Commit 19a2b32f authored by David Matlack's avatar David Matlack Committed by Sean Christopherson
Browse files

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



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: default avatarDavid Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-5-dmatlack@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 50824c6e

tools/testing/selftests/kvm/x86_64/flds_emulation.h

0 → 100644
+55 −0
Original line number Diff line number Diff line 
/* 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 */

tools/testing/selftests/kvm/x86_64/smaller_maxphyaddr_emulation_test.c

+4 −40
Original line number Diff line number Diff line
@@ -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);