Commit 8fe09d6a authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: selftests: Set input function/index in raw CPUID helper(s) 



Set the function/index for CPUID in the helper instead of relying on the
caller to do so.  In addition to reducing the risk of consuming an
uninitialized ECX, having the function/index embedded in the call makes
it easier to understand what is being checked.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-32-seanjc@google.com
parent 813e38cd

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

+13 −3
Original line number Diff line number Diff line
@@ -404,10 +404,13 @@ static inline void outl(uint16_t port, uint32_t value) 
	__asm__ __volatile__("outl %%eax, %%dx" : : "d"(port), "a"(value));

}



static inline void cpuid(uint32_t *eax, uint32_t *ebx,

static inline void __cpuid(uint32_t function, uint32_t index,

			   uint32_t *eax, uint32_t *ebx,

			   uint32_t *ecx, uint32_t *edx)

{

	/* ecx is often an input as well as an output. */

	*eax = function;

	*ecx = index;



	asm volatile("cpuid"

	    : "=a" (*eax),

	      "=b" (*ebx),
@@ -417,6 +420,13 @@ static inline void cpuid(uint32_t *eax, uint32_t *ebx, 
	    : "memory");

}



static inline void cpuid(uint32_t function,

			 uint32_t *eax, uint32_t *ebx,

			 uint32_t *ecx, uint32_t *edx)

{

	return __cpuid(function, 0, eax, ebx, ecx, edx);

}



#define SET_XMM(__var, __xmm) \

	asm volatile("movq %0, %%"#__xmm : : "r"(__var) : #__xmm)

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

+4 −9
Original line number Diff line number Diff line
@@ -1301,9 +1301,7 @@ unsigned long vm_compute_max_gfn(struct kvm_vm *vm) 


	/* Before family 17h, the HyperTransport area is just below 1T.  */

	ht_gfn = (1 << 28) - num_ht_pages;

	eax = 1;

	ecx = 0;

	cpuid(&eax, &ebx, &ecx, &edx);

	cpuid(1, &eax, &ebx, &ecx, &edx);

	if (x86_family(eax) < 0x17)

		goto done;
@@ -1312,18 +1310,15 @@ unsigned long vm_compute_max_gfn(struct kvm_vm *vm) 
	 * reduced due to SME by bits 11:6 of CPUID[0x8000001f].EBX.  Use

	 * the old conservative value if MAXPHYADDR is not enumerated.

	 */

	eax = 0x80000000;

	cpuid(&eax, &ebx, &ecx, &edx);

	cpuid(0x80000000, &eax, &ebx, &ecx, &edx);

	max_ext_leaf = eax;

	if (max_ext_leaf < 0x80000008)

		goto done;



	eax = 0x80000008;

	cpuid(&eax, &ebx, &ecx, &edx);

	cpuid(0x80000008, &eax, &ebx, &ecx, &edx);

	max_pfn = (1ULL << ((eax & 0xff) - vm->page_shift)) - 1;

	if (max_ext_leaf >= 0x8000001f) {

		eax = 0x8000001f;

		cpuid(&eax, &ebx, &ecx, &edx);

		cpuid(0x8000001f, &eax, &ebx, &ecx, &edx);

		max_pfn >>= (ebx >> 6) & 0x3f;

	}

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

+4 −15
Original line number Diff line number Diff line
@@ -122,9 +122,7 @@ static inline void check_cpuid_xsave(void) 
{

	uint32_t eax, ebx, ecx, edx;



	eax = 1;

	ecx = 0;

	cpuid(&eax, &ebx, &ecx, &edx);

	cpuid(1, &eax, &ebx, &ecx, &edx);

	if (!(ecx & CPUID_XSAVE))

		GUEST_ASSERT(!"cpuid: no CPU xsave support!");

	if (!(ecx & CPUID_OSXSAVE))
@@ -140,10 +138,7 @@ static bool enum_xtile_config(void) 
{

	u32 eax, ebx, ecx, edx;



	eax = TILE_CPUID;

	ecx = TILE_PALETTE_CPUID_SUBLEAVE;



	cpuid(&eax, &ebx, &ecx, &edx);

	__cpuid(TILE_CPUID, TILE_PALETTE_CPUID_SUBLEAVE, &eax, &ebx, &ecx, &edx);

	if (!eax || !ebx || !ecx)

		return false;
@@ -165,10 +160,7 @@ static bool enum_xsave_tile(void) 
{

	u32 eax, ebx, ecx, edx;



	eax = XSTATE_CPUID;

	ecx = XFEATURE_XTILEDATA;



	cpuid(&eax, &ebx, &ecx, &edx);

	__cpuid(XSTATE_CPUID, XFEATURE_XTILEDATA, &eax, &ebx, &ecx, &edx);

	if (!eax || !ebx)

		return false;
@@ -183,10 +175,7 @@ static bool check_xsave_size(void) 
	u32 eax, ebx, ecx, edx;

	bool valid = false;



	eax = XSTATE_CPUID;

	ecx = XSTATE_USER_STATE_SUBLEAVE;



	cpuid(&eax, &ebx, &ecx, &edx);

	__cpuid(XSTATE_CPUID, XSTATE_USER_STATE_SUBLEAVE, &eax, &ebx, &ecx, &edx);

	if (ebx && ebx <= XSAVE_SIZE)

		valid = true;

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

+5 −6
Original line number Diff line number Diff line
@@ -31,10 +31,9 @@ static void test_guest_cpuids(struct kvm_cpuid2 *guest_cpuid) 
	u32 eax, ebx, ecx, edx;



	for (i = 0; i < guest_cpuid->nent; i++) {

		eax = guest_cpuid->entries[i].function;

		ecx = guest_cpuid->entries[i].index;



		cpuid(&eax, &ebx, &ecx, &edx);

		__cpuid(guest_cpuid->entries[i].function,

			guest_cpuid->entries[i].index,

			&eax, &ebx, &ecx, &edx);



		GUEST_ASSERT(eax == guest_cpuid->entries[i].eax &&

			     ebx == guest_cpuid->entries[i].ebx &&
@@ -46,9 +45,9 @@ static void test_guest_cpuids(struct kvm_cpuid2 *guest_cpuid) 


static void test_cpuid_40000000(struct kvm_cpuid2 *guest_cpuid)

{

	u32 eax = 0x40000000, ebx, ecx = 0, edx;

	u32 eax, ebx, ecx, edx;



	cpuid(&eax, &ebx, &ecx, &edx);

	cpuid(0x40000000, &eax, &ebx, &ecx, &edx);



	GUEST_ASSERT(eax == 0x40000001);

}