| Message ID | 20180420145409.24485-4-punit.agrawal@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Apr 20, 2018 at 03:54:08PM +0100, Punit Agrawal wrote: > In preparation for creating PUD hugepages at stage 2, add support for > write protecting PUD hugepages when they are encountered. Write > protecting guest tables is used to track dirty pages when migrating > VMs. > > Also, provide trivial implementations of required kvm_s2pud_* helpers > to allow sharing of code with arm32. > > 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 | 16 ++++++++++++++++ > arch/arm64/include/asm/kvm_mmu.h | 10 ++++++++++ > virt/kvm/arm/mmu.c | 9 ++++++--- > 3 files changed, 32 insertions(+), 3 deletions(-) > > diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h > index 5907a81ad5c1..224c22c0a69c 100644 > --- a/arch/arm/include/asm/kvm_mmu.h > +++ b/arch/arm/include/asm/kvm_mmu.h > @@ -80,6 +80,22 @@ void kvm_clear_hyp_idmap(void); > > #define kvm_pmd_mkhuge(pmd) pmd_mkhuge(pmd) > > +/* > + * The following kvm_*pud*() functionas are provided strictly to allow > + * sharing code with arm64. They should never be called in practice. > + */ > +static inline void kvm_set_s2pud_readonly(pud_t *pud) > +{ > + BUG(); > +} > + > +static inline bool kvm_s2pud_readonly(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 d962508ce4b3..f440cf216a23 100644 > --- a/arch/arm64/include/asm/kvm_mmu.h > +++ b/arch/arm64/include/asm/kvm_mmu.h > @@ -240,6 +240,16 @@ static inline bool kvm_s2pmd_exec(pmd_t *pmdp) > return !(READ_ONCE(pmd_val(*pmdp)) & PMD_S2_XN); > } > > +static inline void kvm_set_s2pud_readonly(pud_t *pudp) > +{ > + kvm_set_s2pte_readonly((pte_t *)pudp); > +} > + > +static inline bool kvm_s2pud_readonly(pud_t *pudp) > +{ > + return kvm_s2pte_readonly((pte_t *)pudp); > +} > + > static inline bool kvm_page_empty(void *ptr) > { > struct page *ptr_page = virt_to_page(ptr); > diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c > index f72ae7a6dea0..5f53909da90e 100644 > --- a/virt/kvm/arm/mmu.c > +++ b/virt/kvm/arm/mmu.c > @@ -1286,9 +1286,12 @@ static void stage2_wp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end) > do { > next = stage2_pud_addr_end(addr, end); > if (!stage2_pud_none(*pud)) { > - /* TODO:PUD not supported, revisit later if supported */ > - BUG_ON(stage2_pud_huge(*pud)); > - stage2_wp_pmds(pud, addr, next); > + if (stage2_pud_huge(*pud)) { > + if (!kvm_s2pud_readonly(pud)) > + kvm_set_s2pud_readonly(pud); > + } else { > + stage2_wp_pmds(pud, addr, next); > + } > } > } while (pud++, addr = next, addr != end); > } > -- > 2.17.0 > Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 5907a81ad5c1..224c22c0a69c 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -80,6 +80,22 @@ void kvm_clear_hyp_idmap(void); #define kvm_pmd_mkhuge(pmd) pmd_mkhuge(pmd) +/* + * The following kvm_*pud*() functionas are provided strictly to allow + * sharing code with arm64. They should never be called in practice. + */ +static inline void kvm_set_s2pud_readonly(pud_t *pud) +{ + BUG(); +} + +static inline bool kvm_s2pud_readonly(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 d962508ce4b3..f440cf216a23 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -240,6 +240,16 @@ static inline bool kvm_s2pmd_exec(pmd_t *pmdp) return !(READ_ONCE(pmd_val(*pmdp)) & PMD_S2_XN); } +static inline void kvm_set_s2pud_readonly(pud_t *pudp) +{ + kvm_set_s2pte_readonly((pte_t *)pudp); +} + +static inline bool kvm_s2pud_readonly(pud_t *pudp) +{ + return kvm_s2pte_readonly((pte_t *)pudp); +} + static inline bool kvm_page_empty(void *ptr) { struct page *ptr_page = virt_to_page(ptr); diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index f72ae7a6dea0..5f53909da90e 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1286,9 +1286,12 @@ static void stage2_wp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end) do { next = stage2_pud_addr_end(addr, end); if (!stage2_pud_none(*pud)) { - /* TODO:PUD not supported, revisit later if supported */ - BUG_ON(stage2_pud_huge(*pud)); - stage2_wp_pmds(pud, addr, next); + if (stage2_pud_huge(*pud)) { + if (!kvm_s2pud_readonly(pud)) + kvm_set_s2pud_readonly(pud); + } else { + stage2_wp_pmds(pud, addr, next); + } } } while (pud++, addr = next, addr != end); }
In preparation for creating PUD hugepages at stage 2, add support for write protecting PUD hugepages when they are encountered. Write protecting guest tables is used to track dirty pages when migrating VMs. Also, provide trivial implementations of required kvm_s2pud_* helpers to allow sharing of code with arm32. 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 | 16 ++++++++++++++++ arch/arm64/include/asm/kvm_mmu.h | 10 ++++++++++ virt/kvm/arm/mmu.c | 9 ++++++--- 3 files changed, 32 insertions(+), 3 deletions(-)