kvm: x86: Fix a spurious -E2BIG in __do_cpuid_func (a1a640b8) · Commits · 戴 / test

Don't return -E2BIG from __do_cpuid_func when processing function 0BH or 1FH and the last interesting subleaf occupies the last allocated entry in the result array. Cc: Paolo Bonzini <pbonzini@redhat.com> Fixes: ("KVM: Refactor and simplify kvm_dev_ioctl_get_supported_cpuid") Signed-off-by:

Jim Mattson <jmattson@google.com> Reviewed-by:

Peter Shier <pshier@google.com> Reviewed-by:

Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/cpuid.c

+10 −6

Original line number	Diff line number	Diff line
		@@ -618,16 +618,20 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function,
		*/
		case 0x1f:
		case 0xb: {
		int i, level_type;
		int i;

		/* read more entries until level_type is zero */
		for (i = 1; ; ++i) {
		/*
		* We filled in entry[0] for CPUID(EAX=<function>,
		* ECX=00H) above. If its level type (ECX[15:8]) is
		* zero, then the leaf is unimplemented, and we're
		* done. Otherwise, continue to populate entries
		* until the level type (ECX[15:8]) of the previously
		* added entry is zero.
		*/
		for (i = 1; entry[i - 1].ecx & 0xff00; ++i) {
		if (*nent >= maxnent)
		goto out;

		level_type = entry[i - 1].ecx & 0xff00;
		if (!level_type)
		break;
		do_host_cpuid(&entry[i], function, i);
		++*nent;
		}

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