| Message ID | 20180501102659.13188-3-punit.agrawal@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 01/05/18 11:26, Punit Agrawal wrote: > Introduce helpers to abstract architectural handling of the conversion > of pfn to page table entries and marking a PMD page table entry as a > block entry. > > The helpers are introduced in preparation for supporting PUD hugepages > at stage 2 - which are supported on arm64 but do not exist on arm. Punit, The change are fine by me. However, we usually do not define kvm_* accessors for something which we know matches with the host variant. i.e, PMD and PTE helpers, which are always present and we make use of them directly. (see unmap_stage2_pmds for e.g) Cheers Suzuki > > Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> > Acked-by: Christoffer Dall <christoffer.dall@arm.com> > Cc: Marc Zyngier <marc.zyngier@arm.com> > Cc: Russell King <linux@armlinux.org.uk> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will.deacon@arm.com> > --- > arch/arm/include/asm/kvm_mmu.h | 5 +++++ > arch/arm64/include/asm/kvm_mmu.h | 5 +++++ > virt/kvm/arm/mmu.c | 7 ++++--- > 3 files changed, 14 insertions(+), 3 deletions(-) > > diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h > index 707a1f06dc5d..5907a81ad5c1 100644 > --- a/arch/arm/include/asm/kvm_mmu.h > +++ b/arch/arm/include/asm/kvm_mmu.h > @@ -75,6 +75,11 @@ phys_addr_t kvm_get_idmap_vector(void); > int kvm_mmu_init(void); > void kvm_clear_hyp_idmap(void); > > +#define kvm_pfn_pte(pfn, prot) pfn_pte(pfn, prot) > +#define kvm_pfn_pmd(pfn, prot) pfn_pmd(pfn, prot) > + > +#define kvm_pmd_mkhuge(pmd) pmd_mkhuge(pmd) > + > static inline void kvm_set_pmd(pmd_t *pmd, pmd_t new_pmd) > { > *pmd = new_pmd; > diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h > index 082110993647..d962508ce4b3 100644 > --- a/arch/arm64/include/asm/kvm_mmu.h > +++ b/arch/arm64/include/asm/kvm_mmu.h > @@ -173,6 +173,11 @@ void kvm_clear_hyp_idmap(void); > #define kvm_set_pte(ptep, pte) set_pte(ptep, pte) > #define kvm_set_pmd(pmdp, pmd) set_pmd(pmdp, pmd) > > +#define kvm_pfn_pte(pfn, prot) pfn_pte(pfn, prot) > +#define kvm_pfn_pmd(pfn, prot) pfn_pmd(pfn, prot) > + > +#define kvm_pmd_mkhuge(pmd) pmd_mkhuge(pmd) > + > static inline pte_t kvm_s2pte_mkwrite(pte_t pte) > { > pte_val(pte) |= PTE_S2_RDWR; > diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c > index 686fc6a4b866..74750236f445 100644 > --- a/virt/kvm/arm/mmu.c > +++ b/virt/kvm/arm/mmu.c > @@ -1554,8 +1554,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, > invalidate_icache_guest_page(pfn, vma_pagesize); > > if (hugetlb) { > - pmd_t new_pmd = pfn_pmd(pfn, mem_type); > - new_pmd = pmd_mkhuge(new_pmd); > + pmd_t new_pmd = kvm_pfn_pmd(pfn, mem_type); > + > + new_pmd = kvm_pmd_mkhuge(new_pmd); > if (writable) > new_pmd = kvm_s2pmd_mkwrite(new_pmd); > > @@ -1564,7 +1565,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, > > ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd); > } else { > - pte_t new_pte = pfn_pte(pfn, mem_type); > + pte_t new_pte = kvm_pfn_pte(pfn, mem_type); > > if (writable) { > new_pte = kvm_s2pte_mkwrite(new_pte); >
