| Message ID | 20180709144124.29164-4-punit.agrawal@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 09/07/18 15:41, Punit Agrawal wrote: > In preparation for creating PUD hugepages at stage 2, add support for > detecting execute permissions on PUD page table entries. Faults due to > lack of execute permissions on page table entries is used to perform > i-cache invalidation on first execute. > > Provide trivial implementations of arm32 helpers to allow sharing of > code. > > Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> > Cc: 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 | 6 ++++ > arch/arm64/include/asm/kvm_mmu.h | 5 +++ > arch/arm64/include/asm/pgtable-hwdef.h | 2 ++ > virt/kvm/arm/mmu.c | 49 +++++++++++++++++++++++--- > 4 files changed, 57 insertions(+), 5 deletions(-) > > diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h > index c23722f75d5c..d05c8986e495 100644 > --- a/arch/arm/include/asm/kvm_mmu.h > +++ b/arch/arm/include/asm/kvm_mmu.h > @@ -96,6 +96,12 @@ static inline bool kvm_s2pud_readonly(pud_t *pud) > } > > > +static inline bool kvm_s2pud_exec(pud_t *pud) > +{ > + BUG(); > + return false; > +} > + > 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 84051930ddfe..15bc1be8f82f 100644 > --- a/arch/arm64/include/asm/kvm_mmu.h > +++ b/arch/arm64/include/asm/kvm_mmu.h > @@ -249,6 +249,11 @@ static inline bool kvm_s2pud_readonly(pud_t *pudp) > return kvm_s2pte_readonly((pte_t *)pudp); > } > > +static inline bool kvm_s2pud_exec(pud_t *pudp) > +{ > + return !(READ_ONCE(pud_val(*pudp)) & PUD_S2_XN); > +} > + > static inline bool kvm_page_empty(void *ptr) > { > struct page *ptr_page = virt_to_page(ptr); > diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h > index fd208eac9f2a..10ae592b78b8 100644 > --- a/arch/arm64/include/asm/pgtable-hwdef.h > +++ b/arch/arm64/include/asm/pgtable-hwdef.h > @@ -193,6 +193,8 @@ > #define PMD_S2_RDWR (_AT(pmdval_t, 3) << 6) /* HAP[2:1] */ > #define PMD_S2_XN (_AT(pmdval_t, 2) << 53) /* XN[1:0] */ > > +#define PUD_S2_XN (_AT(pudval_t, 2) << 53) /* XN[1:0] */ > + > /* > * Memory Attribute override for Stage-2 (MemAttr[3:0]) > */ > diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c > index ed8f8271c389..e73909a31e02 100644 > --- a/virt/kvm/arm/mmu.c > +++ b/virt/kvm/arm/mmu.c > @@ -1038,23 +1038,62 @@ static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache > return 0; > } > > -static bool stage2_is_exec(struct kvm *kvm, phys_addr_t addr) > +/* > + * stage2_get_leaf_entry - walk the stage2 VM page tables and return > + * true if a valid and present leaf-entry is found. A pointer to the > + * leaf-entry is returned in the appropriate level variable - pudpp, > + * pmdpp, ptepp. > + */ > +static bool stage2_get_leaf_entry(struct kvm *kvm, phys_addr_t addr, > + pud_t **pudpp, pmd_t **pmdpp, pte_t **ptepp) > { > + pud_t *pudp; > pmd_t *pmdp; > pte_t *ptep; nit: As mentioned in the other thread, you may initialize the reference pointers to NULL to make sure we start clean and avoid the initialization everywhere this is called. > > - pmdp = stage2_get_pmd(kvm, NULL, addr); > + pudp = stage2_get_pud(kvm, NULL, addr); > + if (!pudp || pud_none(*pudp) || !pud_present(*pudp)) > + return false; > + > + if (pud_huge(*pudp)) { > + *pudpp = pudp; > + return true; > + } > + > + pmdp = stage2_pmd_offset(pudp, addr); > if (!pmdp || pmd_none(*pmdp) || !pmd_present(*pmdp)) > return false; > > - if (pmd_thp_or_huge(*pmdp)) > - return kvm_s2pmd_exec(pmdp); > + if (pmd_thp_or_huge(*pmdp)) { > + *pmdpp = pmdp; > + return true; > + } > > ptep = pte_offset_kernel(pmdp, addr); > if (!ptep || pte_none(*ptep) || !pte_present(*ptep)) > return false; > > - return kvm_s2pte_exec(ptep); > + *ptepp = ptep; > + return true; > +} > + > +static bool stage2_is_exec(struct kvm *kvm, phys_addr_t addr) > +{ > + pud_t *pudp = NULL; > + pmd_t *pmdp = NULL; > + pte_t *ptep = NULL; > + bool found; > + > + found = stage2_get_leaf_entry(kvm, addr, &pudp, &pmdp, &ptep); > + if (!found) > + return false; > + > + if (pudp) > + return kvm_s2pud_exec(pudp); > + else if (pmdp) > + return kvm_s2pmd_exec(pmdp); > + else > + return kvm_s2pte_exec(ptep); > } Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Suzuki K Poulose <Suzuki.Poulose@arm.com> writes: > On 09/07/18 15:41, Punit Agrawal wrote: >> In preparation for creating PUD hugepages at stage 2, add support for >> detecting execute permissions on PUD page table entries. Faults due to >> lack of execute permissions on page table entries is used to perform >> i-cache invalidation on first execute. >> >> Provide trivial implementations of arm32 helpers to allow sharing of >> code. >> >> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> >> Cc: 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 | 6 ++++ >> arch/arm64/include/asm/kvm_mmu.h | 5 +++ >> arch/arm64/include/asm/pgtable-hwdef.h | 2 ++ >> virt/kvm/arm/mmu.c | 49 +++++++++++++++++++++++--- >> 4 files changed, 57 insertions(+), 5 deletions(-) >> >> diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h >> index c23722f75d5c..d05c8986e495 100644 >> --- a/arch/arm/include/asm/kvm_mmu.h >> +++ b/arch/arm/include/asm/kvm_mmu.h >> @@ -96,6 +96,12 @@ static inline bool kvm_s2pud_readonly(pud_t *pud) >> } >> +static inline bool kvm_s2pud_exec(pud_t *pud) >> +{ >> + BUG(); >> + return false; >> +} >> + >> 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 84051930ddfe..15bc1be8f82f 100644 >> --- a/arch/arm64/include/asm/kvm_mmu.h >> +++ b/arch/arm64/include/asm/kvm_mmu.h >> @@ -249,6 +249,11 @@ static inline bool kvm_s2pud_readonly(pud_t *pudp) >> return kvm_s2pte_readonly((pte_t *)pudp); >> } >> +static inline bool kvm_s2pud_exec(pud_t *pudp) >> +{ >> + return !(READ_ONCE(pud_val(*pudp)) & PUD_S2_XN); >> +} >> + >> static inline bool kvm_page_empty(void *ptr) >> { >> struct page *ptr_page = virt_to_page(ptr); >> diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h >> index fd208eac9f2a..10ae592b78b8 100644 >> --- a/arch/arm64/include/asm/pgtable-hwdef.h >> +++ b/arch/arm64/include/asm/pgtable-hwdef.h >> @@ -193,6 +193,8 @@ >> #define PMD_S2_RDWR (_AT(pmdval_t, 3) << 6) /* HAP[2:1] */ >> #define PMD_S2_XN (_AT(pmdval_t, 2) << 53) /* XN[1:0] */ >> +#define PUD_S2_XN (_AT(pudval_t, 2) << 53) /* XN[1:0] >> */ >> + >> /* >> * Memory Attribute override for Stage-2 (MemAttr[3:0]) >> */ >> diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c >> index ed8f8271c389..e73909a31e02 100644 >> --- a/virt/kvm/arm/mmu.c >> +++ b/virt/kvm/arm/mmu.c >> @@ -1038,23 +1038,62 @@ static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache >> return 0; >> } >> -static bool stage2_is_exec(struct kvm *kvm, phys_addr_t addr) >> +/* >> + * stage2_get_leaf_entry - walk the stage2 VM page tables and return >> + * true if a valid and present leaf-entry is found. A pointer to the >> + * leaf-entry is returned in the appropriate level variable - pudpp, >> + * pmdpp, ptepp. >> + */ >> +static bool stage2_get_leaf_entry(struct kvm *kvm, phys_addr_t addr, >> + pud_t **pudpp, pmd_t **pmdpp, pte_t **ptepp) >> { >> + pud_t *pudp; >> pmd_t *pmdp; >> pte_t *ptep; > > nit: As mentioned in the other thread, you may initialize the reference > pointers to NULL to make sure we start clean and avoid the initialization > everywhere this is called. I took the approach to not touch the pointers unless they are being assigned a valid pointer. I'll initialise the incoming pointers (p*dpp) before proceeding with the table walk. Thanks, Punit > >> - pmdp = stage2_get_pmd(kvm, NULL, addr); >> + pudp = stage2_get_pud(kvm, NULL, addr); >> + if (!pudp || pud_none(*pudp) || !pud_present(*pudp)) >> + return false; >> + >> + if (pud_huge(*pudp)) { >> + *pudpp = pudp; >> + return true; >> + } >> + >> + pmdp = stage2_pmd_offset(pudp, addr); >> if (!pmdp || pmd_none(*pmdp) || !pmd_present(*pmdp)) >> return false; >> - if (pmd_thp_or_huge(*pmdp)) >> - return kvm_s2pmd_exec(pmdp); >> + if (pmd_thp_or_huge(*pmdp)) { >> + *pmdpp = pmdp; >> + return true; >> + } >> ptep = pte_offset_kernel(pmdp, addr); >> if (!ptep || pte_none(*ptep) || !pte_present(*ptep)) >> return false; >> - return kvm_s2pte_exec(ptep); >> + *ptepp = ptep; >> + return true; >> +} >> + >> +static bool