[RFC PATCH v2 16/17] KVM: selftest: TDX: Add TDG.VP.INFO test

From: Sagi Shahar
Date: Tue Aug 30 2022 - 18:22:39 EST

From: Roger Wang <runanwang@xxxxxxxxxx>

Adds a test for TDG.VP.INFO

Signed-off-by: Roger Wang <runanwang@xxxxxxxxxx>
Signed-off-by: Sagi Shahar <sagis@xxxxxxxxxx>
---
tools/testing/selftests/kvm/lib/x86_64/tdx.h | 103 ++++++++----
.../selftests/kvm/lib/x86_64/tdx_lib.c | 18 ++-
.../selftests/kvm/x86_64/tdx_vm_tests.c | 150 ++++++++++++++++++
3 files changed, 235 insertions(+), 36 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx.h b/tools/testing/selftests/kvm/lib/x86_64/tdx.h
index 3729543a05a3..7af2d189043f 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/tdx.h
+++ b/tools/testing/selftests/kvm/lib/x86_64/tdx.h
@@ -10,6 +10,11 @@
*/
#define TDX_GUEST_MAX_NR_PAGES 10000

+/*
+ * Max number of vCPUs for the guest VM
+ */
+ #define TDX_GUEST_MAX_NUM_VCPUS 3
+
/*
* Page Table Address used when paging is enabled.
*/
@@ -71,6 +76,11 @@
#define TDX_MMIO_READ 0
#define TDX_MMIO_WRITE 1

+#define TDX_TDCALL_INFO 1
+
+#define TDX_TDPARAM_ATTR_SEPT_VE_DISABLE_BIT (1UL << 28)
+#define TDX_TDPARAM_ATTR_PKS_BIT (1UL << 30)
+
#define GDT_ENTRY(flags, base, limit) \
((((base) & 0xff000000ULL) << (56-24)) | \
(((flags) & 0x0000f0ffULL) << 40) | \
@@ -98,6 +108,7 @@ void add_td_memory(struct kvm_vm *vm, void *source_page,
uint64_t gpa, int size);
void finalize_td_memory(struct kvm_vm *vm);
void initialize_td(struct kvm_vm *vm);
+void initialize_td_with_attributes(struct kvm_vm *vm, uint64_t attributes);
void initialize_td_vcpu(struct kvm_vcpu *vcpu);
void prepare_source_image(struct kvm_vm *vm, void *guest_code,
size_t guest_code_size,
@@ -116,40 +127,41 @@ void prepare_source_image(struct kvm_vm *vm, void *guest_code,
static inline void tdcall(struct kvm_regs *regs)
{
asm volatile (
- "mov %13, %%rax;\n\t"
- "mov %14, %%rbx;\n\t"
- "mov %15, %%rcx;\n\t"
- "mov %16, %%rdx;\n\t"
- "mov %17, %%r8;\n\t"
- "mov %18, %%r9;\n\t"
- "mov %19, %%r10;\n\t"
- "mov %20, %%r11;\n\t"
- "mov %21, %%r12;\n\t"
- "mov %22, %%r13;\n\t"
- "mov %23, %%r14;\n\t"
- "mov %24, %%r15;\n\t"
- "mov %25, %%rbp;\n\t"
- "mov %26, %%rsi;\n\t"
- "mov %27, %%rdi;\n\t"
+ "mov %14, %%rax;\n\t"
+ "mov %15, %%rbx;\n\t"
+ "mov %16, %%rcx;\n\t"
+ "mov %17, %%rdx;\n\t"
+ "mov %18, %%r8;\n\t"
+ "mov %19, %%r9;\n\t"
+ "mov %20, %%r10;\n\t"
+ "mov %21, %%r11;\n\t"
+ "mov %22, %%r12;\n\t"
+ "mov %23, %%r13;\n\t"
+ "mov %24, %%r14;\n\t"
+ "mov %25, %%r15;\n\t"
+ "mov %26, %%rbp;\n\t"
+ "mov %27, %%rsi;\n\t"
+ "mov %28, %%rdi;\n\t"
".byte 0x66, 0x0F, 0x01, 0xCC;\n\t"
"mov %%rax, %0;\n\t"
"mov %%rbx, %1;\n\t"
- "mov %%rdx, %2;\n\t"
- "mov %%r8, %3;\n\t"
- "mov %%r9, %4;\n\t"
- "mov %%r10, %5;\n\t"
- "mov %%r11, %6;\n\t"
- "mov %%r12, %7;\n\t"
- "mov %%r13, %8;\n\t"
- "mov %%r14, %9;\n\t"
- "mov %%r15, %10;\n\t"
- "mov %%rsi, %11;\n\t"
- "mov %%rdi, %12;\n\t"
- : "=m" (regs->rax), "=m" (regs->rbx), "=m" (regs->rdx),
- "=m" (regs->r8), "=m" (regs->r9), "=m" (regs->r10),
- "=m" (regs->r11), "=m" (regs->r12), "=m" (regs->r13),
- "=m" (regs->r14), "=m" (regs->r15), "=m" (regs->rsi),
- "=m" (regs->rdi)
+ "mov %%rcx, %2;\n\t"
+ "mov %%rdx, %3;\n\t"
+ "mov %%r8, %4;\n\t"
+ "mov %%r9, %5;\n\t"
+ "mov %%r10, %6;\n\t"
+ "mov %%r11, %7;\n\t"
+ "mov %%r12, %8;\n\t"
+ "mov %%r13, %9;\n\t"
+ "mov %%r14, %10;\n\t"
+ "mov %%r15, %11;\n\t"
+ "mov %%rsi, %12;\n\t"
+ "mov %%rdi, %13;\n\t"
+ : "=m" (regs->rax), "=m" (regs->rbx), "=m" (regs->rcx),
+ "=m" (regs->rdx), "=m" (regs->r8), "=m" (regs->r9),
+ "=m" (regs->r10), "=m" (regs->r11), "=m" (regs->r12),
+ "=m" (regs->r13), "=m" (regs->r14), "=m" (regs->r15),
+ "=m" (regs->rsi), "=m" (regs->rdi)
: "m" (regs->rax), "m" (regs->rbx), "m" (regs->rcx),
"m" (regs->rdx), "m" (regs->r8), "m" (regs->r9),
"m" (regs->r10), "m" (regs->r11), "m" (regs->r12),
@@ -370,6 +382,35 @@ static inline uint64_t tdvmcall_cpuid(uint32_t eax, uint32_t ecx,
return regs.r10;
}

