Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755139AbaDNQME (ORCPT ); Mon, 14 Apr 2014 12:12:04 -0400 Received: from fw-tnat.austin.arm.com ([217.140.110.23]:30299 "EHLO collaborate-mta1.arm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750771AbaDNQMB (ORCPT ); Mon, 14 Apr 2014 12:12:01 -0400 Message-ID: <534C08C3.1080705@arm.com> Date: Mon, 14 Apr 2014 17:11:47 +0100 From: Marc Zyngier User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130330 Thunderbird/17.0.5 MIME-Version: 1.0 To: Jungseok Lee CC: "linux-arm-kernel@lists.infradead.org" , "kvmarm@lists.cs.columbia.edu" , Catalin Marinas , Christoffer Dall , "linux-kernel@vger.kernel.org" , linux-samsung-soc , "sungjinn.chung@samsung.com" , Arnd Bergmann , "kgene.kim@samsung.com" , "ilho215.lee@samsung.com" Subject: Re: [PATCH 8/8] arm64: KVM: Implement 4 levels of translation tables for HYP and stage2 References: <000601cf57b4$e93b9680$bbb2c380$@samsung.com> In-Reply-To: <000601cf57b4$e93b9680$bbb2c380$@samsung.com> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > Reviewed-by: Sungjinn Chung > --- > 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)). > 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. > 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. > /* 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). > 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. M. -- Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/