2023-07-22 02:31:39

by Raghavendra Rao Ananta

[permalink] [raw]
Subject: [PATCH v7 08/12] KVM: arm64: Define kvm_tlb_flush_vmid_range()

Implement the helper kvm_tlb_flush_vmid_range() that acts
as a wrapper for range-based TLB invalidations. For the
given VMID, use the range-based TLBI instructions to do
the job or fallback to invalidating all the TLB entries.

Signed-off-by: Raghavendra Rao Ananta <[email protected]>
Reviewed-by: Gavin Shan <[email protected]>
Reviewed-by: Shaoqin Huang <[email protected]>
---
arch/arm64/include/asm/kvm_pgtable.h | 10 ++++++++++
arch/arm64/kvm/hyp/pgtable.c | 20 ++++++++++++++++++++
2 files changed, 30 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
index 8294a9a7e566..5e8b1ff07854 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h
@@ -754,4 +754,14 @@ enum kvm_pgtable_prot kvm_pgtable_stage2_pte_prot(kvm_pte_t pte);
* kvm_pgtable_prot format.
*/
enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte);
+
+/**
+ * kvm_tlb_flush_vmid_range() - Invalidate/flush a range of TLB entries
+ *
+ * @mmu: Stage-2 KVM MMU struct
+ * @addr: The base Intermediate physical address from which to invalidate
+ * @size: Size of the range from the base to invalidate
+ */
+void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
+ phys_addr_t addr, size_t size);
#endif /* __ARM64_KVM_PGTABLE_H__ */
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index aa740a974e02..5d14d5d5819a 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -670,6 +670,26 @@ static bool stage2_has_fwb(struct kvm_pgtable *pgt)
return !(pgt->flags & KVM_PGTABLE_S2_NOFWB);
}

+void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
+ phys_addr_t addr, size_t size)
+{
+ unsigned long pages, inval_pages;
+
+ if (!system_supports_tlb_range()) {
+ kvm_call_hyp(__kvm_tlb_flush_vmid, mmu);
+ return;
+ }
+
+ pages = size >> PAGE_SHIFT;
+ while (pages > 0) {
+ inval_pages = min(pages, MAX_TLBI_RANGE_PAGES);
+ kvm_call_hyp(__kvm_tlb_flush_vmid_range, mmu, addr, inval_pages);
+
+ addr += inval_pages << PAGE_SHIFT;
+ pages -= inval_pages;
+ }
+}
+
#define KVM_S2_MEMATTR(pgt, attr) PAGE_S2_MEMATTR(attr, stage2_has_fwb(pgt))

static int stage2_set_prot_attr(struct kvm_pgtable *pgt, enum kvm_pgtable_prot prot,
--
2.41.0.487.g6d72f3e995-goog



2023-07-27 13:16:17

by Marc Zyngier

[permalink] [raw]
Subject: Re: [PATCH v7 08/12] KVM: arm64: Define kvm_tlb_flush_vmid_range()

