From patchwork Thu Oct 4 11:55:58 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Mackerras X-Patchwork-Id: 978784 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=kvm-ppc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ozlabs.org Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; secure) header.d=ozlabs.org header.i=@ozlabs.org header.b="QEtBbAAd"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 42Qrw35jDCzB4Nx for ; Thu, 4 Oct 2018 21:56:51 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727648AbeJDStc (ORCPT ); Thu, 4 Oct 2018 14:49:32 -0400 Received: from ozlabs.org ([203.11.71.1]:36059 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727479AbeJDStc (ORCPT ); Thu, 4 Oct 2018 14:49:32 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPSA id 42Qrvf343gz9sjH; Thu, 4 Oct 2018 21:56:30 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ozlabs.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ozlabs.org; s=201707; t=1538654190; bh=TlzTHanZ20gaRIFT+bAUlwrIej8o5OzQMhXY+9cFBF8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QEtBbAAdUA7ClwE/6eukWb8k46bb8afYm+qRsFkTs72gzkc/OwuWHD8ODMeHyi6OY O/wxbKpGk5KvN6kHzmBLIwNeexHUOly9+GP0LWmFXBloNE3ufFK3pSjVMwEfNKgK2T dYgZRTpjYqSLGHoMFUu7J+2WIhQrBEzkO1xpXhRcfduZPowD2xvsj5iTu1RjumBPSC fgsvrGdCILMf7TjWt2PRsnhIBfL/fvbRs13pgajlQ+hN0dquXUxgmKiGr/1RLjg/j9 njQScmms23uUTeuVBptJ+FmudOfCLsMHak5Ty35bbFVEr/q1dmOYQGvnJmlGsGolzR eEoUQuwTmA5YA== From: Paul Mackerras To: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org Cc: linuxppc-dev@ozlabs.org, David Gibson Subject: [PATCH v4 21/32] KVM: PPC: Book3S HV: Handle page fault for a nested guest Date: Thu, 4 Oct 2018 21:55:58 +1000 Message-Id: <1538654169-15602-22-git-send-email-paulus@ozlabs.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1538654169-15602-1-git-send-email-paulus@ozlabs.org> References: <1538654169-15602-1-git-send-email-paulus@ozlabs.org> Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org From: Suraj Jitindar Singh Consider a normal (L1) guest running under the main hypervisor (L0), and then a nested guest (L2) running under the L1 guest which is acting as a nested hypervisor. L0 has page tables to map the address space for L1 providing the translation from L1 real address -> L0 real address; L1 | | (L1 -> L0) | ----> L0 There are also page tables in L1 used to map the address space for L2 providing the translation from L2 real address -> L1 read address. Since the hardware can only walk a single level of page table, we need to maintain in L0 a "shadow_pgtable" for L2 which provides the translation from L2 real address -> L0 real address. Which looks like; L2 L2 | | | (L2 -> L1) | | | ----> L1 | (L2 -> L0) | | | (L1 -> L0) | | | ----> L0 --------> L0 When a page fault occurs while running a nested (L2) guest we need to insert a pte into this "shadow_pgtable" for the L2 -> L0 mapping. To do this we need to: 1. Walk the pgtable in L1 memory to find the L2 -> L1 mapping, and provide a page fault to L1 if this mapping doesn't exist. 2. Use our L1 -> L0 pgtable to convert this L1 address to an L0 address, or try to insert a pte for that mapping if it doesn't exist. 3. Now we have a L2 -> L0 mapping, insert this into our shadow_pgtable Once this mapping exists we can take rc faults when hardware is unable to automatically set the reference and change bits in the pte. On these we need to: 1. Check the rc bits on the L2 -> L1 pte match, and otherwise reflect the fault down to L1. 