On 27/09/2018 05:49, Tianyu Lan wrote:
> This patch is to flush tlb directly in the kvm_handle_hva_range()
> when range flush is available.
>
> Signed-off-by: Lan Tianyu <Tianyu.Lan@xxxxxxxxxxxxx>
> ---
> arch/x86/kvm/mmu.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index d10d8423e8d6..877edae0401f 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -1888,6 +1888,13 @@ static int kvm_handle_hva_range(struct kvm *kvm,
> &iterator)
> ret |= handler(kvm, iterator.rmap, memslot,
> iterator.gfn, iterator.level, data);
> +
> + if (ret && kvm_available_flush_tlb_with_range()) {
> + kvm_flush_remote_tlbs_with_address(kvm,
> + gfn_start,
> + gfn_end - gfn_start);
> + ret = 0;
> + }
> }
> }
>
>
Not all callers need a TLB flush (in particular kvm_test_age_hva)
require a flush. My suggestion is to rewrite kvm_test_age_hva like this:
index 4705a7f4169e..f72364a0ef9c 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1898,12 +1898,13 @@ static int kvm_test_age_rmapp(struct kvm *kvm,
struct kvm_memory_slot *slot, gfn_t gfn,
int level, unsigned long data)
{
+ bool *result = (bool *)data;
u64 *sptep;
struct rmap_iterator iter;
for_each_rmap_spte(rmap_head, &iter, sptep)
if (is_accessed_spte(*sptep))
- return 1;
+ *result = true;
return 0;
}
@@ -1929,7 +1930,10 @@ int kvm_age_hva(struct kvm *kvm,
int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
{
- return kvm_handle_hva(kvm, hva, 0, kvm_test_age_rmapp);
+ bool result = false;
+ kvm_handle_hva(kvm, hva, (unsigned long) &result,
+ kvm_test_age_rmapp);
+ return result;
}
#ifdef MMU_DEBUG
and move the flush from kvm_set_pte_rmapp to
kvm_mmu_notifier_change_pte, making kvm_set_spte_hva return an int;
otherwise, it will flush twice. For non-x86 architectures just grep for
"set_spte_hva" and make the various kvm_set_spte_hva implementations
return false.
Paolo