On Thu, 27 Jul 2023 13:47:06 +0100,
Marc Zyngier <[email protected]> wrote:
>
> On Sat, 22 Jul 2023 03:22:47 +0100,
> Raghavendra Rao Ananta <[email protected]> wrote:
> >
> > Implement the helper kvm_tlb_flush_vmid_range() that acts
> > as a wrapper for range-based TLB invalidations. For the
> > given VMID, use the range-based TLBI instructions to do
> > the job or fallback to invalidating all the TLB entries.
> >
> > Signed-off-by: Raghavendra Rao Ananta <[email protected]>
> > Reviewed-by: Gavin Shan <[email protected]>
> > Reviewed-by: Shaoqin Huang <[email protected]>
> > ---
> > arch/arm64/include/asm/kvm_pgtable.h | 10 ++++++++++
> > arch/arm64/kvm/hyp/pgtable.c | 20 ++++++++++++++++++++
> > 2 files changed, 30 insertions(+)
> >
> > diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
> > index 8294a9a7e566..5e8b1ff07854 100644
> > --- a/arch/arm64/include/asm/kvm_pgtable.h
> > +++ b/arch/arm64/include/asm/kvm_pgtable.h
> > @@ -754,4 +754,14 @@ enum kvm_pgtable_prot kvm_pgtable_stage2_pte_prot(kvm_pte_t pte);
> > * kvm_pgtable_prot format.
> > */
> > enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte);
> > +
> > +/**
> > + * kvm_tlb_flush_vmid_range() - Invalidate/flush a range of TLB entries
> > + *
> > + * @mmu: Stage-2 KVM MMU struct
> > + * @addr: The base Intermediate physical address from which to invalidate
> > + * @size: Size of the range from the base to invalidate
> > + */
> > +void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
> > + phys_addr_t addr, size_t size);
> > #endif /* __ARM64_KVM_PGTABLE_H__ */
> > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
> > index aa740a974e02..5d14d5d5819a 100644
> > --- a/arch/arm64/kvm/hyp/pgtable.c
> > +++ b/arch/arm64/kvm/hyp/pgtable.c
> > @@ -670,6 +670,26 @@ static bool stage2_has_fwb(struct kvm_pgtable *pgt)
> > return !(pgt->flags & KVM_PGTABLE_S2_NOFWB);
> > }
> >
> > +void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
> > + phys_addr_t addr, size_t size)
> > +{
> > + unsigned long pages, inval_pages;
> > +
> > + if (!system_supports_tlb_range()) {
> > + kvm_call_hyp(__kvm_tlb_flush_vmid, mmu);
> > + return;
> > + }
> > +
> > + pages = size >> PAGE_SHIFT;
> > + while (pages > 0) {
> > + inval_pages = min(pages, MAX_TLBI_RANGE_PAGES);
> > + kvm_call_hyp(__kvm_tlb_flush_vmid_range, mmu, addr, inval_pages);
> > +
> > + addr += inval_pages << PAGE_SHIFT;
> > + pages -= inval_pages;
> > + }
> > +}
> > +
>
> This really shouldn't live in pgtable.c. This code gets linked into
> the EL2 object. What do you think happens if, for some reason, this
> gets called *from EL2*?

Ah, actually, nothing too bad would happen, as we convert the
kvm_call_hyp() into a function call.

But still, we don't need two copies of this stuff, and it can live in
mmu.c.

M.

--
Without deviation from the norm, progress is not possible.

2023-07-27 13:57:59

by Marc Zyngier

[permalink] [raw]
Subject: Re: [PATCH v7 08/12] KVM: arm64: Define kvm_tlb_flush_vmid_range()