+/*
+ * Execute TDG.VP.INFO instruction.
+ */
+static inline uint64_t tdcall_vp_info(uint64_t *rcx, uint64_t *rdx,
+ uint64_t *r8, uint64_t *r9,
+ uint64_t *r10, uint64_t *r11)
+{
+ struct kvm_regs regs;
+
+ memset(&regs, 0, sizeof(regs));
+ regs.rax = TDX_TDCALL_INFO;
+ tdcall(&regs);
+
+ if (rcx)
+ *rcx = regs.rcx;
+ if (rdx)
+ *rdx = regs.rdx;
+ if (r8)
+ *r8 = regs.r8;
+ if (r9)
+ *r9 = regs.r9;
+ if (r10)
+ *r10 = regs.r10;
+ if (r11)
+ *r11 = regs.r11;
+
+ return regs.rax;
+}
+
/*
* Reports a 32 bit value from the guest to user space using a TDVM IO call.
* Data is reported on port TDX_DATA_REPORT_PORT.
diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx_lib.c b/tools/testing/selftests/kvm/lib/x86_64/tdx_lib.c
index 72bf2ff24a29..dc9a44ae4064 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/tdx_lib.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/tdx_lib.c
@@ -78,10 +78,10 @@ static struct tdx_cpuid_data get_tdx_cpuid_data(struct kvm_vm *vm)
}

/*
- * Initialize a VM as a TD.
+ * Initialize a VM as a TD with attributes.
*
*/
-void initialize_td(struct kvm_vm *vm)
+void initialize_td_with_attributes(struct kvm_vm *vm, uint64_t attributes)
{
struct tdx_cpuid_data cpuid_data;
int rc;
@@ -99,7 +99,7 @@ void initialize_td(struct kvm_vm *vm)
KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK);
vm_enable_cap(vm, KVM_CAP_SPLIT_IRQCHIP, 24);

