tests */
- rdmsr_fs_base(); /* intercepted */
- rdmsr_fs_base(); /* intercepted */
- rdmsr_gs_base(); /* not intercepted */
+ rdmsr_from_l2(MSR_FS_BASE); /* intercepted */
+ rdmsr_from_l2(MSR_FS_BASE); /* intercepted */
+ rdmsr_from_l2(MSR_GS_BASE); /* not intercepted */
vmcall();
- rdmsr_gs_base(); /* intercepted */
+ rdmsr_from_l2(MSR_GS_BASE); /* intercepted */
/* Done, exit to L1 and never come back. */
vmcall();
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
index 1c3fc38b4f15..3c9a2a1b4cfd 100644
--- a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
@@ -23,6 +23,15 @@
#define L2_GUEST_STACK_SIZE 256
+/* Exit to L1 from L2 with RDMSR instruction */
+static inline void rdmsr_from_l2(uint32_t msr)
+{
+ /* Currently, L1 doesn't preserve GPRs during vmexits. */
+ __asm__ __volatile__ ("rdmsr" : : "c"(msr) :
+ "rax", "rbx", "rdx", "rsi", "rdi", "r8", "r9",
+ "r10", "r11", "r12", "r13", "r14", "r15");
+}
+
void l2_guest_code(void)
{
GUEST_SYNC(3);
@@ -30,11 +39,11 @@ void l2_guest_code(void)
vmmcall();
/* MSR-Bitmap tests */
- rdmsr(MSR_FS_BASE); /* intercepted */
- rdmsr(MSR_FS_BASE); /* intercepted */
- rdmsr(MSR_GS_BASE); /* not intercepted */
+ rdmsr_from_l2(MSR_FS_BASE); /* intercepted */
+ rdmsr_from_l2(MSR_FS_BASE); /* intercepted */
+ rdmsr_from_l2(MSR_GS_BASE); /* not intercepted */
vmmcall();
- rdmsr(MSR_GS_BASE); /* intercepted */
+ rdmsr_from_l2(MSR_GS_BASE); /* intercepted */
GUEST_SYNC(5);