KVM: PPC: Book3S HV: Add basic infrastructure for radix guests

This adds a field in struct kvm_arch and an inline helper to
indicate whether a guest is a radix guest or not, plus a new file
to contain the radix MMU code, which currently contains just a
translate function which knows how to traverse the guest page
tables to translate an address.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 5cf306ae0ac37f69f2c2fd2f691161dffc475652..7adfcc03a35f5d623ed88228bdc3aad99a6caed0 100644 (file)
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -182,6 +182,9 @@ extern void kvmppc_mmu_hpte_sysexit(void);
 extern int kvmppc_mmu_hv_init(void);
 extern int kvmppc_book3s_hcall_implemented(struct kvm *kvm, unsigned long hc);
 
+extern int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
+                       struct kvmppc_pte *gpte, bool data, bool iswrite);
+
 /* XXX remove this export when load_last_inst() is generic */
 extern int kvmppc_ld(struct kvm_vcpu *vcpu, ulong *eaddr, int size, void *ptr, bool data);
 extern void kvmppc_book3s_queue_irqprio(struct kvm_vcpu *vcpu, unsigned int vec);

diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 848292176908da1916f1dd3aeedb5b457e734008..0db010cc4e655c40979b01805d065927703c550f 100644 (file)
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -36,6 +36,12 @@ static inline void svcpu_put(struct kvmppc_book3s_shadow_vcpu *svcpu)
 #endif
 
 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+
+static inline bool kvm_is_radix(struct kvm *kvm)
+{
+       return kvm->arch.radix;
+}
+
 #define KVM_DEFAULT_HPT_ORDER  24      /* 16MB HPT by default */
 #endif
 

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 944532dc4a5747b5bd08e54b2781813d88399876..fb73518bd03bd9258c2fb355d92409d7d7615b5c 100644 (file)
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -264,6 +264,8 @@ struct kvm_arch {
        atomic_t hpte_mod_interest;
        cpumask_t need_tlb_flush;
        int hpt_cma_alloc;
+       u8 radix;
+       pgd_t *pgtable;
        u64 process_table;
        struct dentry *debugfs_dir;
        struct dentry *htab_dentry;

diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 7dd89b79d038065c410f39a5070fc9dc1bf8c05f..b87ccde2137adafada5461881b798a11c1411685 100644 (file)
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -70,7 +70,8 @@ endif
 kvm-hv-y += \
        book3s_hv.o \
        book3s_hv_interrupts.o \
-       book3s_64_mmu_hv.o
+       book3s_64_mmu_hv.o \
+       book3s_64_mmu_radix.o
 
 kvm-book3s_64-builtin-xics-objs-$(CONFIG_KVM_XICS) := \
        book3s_hv_rm_xics.o

diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index b795dd1ac2ef6258f0687288332afb23002d114c..c208bf3b252fe438bc537f228ad4d03cc1caf13a 100644 (file)
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -119,6 +119,9 @@ long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp)
        long err = -EBUSY;
        long order;
 
+       if (kvm_is_radix(kvm))
+               return -EINVAL;
+
        mutex_lock(&kvm->lock);
        if (kvm->arch.hpte_setup_done) {
                kvm->arch.hpte_setup_done = 0;
@@ -157,7 +160,7 @@ void kvmppc_free_hpt(struct kvm *kvm)
        if (kvm->arch.hpt_cma_alloc)
                kvm_release_hpt(virt_to_page(kvm->arch.hpt_virt),
                                1 << (kvm->arch.hpt_order - PAGE_SHIFT));
-       else
+       else if (kvm->arch.hpt_virt)
                free_pages(kvm->arch.hpt_virt,
                           kvm->arch.hpt_order - PAGE_SHIFT);
 }
@@ -1675,7 +1678,10 @@ void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
 
        vcpu->arch.slb_nr = 32;         /* POWER7/POWER8 */
 
-       mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
+       if (kvm_is_radix(vcpu->kvm))
+               mmu->xlate = kvmppc_mmu_radix_xlate;
+       else
+               mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
        mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr;
 
        vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;

diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
new file mode 100644 (file)
index 0000000..9091407
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -0,0 +1,139 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * Copyright 2016 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+
+#include <asm/kvm_ppc.h>
+#include <asm/kvm_book3s.h>
+#include <asm/page.h>
+#include <asm/mmu.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+
+/*
+ * Supported radix tree geometry.
+ * Like p9, we support either 5 or 9 bits at the first (lowest) level,
+ * for a page size of 64k or 4k.
+ */
+static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 };
+
+int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
+                          struct kvmppc_pte *gpte, bool data, bool iswrite)
+{
+       struct kvm *kvm = vcpu->kvm;
+       u32 pid;
+       int ret, level, ps;
+       __be64 prte, rpte;
+       unsigned long root, pte, index;
+       unsigned long rts, bits, offset;
+       unsigned long gpa;
+       unsigned long proc_tbl_size;
+
+       /* Work out effective PID */
+       switch (eaddr >> 62) {
+       case 0:
+               pid = vcpu->arch.pid;
+               break;
+       case 3:
+               pid = 0;
+               break;
+       default:
+               return -EINVAL;
+       }
+       proc_tbl_size = 1 << ((kvm->arch.process_table & PRTS_MASK) + 12);
+       if (pid * 16 >= proc_tbl_size)
+               return -EINVAL;
+
+       /* Read partition table to find root of tree for effective PID */
+       ret = kvm_read_guest(kvm, kvm->arch.process_table + pid * 16,
+                            &prte, sizeof(prte));
+       if (ret)
+               return ret;
+
+       root = be64_to_cpu(prte);
+       rts = ((root & RTS1_MASK) >> (RTS1_SHIFT - 3)) |
+               ((root & RTS2_MASK) >> RTS2_SHIFT);
+       bits = root & RPDS_MASK;
+       root = root & RPDB_MASK;
+
+       /* P9 DD1 interprets RTS (radix tree size) differently */
+       offset = rts + 31;
+       if (cpu_has_feature(CPU_FTR_POWER9_DD1))
+               offset -= 3;
+
+       /* current implementations only support 52-bit space */
+       if (offset != 52)
+               return -EINVAL;
+
+       for (level = 3; level >= 0; --level) {
+               if (level && bits != p9_supported_radix_bits[level])
+                       return -EINVAL;
+               if (level == 0 && !(bits == 5 || bits == 9))
+                       return -EINVAL;
+               offset -= bits;
+               index = (eaddr >> offset) & ((1UL << bits) - 1);
+               /* check that low bits of page table base are zero */
+               if (root & ((1UL << (bits + 3)) - 1))
+                       return -EINVAL;
+               ret = kvm_read_guest(kvm, root + index * 8,
+                                    &rpte, sizeof(rpte));
+               if (ret)
+                       return ret;
+               pte = __be64_to_cpu(rpte);
+               if (!(pte & _PAGE_PRESENT))
+                       return -ENOENT;
+               if (pte & _PAGE_PTE)
+                       break;
+               bits = pte & 0x1f;
+               root = pte & 0x0fffffffffffff00ul;
+       }
+       /* need a leaf at lowest level; 512GB pages not supported */
+       if (level < 0 || level == 3)
+               return -EINVAL;
+
+       /* offset is now log base 2 of the page size */
+       gpa = pte & 0x01fffffffffff000ul;
+       if (gpa & ((1ul << offset) - 1))
+               return -EINVAL;
+       gpa += eaddr & ((1ul << offset) - 1);
+       for (ps = MMU_PAGE_4K; ps < MMU_PAGE_COUNT; ++ps)
+               if (offset == mmu_psize_defs[ps].shift)
+                       break;
+       gpte->page_size = ps;
+
+       gpte->eaddr = eaddr;
+       gpte->raddr = gpa;
+
+       /* Work out permissions */
+       gpte->may_read = !!(pte & _PAGE_READ);
+       gpte->may_write = !!(pte & _PAGE_WRITE);
+       gpte->may_execute = !!(pte & _PAGE_EXEC);
+       if (kvmppc_get_msr(vcpu) & MSR_PR) {
+               if (pte & _PAGE_PRIVILEGED) {
+                       gpte->may_read = 0;
+                       gpte->may_write = 0;
+                       gpte->may_execute = 0;
+               }
+       } else {
+               if (!(pte & _PAGE_PRIVILEGED)) {
+                       /* Check AMR/IAMR to see if strict mode is in force */
+                       if (vcpu->arch.amr & (1ul << 62))
+                               gpte->may_read = 0;
+                       if (vcpu->arch.amr & (1ul << 63))
+                               gpte->may_write = 0;
+                       if (vcpu->arch.iamr & (1ul << 62))
+                               gpte->may_execute = 0;
+               }
+       }
+
+       return 0;
+}
+