Hi Suzuki, Thanks for having a look. Suzuki K Poulose <Suzuki.Poulose@arm.com> writes: > On 01/05/18 11:26, Punit Agrawal wrote: >> Introduce helpers to abstract architectural handling of the conversion >> of pfn to page table entries and marking a PMD page table entry as a >> block entry. >> >> The helpers are introduced in preparation for supporting PUD hugepages >> at stage 2 - which are supported on arm64 but do not exist on arm. > > Punit, > > The change are fine by me. However, we usually do not define kvm_* > accessors for something which we know matches with the host variant. > i.e, PMD and PTE helpers, which are always present and we make use > of them directly. (see unmap_stage2_pmds for e.g) In general, I agree - it makes sense to avoid duplication. Having said that, the helpers here allow following a common pattern for handling the various page sizes - pte, pmd and pud - during stage 2 fault handling (see patch 4). As you've said you're OK with this change, I'd prefer to keep this patch but will drop it if any others reviewers are concerned about the duplication as well. Thanks, Punit > > Cheers > Suzuki > >> >> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> >> Acked-by: Christoffer Dall <christoffer.dall@arm.com> >> Cc: Marc Zyngier <marc.zyngier@arm.com> >> Cc: Russell King <linux@armlinux.org.uk> >> Cc: Catalin Marinas <catalin.marinas@arm.com> >> Cc: Will Deacon <will.deacon@arm.com> >> --- >> arch/arm/include/asm/kvm_mmu.h | 5 +++++ >> arch/arm64/include/asm/kvm_mmu.h | 5 +++++ >> virt/kvm/arm/mmu.c | 7 ++++--- >> 3 files changed, 14 insertions(+), 3 deletions(-) >> >> diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h >> index 707a1f06dc5d..5907a81ad5c1 100644 >> --- a/arch/arm/include/asm/kvm_mmu.h >> +++ b/arch/arm/include/asm/kvm_mmu.h >> @@ -75,6 +75,11 @@ phys_addr_t kvm_get_idmap_vector(void); >> int kvm_mmu_init(void); >> void kvm_clear_hyp_idmap(void); >> +#define kvm_pfn_pte(pfn, prot) pfn_pte(pfn, prot) >> +#define kvm_pfn_pmd(pfn, prot) pfn_pmd(pfn, prot) >> + >> +#define kvm_pmd_mkhuge(pmd) pmd_mkhuge(pmd) >> + >> static inline void kvm_set_pmd(pmd_t *pmd, pmd_t new_pmd) >> { >> *pmd = new_pmd; >> diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h >> index 082110993647..d962508ce4b3 100644 >> --- a/arch/arm64/include/asm/kvm_mmu.h >> +++ b/arch/arm64/include/asm/kvm_mmu.h >> @@ -173,6 +173,11 @@ void kvm_clear_hyp_idmap(void); >> #define kvm_set_pte(ptep, pte) set_pte(ptep, pte) >> #define kvm_set_pmd(pmdp, pmd) set_pmd(pmdp, pmd) >> +#define kvm_pfn_pte(pfn, prot) pfn_pte(pfn, prot) >> +#define kvm_pfn_pmd(pfn, prot) pfn_pmd(pfn, prot) >> + >> +#define kvm_pmd_mkhuge(pmd) pmd_mkhuge(pmd) >> + >> static inline pte_t kvm_s2pte_mkwrite(pte_t pte) >> { >> pte_val(pte) |= PTE_S2_RDWR; >> diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c >> index 686fc6a4b866..74750236f445 100644 >> --- a/virt/kvm/arm/mmu.c >> +++ b/virt/kvm/arm/mmu.c >> @@ -1554,8 +1554,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, >> invalidate_icache_guest_page(pfn, vma_pagesize); >> if (hugetlb) { >> - pmd_t new_pmd = pfn_pmd(pfn, mem_type); >> - new_pmd = pmd_mkhuge(new_pmd); >> + pmd_t new_pmd = kvm_pfn_pmd(pfn, mem_type); >> + >> + new_pmd = kvm_pmd_mkhuge(new_pmd); >> if (writable) >> new_pmd = kvm_s2pmd_mkwrite(new_pmd); >> @@ -1564,7 +1565,7 @@ static int user_mem_abort(struct kvm_vcpu >> *vcpu, phys_addr_t fault_ipa, >> ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, >> &new_pmd); >> } else { >> - pte_t new_pte = pfn_pte(pfn, mem_type); >> + pte_t new_pte = kvm_pfn_pte(pfn, mem_type); >> if (writable) { >> new_pte = kvm_s2pte_mkwrite(new_pte); >>