On Sat, 22 Jul 2023 03:22:47 +0100,
Raghavendra Rao Ananta <[email protected]> wrote:
>
> Implement the helper kvm_tlb_flush_vmid_range() that acts
> as a wrapper for range-based TLB invalidations. For the
> given VMID, use the range-based TLBI instructions to do
> the job or fallback to invalidating all the TLB entries.
>
> Signed-off-by: Raghavendra Rao Ananta <[email protected]>
> Reviewed-by: Gavin Shan <[email protected]>
> Reviewed-by: Shaoqin Huang <[email protected]>
> ---
> arch/arm64/include/asm/kvm_pgtable.h | 10 ++++++++++
> arch/arm64/kvm/hyp/pgtable.c | 20 ++++++++++++++++++++
> 2 files changed, 30 insertions(+)
>
> diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
> index 8294a9a7e566..5e8b1ff07854 100644
> --- a/arch/arm64/include/asm/kvm_pgtable.h
> +++ b/arch/arm64/include/asm/kvm_pgtable.h
> @@ -754,4 +754,14 @@ enum kvm_pgtable_prot kvm_pgtable_stage2_pte_prot(kvm_pte_t pte);
> * kvm_pgtable_prot format.
> */
> enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte);
> +
> +/**
> + * kvm_tlb_flush_vmid_range() - Invalidate/flush a range of TLB entries
> + *
> + * @mmu: Stage-2 KVM MMU struct
> + * @addr: The base Intermediate physical address from which to invalidate
> + * @size: Size of the range from the base to invalidate
> + */
> +void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
> + phys_addr_t addr, size_t size);
> #endif /* __ARM64_KVM_PGTABLE_H__ */
> diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
> index aa740a974e02..5d14d5d5819a 100644
> --- a/arch/arm64/kvm/hyp/pgtable.c
> +++ b/arch/arm64/kvm/hyp/pgtable.c
> @@ -670,6 +670,26 @@ static bool stage2_has_fwb(struct kvm_pgtable *pgt)
> return !(pgt->flags & KVM_PGTABLE_S2_NOFWB);
> }
>
> +void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
> + phys_addr_t addr, size_t size)
> +{
> + unsigned long pages, inval_pages;
> +
> + if (!system_supports_tlb_range()) {
> + kvm_call_hyp(__kvm_tlb_flush_vmid, mmu);
> + return;
> + }
> +
> + pages = size >> PAGE_SHIFT;
> + while (pages > 0) {
> + inval_pages = min(pages, MAX_TLBI_RANGE_PAGES);
> + kvm_call_hyp(__kvm_tlb_flush_vmid_range, mmu, addr, inval_pages);
> +
> + addr += inval_pages << PAGE_SHIFT;
> + pages -= inval_pages;
> + }
> +}
> +

This really shouldn't live in pgtable.c. This code gets linked into
the EL2 object. What do you think happens if, for some reason, this
gets called *from EL2*?

Furthermore, this doesn't deal with page tables at all. Why isn't
mmu.c a convenient place for it, as an integral part of
kvm_arch_flush_remote_tlbs_range?

M.

--
Without deviation from the norm, progress is not possible.

2023-07-31 21:30:53

by Raghavendra Rao Ananta

[permalink] [raw]
Subject: Re: [PATCH v7 08/12] KVM: arm64: Define kvm_tlb_flush_vmid_range()

