Re: [PATCH v6 03/11] KVM: Allow range-based TLB invalidation from common code
From: Raghavendra Rao Ananta
Date: Tue Jul 18 2023 - 12:31:39 EST
Hi Shaoqin,
On Mon, Jul 17, 2023 at 7:49 PM Shaoqin Huang <shahuang@xxxxxxxxxx> wrote:
>
>
>
> On 7/18/23 00:37, Raghavendra Rao Ananta wrote:
> > On Mon, Jul 17, 2023 at 4:40 AM Shaoqin Huang <shahuang@xxxxxxxxxx> wrote:
> >>
> >>
> >>
> >> On 7/15/23 08:53, Raghavendra Rao Ananta wrote:
> >>> From: David Matlack <dmatlack@xxxxxxxxxx>
> >>>
> >>> Make kvm_flush_remote_tlbs_range() visible in common code and create a
> >>> default implementation that just invalidates the whole TLB.
> >>>
> >>> This paves the way for several future features/cleanups:
> >>>
> >>> - Introduction of range-based TLBI on ARM.
> >>> - Eliminating kvm_arch_flush_remote_tlbs_memslot()
> >>> - Moving the KVM/x86 TDP MMU to common code.
> >>>
> >>> No functional change intended.
> >>>
> >>> Signed-off-by: David Matlack <dmatlack@xxxxxxxxxx>
> >>> Signed-off-by: Raghavendra Rao Ananta <rananta@xxxxxxxxxx>
> >>> Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>
> >>> ---
> >>> arch/x86/include/asm/kvm_host.h | 3 +++
> >>> arch/x86/kvm/mmu/mmu.c | 9 ++++-----
> >>> arch/x86/kvm/mmu/mmu_internal.h | 3 ---
> >>> include/linux/kvm_host.h | 9 +++++++++
> >>> virt/kvm/kvm_main.c | 13 +++++++++++++
> >>> 5 files changed, 29 insertions(+), 8 deletions(-)
> >>>
> >>> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> >>> index a2d3cfc2eb75..08900afbf2ad 100644
> >>> --- a/arch/x86/include/asm/kvm_host.h
> >>> +++ b/arch/x86/include/asm/kvm_host.h
> >>> @@ -1804,6 +1804,9 @@ static inline int kvm_arch_flush_remote_tlbs(struct kvm *kvm)
> >>> return -ENOTSUPP;
> >>> }
> >>>
> >>> +#define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS_RANGE
> >>> +int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, u64 pages);
> >>> +
> >>> #define kvm_arch_pmi_in_guest(vcpu) \
> >>> ((vcpu) && (vcpu)->arch.handling_intr_from_guest)
> >>>
> >>> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> >>> index ec169f5c7dce..aaa5e336703a 100644
> >>> --- a/arch/x86/kvm/mmu/mmu.c
> >>> +++ b/arch/x86/kvm/mmu/mmu.c
> >>> @@ -278,16 +278,15 @@ static inline bool kvm_available_flush_remote_tlbs_range(void)
> >>> return kvm_x86_ops.flush_remote_tlbs_range;
> >>> }
> >>>
> >>> -void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn,
> >>> - gfn_t nr_pages)
> >>> +int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, u64 pages)
> >>> {
> >>> int ret = -EOPNOTSUPP;
> >>>
> >>> if (kvm_x86_ops.flush_remote_tlbs_range)
> >>> ret = static_call(kvm_x86_flush_remote_tlbs_range)(kvm, start_gfn,
> >>> - nr_pages);
> >>> - if (ret)
> >>> - kvm_flush_remote_tlbs(kvm);
> >>> + pages);
> >> This will be good if parameter pages aligned with parameter kvm.
> >>
> > Agreed, but pulling 'pages' above brings the char count to 83. If
> > that's acceptable, I'm happy to do it in v7.
> > Hi Raghavendra,
>
> no need to pulling 'pages' above, just delete one tab, and add some
> space before the pages, just like the original `nr_pages` position.
>
Oh yes, that can be done. Thanks!
- Raghavendra
> Thanks,
> Shaoqin
> > Thank you.
> > Raghavendra
> >> Reviewed-by: Shaoqin Huang <shahuang@xxxxxxxxxx>
> >>> +
> >>> + return ret;
> >>> }
> >>>
> >>> static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index);
> >>> diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
> >>> index d39af5639ce9..86cb83bb3480 100644
> >>> --- a/arch/x86/kvm/mmu/mmu_internal.h
> >>> +++ b/arch/x86/kvm/mmu/mmu_internal.h
> >>> @@ -170,9 +170,6 @@ bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
> >>> struct kvm_memory_slot *slot, u64 gfn,
> >>> int min_level);
> >>>
> >>> -void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn,
> >>> - gfn_t nr_pages);
> >>> -
> >>> /* Flush the given page (huge or not) of guest memory. */
> >>> static inline void kvm_flush_remote_tlbs_gfn(struct kvm *kvm, gfn_t gfn, int level)
> >>> {
> >>> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> >>> index e3f968b38ae9..a731967b24ff 100644
> >>> --- a/include/linux/kvm_host.h
> >>> +++ b/include/linux/kvm_host.h
> >>> @@ -1359,6 +1359,7 @@ int kvm_vcpu_yield_to(struct kvm_vcpu *target);
> >>> void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu, bool yield_to_kernel_mode);
> >>>
> >>> void kvm_flush_remote_tlbs(struct kvm *kvm);
> >>> +void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn, u64 pages);
> >>>
> >>> #ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE
> >>> int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min);
> >>> @@ -1486,6 +1487,14 @@ static inline int kvm_arch_flush_remote_tlbs(struct kvm *kvm)
> >>> }
> >>> #endif
> >>>
> >>> +#ifndef __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS_RANGE
> >>> +static inline int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm,
> >>> + gfn_t gfn, u64 pages)
> >>> +{
> >>> + return -EOPNOTSUPP;
> >>> +}
> >>> +#endif
> >>> +
> >>> #ifdef __KVM_HAVE_ARCH_NONCOHERENT_DMA
> >>> void kvm_arch_register_noncoherent_dma(struct kvm *kvm);
> >>> void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm);
> >>> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> >>> index d6b050786155..804470fccac7 100644
> >>> --- a/virt/kvm/kvm_main.c
> >>> +++ b/virt/kvm/kvm_main.c
> >>> @@ -366,6 +366,19 @@ void kvm_flush_remote_tlbs(struct kvm *kvm)
> >>> }
> >>> EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs);
> >>>
> >>> +void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn, u64 pages)
> >>> +{
> >>> + if (!kvm_arch_flush_remote_tlbs_range(kvm, gfn, pages))
> >>> + return;
> >>> +
> >>> + /*
> >>> + * Fall back to a flushing entire TLBs if the architecture range-based
> >>> + * TLB invalidation is unsupported or can't be performed for whatever
> >>> + * reason.
> >>> + */
> >>> + kvm_flush_remote_tlbs(kvm);
> >>> +}
> >>> +
> >>> static void kvm_flush_shadow_all(struct kvm *kvm)
> >>> {
> >>> kvm_arch_flush_shadow_all(kvm);
> >>
> >> --
> >> Shaoqin
> >>
> >
>
> --
> Shaoqin
>