kvm/x86_64/xen_vmcall_test.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * xen_vmcall_test
0004  *
0005  * Copyright © 2020 Amazon.com, Inc. or its affiliates.
0006  *
0007  * Userspace hypercall testing
0008  */
0009
0010 #include "test_util.h"
0011 #include "kvm_util.h"
0012 #include "processor.h"
0013
0014 #define HCALL_REGION_GPA    0xc0000000ULL
0015 #define HCALL_REGION_SLOT   10
0016
0017 #define INPUTVALUE 17
0018 #define ARGVALUE(x) (0xdeadbeef5a5a0000UL + x)
0019 #define RETVALUE 0xcafef00dfbfbffffUL
0020
0021 #define XEN_HYPERCALL_MSR   0x40000200
0022 #define HV_GUEST_OS_ID_MSR  0x40000000
0023 #define HV_HYPERCALL_MSR    0x40000001
0024
0025 #define HVCALL_SIGNAL_EVENT     0x005d
0026 #define HV_STATUS_INVALID_ALIGNMENT 4
0027
0028 static void guest_code(void)
0029 {
0030     unsigned long rax = INPUTVALUE;
0031     unsigned long rdi = ARGVALUE(1);
0032     unsigned long rsi = ARGVALUE(2);
0033     unsigned long rdx = ARGVALUE(3);
0034     unsigned long rcx;
0035     register unsigned long r10 __asm__("r10") = ARGVALUE(4);
0036     register unsigned long r8 __asm__("r8") = ARGVALUE(5);
0037     register unsigned long r9 __asm__("r9") = ARGVALUE(6);
0038
0039     /* First a direct invocation of 'vmcall' */
0040     __asm__ __volatile__("vmcall" :
0041                  "=a"(rax) :
0042                  "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
0043                  "r"(r10), "r"(r8), "r"(r9));
0044     GUEST_ASSERT(rax == RETVALUE);
0045
0046     /* Fill in the Xen hypercall page */
0047     __asm__ __volatile__("wrmsr" : : "c" (XEN_HYPERCALL_MSR),
0048                  "a" (HCALL_REGION_GPA & 0xffffffff),
0049                  "d" (HCALL_REGION_GPA >> 32));
0050
0051     /* Set Hyper-V Guest OS ID */
0052     __asm__ __volatile__("wrmsr" : : "c" (HV_GUEST_OS_ID_MSR),
0053                  "a" (0x5a), "d" (0));
0054
0055     /* Hyper-V hypercall page */
0056     u64 msrval = HCALL_REGION_GPA + PAGE_SIZE + 1;
0057     __asm__ __volatile__("wrmsr" : : "c" (HV_HYPERCALL_MSR),
0058                  "a" (msrval & 0xffffffff),
0059                  "d" (msrval >> 32));
0060
0061     /* Invoke a Xen hypercall */
0062     __asm__ __volatile__("call *%1" : "=a"(rax) :
0063                  "r"(HCALL_REGION_GPA + INPUTVALUE * 32),
0064                  "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
0065                  "r"(r10), "r"(r8), "r"(r9));
0066     GUEST_ASSERT(rax == RETVALUE);
0067
0068     /* Invoke a Hyper-V hypercall */
0069     rax = 0;
0070     rcx = HVCALL_SIGNAL_EVENT;  /* code */
0071     rdx = 0x5a5a5a5a;       /* ingpa (badly aligned) */
0072     __asm__ __volatile__("call *%1" : "=a"(rax) :
0073                  "r"(HCALL_REGION_GPA + PAGE_SIZE),
0074                  "a"(rax), "c"(rcx), "d"(rdx),
0075                  "r"(r8));
0076     GUEST_ASSERT(rax == HV_STATUS_INVALID_ALIGNMENT);
0077
0078     GUEST_DONE();
0079 }
0080
0081 int main(int argc, char *argv[])
0082 {
0083     unsigned int xen_caps;
0084     struct kvm_vcpu *vcpu;
0085     struct kvm_vm *vm;
0086
0087     xen_caps = kvm_check_cap(KVM_CAP_XEN_HVM);
0088     TEST_REQUIRE(xen_caps & KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL);
0089
0090     vm = vm_create_with_one_vcpu(&vcpu, guest_code);
0091     vcpu_set_hv_cpuid(vcpu);
0092
0093     struct kvm_xen_hvm_config hvmc = {
0094         .flags = KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL,
0095         .msr = XEN_HYPERCALL_MSR,
0096     };
0097     vm_ioctl(vm, KVM_XEN_HVM_CONFIG, &hvmc);
0098
0099     /* Map a region for the hypercall pages */
0100     vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
0101                     HCALL_REGION_GPA, HCALL_REGION_SLOT, 2, 0);
0102     virt_map(vm, HCALL_REGION_GPA, HCALL_REGION_GPA, 2);
0103
0104     for (;;) {
0105         volatile struct kvm_run *run = vcpu->run;
0106         struct ucall uc;
0107
0108         vcpu_run(vcpu);
0109
0110         if (run->exit_reason == KVM_EXIT_XEN) {
0111             ASSERT_EQ(run->xen.type, KVM_EXIT_XEN_HCALL);
0112             ASSERT_EQ(run->xen.u.hcall.cpl, 0);
0113             ASSERT_EQ(run->xen.u.hcall.longmode, 1);
0114             ASSERT_EQ(run->xen.u.hcall.input, INPUTVALUE);
0115             ASSERT_EQ(run->xen.u.hcall.params[0], ARGVALUE(1));
0116             ASSERT_EQ(run->xen.u.hcall.params[1], ARGVALUE(2));
0117             ASSERT_EQ(run->xen.u.hcall.params[2], ARGVALUE(3));
0118             ASSERT_EQ(run->xen.u.hcall.params[3], ARGVALUE(4));
0119             ASSERT_EQ(run->xen.u.hcall.params[4], ARGVALUE(5));
0120             ASSERT_EQ(run->xen.u.hcall.params[5], ARGVALUE(6));
0121             run->xen.u.hcall.result = RETVALUE;
0122             continue;
0123         }
0124
0125         TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
0126                 "Got exit_reason other than KVM_EXIT_IO: %u (%s)\n",
0127                 run->exit_reason,
0128                 exit_reason_str(run->exit_reason));
0129
0130         switch (get_ucall(vcpu, &uc)) {
0131         case UCALL_ABORT:
0132             REPORT_GUEST_ASSERT(uc);
0133             /* NOT REACHED */
0134         case UCALL_SYNC:
0135             break;
0136         case UCALL_DONE:
0137             goto done;
0138         default:
0139             TEST_FAIL("Unknown ucall 0x%lx.", uc.cmd);
0140         }
0141     }
0142 done:
0143     kvm_vm_free(vm);
0144     return 0;
0145 }