Merge tag 'kvm-4.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm
[linux-2.6-block.git] / arch / arm64 / kvm / sys_regs.c
index bb0e41b3154e619458a61abff97960842a198276..1830ebc227d18d7c5ad06e8f1858bbe8f33fa53a 100644 (file)
@@ -23,6 +23,7 @@
 #include <linux/bsearch.h>
 #include <linux/kvm_host.h>
 #include <linux/mm.h>
+#include <linux/printk.h>
 #include <linux/uaccess.h>
 
 #include <asm/cacheflush.h>
@@ -879,6 +880,146 @@ static bool access_cntp_cval(struct kvm_vcpu *vcpu,
        return true;
 }
 
+/* Read a sanitised cpufeature ID register by sys_reg_desc */
+static u64 read_id_reg(struct sys_reg_desc const *r, bool raz)
+{
+       u32 id = sys_reg((u32)r->Op0, (u32)r->Op1,
+                        (u32)r->CRn, (u32)r->CRm, (u32)r->Op2);
+       u64 val = raz ? 0 : read_sanitised_ftr_reg(id);
+
+       if (id == SYS_ID_AA64PFR0_EL1) {
+               if (val & (0xfUL << ID_AA64PFR0_SVE_SHIFT))
+                       pr_err_once("kvm [%i]: SVE unsupported for guests, suppressing\n",
+                                   task_pid_nr(current));
+
+               val &= ~(0xfUL << ID_AA64PFR0_SVE_SHIFT);
+       }
+
+       return val;
+}
+
+/* cpufeature ID register access trap handlers */
+
+static bool __access_id_reg(struct kvm_vcpu *vcpu,
+                           struct sys_reg_params *p,
+                           const struct sys_reg_desc *r,
+                           bool raz)
+{
+       if (p->is_write)
+               return write_to_read_only(vcpu, p, r);
+
+       p->regval = read_id_reg(r, raz);
+       return true;
+}
+
+static bool access_id_reg(struct kvm_vcpu *vcpu,
+                         struct sys_reg_params *p,
+                         const struct sys_reg_desc *r)
+{
+       return __access_id_reg(vcpu, p, r, false);
+}
+
+static bool access_raz_id_reg(struct kvm_vcpu *vcpu,
+                             struct sys_reg_params *p,
+                             const struct sys_reg_desc *r)
+{
+       return __access_id_reg(vcpu, p, r, true);
+}
+
+static int reg_from_user(u64 *val, const void __user *uaddr, u64 id);
+static int reg_to_user(void __user *uaddr, const u64 *val, u64 id);
+static u64 sys_reg_to_index(const struct sys_reg_desc *reg);
+
+/*
+ * cpufeature ID register user accessors
+ *
+ * For now, these registers are immutable for userspace, so no values
+ * are stored, and for set_id_reg() we don't allow the effective value
+ * to be changed.
+ */
+static int __get_id_reg(const struct sys_reg_desc *rd, void __user *uaddr,
+                       bool raz)
+{
+       const u64 id = sys_reg_to_index(rd);
+       const u64 val = read_id_reg(rd, raz);
+
+       return reg_to_user(uaddr, &val, id);
+}
+
+static int __set_id_reg(const struct sys_reg_desc *rd, void __user *uaddr,
+                       bool raz)
+{
+       const u64 id = sys_reg_to_index(rd);
+       int err;
+       u64 val;
+
+       err = reg_from_user(&val, uaddr, id);
+       if (err)
+               return err;
+
+       /* This is what we mean by invariant: you can't change it. */
+       if (val != read_id_reg(rd, raz))
+               return -EINVAL;
+
+       return 0;
+}
+
+static int get_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
+                     const struct kvm_one_reg *reg, void __user *uaddr)
+{
+       return __get_id_reg(rd, uaddr, false);
+}
+
+static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
+                     const struct kvm_one_reg *reg, void __user *uaddr)
+{
+       return __set_id_reg(rd, uaddr, false);
+}
+
+static int get_raz_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
+                         const struct kvm_one_reg *reg, void __user *uaddr)
+{
+       return __get_id_reg(rd, uaddr, true);
+}
+
+static int set_raz_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
+                         const struct kvm_one_reg *reg, void __user *uaddr)
+{
+       return __set_id_reg(rd, uaddr, true);
+}
+
+/* sys_reg_desc initialiser for known cpufeature ID registers */
+#define ID_SANITISED(name) {                   \
+       SYS_DESC(SYS_##name),                   \
+       .access = access_id_reg,                \
+       .get_user = get_id_reg,                 \
+       .set_user = set_id_reg,                 \
+}
+
+/*
+ * sys_reg_desc initialiser for architecturally unallocated cpufeature ID
+ * register with encoding Op0=3, Op1=0, CRn=0, CRm=crm, Op2=op2
+ * (1 <= crm < 8, 0 <= Op2 < 8).
+ */
+#define ID_UNALLOCATED(crm, op2) {                     \
+       Op0(3), Op1(0), CRn(0), CRm(crm), Op2(op2),     \
+       .access = access_raz_id_reg,                    \
+       .get_user = get_raz_id_reg,                     \
+       .set_user = set_raz_id_reg,                     \
+}
+
+/*
+ * sys_reg_desc initialiser for known ID registers that we hide from guests.
+ * For now, these are exposed just like unallocated ID regs: they appear
+ * RAZ for the guest.
+ */
+#define ID_HIDDEN(name) {                      \
+       SYS_DESC(SYS_##name),                   \
+       .access = access_raz_id_reg,            \
+       .get_user = get_raz_id_reg,             \
+       .set_user = set_raz_id_reg,             \
+}
+
 /*
  * Architected system registers.
  * Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2
@@ -931,6 +1072,84 @@ static const struct sys_reg_desc sys_reg_descs[] = {
        { SYS_DESC(SYS_DBGVCR32_EL2), NULL, reset_val, DBGVCR32_EL2, 0 },
 