2. Set the rc bits in the L1 -> L0 pte which corresponds to the same host page. 3. Set the rc bits in the L2 -> L0 pte. As we reuse a large number of functions in book3s_64_mmu_radix.c for this we also needed to refactor a number of these functions to take an lpid parameter so that the correct lpid is used for tlb invalidations. The functionality however has remained the same. Reviewed-by: David Gibson Signed-off-by: Suraj Jitindar Singh Signed-off-by: Paul Mackerras --- .../powerpc/include/asm/book3s/64/tlbflush-radix.h | 1 + arch/powerpc/include/asm/kvm_book3s.h | 17 ++ arch/powerpc/include/asm/kvm_book3s_64.h | 4 + arch/powerpc/include/asm/kvm_host.h | 2 + arch/powerpc/kvm/book3s_64_mmu_radix.c | 194 ++++++------ arch/powerpc/kvm/book3s_hv_nested.c | 332 ++++++++++++++++++++- arch/powerpc/mm/tlb-radix.c | 9 + 7 files changed, 473 insertions(+), 86 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h index 1154a6d..671316f 100644 --- a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h +++ b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h @@ -53,6 +53,7 @@ extern void radix__flush_tlb_lpid_page(unsigned int lpid, unsigned long addr, unsigned long page_size); extern void radix__flush_pwc_lpid(unsigned int lpid); +extern void radix__flush_tlb_lpid(unsigned int lpid); extern void radix__local_flush_tlb_lpid(unsigned int lpid); extern void radix__local_flush_tlb_lpid_guest(unsigned int lpid); diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h index 093fd70..63f7ccf 100644 --- a/arch/powerpc/include/asm/kvm_book3s.h +++ b/arch/powerpc/include/asm/kvm_book3s.h @@ -188,17 +188,34 @@ extern int kvmppc_book3s_hcall_implemented(struct kvm *kvm, unsigned long hc); extern int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, unsigned long ea, unsigned long dsisr); +extern int kvmppc_mmu_walk_radix_tree(struct kvm_vcpu *vcpu, gva_t eaddr, + struct kvmppc_pte *gpte, u64 root, + u64 *pte_ret_p); extern int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr, struct kvmppc_pte *gpte, u64 table, int table_index, u64 *pte_ret_p); extern int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, struct kvmppc_pte *gpte, bool data, bool iswrite); +extern bool kvmppc_hv_handle_set_rc(struct kvm *kvm, pgd_t *pgtable, + bool writing, unsigned long gpa, + unsigned int lpid); +extern int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu, + unsigned long gpa, + struct kvm_memory_slot *memslot, + bool writing, bool kvm_ro, + pte_t *inserted_pte, unsigned int *levelp); extern int kvmppc_init_vm_radix(struct kvm *kvm); extern void kvmppc_free_radix(struct kvm *kvm); +extern void kvmppc_free_pgtable_radix(struct kvm *kvm, pgd_t *pgd, + unsigned int lpid); extern int kvmppc_radix_init(void); extern void kvmppc_radix_exit(void); extern int kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot, unsigned long gfn); +extern void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte, + unsigned long gpa, unsigned int shift, + struct kvm_memory_slot *memslot, + unsigned int lpid); extern int kvm_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot, unsigned long gfn); extern int kvm_test_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot, diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h index 6d67b6a..5496152 100644 --- a/arch/powerpc/include/asm/kvm_book3s_64.h +++ b/arch/powerpc/include/asm/kvm_book3s_64.h @@ -549,6 +549,10 @@ static inline void copy_to_checkpoint(struct kvm_vcpu *vcpu) } #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ +extern int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte, + unsigned long gpa, unsigned int level, + unsigned long mmu_seq, unsigned int lpid); + #endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */ #endif /* __ASM_KVM_BOOK3S_64_H__ */ diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index ceb9f20..fac6f63 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -367,7 +367,9 @@ struct kvmppc_pte { bool may_write : 1; bool may_execute : 1; unsigned long wimg; + unsigned long rc; u8 page_size; /* MMU_PAGE_xxx */ + u8 page_shift; }; struct kvmppc_mmu { diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c index bd06a95..c4b1a9e 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c @@ -29,43 +29,16 @@ */ static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 }; -/* - * Used to walk a partition or process table radix tree