Skip to content

Commit

Permalink
KVM: Fix cpuid iteration on multiple leaves per eac
Browse files Browse the repository at this point in the history
The code to traverse the cpuid data array list for counting type of leaves is
currently broken.

This patches fixes the 2 things in it.

 1. Set the 1st counting entry's flag KVM_CPUID_FLAG_STATE_READ_NEXT. Without
    it the code will never find a valid entry.

 2. Also the stop condition in the for loop while looking for the next unflaged
    entry is broken. It needs to stop when it find one matching entry;
    and in the case of count of 1, it will be the same entry found in this
    iteration.

Signed-Off-By: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
  • Loading branch information
Nitin A Kamble authored and Avi Kivity committed Dec 31, 2008
1 parent 0853d2c commit 0fdf8e5
Showing 1 changed file with 2 additions and 1 deletion.
3 changes: 2 additions & 1 deletion arch/x86/kvm/x86.c
Original file line number Diff line number Diff line change
Expand Up @@ -1246,6 +1246,7 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
int t, times = entry->eax & 0xff;

entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
for (t = 1; t < times && *nent < maxnent; ++t) {
do_cpuid_1_ent(&entry[t], function, 0);
entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
Expand Down Expand Up @@ -2801,7 +2802,7 @@ static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)

e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
/* when no next entry is found, the current entry[i] is reselected */
for (j = i + 1; j == i; j = (j + 1) % nent) {
for (j = i + 1; ; j = (j + 1) % nent) {
struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j];
if (ej->function == e->function) {
ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
Expand Down

0 comments on commit 0fdf8e5

Please sign in to comment.