On Tue, May 01, 2018 at 02:00:43PM +0100, Punit Agrawal wrote: > Hi Suzuki, > > Thanks for having a look. > > Suzuki K Poulose <Suzuki.Poulose@arm.com> writes: > > > On 01/05/18 11:26, Punit Agrawal wrote: > >> Introduce helpers to abstract architectural handling of the conversion > >> of pfn to page table entries and marking a PMD page table entry as a > >> block entry. > >> > >> The helpers are introduced in preparation for supporting PUD hugepages > >> at stage 2 - which are supported on arm64 but do not exist on arm. > > > > Punit, > > > > The change are fine by me. However, we usually do not define kvm_* > > accessors for something which we know matches with the host variant. > > i.e, PMD and PTE helpers, which are always present and we make use > > of them directly. (see unmap_stage2_pmds for e.g) > > In general, I agree - it makes sense to avoid duplication. > > Having said that, the helpers here allow following a common pattern for > handling the various page sizes - pte, pmd and pud - during stage 2 > fault handling (see patch 4). > > As you've said you're OK with this change, I'd prefer to keep this patch > but will drop it if any others reviewers are concerned about the > duplication as well. There are arguments for both keeping the kvm_ wrappers and not having them. I see no big harm or increase in complexity by keeping them though. Thanks, -Christoffer
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 707a1f06dc5d..5907a81ad5c1 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -75,6 +75,11 @@ phys_addr_t kvm_get_idmap_vector(void); int kvm_mmu_init(void); void kvm_clear_hyp_idmap(void); +#define kvm_pfn_pte(pfn, prot) pfn_pte(pfn, prot) +#define kvm_pfn_pmd(pfn, prot) pfn_pmd(pfn, prot) + +#define kvm_pmd_mkhuge(pmd) pmd_mkhuge(pmd) + static inline void kvm_set_pmd(pmd_t *pmd, pmd_t new_pmd) { *pmd = new_pmd; diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 082110993647..d962508ce4b3 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -173,6 +173,11 @@ void kvm_clear_hyp_idmap(void); #define kvm_set_pte(ptep, pte) set_pte(ptep, pte) #define kvm_set_pmd(pmdp, pmd) set_pmd(pmdp, pmd) +#define kvm_pfn_pte(pfn, prot) pfn_pte(pfn, prot) +#define kvm_pfn_pmd(pfn, prot) pfn_pmd(pfn, prot) + +#define kvm_pmd_mkhuge(pmd) pmd_mkhuge(pmd) + static inline pte_t kvm_s2pte_mkwrite(pte_t pte) { pte_val(pte) |= PTE_S2_RDWR; diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 686fc6a4b866..74750236f445 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1554,8 +1554,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, invalidate_icache_guest_page(pfn, vma_pagesize); if (hugetlb) { - pmd_t new_pmd = pfn_pmd(pfn, mem_type); - new_pmd = pmd_mkhuge(new_pmd); + pmd_t new_pmd = kvm_pfn_pmd(pfn, mem_type); + + new_pmd = kvm_pmd_mkhuge(new_pmd); if (writable) new_pmd = kvm_s2pmd_mkwrite(new_pmd); @@ -1564,7 +1565,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd); } else { - pte_t new_pte = pfn_pte(pfn, mem_type); + pte_t new_pte = kvm_pfn_pte(pfn, mem_type); if (writable) { new_pte = kvm_s2pte_mkwrite(new_pte);