in guest memory - * Note: We exploit the fact that a partition table and a process - * table have the same layout, a partition-scoped page table and a - * process-scoped page table have the same layout, and the 2nd - * doubleword of a partition table entry has the same layout as - * the PTCR register. - */ -int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr, - struct kvmppc_pte *gpte, u64 table, - int table_index, u64 *pte_ret_p) +int kvmppc_mmu_walk_radix_tree(struct kvm_vcpu *vcpu, gva_t eaddr, + struct kvmppc_pte *gpte, u64 root, + u64 *pte_ret_p) { struct kvm *kvm = vcpu->kvm; int ret, level, ps; - unsigned long ptbl, root; - unsigned long rts, bits, offset; - unsigned long size, index; - struct prtb_entry entry; + unsigned long rts, bits, offset, index; u64 pte, base, gpa; __be64 rpte; - if ((table & PRTS_MASK) > 24) - return -EINVAL; - size = 1ul << ((table & PRTS_MASK) + 12); - - /* Is the table big enough to contain this entry? */ - if ((table_index * sizeof(entry)) >= size) - return -EINVAL; - - /* Read the table to find the root of the radix tree */ - ptbl = (table & PRTB_MASK) + (table_index * sizeof(entry)); - ret = kvm_read_guest(kvm, ptbl, &entry, sizeof(entry)); - if (ret) - return ret; - - /* Root is stored in the first double word */ - root = be64_to_cpu(entry.prtb0); rts = ((root & RTS1_MASK) >> (RTS1_SHIFT - 3)) | ((root & RTS2_MASK) >> RTS2_SHIFT); bits = root & RPDS_MASK; @@ -79,6 +52,7 @@ int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr, /* Walk each level of the radix tree */ for (level = 3; level >= 0; --level) { + u64 addr; /* Check a valid size */ if (level && bits != p9_supported_radix_bits[level]) return -EINVAL; @@ -90,10 +64,13 @@ int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr, if (base & ((1UL << (bits + 3)) - 1)) return -EINVAL; /* Read the entry from guest memory */ - ret = kvm_read_guest(kvm, base + (index * sizeof(rpte)), - &rpte, sizeof(rpte)); - if (ret) + addr = base + (index * sizeof(rpte)); + ret = kvm_read_guest(kvm, addr, &rpte, sizeof(rpte)); + if (ret) { + if (pte_ret_p) + *pte_ret_p = addr; return ret; + } pte = __be64_to_cpu(rpte); if (!(pte & _PAGE_PRESENT)) return -ENOENT; @@ -119,6 +96,7 @@ int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr, if (offset == mmu_psize_defs[ps].shift) break; gpte->page_size = ps; + gpte->page_shift = offset; gpte->eaddr = eaddr; gpte->raddr = gpa; @@ -128,12 +106,51 @@ int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr, gpte->may_write = !!(pte & _PAGE_WRITE); gpte->may_execute = !!(pte & _PAGE_EXEC); + gpte->rc = pte & (_PAGE_ACCESSED | _PAGE_DIRTY); + if (pte_ret_p) *pte_ret_p = pte; return 0; } +/* + * Used to walk a partition or process table radix tree in guest memory + * Note: We exploit the fact that a partition table and a process + * table have the same layout, a partition-scoped page table and a + * process-scoped page table have the same layout, and the 2nd + * doubleword of a partition table entry has the same layout as + * the PTCR register. + */ +int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr, + struct kvmppc_pte *gpte, u64 table, + int table_index, u64 *pte_ret_p) +{ + struct kvm *kvm = vcpu->kvm; + int ret; + unsigned long size, ptbl, root; + struct prtb_entry entry; + + if ((table & PRTS_MASK) > 24) + return -EINVAL; + size = 1ul << ((table & PRTS_MASK) + 12); + + /* Is the table big enough to contain this entry? */ + if ((table_index * sizeof(entry)) >= size) + return -EINVAL; + + /* Read the table to find the root of the radix tree */ + ptbl = (table & PRTB_MASK) + (table_index * sizeof(entry)); + ret = kvm_read_guest(kvm, ptbl, &entry, sizeof(entry)); + if (ret) + return ret; + + /* Root is stored in the first double word */ + root = be64_to_cpu(entry.prtb0); + + return kvmppc_mmu_walk_radix_tree(vcpu, eaddr, gpte, root, pte_ret_p); +} + int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, struct