stage2_is_exec(struct kvm *kvm, phys_addr_t addr) >> +{ >> + pud_t *pudp = NULL; >> + pmd_t *pmdp = NULL; >> + pte_t *ptep = NULL; >> + bool found; >> + >> + found = stage2_get_leaf_entry(kvm, addr, &pudp, &pmdp, &ptep); >> + if (!found) >> + return false; >> + >> + if (pudp) >> + return kvm_s2pud_exec(pudp); >> + else if (pmdp) >> + return kvm_s2pmd_exec(pmdp); >> + else >> + return kvm_s2pte_exec(ptep); >> } > > Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> > _______________________________________________ > kvmarm mailing list > kvmarm@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index c23722f75d5c..d05c8986e495 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -96,6 +96,12 @@ static inline bool kvm_s2pud_readonly(pud_t *pud) } +static inline bool kvm_s2pud_exec(pud_t *pud) +{ + BUG(); + return false; +} + 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 84051930ddfe..15bc1be8f82f 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -249,6 +249,11 @@ static inline bool kvm_s2pud_readonly(pud_t *pudp) return kvm_s2pte_readonly((pte_t *)pudp); } +static inline bool kvm_s2pud_exec(pud_t *pudp) +{ + return !(READ_ONCE(pud_val(*pudp)) & PUD_S2_XN); +} + static inline bool kvm_page_empty(void *ptr) { struct page *ptr_page = virt_to_page(ptr); diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h index fd208eac9f2a..10ae592b78b8 100644 --- a/arch/arm64/include/asm/pgtable-hwdef.h +++ b/arch/arm64/include/asm/pgtable-hwdef.h @@ -193,6 +193,8 @@ #define PMD_S2_RDWR (_AT(pmdval_t, 3) << 6) /* HAP[2:1] */ #define PMD_S2_XN (_AT(pmdval_t, 2) << 53) /* XN[1:0] */ +#define PUD_S2_XN (_AT(pudval_t, 2) << 53) /* XN[1:0] */ + /* * Memory Attribute override for Stage-2 (MemAttr[3:0]) */ diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index ed8f8271c389..e73909a31e02 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1038,23 +1038,62 @@ static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache return 0; } -static bool stage2_is_exec(struct kvm *kvm, phys_addr_t addr) +/* + * stage2_get_leaf_entry - walk the stage2 VM page tables and return + * true if a valid and present leaf-entry is found. A pointer to the + * leaf-entry is returned in the appropriate level variable - pudpp, + * pmdpp, ptepp. + */ +static bool stage2_get_leaf_entry(struct kvm *kvm, phys_addr_t addr, + pud_t **pudpp, pmd_t **pmdpp, pte_t **ptepp) { + pud_t *pudp; pmd_t *pmdp; pte_t *ptep; - pmdp = stage2_get_pmd(kvm, NULL, addr); + pudp = stage2_get_pud(kvm, NULL, addr); + if (!pudp || pud_none(*pudp) || !pud_present(*pudp)) + return false; + + if (pud_huge(*pudp)) { + *pudpp = pudp; + return true; + } + + pmdp = stage2_pmd_offset(pudp, addr); if (!pmdp || pmd_none(*pmdp) || !pmd_present(*pmdp)) return false; - if (pmd_thp_or_huge(*pmdp)) - return kvm_s2pmd_exec(pmdp); + if (pmd_thp_or_huge(*pmdp)) { + *pmdpp = pmdp; + return true; + } ptep = pte_offset_kernel(pmdp, addr); if (!ptep || pte_none(*ptep) || !pte_present(*ptep)) return false; - return kvm_s2pte_exec(ptep); + *ptepp = ptep; + return true; +} + +static bool stage2_is_exec(struct kvm *kvm, phys_addr_t addr) +{ + pud_t *pudp = NULL; + pmd_t *pmdp = NULL; + pte_t *ptep = NULL; + bool found; + + found = stage2_get_leaf_entry(kvm, addr, &pudp, &pmdp, &ptep); + if (!found) + return false; + + if (pudp) + return kvm_s2pud_exec(pudp); + else if (pmdp) + return kvm_s2pmd_exec(pmdp); + else + return kvm_s2pte_exec(ptep); } static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
In preparation for creating PUD hugepages at stage 2, add support for detecting execute permissions on PUD page table entries. Faults due to lack of execute permissions on page table entries is used to perform i-cache invalidation on first execute. Provide trivial implementations of arm32 helpers to allow sharing of code. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Cc: 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 | 6 ++++ arch/arm64/include/asm/kvm_mmu.h | 5 +++ arch/arm64/include/asm/pgtable-hwdef.h | 2 ++ virt/kvm/arm/mmu.c | 49 +++++++++++++++++++++++--- 4 files changed, 57 insertions(+), 5 deletions(-)