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KVM: selftests: Move flds instruction emulation failure handling to header

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Move the flds instruction emulation failure handling code to a header
so it can be re-used in an upcoming test.

No functional change intended.

Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-5-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
David Matlack 2022-11-02 11:46:48 -07:00 committed by Sean Christopherson
parent 50824c6eee
commit 19a2b32f5d
2 changed files with 59 additions and 40 deletions
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55
tools/testing/selftests/kvm/x86_64/flds_emulation.h Normal file
View File

@ -0,0 +1,55 @@
/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef SELFTEST_KVM_FLDS_EMULATION_H
#define SELFTEST_KVM_FLDS_EMULATION_H
#include "kvm_util.h"
#define FLDS_MEM_EAX ".byte 0xd9, 0x00"
/*
* flds is an instruction that the KVM instruction emulator is known not to
* support. This can be used in guest code along with a mechanism to force
* KVM to emulate the instruction (e.g. by providing an MMIO address) to
* exercise emulation failures.
*/
static inline void flds(uint64_t address)
{
__asm__ __volatile__(FLDS_MEM_EAX :: "a"(address));
}
static inline void handle_flds_emulation_failure_exit(struct kvm_vcpu *vcpu)
{
struct kvm_run *run = vcpu->run;
struct kvm_regs regs;
uint8_t *insn_bytes;
uint64_t flags;
TEST_ASSERT(run->exit_reason == KVM_EXIT_INTERNAL_ERROR,
"Unexpected exit reason: %u (%s)",
run->exit_reason,
exit_reason_str(run->exit_reason));
TEST_ASSERT(run->emulation_failure.suberror == KVM_INTERNAL_ERROR_EMULATION,
"Unexpected suberror: %u",
run->emulation_failure.suberror);
flags = run->emulation_failure.flags;
TEST_ASSERT(run->emulation_failure.ndata >= 3 &&
flags & KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES,
"run->emulation_failure is missing instruction bytes");
TEST_ASSERT(run->emulation_failure.insn_size >= 2,
"Expected a 2-byte opcode for 'flds', got %d bytes",
run->emulation_failure.insn_size);
insn_bytes = run->emulation_failure.insn_bytes;
TEST_ASSERT(insn_bytes[0] == 0xd9 && insn_bytes[1] == 0,
"Expected 'flds [eax]', opcode '0xd9 0x00', got opcode 0x%02x 0x%02x\n",
insn_bytes[0], insn_bytes[1]);
vcpu_regs_get(vcpu, &regs);
regs.rip += 2;
vcpu_regs_set(vcpu, &regs);
}
#endif /* !SELFTEST_KVM_FLDS_EMULATION_H */

44
tools/testing/selftests/kvm/x86_64/smaller_maxphyaddr_emulation_test.c
View File

@ -8,6 +8,8 @@
#define _GNU_SOURCE /* for program_invocation_short_name */
#include "flds_emulation.h"
#include "test_util.h"
#include "kvm_util.h"
#include "vmx.h"
@ -19,50 +21,12 @@
#define MEM_REGION_SLOT 10
#define MEM_REGION_SIZE PAGE_SIZE
#define FLDS_MEM_EAX ".byte 0xd9, 0x00"
static void guest_code(void)
{
__asm__ __volatile__(FLDS_MEM_EAX :: "a"(MEM_REGION_GVA));
flds(MEM_REGION_GVA);
GUEST_DONE();
}
static void process_exit_on_emulation_error(struct kvm_vcpu *vcpu)
{
struct kvm_run *run = vcpu->run;
struct kvm_regs regs;
uint8_t *insn_bytes;
uint64_t flags;
TEST_ASSERT(run->exit_reason == KVM_EXIT_INTERNAL_ERROR,
"Unexpected exit reason: %u (%s)",
run->exit_reason,
exit_reason_str(run->exit_reason));
TEST_ASSERT(run->emulation_failure.suberror == KVM_INTERNAL_ERROR_EMULATION,
"Unexpected suberror: %u",
run->emulation_failure.suberror);
flags = run->emulation_failure.flags;
TEST_ASSERT(run->emulation_failure.ndata >= 3 &&
flags & KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES,
"run->emulation_failure is missing instruction bytes");
TEST_ASSERT(run->emulation_failure.insn_size >= 2,
"Expected a 2-byte opcode for 'flds', got %d bytes",
run->emulation_failure.insn_size);
insn_bytes = run->emulation_failure.insn_bytes;
TEST_ASSERT(insn_bytes[0] == 0xd9 && insn_bytes[1] == 0,
"Expected 'flds [eax]', opcode '0xd9 0x00', got opcode 0x%02x 0x%02x\n",
insn_bytes[0], insn_bytes[1]);
vcpu_regs_get(vcpu, &regs);
regs.rip += 2;
vcpu_regs_set(vcpu, &regs);
}
int main(int argc, char *argv[])
{
struct kvm_vcpu *vcpu;
@ -96,7 +60,7 @@ int main(int argc, char *argv[])
*pte |= BIT_ULL(MAXPHYADDR);
vcpu_run(vcpu);
process_exit_on_emulation_error(vcpu);
handle_flds_emulation_failure_exit(vcpu);
vcpu_run(vcpu);
ASSERT_EQ(get_ucall(vcpu, NULL), UCALL_DONE);