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| author | Christoph Egger <Christoph.Egger@amd.com> | 2012-07-09 10:28:50 +0100 |
|---|---|---|
| committer | Christoph Egger <Christoph.Egger@amd.com> | 2012-07-09 10:28:50 +0100 |
| commit | eff23cb0e5fa78b33af6e97d6a96fe106e40c4ae (patch) | |
| tree | 082860bb8efa1fe478bee7f60299da0a5d8e0b5a | |
| parent | 4e8f99fc6e93baff90fcff4993cc40f4be77b2df (diff) | |
| download | xen-eff23cb0e5fa78b33af6e97d6a96fe106e40c4ae.tar.gz xen-eff23cb0e5fa78b33af6e97d6a96fe106e40c4ae.tar.bz2 xen-eff23cb0e5fa78b33af6e97d6a96fe106e40c4ae.zip | |
SVM: fix performance decrease with asid assignment
Do not clear asid cleanbit unconditionally. This shaves off 100 cycles
from the VMRUN instruction.
Signed-off-by: Christoph Egger <Christoph.Egger@amd.com>
Committed-by: Jan Beulich <jbeulich@suse.com>
xen-unstable changeset: 25482:34c725807d21
xen-unstable date: Wed Jun 13 11:51:26 2012 +0200
| -rw-r--r-- | xen/arch/x86/hvm/svm/asid.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/xen/arch/x86/hvm/svm/asid.c b/xen/arch/x86/hvm/svm/asid.c index 3b9c6ce0f6..7bc17b5f3e 100644 --- a/xen/arch/x86/hvm/svm/asid.c +++ b/xen/arch/x86/hvm/svm/asid.c @@ -52,7 +52,8 @@ void svm_asid_handle_vmrun(void) return; } - vmcb_set_guest_asid(vmcb, curr->arch.hvm_vcpu.asid); + if (vmcb_get_guest_asid(vmcb) != curr->arch.hvm_vcpu.asid) + vmcb_set_guest_asid(vmcb, curr->arch.hvm_vcpu.asid); vmcb->tlb_control = need_flush; } |