On Thu, Jul 27, 2023 at 6:01 AM Marc Zyngier <[email protected]> wrote:
>
> On Thu, 27 Jul 2023 13:47:06 +0100,
> Marc Zyngier <[email protected]> wrote:
> >
> > On Sat, 22 Jul 2023 03:22:47 +0100,
> > Raghavendra Rao Ananta <[email protected]> wrote:
> > >
> > > Implement the helper kvm_tlb_flush_vmid_range() that acts
> > > as a wrapper for range-based TLB invalidations. For the
> > > given VMID, use the range-based TLBI instructions to do
> > > the job or fallback to invalidating all the TLB entries.
> > >
> > > Signed-off-by: Raghavendra Rao Ananta <[email protected]>
> > > Reviewed-by: Gavin Shan <[email protected]>
> > > Reviewed-by: Shaoqin Huang <[email protected]>
> > > ---
> > > arch/arm64/include/asm/kvm_pgtable.h | 10 ++++++++++
> > > arch/arm64/kvm/hyp/pgtable.c | 20 ++++++++++++++++++++
> > > 2 files changed, 30 insertions(+)
> > >
> > > diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
> > > index 8294a9a7e566..5e8b1ff07854 100644
> > > --- a/arch/arm64/include/asm/kvm_pgtable.h
> > > +++ b/arch/arm64/include/asm/kvm_pgtable.h
> > > @@ -754,4 +754,14 @@ enum kvm_pgtable_prot kvm_pgtable_stage2_pte_prot(kvm_pte_t pte);
> > > * kvm_pgtable_prot format.
> > > */
> > > enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte);
> > > +
> > > +/**
> > > + * kvm_tlb_flush_vmid_range() - Invalidate/flush a range of TLB entries
> > > + *
> > > + * @mmu: Stage-2 KVM MMU struct
> > > + * @addr: The base Intermediate physical address from which to invalidate
> > > + * @size: Size of the range from the base to invalidate
> > > + */
> > > +void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
> > > + phys_addr_t addr, size_t size);
> > > #endif /* __ARM64_KVM_PGTABLE_H__ */
> > > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
> > > index aa740a974e02..5d14d5d5819a 100644
> > > --- a/arch/arm64/kvm/hyp/pgtable.c
> > > +++ b/arch/arm64/kvm/hyp/pgtable.c
> > > @@ -670,6 +670,26 @@ static bool stage2_has_fwb(struct kvm_pgtable *pgt)
> > > return !(pgt->flags & KVM_PGTABLE_S2_NOFWB);
> > > }
> > >
> > > +void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
> > > + phys_addr_t addr, size_t size)
> > > +{
> > > + unsigned long pages, inval_pages;
> > > +
> > > + if (!system_supports_tlb_range()) {
> > > + kvm_call_hyp(__kvm_tlb_flush_vmid, mmu);
> > > + return;
> > > + }
> > > +
> > > + pages = size >> PAGE_SHIFT;
> > > + while (pages > 0) {
> > > + inval_pages = min(pages, MAX_TLBI_RANGE_PAGES);
> > > + kvm_call_hyp(__kvm_tlb_flush_vmid_range, mmu, addr, inval_pages);
> > > +
> > > + addr += inval_pages << PAGE_SHIFT;
> > > + pages -= inval_pages;
> > > + }
> > > +}
> > > +
> >
> > This really shouldn't live in pgtable.c. This code gets linked into
> > the EL2 object. What do you think happens if, for some reason, this
> > gets called *from EL2*?
>
> Ah, actually, nothing too bad would happen, as we convert the
> kvm_call_hyp() into a function call.
>
> But still, we don't need two copies of this stuff, and it can live in
> mmu.c.
>
But since we have a couple of references in pgtable.c to
kvm_tlb_flush_vmid_range(), wouldn't that be an (linking) issue if we
moved the definition to mmu.c?

ld: error: undefined symbol: __kvm_nvhe_kvm_tlb_flush_vmid_range
>>> referenced by pgtable.c:1148 (./arch/arm64/kvm/hyp/nvhe/../pgtable.c:1148)
>>> arch/arm64/kvm/hyp/nvhe/kvm_nvhe.o:(__kvm_nvhe_kvm_pgtable_stage2_unmap) in archive vmlinux.a
...

Or is there some other way to make it work?

- Raghavendra

> M.
>
> --
> Without deviation from the norm, progress is not possible.

2023-08-02 23:46:44

by Marc Zyngier

[permalink] [raw]
Subject: Re: [PATCH v7 08/12] KVM: arm64: Define kvm_tlb_flush_vmid_range()

