[V2 PATCH 6/8] KVM: selftests: x86: Execute cpu specific hypercall from nested guests

From: Vishal Annapurve
Date: Wed Sep 14 2022 - 20:05:38 EST


Execute vmcall/vmmcall from nested guests according to the cpu type.
This avoid exit to KVM which would anyway patch the hypercall
instruction according to the cpu type.

Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Vishal Annapurve <vannapurve@xxxxxxxxxx>
---
.../selftests/kvm/include/x86_64/processor.h | 2 ++
tools/testing/selftests/kvm/include/x86_64/vmx.h | 9 ---------
.../selftests/kvm/lib/x86_64/perf_test_util.c | 2 +-
.../testing/selftests/kvm/lib/x86_64/processor.c | 15 +++++++++++++++
tools/testing/selftests/kvm/x86_64/smm_test.c | 2 +-
tools/testing/selftests/kvm/x86_64/state_test.c | 8 ++++----
.../selftests/kvm/x86_64/vmx_dirty_log_test.c | 2 +-
.../kvm/x86_64/vmx_preemption_timer_test.c | 2 +-
8 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 0cbc71b7af50..18a8a6a2b786 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -833,6 +833,8 @@ void vm_set_page_table_entry(struct kvm_vm *vm, struct kvm_vcpu *vcpu,
uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2,
uint64_t a3);

+void nested_guest_vmcall(void);
+
void __vm_xsave_require_permission(int bit, const char *name);

#define vm_xsave_require_permission(perm) \
diff --git a/tools/testing/selftests/kvm/include/x86_64/vmx.h b/tools/testing/selftests/kvm/include/x86_64/vmx.h
index 99fa1410964c..d8d4fd3353e5 100644
--- a/tools/testing/selftests/kvm/include/x86_64/vmx.h
+++ b/tools/testing/selftests/kvm/include/x86_64/vmx.h
@@ -480,15 +480,6 @@ static inline int vmresume(void)
return ret;
}

-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");
-}
-
static inline int vmread(uint64_t encoding, uint64_t *value)
{
uint64_t tmp;
diff --git a/tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c b/tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c
index 0f344a7c89c4..b420b35b7f45 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c
@@ -18,7 +18,7 @@
void perf_test_l2_guest_code(uint64_t vcpu_id)
{
perf_test_guest_code(vcpu_id);
- vmcall();
+ nested_guest_vmcall();
}

extern char perf_test_l2_guest_entry[];
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index c0ae938772f6..e12c8b543b8f 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -1195,6 +1195,21 @@ uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2,
return r;
}

+void nested_guest_vmcall(void)
+{
+ /* Currently, L1 destroys our GPRs during vmexits. */
+ if (is_amd_cpu())
+ __asm__ __volatile__("push %%rbp; vmmcall; pop %%rbp" : : :
+ "rax", "rbx", "rcx", "rdx",
+ "rsi", "rdi", "r8", "r9", "r10", "r11", "r12",
+ "r13", "r14", "r15");
+ else
+ __asm__ __volatile__("push %%rbp; vmcall; pop %%rbp" : : :
+ "rax", "rbx", "rcx", "rdx",
+ "rsi", "rdi", "r8", "r9", "r10", "r11", "r12",
+ "r13", "r14", "r15");
+}
+
const struct kvm_cpuid2 *kvm_get_supported_hv_cpuid(void)
{
static struct kvm_cpuid2 *cpuid;
diff --git a/tools/testing/selftests/kvm/x86_64/smm_test.c b/tools/testing/selftests/kvm/x86_64/smm_test.c
index 1f136a81858e..bf04c78c9c8e 100644
--- a/tools/testing/selftests/kvm/x86_64/smm_test.c
+++ b/tools/testing/selftests/kvm/x86_64/smm_test.c
@@ -61,7 +61,7 @@ static void l2_guest_code(void)

sync_with_host(10);

- vmcall();
+ nested_guest_vmcall();
}

static void guest_code(void *arg)
diff --git a/tools/testing/selftests/kvm/x86_64/state_test.c b/tools/testing/selftests/kvm/x86_64/state_test.c
index ea578971fb9f..a9634c06dc60 100644
--- a/tools/testing/selftests/kvm/x86_64/state_test.c
+++ b/tools/testing/selftests/kvm/x86_64/state_test.c
@@ -26,10 +26,10 @@ void svm_l2_guest_code(void)
{
GUEST_SYNC(4);
/* Exit to L1 */
- vmcall();
+ nested_guest_vmcall();
GUEST_SYNC(6);
/* Done, exit to L1 and never come back. */
- vmcall();
+ nested_guest_vmcall();
}

static void svm_l1_guest_code(struct svm_test_data *svm)
@@ -57,7 +57,7 @@ void vmx_l2_guest_code(void)
GUEST_SYNC(6);

/* Exit to L1 */
- vmcall();
+ nested_guest_vmcall();

/* L1 has now set up a shadow VMCS for us. */
GUEST_ASSERT(vmreadz(GUEST_RIP) == 0xc0ffee);
@@ -70,7 +70,7 @@ void vmx_l2_guest_code(void)
GUEST_SYNC(12);

/* Done, exit to L1 and never come back. */
- vmcall();
+ nested_guest_vmcall();
}

static void vmx_l1_guest_code(struct vmx_pages *vmx_pages)
diff --git a/tools/testing/selftests/kvm/x86_64/vmx_dirty_log_test.c b/tools/testing/selftests/kvm/x86_64/vmx_dirty_log_test.c
index 2d8c23d639f7..fa24e69a806c 100644
--- a/tools/testing/selftests/kvm/x86_64/vmx_dirty_log_test.c
+++ b/tools/testing/selftests/kvm/x86_64/vmx_dirty_log_test.c
@@ -42,7 +42,7 @@ static void l2_guest_code(void)
GUEST_SYNC(false);

/* Exit to L1 and never come back. */
- vmcall();
+ nested_guest_vmcall();
}

void l1_guest_code(struct vmx_pages *vmx)
diff --git a/tools/testing/selftests/kvm/x86_64/vmx_preemption_timer_test.c b/tools/testing/selftests/kvm/x86_64/vmx_preemption_timer_test.c
index 0efdc05969a5..04bae6995344 100644
--- a/tools/testing/selftests/kvm/x86_64/vmx_preemption_timer_test.c
+++ b/tools/testing/selftests/kvm/x86_64/vmx_preemption_timer_test.c
@@ -38,7 +38,7 @@ void l2_guest_code(void)
{
u64 vmx_pt_delta;

- vmcall();
+ nested_guest_vmcall();
l2_vmx_pt_start = (rdtsc() >> vmx_pt_rate) << vmx_pt_rate;

/*
--
2.37.2.789.g6183377224-goog