Re: [PATCH 6/6] KVM: MMU: trace pte prefetch
From: Avi Kivity
Date: Tue Jun 15 2010 - 08:09:29 EST
On 06/15/2010 05:47 AM, Xiao Guangrong wrote:
Trace pte prefetch to see what trouble we meet, if can help us to
improve the prefetch
Signed-off-by: Xiao Guangrong<xiaoguangrong@xxxxxxxxxxxxxx>
---
arch/x86/kvm/mmu.c | 12 +++++++++++-
arch/x86/kvm/mmutrace.h | 26 ++++++++++++++++++++++++++
arch/x86/kvm/paging_tmpl.h | 9 ++++++++-
3 files changed, 45 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 941c86b..0aaa18d 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -91,6 +91,11 @@ module_param(oos_shadow, bool, 0644);
#define PTE_PREFETCH_NUM 16
+#define PREFETCH_SUCCESS 0
+#define PREFETCH_ERR_GFN2PFN 1
+#define PREFETCH_ERR_ALLOC_MEM 2
+#define PREFETCH_ERR_READ_GPTE 3
+
#define PT_FIRST_AVAIL_BITS_SHIFT 9
#define PT64_SECOND_AVAIL_BITS_SHIFT 52
@@ -2066,11 +2071,16 @@ static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep)
pfn = gfn_to_pfn_atomic(vcpu->kvm, gfn);
if (is_error_pfn(pfn)) {
kvm_release_pfn_clean(pfn);
+ trace_pte_prefetch(true, PREFETCH_ERR_GFN2PFN);
break;
}
What about virtual addresses and gptes? They can be helpful too.
--
error compiling committee.c: too many arguments to function
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