        { SYS_DESC(SYS_MPIDR_EL1), NULL, reset_mpidr, MPIDR_EL1 },
+
+       /*
+        * ID regs: all ID_SANITISED() entries here must have corresponding
+        * entries in arm64_ftr_regs[].
+        */
+
+       /* AArch64 mappings of the AArch32 ID registers */
+       /* CRm=1 */
+       ID_SANITISED(ID_PFR0_EL1),
+       ID_SANITISED(ID_PFR1_EL1),
+       ID_SANITISED(ID_DFR0_EL1),
+       ID_HIDDEN(ID_AFR0_EL1),
+       ID_SANITISED(ID_MMFR0_EL1),
+       ID_SANITISED(ID_MMFR1_EL1),
+       ID_SANITISED(ID_MMFR2_EL1),
+       ID_SANITISED(ID_MMFR3_EL1),
+
+       /* CRm=2 */
+       ID_SANITISED(ID_ISAR0_EL1),
+       ID_SANITISED(ID_ISAR1_EL1),
+       ID_SANITISED(ID_ISAR2_EL1),
+       ID_SANITISED(ID_ISAR3_EL1),
+       ID_SANITISED(ID_ISAR4_EL1),
+       ID_SANITISED(ID_ISAR5_EL1),
+       ID_SANITISED(ID_MMFR4_EL1),
+       ID_UNALLOCATED(2,7),
+
+       /* CRm=3 */
+       ID_SANITISED(MVFR0_EL1),
+       ID_SANITISED(MVFR1_EL1),
+       ID_SANITISED(MVFR2_EL1),
+       ID_UNALLOCATED(3,3),
+       ID_UNALLOCATED(3,4),
+       ID_UNALLOCATED(3,5),
+       ID_UNALLOCATED(3,6),
+       ID_UNALLOCATED(3,7),
+
+       /* AArch64 ID registers */
+       /* CRm=4 */
+       ID_SANITISED(ID_AA64PFR0_EL1),
+       ID_SANITISED(ID_AA64PFR1_EL1),
+       ID_UNALLOCATED(4,2),
+       ID_UNALLOCATED(4,3),
+       ID_UNALLOCATED(4,4),
+       ID_UNALLOCATED(4,5),
+       ID_UNALLOCATED(4,6),
+       ID_UNALLOCATED(4,7),
+
+       /* CRm=5 */
+       ID_SANITISED(ID_AA64DFR0_EL1),
+       ID_SANITISED(ID_AA64DFR1_EL1),
+       ID_UNALLOCATED(5,2),
+       ID_UNALLOCATED(5,3),
+       ID_HIDDEN(ID_AA64AFR0_EL1),
+       ID_HIDDEN(ID_AA64AFR1_EL1),
+       ID_UNALLOCATED(5,6),
+       ID_UNALLOCATED(5,7),
+
+       /* CRm=6 */
+       ID_SANITISED(ID_AA64ISAR0_EL1),
+       ID_SANITISED(ID_AA64ISAR1_EL1),
+       ID_UNALLOCATED(6,2),
+       ID_UNALLOCATED(6,3),
+       ID_UNALLOCATED(6,4),
+       ID_UNALLOCATED(6,5),
+       ID_UNALLOCATED(6,6),
+       ID_UNALLOCATED(6,7),
+
+       /* CRm=7 */
+       ID_SANITISED(ID_AA64MMFR0_EL1),
+       ID_SANITISED(ID_AA64MMFR1_EL1),
+       ID_SANITISED(ID_AA64MMFR2_EL1),
+       ID_UNALLOCATED(7,3),
+       ID_UNALLOCATED(7,4),
+       ID_UNALLOCATED(7,5),
+       ID_UNALLOCATED(7,6),
+       ID_UNALLOCATED(7,7),
+
        { SYS_DESC(SYS_SCTLR_EL1), access_vm_reg, reset_val, SCTLR_EL1, 0x00C50078 },
        { SYS_DESC(SYS_CPACR_EL1), NULL, reset_val, CPACR_EL1, 0 },
        { SYS_DESC(SYS_TTBR0_EL1), access_vm_reg, reset_unknown, TTBR0_EL1 },
@@ -1777,8 +1996,8 @@ static const struct sys_reg_desc *index_to_sys_reg_desc(struct kvm_vcpu *vcpu,
        if (!r)
                r = find_reg(&params, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
 
