cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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hyperv_svm_test.c (4437B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * KVM_GET/SET_* tests
      4 *
      5 * Copyright (C) 2022, Red Hat, Inc.
      6 *
      7 * Tests for Hyper-V extensions to SVM.
      8 */
      9#define _GNU_SOURCE /* for program_invocation_short_name */
     10#include <fcntl.h>
     11#include <stdio.h>
     12#include <stdlib.h>
     13#include <string.h>
     14#include <sys/ioctl.h>
     15#include <linux/bitmap.h>
     16
     17#include "test_util.h"
     18
     19#include "kvm_util.h"
     20#include "processor.h"
     21#include "svm_util.h"
     22#include "hyperv.h"
     23
     24#define VCPU_ID		1
     25#define L2_GUEST_STACK_SIZE 256
     26
     27struct hv_enlightenments {
     28	struct __packed hv_enlightenments_control {
     29		u32 nested_flush_hypercall:1;
     30		u32 msr_bitmap:1;
     31		u32 enlightened_npt_tlb: 1;
     32		u32 reserved:29;
     33	} __packed hv_enlightenments_control;
     34	u32 hv_vp_id;
     35	u64 hv_vm_id;
     36	u64 partition_assist_page;
     37	u64 reserved;
     38} __packed;
     39
     40/*
     41 * Hyper-V uses the software reserved clean bit in VMCB
     42 */
     43#define VMCB_HV_NESTED_ENLIGHTENMENTS (1U << 31)
     44
     45static inline void vmmcall(void)
     46{
     47	__asm__ __volatile__("vmmcall");
     48}
     49
     50void l2_guest_code(void)
     51{
     52	GUEST_SYNC(3);
     53	/* Exit to L1 */
     54	vmmcall();
     55
     56	/* MSR-Bitmap tests */
     57	rdmsr(MSR_FS_BASE); /* intercepted */
     58	rdmsr(MSR_FS_BASE); /* intercepted */
     59	rdmsr(MSR_GS_BASE); /* not intercepted */
     60	vmmcall();
     61	rdmsr(MSR_GS_BASE); /* intercepted */
     62
     63	GUEST_SYNC(5);
     64
     65	/* Done, exit to L1 and never come back.  */
     66	vmmcall();
     67}
     68
     69static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm)
     70{
     71	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
     72	struct vmcb *vmcb = svm->vmcb;
     73	struct hv_enlightenments *hve =
     74		(struct hv_enlightenments *)vmcb->control.reserved_sw;
     75
     76	GUEST_SYNC(1);
     77
     78	wrmsr(HV_X64_MSR_GUEST_OS_ID, (u64)0x8100 << 48);
     79
     80	GUEST_ASSERT(svm->vmcb_gpa);
     81	/* Prepare for L2 execution. */
     82	generic_svm_setup(svm, l2_guest_code,
     83			  &l2_guest_stack[L2_GUEST_STACK_SIZE]);
     84
     85	GUEST_SYNC(2);
     86	run_guest(vmcb, svm->vmcb_gpa);
     87	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
     88	GUEST_SYNC(4);
     89	vmcb->save.rip += 3;
     90
     91	/* Intercept RDMSR 0xc0000100 */
     92	vmcb->control.intercept |= 1ULL << INTERCEPT_MSR_PROT;
     93	set_bit(2 * (MSR_FS_BASE & 0x1fff), svm->msr + 0x800);
     94	run_guest(vmcb, svm->vmcb_gpa);
     95	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
     96	vmcb->save.rip += 2; /* rdmsr */
     97
     98	/* Enable enlightened MSR bitmap */
     99	hve->hv_enlightenments_control.msr_bitmap = 1;
    100	run_guest(vmcb, svm->vmcb_gpa);
    101	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
    102	vmcb->save.rip += 2; /* rdmsr */
    103
    104	/* Intercept RDMSR 0xc0000101 without telling KVM about it */
    105	set_bit(2 * (MSR_GS_BASE & 0x1fff), svm->msr + 0x800);
    106	/* Make sure HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP is set */
    107	vmcb->control.clean |= VMCB_HV_NESTED_ENLIGHTENMENTS;
    108	run_guest(vmcb, svm->vmcb_gpa);
    109	/* Make sure we don't see SVM_EXIT_MSR here so eMSR bitmap works */
    110	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
    111	vmcb->save.rip += 3; /* vmcall */
    112
    113	/* Now tell KVM we've changed MSR-Bitmap */
    114	vmcb->control.clean &= ~VMCB_HV_NESTED_ENLIGHTENMENTS;
    115	run_guest(vmcb, svm->vmcb_gpa);
    116	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
    117	vmcb->save.rip += 2; /* rdmsr */
    118
    119	run_guest(vmcb, svm->vmcb_gpa);
    120	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
    121	GUEST_SYNC(6);
    122
    123	GUEST_DONE();
    124}
    125
    126int main(int argc, char *argv[])
    127{
    128	vm_vaddr_t nested_gva = 0;
    129
    130	struct kvm_vm *vm;
    131	struct kvm_run *run;
    132	struct ucall uc;
    133	int stage;
    134
    135	if (!nested_svm_supported()) {
    136		print_skip("Nested SVM not supported");
    137		exit(KSFT_SKIP);
    138	}
    139	/* Create VM */
    140	vm = vm_create_default(VCPU_ID, 0, guest_code);
    141	vcpu_set_hv_cpuid(vm, VCPU_ID);
    142	run = vcpu_state(vm, VCPU_ID);
    143	vcpu_alloc_svm(vm, &nested_gva);
    144	vcpu_args_set(vm, VCPU_ID, 1, nested_gva);
    145
    146	for (stage = 1;; stage++) {
    147		_vcpu_run(vm, VCPU_ID);
    148		TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
    149			    "Stage %d: unexpected exit reason: %u (%s),\n",
    150			    stage, run->exit_reason,
    151			    exit_reason_str(run->exit_reason));
    152
    153		switch (get_ucall(vm, VCPU_ID, &uc)) {
    154		case UCALL_ABORT:
    155			TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0],
    156				  __FILE__, uc.args[1]);
    157			/* NOT REACHED */
    158		case UCALL_SYNC:
    159			break;
    160		case UCALL_DONE:
    161			goto done;
    162		default:
    163			TEST_FAIL("Unknown ucall %lu", uc.cmd);
    164		}
    165
    166		/* UCALL_SYNC is handled here.  */
    167		TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
    168			    uc.args[1] == stage, "Stage %d: Unexpected register values vmexit, got %lx",
    169			    stage, (ulong)uc.args[1]);
    170
    171	}
    172
    173done:
    174	kvm_vm_free(vm);
    175}