kvmppc_pte *gpte, bool data, bool iswrite) { @@ -181,7 +198,7 @@ int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, } static void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr, - unsigned int pshift) + unsigned int pshift, unsigned int lpid) { unsigned long psize = PAGE_SIZE; @@ -189,12 +206,12 @@ static void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr, psize = 1UL << pshift; addr &= ~(psize - 1); - radix__flush_tlb_lpid_page(kvm->arch.lpid, addr, psize); + radix__flush_tlb_lpid_page(lpid, addr, psize); } -static void kvmppc_radix_flush_pwc(struct kvm *kvm) +static void kvmppc_radix_flush_pwc(struct kvm *kvm, unsigned int lpid) { - radix__flush_pwc_lpid(kvm->arch.lpid); + radix__flush_pwc_lpid(lpid); } static unsigned long kvmppc_radix_update_pte(struct kvm *kvm, pte_t *ptep, @@ -239,16 +256,17 @@ static void kvmppc_pmd_free(pmd_t *pmdp) kmem_cache_free(kvm_pmd_cache, pmdp); } -static void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte, - unsigned long gpa, unsigned int shift, - struct kvm_memory_slot *memslot) +void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte, + unsigned long gpa, unsigned int shift, + struct kvm_memory_slot *memslot, + unsigned int lpid) { unsigned long old; old = kvmppc_radix_update_pte(kvm, pte, ~0UL, 0, gpa, shift); - kvmppc_radix_tlbie_page(kvm, gpa, shift); - if (old & _PAGE_DIRTY) { + kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid); + if ((old & _PAGE_DIRTY) && (lpid == kvm->arch.lpid)) { unsigned long gfn = gpa >> PAGE_SHIFT; unsigned long page_size = PAGE_SIZE; @@ -271,7 +289,8 @@ static void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte, * and emit a warning if encountered, but there may already be data * corruption due to the unexpected mappings. */ -static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full) +static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full, + unsigned int lpid) { if (full) { memset(pte, 0, sizeof(long) << PTE_INDEX_SIZE); @@ -285,14 +304,15 @@ static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full) WARN_ON_ONCE(1); kvmppc_unmap_pte(kvm, p, pte_pfn(*p) << PAGE_SHIFT, - PAGE_SHIFT, NULL); + PAGE_SHIFT, NULL, lpid); } } kvmppc_pte_free(pte); } -static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full) +static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full, + unsigned int lpid) { unsigned long im; pmd_t *p = pmd; @@ -307,20 +327,21 @@ static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full) WARN_ON_ONCE(1); kvmppc_unmap_pte(kvm, (pte_t *)p, pte_pfn(*(pte_t *)p) << PAGE_SHIFT, - PMD_SHIFT, NULL); + PMD_SHIFT, NULL, lpid); } } else { pte_t *pte; pte = pte_offset_map(p, 0); - kvmppc_unmap_free_pte(kvm, pte, full); + kvmppc_unmap_free_pte(kvm, pte, full, lpid); pmd_clear(p); } } kvmppc_pmd_free(pmd); } -static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud) +static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud, + unsigned int lpid) { unsigned long iu; pud_t *p = pud; @@ -334,36 +355,40 @@ static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud) pmd_t *pmd; pmd = pmd_offset(p, 0); - kvmppc_unmap_free_pmd(kvm, pmd, true); + kvmppc_unmap_free_pmd(kvm, pmd, true, lpid); pud_clear(p); } } pud_free(kvm->mm, pud); } -void kvmppc_free_radix(struct kvm *kvm) +void kvmppc_free_pgtable_radix(struct kvm *kvm, pgd_t *pgd, unsigned int lpid) { unsigned long ig; - pgd_t *pgd; - if (!kvm->arch.pgtable) - return; - pgd = kvm->arch.pgtable; for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) { pud_t *pud; if (!pgd_present(*pgd)) continue; pud = pud_offset(pgd, 0); - kvmppc_unmap_free_pud(kvm, pud); + kvmppc_unmap_free_pud(kvm, pud, lpid); pgd_clear(pgd); } - pgd_free(kvm->mm, kvm->arch.pgtable); - kvm->arch.pgtable = NULL; +} + +void kvmppc_free_radix(struct kvm *kvm) +{ + if (kvm->arch.pgtable) { + kvmppc_free_pgtable_radix(kvm, kvm->arch.pgtable, + kvm->arch.lpid); + pgd_free(kvm->mm, kvm->arch.pgtable); + kvm->arch.pgtable = NULL; + } } static void kvmppc_unmap_free_pmd_entry_table(struct kvm *kvm, pmd_t *pmd, - unsigned long gpa) + unsigned long gpa, unsigned int lpid) { pte_t *pte = pte_offset_kernel(pmd, 0); @@ -373,13 +398,13 @@ static void kvmppc_unmap_free_pmd_entry_table(struct kvm *kvm, pmd_t *pmd, * flushing the PWC again. */ pmd_clear(pmd); - kvmppc_radix_flush_pwc(kvm); + kvmppc_radix_flush_pwc(kvm, lpid); - kvmppc_unmap_free_pte(kvm, pte, false); + kvmppc_unmap_free_pte(kvm, pte, false, lpid); } static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud, - unsigned long gpa) + unsigned long gpa, unsigned int lpid) { pmd_t *pmd = pmd_offset(pud, 0); @@ -389,9 +414,9 @@ static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud, * so can be freed without flushing the PWC again. */ pud_clear(pud); - kvmppc_radix_flush_pwc(kvm); + kvmppc_radix_flush_pwc(kvm, lpid); - kvmppc_unmap_free_pmd(kvm, pmd, false); + kvmppc_unmap_free_pmd(kvm, pmd, false, lpid); } /* @@ -403,9 +428,9 @@ static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud, */ #define PTE_BITS_MUST_MATCH (~(_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED)) -static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte, - unsigned long gpa, unsigned int level, - unsigned long mmu_seq) +int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte, + unsigned long gpa, unsigned int level, + unsigned long mmu_seq, unsigned int lpid) { pgd_t *pgd; pud_t *pud, *new_pud = NULL; @@ -471,7 +496,8 @@ static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte, goto out_unlock; } /* Valid 1GB page here already, remove it */ - kvmppc_unmap_pte(kvm, (pte_t *)pud, hgpa, PUD_SHIFT, NULL); + kvmppc_unmap_pte(kvm, (pte_t *)pud, hgpa, PUD_SHIFT, NULL, + lpid); } if (level == 2) { if (!pud_none(*pud)) { @@ -480,7 +506,7 @@ static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte, * install a large page, so remove and free the page * table page. */ - kvmppc_unmap_free_pud_entry_table(kvm, pud, gpa); + kvmppc_unmap_free_pud_entry_table(kvm, pud, gpa, lpid); } kvmppc_radix_set_pte_at(kvm, gpa, (pte_t *)pud, pte); ret = 0; @@ -506,7 +532,7 @@ static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte, WARN_ON_ONCE((pmd_val(*pmd) ^ pte_val(pte)) & PTE_BITS_MUST_MATCH); kvmppc_radix_update_pte(kvm, pmdp_ptep(pmd), - 0, pte_val(pte), lgpa, PMD_SHIFT); + 0, pte_val(pte), lgpa, PMD_SHIFT); ret = 0; goto out_unlock; } @@ -520,7 +546,8 @@ static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte, goto out_unlock; } /* Valid 2MB page here already, remove it */ - kvmppc_unmap_pte(kvm, pmdp_ptep(pmd), lgpa, PMD_SHIFT, NULL); + kvmppc_unmap_pte(kvm, pmdp_ptep(pmd), lgpa, PMD_SHIFT, NULL, + lpid); } if (level == 1) { if (!pmd_none(*pmd)) { @@ -529,7 +556,7 @@ static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte, * install a large page, so remove and free the page * table page. */ - kvmppc_unmap_free_pmd_entry_table(kvm, pmd, gpa); + kvmppc_unmap_free_pmd_entry_table(kvm, pmd, gpa, lpid); } kvmppc_radix_set_pte_at(kvm, gpa, pmdp_ptep(pmd), pte); ret = 0; @@ -569,8 +596,8 @@ static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte, return ret; } -static bool kvmppc_hv_handle_set_rc(struct kvm *kvm, pgd_t *pgtable, - bool writing, unsigned long gpa) +bool kvmppc_hv_handle_set_rc(struct kvm *kvm, pgd_t *pgtable, bool writing, + unsigned long gpa, unsigned int lpid) { unsigned long pgflags; unsigned int shift; @@ -597,11 +624,11 @@ static bool kvmppc_hv_handle_set_rc(struct kvm *kvm, pgd_t *pgtable, return false; } -static int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu, - unsigned long gpa, - struct kvm_memory_slot *memslot, - bool writing, bool kvm_ro, - pte_t *inserted_pte, unsigned int *levelp) +int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu, + unsigned long gpa, + struct kvm_memory_slot *memslot, + bool writing, bool kvm_ro, + pte_t *inserted_pte, unsigned int *levelp) { struct kvm *kvm = vcpu->kvm; struct page *page = NULL; @@ -683,7 +710,7 @@ static int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu, /* Allocate space in the tree and write the PTE */ ret = kvmppc_create_pte(kvm, kvm->arch.pgtable, pte, gpa, level, - mmu_seq); + mmu_seq, kvm->arch.lpid); if (inserted_pte) *inserted_pte = pte; if (levelp) @@ -758,7 +785,7 @@ int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, if (dsisr & DSISR_SET_RC) { spin_lock(&kvm->mmu_lock); if (kvmppc_hv_handle_set_rc(kvm, kvm->arch.pgtable, - writing, gpa)) + writing, gpa, kvm->arch.lpid)) dsisr &= ~DSISR_SET_RC; spin_unlock(&kvm->mmu_lock); @@ -786,7 +813,8 @@ int kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot, ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift); if (ptep && pte_present(*ptep)) - kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot); + kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot, + kvm->arch.lpid); return 0; } @@ -841,7 +869,7 @@ static int kvm_radix_test_clear_dirty(struct kvm *kvm, ret = 1 << (shift - PAGE_SHIFT); kvmppc_radix_update_pte(kvm, ptep, _PAGE_DIRTY, 0, gpa, shift); - kvmppc_radix_tlbie_page(kvm, gpa, shift); + kvmppc_radix_tlbie_page(kvm, gpa, shift, kvm->arch.lpid); } return ret; } diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c index ade38dc..9c04242 100644 --- a/arch/powerpc/kvm/book3s_hv_nested.c +++ b/arch/powerpc/kvm/book3s_hv_nested.c @@ -12,9 +12,12 @@ #include #include +#include #include #include #include +#include +#include static struct patb_entry *pseries_partition_tb; @@ -403,10 +406,20 @@ struct kvm_nested_guest *kvmhv_alloc_nested(struct kvm *kvm, unsigned int lpid) */ static void kvmhv_release_nested(struct kvm_nested_guest *gp) { + struct kvm *kvm = gp->l1_host; + + if (gp->shadow_pgtable) { + /* + * No vcpu is using this struct and no call to + * kvmhv_get_nested can find this struct, + * so we don't need to hold kvm->mmu_lock. + */ + kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable, + gp->shadow_lpid); + pgd_free(kvm->mm, gp->shadow_pgtable); + } kvmhv_set_ptbl_entry(gp->shadow_lpid, 0, 0); kvmppc_free_lpid(gp->shadow_lpid); - if (gp->shadow_pgtable) - pgd_free(gp->l1_host->mm, gp->shadow_pgtable); kfree(gp); } @@ -463,6 +476,12 @@ void kvmhv_release_all_nested(struct kvm *kvm) /* caller must hold gp->tlb_lock */ void kvmhv_flush_nested(struct kvm_nested_guest *gp) { + struct kvm *kvm = gp->l1_host; + + spin_lock(&kvm->mmu_lock); + kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable, gp->shadow_lpid); + spin_unlock(&kvm->mmu_lock); + radix__flush_tlb_lpid(gp->shadow_lpid); kvmhv_update_ptbl_cache(gp); if (gp->l1_gr_to_hr == 0) kvmhv_remove_nested(gp); @@ -522,7 +541,314 @@ void kvmhv_put_nested(struct kvm_nested_guest *gp) kvmhv_release_nested(gp); } -long kvmhv_nested_page_fault(struct kvm_vcpu *vcpu) +static bool kvmhv_invalidate_shadow_pte(struct kvm_vcpu *vcpu, + struct kvm_nested_guest *gp, + long gpa, int *shift_ret) +{ + struct kvm *kvm = vcpu->kvm; + bool ret = false; + pte_t *ptep; + int shift; + + spin_lock(&kvm->mmu_lock); + ptep = __find_linux_pte(gp->shadow_pgtable, gpa, NULL, &shift); + if (!shift) + shift = PAGE_SHIFT; + if (ptep && pte_present(*ptep)) { + kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid); + ret = true; + } + spin_unlock(&kvm->mmu_lock); + + if (shift_ret) + *shift_ret = shift; + return ret; +} + +/* Used to convert a nested guest real address to a L1 guest real address */ +static int kvmhv_translate_addr_nested(struct kvm_vcpu *vcpu, + struct kvm_nested_guest *gp, + unsigned long n_gpa, unsigned long dsisr, + struct kvmppc_pte *gpte_p) { + u64 fault_addr, flags = dsisr & DSISR_ISSTORE; + int ret; + + ret = kvmppc_mmu_walk_radix_tree(vcpu, n_gpa, gpte_p, gp->l1_gr_to_hr, + &fault_addr); + + if (ret) { + /* We didn't find a pte */ + if (ret == -EINVAL) { + /* Unsupported mmu config */ + flags |= DSISR_UNSUPP_MMU; + } else if (ret == -ENOENT) { + /* No translation found */ + flags |= DSISR_NOHPTE; + } else if (ret == -EFAULT) { + /* Couldn't access L1 real address */ + flags |= DSISR_PRTABLE_FAULT; + vcpu->arch.fault_gpa = fault_addr; + } else { + /* Unknown error */ + return ret; + } + goto forward_to_l1; + } else { + /* We found a pte -> check permissions */ + if (dsisr & DSISR_ISSTORE) { + /* Can we write? */ + if (!gpte_p->may_write) { + flags |= DSISR_PROTFAULT; + goto forward_to_l1; + } + } else if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) { + /* Can we execute? */ + if (!gpte_p->may_execute) { + flags |= SRR1_ISI_N_OR_G; + goto forward_to_l1; + } + } else { + /* Can we read? */ + if (!gpte_p->may_read && !gpte_p->may_write) { + flags |= DSISR_PROTFAULT; + goto forward_to_l1; + } + } + } + + return 0; + +forward_to_l1: + vcpu->arch.fault_dsisr = flags; + if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) { + vcpu->arch.shregs.msr &= ~0x783f0000ul; + vcpu->arch.shregs.msr |= flags; + } return RESUME_HOST; } + +static long kvmhv_handle_nested_set_rc(struct kvm_vcpu *vcpu, + struct kvm_nested_guest *gp, + unsigned long n_gpa, + struct kvmppc_pte gpte, + unsigned long dsisr) +{ + struct kvm *kvm = vcpu->kvm; + bool writing = !!(dsisr & DSISR_ISSTORE); + u64 pgflags; + bool ret; + + /* Are the rc bits set in the L1 partition scoped pte? */ + pgflags = _PAGE_ACCESSED; + if (writing) + pgflags |= _PAGE_DIRTY; + if (pgflags & ~gpte.rc) + return RESUME_HOST; + + spin_lock(&kvm->mmu_lock); + /* Set the rc bit in the pte of our (L0) pgtable for the L1 guest */ + ret = kvmppc_hv_handle_set_rc(kvm, kvm->arch.pgtable, writing, + gpte.raddr, kvm->arch.lpid); + spin_unlock(&kvm->mmu_lock); + if (!ret) + return -EINVAL; + + /* Set the rc bit in the pte of the shadow_pgtable for the nest guest */ + ret = kvmppc_hv_handle_set_rc(kvm, gp->shadow_pgtable, writing, n_gpa, + gp->shadow_lpid); + if (!ret) + return -EINVAL; + return 0; +} + +static inline int kvmppc_radix_level_to_shift(int level) +{ + switch (level) { + case 2: + return PUD_SHIFT; + case 1: + return PMD_SHIFT; + default: + return PAGE_SHIFT; + } +} + +static inline int kvmppc_radix_shift_to_level(int shift) +{ + if (shift == PUD_SHIFT) + return 2; + if (shift == PMD_SHIFT) + return 1; + if (shift == PAGE_SHIFT) + return 0; + WARN_ON_ONCE(1); + return 0; +} + +/* called with gp->tlb_lock held */ +static long int __kvmhv_nested_page_fault(struct kvm_vcpu *vcpu, + struct kvm_nested_guest *gp) +{ + struct kvm *kvm = vcpu->kvm; + struct kvm_memory_slot *memslot; + struct kvmppc_pte gpte; + pte_t pte, *pte_p; + unsigned long mmu_seq; + unsigned long dsisr = vcpu->arch.fault_dsisr; + unsigned long ea = vcpu->arch.fault_dar; + unsigned long n_gpa, gpa, gfn, perm = 0UL; + unsigned int shift, l1_shift, level; + bool writing = !!(dsisr & DSISR_ISSTORE); + bool kvm_ro = false; + long int ret; + + if (!gp->l1_gr_to_hr) { + kvmhv_update_ptbl_cache(gp); + if (!gp->l1_gr_to_hr) + return RESUME_HOST; + } + + /* Convert the nested guest real address into a L1 guest real address */ + + n_gpa = vcpu->arch.fault_gpa & ~0xF000000000000FFFULL; + if (!(dsisr & DSISR_PRTABLE_FAULT)) + n_gpa |= ea & 0xFFF; + ret = kvmhv_translate_addr_nested(vcpu, gp, n_gpa, dsisr, &gpte); + + /* + * If the hardware found a translation but we don't now have a usable + * translation in the l1 partition-scoped tree, remove the shadow pte + * and let the guest retry. + */ + if (ret == RESUME_HOST && + (dsisr & (DSISR_PROTFAULT | DSISR_BADACCESS | DSISR_NOEXEC_OR_G | + DSISR_BAD_COPYPASTE))) + goto inval; + if (ret) + return ret; + + /* Failed to set the reference/change bits */ + if (dsisr & DSISR_SET_RC) { + ret = kvmhv_handle_nested_set_rc(vcpu, gp, n_gpa, gpte, dsisr); + if (ret == RESUME_HOST) + return ret; + if (ret) + goto inval; + dsisr &= ~DSISR_SET_RC; + if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE | + DSISR_PROTFAULT))) + return RESUME_GUEST; + } + + /* + * We took an HISI or HDSI while we were running a nested guest which + * means we have no partition scoped translation for that. This means + * we need to insert a pte for the mapping into our shadow_pgtable. + */ + + l1_shift = gpte.page_shift; + if (l1_shift < PAGE_SHIFT) { + /* We don't support l1 using a page size smaller than our own */ + pr_err("KVM: L1 guest page shift (%d) less than our own (%d)\n", + l1_shift, PAGE_SHIFT); + return -EINVAL; + } + gpa = gpte.raddr; + gfn = gpa >> PAGE_SHIFT; + + /* 1. Get the corresponding host memslot */ + + memslot = gfn_to_memslot(kvm, gfn); + if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) { + if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS)) { + /* unusual error -> reflect to the guest as a DSI */ + kvmppc_core_queue_data_storage(vcpu, ea, dsisr); + return RESUME_GUEST; + } + /* passthrough of emulated MMIO case... */ + pr_err("emulated MMIO passthrough?\n"); + return -EINVAL; + } + if (memslot->flags & KVM_MEM_READONLY) { + if (writing) { + /* Give the guest a DSI */ + kvmppc_core_queue_data_storage(vcpu, ea, + DSISR_ISSTORE | DSISR_PROTFAULT); + return RESUME_GUEST; + } + kvm_ro = true; + } + + /* 2. Find the host pte for this L1 guest real address */ + + /* Used to check for invalidations in progress */ + mmu_seq = kvm->mmu_notifier_seq; + smp_rmb(); + + /* See if can find translation in our partition scoped tables for L1 */ + pte = __pte(0); + spin_lock(&kvm->mmu_lock); + pte_p = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift); + if (!shift) + shift = PAGE_SHIFT; + if (pte_p) + pte = *pte_p; + spin_unlock(&kvm->mmu_lock); + + if (!pte_present(pte) || (writing && !(pte_val(pte) & _PAGE_WRITE))) { + /* No suitable pte found -> try to insert a mapping */ + ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot, + writing, kvm_ro, &pte, &level); + if (ret == -EAGAIN) + return RESUME_GUEST; + else if (ret) + return ret; + shift = kvmppc_radix_level_to_shift(level); + } + + /* 3. Compute the pte we need to insert for nest_gpa -> host r_addr */ + + /* The permissions is the combination of the host and l1 guest ptes */ + perm |= gpte.may_read ? 0UL : _PAGE_READ; + perm |= gpte.may_write ? 0UL : _PAGE_WRITE; + perm |= gpte.may_execute ? 0UL : _PAGE_EXEC; + pte = __pte(pte_val(pte) & ~perm); + + /* What size pte can we insert? */ + if (shift > l1_shift) { + u64 mask; + unsigned int actual_shift = PAGE_SHIFT; + if (PMD_SHIFT < l1_shift) + actual_shift = PMD_SHIFT; + mask = (1UL << shift) - (1UL << actual_shift); + pte = __pte(pte_val(pte) | (gpa & mask)); + shift = actual_shift; + } + level = kvmppc_radix_shift_to_level(shift); + n_gpa &= ~((1UL << shift) - 1); + + /* 4. Insert the pte into our shadow_pgtable */ + + ret = kvmppc_create_pte(kvm, gp->shadow_pgtable, pte, n_gpa, level, + mmu_seq, gp->shadow_lpid); + if (ret == -EAGAIN) + ret = RESUME_GUEST; /* Let the guest try again */ + + return ret; + + inval: + kvmhv_invalidate_shadow_pte(vcpu, gp, n_gpa, NULL); + return RESUME_GUEST; +} + +long int kvmhv_nested_page_fault(struct kvm_vcpu *vcpu) +{ + struct kvm_nested_guest *gp = vcpu->arch.nested; + long int ret; + + mutex_lock(&gp->tlb_lock); + ret = __kvmhv_nested_page_fault(vcpu, gp); + mutex_unlock(&gp->tlb_lock); + return ret; +} diff --git a/arch/powerpc/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c index fef3e1e..4c4dfc4 100644 --- a/arch/powerpc/mm/tlb-radix.c +++ b/arch/powerpc/mm/tlb-radix.c @@ -833,6 +833,15 @@ EXPORT_SYMBOL_GPL(radix__flush_pwc_lpid); /* * Flush partition scoped translations from LPID (=LPIDR) */ +void radix__flush_tlb_lpid(unsigned int lpid) +{ + _tlbie_lpid(lpid, RIC_FLUSH_ALL); +} +EXPORT_SYMBOL_GPL(radix__flush_tlb_lpid); + +/* + * Flush partition scoped translations from LPID (=LPIDR) + */ void radix__local_flush_tlb_lpid(unsigned int lpid) { _tlbiel_lpid(lpid, RIC_FLUSH_ALL);