Recent kernels check for MSR_IA32_MISC_ENABLE_FAST_STRING in the
MSR_IA32_MISC_ENABLE MSR before enabling reps/movs memcpy.
So far we didn't set it, and got a slower memcpy and a warning:
[ 0.000000] Disabled fast string operations
This patch enables fast string operations.
Signed-off-by: Sasha Levin <[email protected]>
---
tools/kvm/kvm-cpu.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/tools/kvm/kvm-cpu.c b/tools/kvm/kvm-cpu.c
index fc0d6d4..d7ae5ce 100644
--- a/tools/kvm/kvm-cpu.c
+++ b/tools/kvm/kvm-cpu.c
@@ -142,6 +142,8 @@ static void kvm_cpu__setup_msrs(struct kvm_cpu *vcpu)
vcpu->msrs->entries[ndx++] = KVM_MSR_ENTRY(MSR_LSTAR,
0x0);
#endif
vcpu->msrs->entries[ndx++] = KVM_MSR_ENTRY(MSR_IA32_TSC,
0x0);
+ vcpu->msrs->entries[ndx++] = KVM_MSR_ENTRY(MSR_IA32_MISC_ENABLE,
+
MSR_IA32_MISC_ENABLE_FAST_STRING);
vcpu->msrs->nmsrs = ndx;
--
1.7.7
--
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