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| author |   Jim Mattson <jmattson@google.com> | 2019-09-25 11:17:14 -0700 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2019-09-26 12:31:30 +0200 |
| commit | a1a640b8c0cd8a2a7f84ab694f04bc64dc6988af (patch) | |
| tree | 369893c787df8ebb498a44ef98cb7f570c2d4dab /arch/x86/kvm | |
| parent | KVM: LAPIC: Loosen filter for adaptive tuning of lapic_timer_advance_ns (diff) | |
| download | linux-dev-a1a640b8c0cd8a2a7f84ab694f04bc64dc6988af.tar.xz linux-dev-a1a640b8c0cd8a2a7f84ab694f04bc64dc6988af.zip | |
kvm: x86: Fix a spurious -E2BIG in __do_cpuid_func
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: 831bf664e9c1fc ("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>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 63316036f85a..6bf4a261b308 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -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; } |