Commit 9dba988e authored by Aaron Lewis's avatar Aaron Lewis Committed by Paolo Bonzini
Browse files

tests: kvm: Check for a kernel warning 

When running with /sys/module/kvm_intel/parameters/unrestricted_guest=N,
test that a kernel warning does not occur informing us that
vcpu->mmio_needed=1.  This can happen when KVM_RUN is called after a
triple fault.
This test was made to detect a bug that was reported by Syzkaller
(https://groups.google.com/forum/#!topic/syzkaller/lHfau8E3SOE

) and
fixed with commit bbeac283 ("KVM: X86: Fix residual mmio emulation
request to userspace").

Signed-off-by: default avatarAaron Lewis <aaronlewis@google.com>
Reviewed-by: default avatarJim Mattson <jmattson@google.com>
Reviewed-by: default avatarPeter Shier <pshier@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 61cfcd54

tools/testing/selftests/kvm/.gitignore

+1 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
/x86_64/evmcs_test

/x86_64/hyperv_cpuid

/x86_64/kvm_create_max_vcpus

/x86_64/mmio_warning_test

/x86_64/platform_info_test

/x86_64/set_sregs_test

/x86_64/smm_test

tools/testing/selftests/kvm/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test 
TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test

TEST_GEN_PROGS_x86_64 += x86_64/hyperv_cpuid

TEST_GEN_PROGS_x86_64 += x86_64/kvm_create_max_vcpus

TEST_GEN_PROGS_x86_64 += x86_64/mmio_warning_test

TEST_GEN_PROGS_x86_64 += x86_64/platform_info_test

TEST_GEN_PROGS_x86_64 += x86_64/set_sregs_test

TEST_GEN_PROGS_x86_64 += x86_64/smm_test

tools/testing/selftests/kvm/include/kvm_util.h

+2 −0
Original line number Diff line number Diff line
@@ -139,6 +139,8 @@ struct kvm_vm *vm_create_default(uint32_t vcpuid, uint64_t extra_mem_size, 
				 void *guest_code);

void vm_vcpu_add_default(struct kvm_vm *vm, uint32_t vcpuid, void *guest_code);



bool vm_is_unrestricted_guest(struct kvm_vm *vm);



struct kvm_userspace_memory_region *

kvm_userspace_memory_region_find(struct kvm_vm *vm, uint64_t start,

				 uint64_t end);

tools/testing/selftests/kvm/include/x86_64/processor.h

+2 −0
Original line number Diff line number Diff line
@@ -303,6 +303,8 @@ static inline unsigned long get_xmm(int n) 
	return 0;

}



bool is_intel_cpu(void);



struct kvm_x86_state;

struct kvm_x86_state *vcpu_save_state(struct kvm_vm *vm, uint32_t vcpuid);

void vcpu_load_state(struct kvm_vm *vm, uint32_t vcpuid,

tools/testing/selftests/kvm/lib/kvm_util.c

+36 −0
Original line number Diff line number Diff line
@@ -1583,3 +1583,39 @@ void *addr_gva2hva(struct kvm_vm *vm, vm_vaddr_t gva) 
{

	return addr_gpa2hva(vm, addr_gva2gpa(vm, gva));

}



/*

 * Is Unrestricted Guest

 *

 * Input Args:

 *   vm - Virtual Machine

 *

 * Output Args: None

 *

 * Return: True if the unrestricted guest is set to 'Y', otherwise return false.

 *

 * Check if the unrestricted guest flag is enabled.

 */

bool vm_is_unrestricted_guest(struct kvm_vm *vm)

{

	char val = 'N';

	size_t count;

	FILE *f;



	if (vm == NULL) {

		/* Ensure that the KVM vendor-specific module is loaded. */

		f = fopen(KVM_DEV_PATH, "r");

		TEST_ASSERT(f != NULL, "Error in opening KVM dev file: %d",

			    errno);

		fclose(f);

	}



	f = fopen("/sys/module/kvm_intel/parameters/unrestricted_guest", "r");

	if (f) {

		count = fread(&val, sizeof(char), 1, f);

		TEST_ASSERT(count == 1, "Unable to read from param file.");

		fclose(f);

	}



	return val == 'Y';

}

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