Al Tobey wrote:
On Sat, Oct 11, 2008 at 11:04 AM, Marcelo Tosatti <[EMAIL PROTECTED]> wrote:
On Fri, Oct 10, 2008 at 06:11:08PM +0200, xming wrote:
Kernel 2.6.27 + kvm-76 on the host really gives some performance boost here.
but:
When running 2.6.27 compiled with CONFIG_KVM_GUEST=y in the guest, the guest
won't start, lot's of segfaults (in the guest) especially udev initializations.
unset CONFIG_KVM_GUEST=y, then the guest runs fine
Does the attached work for you?
I was running a bunch of VM's on kvm-75 (gentoo/intel x86_64/virtio
guests) just fine. I upgraded to kvm-77 this morning and the VM's
failed to mount root read-write. I checked the list before digging
too deep and found a reference to this thread. Adding this patch on
top of stock kvm-77 appears to have fixed the issue.
Thanks,
-Al
Avi, do you have thoughts on how to proceed with pvmmu? Using hypercalls
instead of faults can still be beneficial (for the first write before
page goes out of sync, or for non-leaf tables which currently don't go
oos). But at the current state pvmmu should be slower in most loads.
Perhaps disable it?
KVM: MMU: sync root on paravirt TLB flush
The pvmmu TLB flush handler should request a root sync, similarly to
a native read-write CR3.
Signed-off-by: Marcelo Tosatti <[EMAIL PROTECTED]>
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 79cb4a9..7e70e97 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2747,6 +2747,7 @@ static int kvm_pv_mmu_write(struct kvm_vcpu *vcpu,
static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu *vcpu)
{
kvm_x86_ops->tlb_flush(vcpu);
+ set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests);
return 1;
}
--
Ok I was patching the wrong file...sorry.
It works well with 2.6.27 (host and guest) and kvm-77
Xavier
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