On Mon, 31 Jul 2023 19:01:53 +0100,
Raghavendra Rao Ananta <[email protected]> wrote:
>
> On Thu, Jul 27, 2023 at 6:01 AM Marc Zyngier <[email protected]> wrote:
> >
> > On Thu, 27 Jul 2023 13:47:06 +0100,
> > Marc Zyngier <[email protected]> wrote:
> > >
> > > On Sat, 22 Jul 2023 03:22:47 +0100,
> > > Raghavendra Rao Ananta <[email protected]> wrote:
> > > >
> > > > Implement the helper kvm_tlb_flush_vmid_range() that acts
> > > > as a wrapper for range-based TLB invalidations. For the
> > > > given VMID, use the range-based TLBI instructions to do
> > > > the job or fallback to invalidating all the TLB entries.
> > > >
> > > > Signed-off-by: Raghavendra Rao Ananta <[email protected]>
> > > > Reviewed-by: Gavin Shan <[email protected]>
> > > > Reviewed-by: Shaoqin Huang <[email protected]>
> > > > ---
> > > > arch/arm64/include/asm/kvm_pgtable.h | 10 ++++++++++
> > > > arch/arm64/kvm/hyp/pgtable.c | 20 ++++++++++++++++++++
> > > > 2 files changed, 30 insertions(+)
> > > >
> > > > diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
> > > > index 8294a9a7e566..5e8b1ff07854 100644
> > > > --- a/arch/arm64/include/asm/kvm_pgtable.h
> > > > +++ b/arch/arm64/include/asm/kvm_pgtable.h
> > > > @@ -754,4 +754,14 @@ enum kvm_pgtable_prot kvm_pgtable_stage2_pte_prot(kvm_pte_t pte);
> > > > * kvm_pgtable_prot format.
> > > > */
> > > > enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte);
> > > > +
> > > > +/**
> > > > + * kvm_tlb_flush_vmid_range() - Invalidate/flush a range of TLB entries
> > > > + *
> > > > + * @mmu: Stage-2 KVM MMU struct
> > > > + * @addr: The base Intermediate physical address from which to invalidate
> > > > + * @size: Size of the range from the base to invalidate
> > > > + */
> > > > +void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
> > > > + phys_addr_t addr, size_t size);
> > > > #endif /* __ARM64_KVM_PGTABLE_H__ */
> > > > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
> > > > index aa740a974e02..5d14d5d5819a 100644
> > > > --- a/arch/arm64/kvm/hyp/pgtable.c
> > > > +++ b/arch/arm64/kvm/hyp/pgtable.c
> > > > @@ -670,6 +670,26 @@ static bool stage2_has_fwb(struct kvm_pgtable *pgt)
> > > > return !(pgt->flags & KVM_PGTABLE_S2_NOFWB);
> > > > }
> > > >
> > > > +void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
> > > > + phys_addr_t addr, size_t size)
> > > > +{
> > > > + unsigned long pages, inval_pages;
> > > > +
> > > > + if (!system_supports_tlb_range()) {
> > > > + kvm_call_hyp(__kvm_tlb_flush_vmid, mmu);
> > > > + return;
> > > > + }
> > > > +
> > > > + pages = size >> PAGE_SHIFT;
> > > > + while (pages > 0) {
> > > > + inval_pages = min(pages, MAX_TLBI_RANGE_PAGES);
> > > > + kvm_call_hyp(__kvm_tlb_flush_vmid_range, mmu, addr, inval_pages);
> > > > +
> > > > + addr += inval_pages << PAGE_SHIFT;
> > > > + pages -= inval_pages;
> > > > + }
> > > > +}
> > > > +
> > >
> > > This really shouldn't live in pgtable.c. This code gets linked into
> > > the EL2 object. What do you think happens if, for some reason, this
> > > gets called *from EL2*?
> >
> > Ah, actually, nothing too bad would happen, as we convert the
> > kvm_call_hyp() into a function call.
> >
> > But still, we don't need two copies of this stuff, and it can live in
> > mmu.c.
> >
> But since we have a couple of references in pgtable.c to
> kvm_tlb_flush_vmid_range(), wouldn't that be an (linking) issue if we
> moved the definition to mmu.c?
>
> ld: error: undefined symbol: __kvm_nvhe_kvm_tlb_flush_vmid_range
> >>> referenced by pgtable.c:1148 (./arch/arm64/kvm/hyp/nvhe/../pgtable.c:1148)
> >>> arch/arm64/kvm/hyp/nvhe/kvm_nvhe.o:(__kvm_nvhe_kvm_pgtable_stage2_unmap) in archive vmlinux.a
> ...

Ah crap, I missed that. What a mess. Forget it then. It really is a
shame that all the neat separation between mmu.c and pgtable.c that we
were aiming for is ultimately lost.

M.

--
Without deviation from the norm, progress is not possible.