- /* Allocate and setup memoryfor the td guest. */
+ /* Allocate and setup memory for the td guest. */
vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
TDX_GUEST_PT_FIXED_ADDR,
0, TDX_GUEST_MAX_NR_PAGES, 0);
@@ -108,12 +108,20 @@ void initialize_td(struct kvm_vm *vm)

cpuid_data = get_tdx_cpuid_data(vm);

- init_vm.max_vcpus = 1;
- init_vm.attributes = 0;
+ init_vm.max_vcpus = TDX_GUEST_MAX_NUM_VCPUS;
+ init_vm.attributes = attributes;
memcpy(&init_vm.cpuid, &cpuid_data, sizeof(cpuid_data));
tdx_ioctl(vm->fd, KVM_TDX_INIT_VM, 0, &init_vm);
}

+/*
+ * Initialize a VM as a TD with no attributes.
+ *
+ */
+void initialize_td(struct kvm_vm *vm)
+{
+ initialize_td_with_attributes(vm, 0);
+}

void initialize_td_vcpu(struct kvm_vcpu *vcpu)
{
diff --git a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
index 1776b39b7d9e..8d49099e1ed8 100644
--- a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
+++ b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
@@ -2,6 +2,7 @@

#include "asm/kvm.h"
#include "linux/kernel.h"
+#include <assert.h>
#include <bits/stdint-uintn.h>
#include <fcntl.h>
#include <limits.h>
@@ -1366,6 +1367,154 @@ void verify_host_reading_private_mem(void)
printf("\t ... PASSED\n");
}

