Re: IO on guest is 20 times slower than host

Avi Kivity
2009-03-31T10:02:54Z

Joerg Roedel wrote:
>> --- a/kernel/x86/kvm/svm.c
>> +++ b/kernel/x86/kvm/svm.c
>> @@ -575,7 +575,7 @@ static void init_vmcb(struct vcpu_svm *svm)
>> INTERCEPT_CR3_MASK);
>> control->intercept_cr_write &= ~(INTERCEPT_CR0_MASK|
>> INTERCEPT_CR3_MASK);
>> - save->g_pat = 0x0007040600070406ULL;
>> + save->g_pat = 0x0606060606060606ULL;
>> /* enable caching because the QEMU Bios doesn't enable it */
>> save->cr0 = X86_CR0_ET;
>> save->cr3 = 0;
>>
>
> Yeah, that patch makes sense. But I think we need some more work on this
> because the guest may change the pat msr afterwards. Best would be a simple
> shadow of the pat msr. Last question is how this will effect pci passthrough.

This is just a stopgap; we can later add proper pat shadowing.

--
error compiling committee.c: too many arguments to function