Re: [PATCH v2 2/4] KVM: MMU: Move accessed/dirty bit checks from rmap_remove() to drop_spte()

Avi Kivity
2010-06-07T09:01:42Z

On 06/07/2010 11:16 AM, Lai Jiangshan wrote:
> Avi Kivity wrote:
>
>> Since we need to make the check atomic, move it to the place that will
>> set the new spte.
>>
>> Signed-off-by: Avi Kivity<avi@redhat.com>
>> ---
>> arch/x86/kvm/mmu.c | 17 +++++++++--------
>> 1 files changed, 9 insertions(+), 8 deletions(-)
>>
>> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
>> index 16cedc9..b5a2d3d 100644
>> --- a/arch/x86/kvm/mmu.c
>> +++ b/arch/x86/kvm/mmu.c
>> @@ -620,19 +620,11 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
>> struct kvm_rmap_desc *desc;
>> struct kvm_rmap_desc *prev_desc;
>> struct kvm_mmu_page *sp;
>> - pfn_t pfn;
>> gfn_t gfn;
>> unsigned long *rmapp;
>> int i;
>>
>> - if (!is_rmap_spte(*spte))
>> - return;
>> sp = page_header(__pa(spte));
>> - pfn = spte_to_pfn(*spte);
>> - if (*spte& shadow_accessed_mask)
>> - kvm_set_pfn_accessed(pfn);
>> - if (is_writable_pte(*spte))
>> - kvm_set_pfn_dirty(pfn);
>> gfn = kvm_mmu_page_get_gfn(sp, spte - sp->spt);
>> rmapp = gfn_to_rmap(kvm, gfn, sp->role.level);
>> if (!*rmapp) {
>> @@ -668,6 +660,15 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
>>
>> static void drop_spte(struct kvm *kvm, u64 *sptep, u64 new_spte)
>> {
>> + pfn_t pfn;
>> +
>> + if (!is_rmap_spte(*sptep))
>> + return;
>>
> Missing __set_spte(sptep, new_spte); ?
>

Yup, will fix.

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