+/*
+ * Do a TDG.VP.INFO call from the guest
+ */
+TDX_GUEST_FUNCTION(guest_tdcall_vp_info)
+{
+ uint64_t err;
+ uint64_t rcx, rdx, r8, r9, r10, r11;
+
+ err = tdcall_vp_info(&rcx, &rdx, &r8, &r9, &r10, &r11);
+ if (err)
+ tdvmcall_fatal(err);
+
+ /* return values to user space host */
+ err = tdvm_report_64bit_to_user_space(rcx);
+ if (err)
+ tdvmcall_fatal(err);
+
+ err = tdvm_report_64bit_to_user_space(rdx);
+ if (err)
+ tdvmcall_fatal(err);
+
+ err = tdvm_report_64bit_to_user_space(r8);
+ if (err)
+ tdvmcall_fatal(err);
+
+ err = tdvm_report_64bit_to_user_space(r9);
+ if (err)
+ tdvmcall_fatal(err);
+
+ err = tdvm_report_64bit_to_user_space(r10);
+ if (err)
+ tdvmcall_fatal(err);
+
+ err = tdvm_report_64bit_to_user_space(r11);
+ if (err)
+ tdvmcall_fatal(err);
+
+ tdvmcall_success();
+}
+
+/*
+ * TDG.VP.INFO call from the guest. Verify the right values are returned
+ */
+void verify_tdcall_vp_info(void)
+{
+ const int num_vcpus = 2;
+ struct kvm_vcpu *vcpus[num_vcpus];
+ struct kvm_vm *vm;
+ uint64_t rcx, rdx, r8, r9, r10, r11;
+ uint32_t ret_num_vcpus, ret_max_vcpus;
+ uint64_t attributes;
+ uint32_t i;
+ struct kvm_cpuid_entry2 *cpuid_entry;
+ struct tdx_cpuid_data cpuid_data;
+ int max_pa = -1;
+ int ret;
+
+ printf("Verifying TDG.VP.INFO call:\n");
+ /* Create a TD VM with no memory.*/
+ vm = vm_create_tdx();
+
+ /* Setting attributes parameter used by TDH.MNG.INIT to 0x50000000 */
+ attributes = TDX_TDPARAM_ATTR_SEPT_VE_DISABLE_BIT |
+ TDX_TDPARAM_ATTR_PKS_BIT;
+
+ /* Allocate TD guest memory and initialize the TD.*/
+ initialize_td_with_attributes(vm, attributes);
+
+ /* Create vCPUs*/
+ for (i = 0; i < num_vcpus; i++)
+ vcpus[i] = vm_vcpu_add_tdx(vm, i);
+
+ /* Setup and initialize VM memory */
+ prepare_source_image(vm, guest_tdcall_vp_info,
+ TDX_FUNCTION_SIZE(guest_tdcall_vp_info), 0);
+ finalize_td_memory(vm);
+
+ /* Get KVM CPUIDs for reference */
+ memset(&cpuid_data, 0, sizeof(cpuid_data));
+ cpuid_data.cpuid.nent = KVM_MAX_CPUID_ENTRIES;
+ ret = ioctl(vm->kvm_fd, KVM_GET_SUPPORTED_CPUID, &cpuid_data);
+ TEST_ASSERT(!ret, "KVM_GET_SUPPORTED_CPUID failed\n");
+ cpuid_entry = find_cpuid_entry(cpuid_data, 0x80000008, 0);
+ TEST_ASSERT(cpuid_entry, "CPUID entry missing\n");
+ max_pa = cpuid_entry->eax & 0xff;
+
+ for (i = 0; i < num_vcpus; i++) {
+ struct kvm_vcpu *vcpu = vcpus[i];
+
+ /* Wait for guest to report rcx value */
+ vcpu_run(vcpu);
+ CHECK_GUEST_FAILURE(vcpu);
+ rcx = read_64bit_from_guest(vcpu, TDX_DATA_REPORT_PORT);
+
+ /* Wait for guest to report rdx value */
+ vcpu_run(vcpu);
+ CHECK_GUEST_FAILURE(vcpu);
+ rdx = read_64bit_from_guest(vcpu, TDX_DATA_REPORT_PORT);
+
+ /* Wait for guest to report r8 value */
+ vcpu_run(vcpu);
+ CHECK_GUEST_FAILURE(vcpu);
+ r8 = read_64bit_from_guest(vcpu, TDX_DATA_REPORT_PORT);
+
+ /* Wait for guest to report r9 value */
+ vcpu_run(vcpu);
+ CHECK_GUEST_FAILURE(vcpu);
+ r9 = read_64bit_from_guest(vcpu, TDX_DATA_REPORT_PORT);
+
+ /* Wait for guest to report r10 value */
+ vcpu_run(vcpu);
+ CHECK_GUEST_FAILURE(vcpu);
+ r10 = read_64bit_from_guest(vcpu, TDX_DATA_REPORT_PORT);
+
+ /* Wait for guest to report r11 value */
+ vcpu_run(vcpu);
+ CHECK_GUEST_FAILURE(vcpu);
+ r11 = read_64bit_from_guest(vcpu, TDX_DATA_REPORT_PORT);
+
+ ret_num_vcpus = r8 & 0xFFFFFFFF;
+ ret_max_vcpus = (r8 >> 32) & 0xFFFFFFFF;
+
+ /* first bits 5:0 of rcx represent the GPAW */
+ ASSERT_EQ(rcx & 0x3F, max_pa);
+ /* next 63:6 bits of rcx is reserved and must be 0 */
+ ASSERT_EQ(rcx >> 6, 0);
+ ASSERT_EQ(rdx, attributes);
+ ASSERT_EQ(ret_num_vcpus, num_vcpus);
+ ASSERT_EQ(ret_max_vcpus, TDX_GUEST_MAX_NUM_VCPUS);
+ /* VCPU_INDEX = i */
+ ASSERT_EQ(r9, i);
+ /* verify reserved registers are 0 */
+ ASSERT_EQ(r10, 0);
+ ASSERT_EQ(r11, 0);
+
+ /* Wait for guest to complete execution */
+ vcpu_run(vcpu);
+
+ CHECK_GUEST_FAILURE(vcpu);
+ CHECK_GUEST_COMPLETION(vcpu);
+
+ printf("\t ... Guest completed run on VCPU=%u\n", i);
+ }
+
+ kvm_vm_free(vm);
+ printf("\t ... PASSED\n");
+}
+
int main(int argc, char **argv)
{
if (!is_tdx_enabled()) {
@@ -1387,6 +1536,7 @@ int main(int argc, char **argv)
run_in_new_process(&verify_mmio_reads);
run_in_new_process(&verify_mmio_writes);
run_in_new_process(&verify_host_reading_private_mem);
+ run_in_new_process(&verify_tdcall_vp_info);

return 0;
}
--
2.37.2.789.g6183377224-goog