Commit aa10a7dc authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86: Consolidate CPUID array max num entries checking 



Move the nent vs. maxnent check and nent increment into do_host_cpuid()
to consolidate what is now identical code.  To signal success vs.
failure, return the entry and NULL respectively.  A future patch will
build on this to also move the entry retrieval into do_host_cpuid().

No functional change intended.

Reviewed-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent acfad336

arch/x86/kvm/cpuid.c

+17 −32
Original line number Diff line number Diff line
@@ -287,9 +287,14 @@ static __always_inline void cpuid_mask(u32 *word, int wordnum) 
	*word &= boot_cpu_data.x86_capability[wordnum];

}



static void do_host_cpuid(struct kvm_cpuid_entry2 *entry, u32 function,

			   u32 index)

static struct kvm_cpuid_entry2 *do_host_cpuid(struct kvm_cpuid_entry2 *entry,

					      int *nent, int maxnent,

					      u32 function, u32 index)

{

	if (*nent >= maxnent)

		return NULL;

	++*nent;



	entry->function = function;

	entry->index = index;

	entry->flags = 0;
@@ -316,6 +321,8 @@ static void do_host_cpuid(struct kvm_cpuid_entry2 *entry, u32 function, 
		entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;

		break;

	}



	return entry;

}



static int __do_cpuid_func_emulated(struct kvm_cpuid_entry2 *entry,
@@ -507,12 +514,9 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, 


	r = -E2BIG;



	if (WARN_ON(*nent >= maxnent))

	if (WARN_ON(!do_host_cpuid(entry, nent, maxnent, function, 0)))

		goto out;



	do_host_cpuid(entry, function, 0);

	++*nent;



	switch (function) {

	case 0:

		/* Limited to the highest leaf implemented in KVM. */
@@ -536,11 +540,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, 


		entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;

		for (t = 1; t < times; ++t) {

			if (*nent >= maxnent)

			if (!do_host_cpuid(&entry[t], nent, maxnent, function, 0))

				goto out;



			do_host_cpuid(&entry[t], function, 0);

			++*nent;

		}

		break;

	}
@@ -555,10 +556,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, 
			if (!cache_type)

				break;



			if (*nent >= maxnent)

			if (!do_host_cpuid(&entry[i], nent, maxnent, function, i))

				goto out;

			do_host_cpuid(&entry[i], function, i);

			++*nent;

		}

		break;

	}
@@ -575,12 +574,9 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, 
		do_cpuid_7_mask(entry);



		for (i = 1; i <= entry->eax; i++) {

			if (*nent >= maxnent)

			if (!do_host_cpuid(&entry[i], nent, maxnent, function, i))

				goto out;



			do_host_cpuid(&entry[i], function, i);

			++*nent;



			do_cpuid_7_mask(&entry[i]);

		}

		break;
@@ -633,11 +629,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, 
		 * added entry is zero.

		 */

		for (i = 1; entry[i - 1].ecx & 0xff00; ++i) {

			if (*nent >= maxnent)

			if (!do_host_cpuid(&entry[i], nent, maxnent, function, i))

				goto out;



			do_host_cpuid(&entry[i], function, i);

			++*nent;

		}

		break;

	}
@@ -652,12 +645,9 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, 
		if (!supported)

			break;



		if (*nent >= maxnent)

		if (!do_host_cpuid(&entry[1], nent, maxnent, function, 1))

			goto out;



		do_host_cpuid(&entry[1], function, 1);

		++*nent;



		entry[1].eax &= kvm_cpuid_D_1_eax_x86_features;

		cpuid_mask(&entry[1].eax, CPUID_D_1_EAX);

		if (entry[1].eax & (F(XSAVES)|F(XSAVEC)))
@@ -672,12 +662,9 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, 
			if (!(supported & BIT_ULL(idx)))

				continue;



			if (*nent >= maxnent)

			if (!do_host_cpuid(&entry[i], nent, maxnent, function, idx))

				goto out;



			do_host_cpuid(&entry[i], function, idx);

			++*nent;



			/*

			 * The @supported check above should have filtered out

			 * invalid sub-leafs as well as sub-leafs managed by
@@ -704,10 +691,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, 
			break;



		for (t = 1; t <= times; ++t) {

			if (*nent >= maxnent)

			if (!do_host_cpuid(&entry[t], nent, maxnent, function, t))

				goto out;

			do_host_cpuid(&entry[t], function, t);

			++*nent;

		}

		break;

	}

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