Commit 1940af0b authored by Sean Christopherson's avatar Sean Christopherson
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KVM: selftests: Add and use helper to set vCPU's CPUID maxphyaddr 



Add a helper to set a vCPU's guest.MAXPHYADDR, and use it in the test
that verifies the emulator returns an error on an unknown instruction
when KVM emulates in response to an EPT violation with a GPA that is
legal in hardware but illegal with respect to the guest's MAXPHYADDR.

Add a helper even though there's only a single user at this time.  Before
its removal, mmu_role_test also stuffed guest.MAXPHYADDR, and the helper
provides a small amount of clarity.

More importantly, this eliminates a set_cpuid() user and an instance of
modifying kvm_get_supported_cpuid()'s static "cpuid".

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-25-seanjc@google.com
parent 7af7161d

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

+2 −0
Original line number Diff line number Diff line
@@ -658,6 +658,8 @@ static inline void vcpu_set_cpuid(struct kvm_vcpu *vcpu) 
	vcpu_ioctl(vcpu, KVM_GET_CPUID2, vcpu->cpuid);

}



void vcpu_set_cpuid_maxphyaddr(struct kvm_vcpu *vcpu, uint8_t maxphyaddr);



void vcpu_set_or_clear_cpuid_feature(struct kvm_vcpu *vcpu,

				     struct kvm_x86_cpu_feature feature,

				     bool set);

tools/testing/selftests/kvm/lib/x86_64/processor.c

+8 −0
Original line number Diff line number Diff line
@@ -762,6 +762,14 @@ void vcpu_init_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid) 
	vcpu_set_cpuid(vcpu);

}



void vcpu_set_cpuid_maxphyaddr(struct kvm_vcpu *vcpu, uint8_t maxphyaddr)

{

	struct kvm_cpuid_entry2 *entry = vcpu_get_cpuid_entry(vcpu, 0x80000008);



	entry->eax = (entry->eax & ~0xff) | maxphyaddr;

	vcpu_set_cpuid(vcpu);

}



void vcpu_set_or_clear_cpuid_feature(struct kvm_vcpu *vcpu,

				     struct kvm_x86_cpu_feature feature,

				     bool set)

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

+1 −9
Original line number Diff line number Diff line
@@ -150,8 +150,6 @@ static uint64_t process_ucall(struct kvm_vcpu *vcpu) 


int main(int argc, char *argv[])

{

	struct kvm_cpuid_entry2 *entry;

	struct kvm_cpuid2 *cpuid;

	struct kvm_vcpu *vcpu;

	struct kvm_vm *vm;

	uint64_t gpa, pte;
@@ -165,13 +163,7 @@ int main(int argc, char *argv[]) 


	vm = vm_create_with_one_vcpu(&vcpu, guest_code);



	cpuid = kvm_get_supported_cpuid();



	entry = kvm_get_supported_cpuid_index(0x80000008, 0);

	entry->eax = (entry->eax & 0xffffff00) | MAXPHYADDR;

	set_cpuid(cpuid, entry);



	vcpu_init_cpuid(vcpu, cpuid);

	vcpu_set_cpuid_maxphyaddr(vcpu, MAXPHYADDR);



	rc = kvm_check_cap(KVM_CAP_EXIT_ON_EMULATION_FAILURE);

	TEST_ASSERT(rc, "KVM_CAP_EXIT_ON_EMULATION_FAILURE is unavailable");