2020-02-18 21:08:59

by Sean Christopherson

Subject: [PATCH v6 21/22] KVM: x86/mmu: Use ranged-based TLB flush for dirty log memslot flush

Use the with_address() variant to when performing a TLB flush for a
specific memslot via kvm_arch_flush_remote_tlbs_memslot(), i.e. when
flushing after clearing dirty bits during KVM_{GET,CLEAR}_DIRTY_LOG.
This aligns all dirty log memslot-specific TLB flushes to use the
with_address() variant and paves the way for consolidating the relevant
code.

Note, moving to the with_address() variant only affects functionality
when running as a HyperV guest.

Cc: Vitaly Kuznetsov <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
---
arch/x86/kvm/mmu/mmu.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 026e4a5c8e86..8a6516ce2983 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5950,7 +5950,8 @@ void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
* kvm_mmu_slot_remove_write_access().
*/
lockdep_assert_held(&kvm->slots_lock);
- kvm_flush_remote_tlbs(kvm);
+ kvm_flush_remote_tlbs_with_address(kvm, memslot->base_gfn,
+ memslot->npages);
}

void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm,
--
2.24.1

2020-02-19 09:24:46

by Sergei Shtylyov

Subject: Re: [PATCH v6 21/22] KVM: x86/mmu: Use ranged-based TLB flush for dirty log memslot flush

Hello!

On 19.02.2020 0:07, Sean Christopherson wrote:

> Use the with_address() variant to when performing a TLB flush for a
^^ is it really needed here?

> specific memslot via kvm_arch_flush_remote_tlbs_memslot(), i.e. when
> flushing after clearing dirty bits during KVM_{GET,CLEAR}_DIRTY_LOG.
> This aligns all dirty log memslot-specific TLB flushes to use the
> with_address() variant and paves the way for consolidating the relevant
> code.
>
> Note, moving to the with_address() variant only affects functionality
> when running as a HyperV guest.
>
> Cc: Vitaly Kuznetsov <[email protected]>
> Signed-off-by: Sean Christopherson <[email protected]>
[...]

MBR, Sergei

2020-02-19 15:19:34

by Sean Christopherson

Subject: Re: [PATCH v6 21/22] KVM: x86/mmu: Use ranged-based TLB flush for dirty log memslot flush

On Wed, Feb 19, 2020 at 12:22:58PM +0300, Sergei Shtylyov wrote:
> Hello!
>
> On 19.02.2020 0:07, Sean Christopherson wrote:
>
> >Use the with_address() variant to when performing a TLB flush for a
> ^^ is it really needed here?

Doh, thanks. The subject also has a typo, it should be "range-based", not
"ranged-based".

> >specific memslot via kvm_arch_flush_remote_tlbs_memslot(), i.e. when
> >flushing after clearing dirty bits during KVM_{GET,CLEAR}_DIRTY_LOG.
> >This aligns all dirty log memslot-specific TLB flushes to use the
> >with_address() variant and paves the way for consolidating the relevant
> >code.
> >
> >Note, moving to the with_address() variant only affects functionality
> >when running as a HyperV guest.
> >
> >Cc: Vitaly Kuznetsov <[email protected]>
> >Signed-off-by: Sean Christopherson <[email protected]>
> [...]
>
> MBR, Sergei