On Tuesday, April 15, 2014 1:12 AM, Marc Zyngier wrote:
> On 14/04/14 08:41, Jungseok Lee wrote:
> > This patch adds 4 levels of translation tables implementation for both
> > HYP and stage2. A combination of 4KB + 4 levels host and 4KB + 4
> > levels guest can run on ARMv8 architecture as introducing this feature.
> >
> > Signed-off-by: Jungseok Lee <jays.lee@xxxxxxxxxxx>
> > Reviewed-by: Sungjinn Chung <sungjinn.chung@xxxxxxxxxxx>
> > ---
> > arch/arm/kvm/mmu.c | 96 +++++++++++++++++++++++++++++++++-----
> > arch/arm64/include/asm/kvm_arm.h | 20 ++++++++
> > arch/arm64/include/asm/kvm_mmu.h | 1 +
> > 3 files changed, 106 insertions(+), 11 deletions(-)
> >
> > diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index
> > e0d4f24..6cf89ad 100644
> > --- a/arch/arm/kvm/mmu.c
> > +++ b/arch/arm/kvm/mmu.c
> > @@ -388,13 +388,46 @@ static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start,
> > return 0;
> > }
> >
> > +static int create_hyp_pud_mappings(pgd_t *pgd, unsigned long start,
> > + unsigned long end, unsigned long pfn,
> > + pgprot_t prot)
> > +{
> > + pud_t *pud;
> > + pmd_t *pmd;
> > + unsigned long addr, next;
> > +
> > + addr = start;
> > + do {
> > + pud = pud_offset(pgd, addr);
> > +
> > + if (pud_none_or_clear_bad(pud)) {
> > + pmd = pmd_alloc_one(NULL, addr);
> > + if (!pmd) {
> > + kvm_err("Cannot allocate Hyp pmd\n");
> > + return -ENOMEM;
> > + }
> > + pud_populate(NULL, pud, pmd);
> > + get_page(virt_to_page(pud));
> > + kvm_flush_dcache_to_poc(pud, sizeof(*pud));
> > + }
> > +
> > + next = pud_addr_end(addr, end);
> > +
> > + create_hyp_pmd_mappings(pud, addr, next, pfn, prot);
> > + pfn += (next - addr) >> PAGE_SHIFT;
> > + } while (addr = next, addr != end);
> > +
> > + return 0;
> > +}
> > +
> > static int __create_hyp_mappings(pgd_t *pgdp,
> > unsigned long start, unsigned long end,
> > unsigned long pfn, pgprot_t prot) {
> > pgd_t *pgd;
> > +#ifdef CONFIG_ARM64_4_LEVELS
> > pud_t *pud;
> > - pmd_t *pmd;
> > +#endif
> > unsigned long addr, next;
> > int err = 0;
> >
> > @@ -403,22 +436,25 @@ static int __create_hyp_mappings(pgd_t *pgdp,
> > end = PAGE_ALIGN(end);
> > do {
> > pgd = pgdp + pgd_index(addr);
> > - pud = pud_offset(pgd, addr);
> >
> > - if (pud_none_or_clear_bad(pud)) {
> > - pmd = pmd_alloc_one(NULL, addr);
> > - if (!pmd) {
> > - kvm_err("Cannot allocate Hyp pmd\n");
> > +#ifdef CONFIG_ARM64_4_LEVELS
> > + if (pgd_none(*pgd)) {
> > + pud = pud_alloc_one(NULL, addr);
> > + if (!pud) {
> > + kvm_err("Cannot allocate Hyp pud\n");
> > err = -ENOMEM;
> > goto out;
> > }
> > - pud_populate(NULL, pud, pmd);
> > - get_page(virt_to_page(pud));
> > - kvm_flush_dcache_to_poc(pud, sizeof(*pud));
> > + pgd_populate(NULL, pgd, pud);
> > + get_page(virt_to_page(pgd));
> > + kvm_flush_dcache_to_poc(pgd, sizeof(*pgd));
> > }
> > +#endif
>
> Why do you need all these #ifdefs? The page table code should be able to cope with all the variations
> of presence/absence of pud/pmd (see how there is no code difference between 4kB (3 levels) and 64kB (2
> levels)).
Okay, I will remove it.
> > next = pgd_addr_end(addr, end);
> > - err = create_hyp_pmd_mappings(pud, addr, next, pfn, prot);
> > +
> > + err = create_hyp_pud_mappings(pgd, addr, next, pfn, prot);
> > +
> > if (err)
> > goto out;
> > pfn += (next - addr) >> PAGE_SHIFT; @@ -563,6 +599,26 @@ void
> > kvm_free_stage2_pgd(struct kvm *kvm)
> > kvm->arch.pgd = NULL;
> > }
> >
> > +#ifdef CONFIG_ARM64_4_LEVELS
> > +static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache
> > + *cache, phys_addr_t addr)
> > +{
> > + pgd_t *pgd;
> > + pud_t *pud;
> > +
> > + pgd = kvm->arch.pgd + pgd_index(addr);
> > + if (pgd_none(*pgd)) {
> > + if (!cache)
> > + return NULL;
> > + pud = mmu_memory_cache_alloc(cache);
> > + pgd_populate(NULL, pgd, pud);
> > + get_page(virt_to_page(pgd));
> > + }
> > +
> > + return pud_offset(pgd, addr);
> > +}
> > +#endif
>
> Same here.
Okay.
