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| author | Dietmar Hahn <dietmar.hahn@ts.fujitsu.com> | 2013-03-26 14:24:25 +0100 |
|---|---|---|
| committer | Jan Beulich <jbeulich@suse.com> | 2013-03-26 14:24:25 +0100 |
| commit | 25250ed7c8094a905c5f03b8ae25c8694d3fa9b3 (patch) | |
| tree | dadd1ea3edda3aa7e14b5113f09dd7890b8fd005 /xen/arch/x86/hvm/svm | |
| parent | db537fe3023bf157b85c8246782cb72a6f989b31 (diff) | |
| download | xen-25250ed7c8094a905c5f03b8ae25c8694d3fa9b3.tar.gz xen-25250ed7c8094a905c5f03b8ae25c8694d3fa9b3.tar.bz2 xen-25250ed7c8094a905c5f03b8ae25c8694d3fa9b3.zip | |
vpmu intel: Add cpuid handling when vpmu disabled
Even though vpmu is disabled in the hypervisor in the HVM guest the call of
cpuid(0xa) returns informations about usable performance counters.
This may confuse guest software when trying to use the counters and nothing
happens.
This patch clears most bits in registers eax and edx of cpuid(0xa) instruction
for the guest when vpmu is disabled:
- version ID of architectural performance counting
- number of general pmu registers
- width of general pmu registers
- number of fixed pmu registers
- width of ixed pmu registers
Signed-off-by: Dietmar Hahn <dietmar.hahn@ts.fujitsu.com>
Acked-by: Keir Fraser <keir@xen.org>
Diffstat (limited to 'xen/arch/x86/hvm/svm')
| -rw-r--r-- | xen/arch/x86/hvm/svm/vpmu.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/xen/arch/x86/hvm/svm/vpmu.c b/xen/arch/x86/hvm/svm/vpmu.c index bf186fea3d..16170da3c8 100644 --- a/xen/arch/x86/hvm/svm/vpmu.c +++ b/xen/arch/x86/hvm/svm/vpmu.c @@ -370,6 +370,10 @@ int svm_vpmu_initialise(struct vcpu *v, unsigned int vpmu_flags) uint8_t family = current_cpu_data.x86; int ret = 0; + /* vpmu enabled? */ + if ( !vpmu_flags ) + return 0; + switch ( family ) { case 0x10: |