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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vmx_invalid_nested_guest_state.c (2846B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2#include "test_util.h"
      3#include "kvm_util.h"
      4#include "processor.h"
      5#include "vmx.h"
      6
      7#include <string.h>
      8#include <sys/ioctl.h>
      9
     10#include "kselftest.h"
     11
     12#define VCPU_ID	0
     13#define ARBITRARY_IO_PORT 0x2000
     14
     15static struct kvm_vm *vm;
     16
     17static void l2_guest_code(void)
     18{
     19	/*
     20	 * Generate an exit to L0 userspace, i.e. main(), via I/O to an
     21	 * arbitrary port.
     22	 */
     23	asm volatile("inb %%dx, %%al"
     24		     : : [port] "d" (ARBITRARY_IO_PORT) : "rax");
     25}
     26
     27static void l1_guest_code(struct vmx_pages *vmx_pages)
     28{
     29#define L2_GUEST_STACK_SIZE 64
     30	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
     31
     32	GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
     33	GUEST_ASSERT(load_vmcs(vmx_pages));
     34
     35	/* Prepare the VMCS for L2 execution. */
     36	prepare_vmcs(vmx_pages, l2_guest_code,
     37		     &l2_guest_stack[L2_GUEST_STACK_SIZE]);
     38
     39	/*
     40	 * L2 must be run without unrestricted guest, verify that the selftests
     41	 * library hasn't enabled it.  Because KVM selftests jump directly to
     42	 * 64-bit mode, unrestricted guest support isn't required.
     43	 */
     44	GUEST_ASSERT(!(vmreadz(CPU_BASED_VM_EXEC_CONTROL) & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) ||
     45		     !(vmreadz(SECONDARY_VM_EXEC_CONTROL) & SECONDARY_EXEC_UNRESTRICTED_GUEST));
     46
     47	GUEST_ASSERT(!vmlaunch());
     48
     49	/* L2 should triple fault after main() stuffs invalid guest state. */
     50	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_TRIPLE_FAULT);
     51	GUEST_DONE();
     52}
     53
     54int main(int argc, char *argv[])
     55{
     56	vm_vaddr_t vmx_pages_gva;
     57	struct kvm_sregs sregs;
     58	struct kvm_run *run;
     59	struct ucall uc;
     60
     61	nested_vmx_check_supported();
     62
     63	vm = vm_create_default(VCPU_ID, 0, (void *) l1_guest_code);
     64
     65	/* Allocate VMX pages and shared descriptors (vmx_pages). */
     66	vcpu_alloc_vmx(vm, &vmx_pages_gva);
     67	vcpu_args_set(vm, VCPU_ID, 1, vmx_pages_gva);
     68
     69	vcpu_run(vm, VCPU_ID);
     70
     71	run = vcpu_state(vm, VCPU_ID);
     72
     73	/*
     74	 * The first exit to L0 userspace should be an I/O access from L2.
     75	 * Running L1 should launch L2 without triggering an exit to userspace.
     76	 */
     77	TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
     78		    "Expected KVM_EXIT_IO, got: %u (%s)\n",
     79		    run->exit_reason, exit_reason_str(run->exit_reason));
     80
     81	TEST_ASSERT(run->io.port == ARBITRARY_IO_PORT,
     82		    "Expected IN from port %d from L2, got port %d",
     83		    ARBITRARY_IO_PORT, run->io.port);
     84
     85	/*
     86	 * Stuff invalid guest state for L2 by making TR unusuable.  The next
     87	 * KVM_RUN should induce a TRIPLE_FAULT in L2 as KVM doesn't support
     88	 * emulating invalid guest state for L2.
     89	 */
     90	memset(&sregs, 0, sizeof(sregs));
     91	vcpu_sregs_get(vm, VCPU_ID, &sregs);
     92	sregs.tr.unusable = 1;
     93	vcpu_sregs_set(vm, VCPU_ID, &sregs);
     94
     95	vcpu_run(vm, VCPU_ID);
     96
     97	switch (get_ucall(vm, VCPU_ID, &uc)) {
     98	case UCALL_DONE:
     99		break;
    100	case UCALL_ABORT:
    101		TEST_FAIL("%s", (const char *)uc.args[0]);
    102	default:
    103		TEST_FAIL("Unexpected ucall: %lu", uc.cmd);
    104	}
    105}