> > static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache
> > *cache, phys_addr_t addr)
> > {
> > @@ -617,6 +673,24 @@ static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
> > pmd_t *pmd;
> > pte_t *pte, old_pte;
> >
> > +#ifdef CONFIG_ARM64_4_LEVELS
> > + pud_t *pud;
> > +
> > + /* Create stage-2 page table mapping - Level 0 */
> > + pud = stage2_get_pud(kvm, cache, addr);
> > + if (!pud)
> > + return 0;
> > +
> > + if (pud_none(*pud)) {
> > + if (!cache)
> > + return 0;
> > + pmd = mmu_memory_cache_alloc(cache);
> > + kvm_clean_pmd(pmd);
> > + pud_populate(NULL, pud, pmd);
> > + get_page(virt_to_page(pud));
> > + }
> > +#endif
> > +
>
> And here.
Okay.
> > /* Create stage-2 page table mapping - Level 1 */
> > pmd = stage2_get_pmd(kvm, cache, addr);
> > if (!pmd) {
> > @@ -675,7 +749,7 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
> > for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
> > pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);
> >
> > - ret = mmu_topup_memory_cache(&cache, 2, 2);
> > + ret = mmu_topup_memory_cache(&cache, 3, 3);
>
> It would be good to make this depend of the number of levels we're actually using (2, 3 or 4).
I will fix it in the next version.
> > if (ret)
> > goto out;
> > spin_lock(&kvm->mmu_lock);
> > diff --git a/arch/arm64/include/asm/kvm_arm.h
> > b/arch/arm64/include/asm/kvm_arm.h
> > index 3d69030..295eda6 100644
> > --- a/arch/arm64/include/asm/kvm_arm.h
> > +++ b/arch/arm64/include/asm/kvm_arm.h
> > @@ -117,9 +117,11 @@
> > #define VTCR_EL2_IRGN0_MASK (3 << 8)
> > #define VTCR_EL2_IRGN0_WBWA (1 << 8)
> > #define VTCR_EL2_SL0_MASK (3 << 6)
> > +#define VTCR_EL2_SL0_LVL0 (2 << 6)
> > #define VTCR_EL2_SL0_LVL1 (1 << 6)
> > #define VTCR_EL2_T0SZ_MASK 0x3f
> > #define VTCR_EL2_T0SZ_40B 24
> > +#define VTCR_EL2_T0SZ_48B 16
> >
> > #ifdef CONFIG_ARM64_64K_PAGES
> > /*
> > @@ -134,6 +136,7 @@
> > VTCR_EL2_SL0_LVL1 | VTCR_EL2_T0SZ_40B)
> > #define VTTBR_X (38 - VTCR_EL2_T0SZ_40B)
> > #else
> > +#ifndef CONFIG_ARM64_4_LEVELS
> > /*
> > * Stage2 translation configuration:
> > * 40bits output (PS = 2)
> > @@ -145,10 +148,27 @@
> > VTCR_EL2_ORGN0_WBWA | VTCR_EL2_IRGN0_WBWA | \
> > VTCR_EL2_SL0_LVL1 | VTCR_EL2_T0SZ_40B)
> > #define VTTBR_X (37 - VTCR_EL2_T0SZ_40B)
> > +#else
> > +/*
> > + * Stage2 translation configuration:
> > + * 40bits output (PS = 2)
> > + * 48bits input (T0SZ = 16)
> > + * 4kB pages (TG0 = 0)
> > + * 4 level page tables (SL = 2)
> > + */
> > +#define VTCR_EL2_FLAGS (VTCR_EL2_TG0_4K | VTCR_EL2_SH0_INNER | \
> > + VTCR_EL2_ORGN0_WBWA | VTCR_EL2_IRGN0_WBWA | \
> > + VTCR_EL2_SL0_LVL0 | VTCR_EL2_T0SZ_48B)
> > +#define VTTBR_X (29 - VTCR_EL2_T0SZ_48B)
> > +#endif
> > #endif
> >
> > #define VTTBR_BADDR_SHIFT (VTTBR_X - 1)
> > +#ifndef CONFIG_ARM64_4_LEVELS
> > #define VTTBR_BADDR_MASK (((1LLU << (40 - VTTBR_X)) - 1) <<
> > VTTBR_BADDR_SHIFT)
> > +#else
> > +#define VTTBR_BADDR_MASK (((1LLU << (48 - VTTBR_X)) - 1) <<
> > +VTTBR_BADDR_SHIFT) #endif
> > #define VTTBR_VMID_SHIFT (48LLU)
> > #define VTTBR_VMID_MASK (0xffLLU << VTTBR_VMID_SHIFT)
> >
> > diff --git a/arch/arm64/include/asm/kvm_mmu.h
> > b/arch/arm64/include/asm/kvm_mmu.h
> > index 7d29847..ec76cf3 100644
> > --- a/arch/arm64/include/asm/kvm_mmu.h
> > +++ b/arch/arm64/include/asm/kvm_mmu.h
> > @@ -107,6 +107,7 @@ static inline bool kvm_is_write_fault(unsigned
> > long esr) }
> >
> > static inline void kvm_clean_pgd(pgd_t *pgd) {}
> > +static inline void kvm_clean_pmd(pud_t *pud) {}
> > static inline void kvm_clean_pmd_entry(pmd_t *pmd) {} static inline
> > void kvm_clean_pte(pte_t *pte) {} static inline void
> > kvm_clean_pte_entry(pte_t *pte) {}
> >
>
> You'll need to add the 32bit ARM equivalent once you've removed the #ifdefs.
Okay.
Best Regards
Jungseok Lee
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