Commit 7040e54f authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: selftests: Rework dynamic XFeature helper to take mask, not bit 



Take the XFeature mask in __vm_xsave_require_permission() instead of the
bit so that there's no need to define macros for both the bit and the
mask.  Asserting that only a single bit is set and retrieving said bit
is easy enough via log2 helpers.

Opportunistically clean up the error message for the
ARCH_REQ_XCOMP_GUEST_PERM sanity check.

Reviewed-by: default avatarAaron Lewis <aaronlewis@google.com>
Tested-by: default avatarAaron Lewis <aaronlewis@google.com>
Link: https://lore.kernel.org/r/20230405004520.421768-5-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent b213812d

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

+3 −3
Original line number Diff line number Diff line
@@ -1098,10 +1098,10 @@ uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2, 
uint64_t __xen_hypercall(uint64_t nr, uint64_t a0, void *a1);

void xen_hypercall(uint64_t nr, uint64_t a0, void *a1);



void __vm_xsave_require_permission(int bit, const char *name);

void __vm_xsave_require_permission(uint64_t xfeature, const char *name);



#define vm_xsave_require_permission(perm)	\

	__vm_xsave_require_permission(perm, #perm)

#define vm_xsave_require_permission(xfeature)	\

	__vm_xsave_require_permission(xfeature, #xfeature)



enum pg_level {

	PG_LEVEL_NONE,

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

+10 −7
Original line number Diff line number Diff line
@@ -697,7 +697,7 @@ uint64_t kvm_get_feature_msr(uint64_t msr_index) 
	return buffer.entry.data;

}



void __vm_xsave_require_permission(int bit, const char *name)

void __vm_xsave_require_permission(uint64_t xfeature, const char *name)

{

	int kvm_fd;

	u64 bitmask;
@@ -705,12 +705,15 @@ void __vm_xsave_require_permission(int bit, const char *name) 
	struct kvm_device_attr attr = {

		.group = 0,

		.attr = KVM_X86_XCOMP_GUEST_SUPP,

		.addr = (unsigned long) &bitmask

		.addr = (unsigned long) &bitmask,

	};



	TEST_ASSERT(!kvm_supported_cpuid,

		    "kvm_get_supported_cpuid() cannot be used before ARCH_REQ_XCOMP_GUEST_PERM");



	TEST_ASSERT(is_power_of_2(xfeature),

		    "Dynamic XFeatures must be enabled one at a time");



	kvm_fd = open_kvm_dev_path_or_exit();

	rc = __kvm_ioctl(kvm_fd, KVM_GET_DEVICE_ATTR, &attr);

	close(kvm_fd);
@@ -720,16 +723,16 @@ void __vm_xsave_require_permission(int bit, const char *name) 


	TEST_ASSERT(rc == 0, "KVM_GET_DEVICE_ATTR(0, KVM_X86_XCOMP_GUEST_SUPP) error: %ld", rc);



	__TEST_REQUIRE(bitmask & (1ULL << bit),

	__TEST_REQUIRE(bitmask & xfeature,

		       "Required XSAVE feature '%s' not supported", name);



	TEST_REQUIRE(!syscall(SYS_arch_prctl, ARCH_REQ_XCOMP_GUEST_PERM, bit));

	TEST_REQUIRE(!syscall(SYS_arch_prctl, ARCH_REQ_XCOMP_GUEST_PERM, ilog2(xfeature)));



	rc = syscall(SYS_arch_prctl, ARCH_GET_XCOMP_GUEST_PERM, &bitmask);

	TEST_ASSERT(rc == 0, "prctl(ARCH_GET_XCOMP_GUEST_PERM) error: %ld", rc);

	TEST_ASSERT(bitmask & (1ULL << bit),

		    "prctl(ARCH_REQ_XCOMP_GUEST_PERM) failure bitmask=0x%lx",

		    bitmask);

	TEST_ASSERT(bitmask & xfeature,

		    "'%s' (0x%lx) not permitted after prctl(ARCH_REQ_XCOMP_GUEST_PERM) perrmited=0x%lx",

		    name, xfeature, bitmask);

}



void vcpu_init_cpuid(struct kvm_vcpu *vcpu, const struct kvm_cpuid2 *cpuid)

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

+1 −1
Original line number Diff line number Diff line
@@ -233,7 +233,7 @@ int main(int argc, char *argv[]) 
	 * Note, all off-by-default features must be enabled before anything

	 * caches KVM_GET_SUPPORTED_CPUID, e.g. before using kvm_cpu_has().

	 */

	vm_xsave_require_permission(XSTATE_XTILE_DATA_BIT);

	vm_xsave_require_permission(XFEATURE_MASK_XTILEDATA);



	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_XFD));

	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_XSAVE));