-       /* Not saved in the sys_reg array? */
-       if (r && !r->reg)
+       /* Not saved in the sys_reg array and not otherwise accessible? */
+       if (r && !(r->reg || r->get_user))
                r = NULL;
 
        return r;
@@ -1802,20 +2021,6 @@ static const struct sys_reg_desc *index_to_sys_reg_desc(struct kvm_vcpu *vcpu,
 FUNCTION_INVARIANT(midr_el1)
 FUNCTION_INVARIANT(ctr_el0)
 FUNCTION_INVARIANT(revidr_el1)
-FUNCTION_INVARIANT(id_pfr0_el1)
-FUNCTION_INVARIANT(id_pfr1_el1)
-FUNCTION_INVARIANT(id_dfr0_el1)
-FUNCTION_INVARIANT(id_afr0_el1)
-FUNCTION_INVARIANT(id_mmfr0_el1)
-FUNCTION_INVARIANT(id_mmfr1_el1)
-FUNCTION_INVARIANT(id_mmfr2_el1)
-FUNCTION_INVARIANT(id_mmfr3_el1)
-FUNCTION_INVARIANT(id_isar0_el1)
-FUNCTION_INVARIANT(id_isar1_el1)
-FUNCTION_INVARIANT(id_isar2_el1)
-FUNCTION_INVARIANT(id_isar3_el1)
-FUNCTION_INVARIANT(id_isar4_el1)
-FUNCTION_INVARIANT(id_isar5_el1)
 FUNCTION_INVARIANT(clidr_el1)
 FUNCTION_INVARIANT(aidr_el1)
 
@@ -1823,20 +2028,6 @@ FUNCTION_INVARIANT(aidr_el1)
 static struct sys_reg_desc invariant_sys_regs[] = {
        { SYS_DESC(SYS_MIDR_EL1), NULL, get_midr_el1 },
        { SYS_DESC(SYS_REVIDR_EL1), NULL, get_revidr_el1 },
-       { SYS_DESC(SYS_ID_PFR0_EL1), NULL, get_id_pfr0_el1 },
-       { SYS_DESC(SYS_ID_PFR1_EL1), NULL, get_id_pfr1_el1 },
-       { SYS_DESC(SYS_ID_DFR0_EL1), NULL, get_id_dfr0_el1 },
-       { SYS_DESC(SYS_ID_AFR0_EL1), NULL, get_id_afr0_el1 },
-       { SYS_DESC(SYS_ID_MMFR0_EL1), NULL, get_id_mmfr0_el1 },
-       { SYS_DESC(SYS_ID_MMFR1_EL1), NULL, get_id_mmfr1_el1 },
-       { SYS_DESC(SYS_ID_MMFR2_EL1), NULL, get_id_mmfr2_el1 },
-       { SYS_DESC(SYS_ID_MMFR3_EL1), NULL, get_id_mmfr3_el1 },
-       { SYS_DESC(SYS_ID_ISAR0_EL1), NULL, get_id_isar0_el1 },
-       { SYS_DESC(SYS_ID_ISAR1_EL1), NULL, get_id_isar1_el1 },
-       { SYS_DESC(SYS_ID_ISAR2_EL1), NULL, get_id_isar2_el1 },
-       { SYS_DESC(SYS_ID_ISAR3_EL1), NULL, get_id_isar3_el1 },
-       { SYS_DESC(SYS_ID_ISAR4_EL1), NULL, get_id_isar4_el1 },
-       { SYS_DESC(SYS_ID_ISAR5_EL1), NULL, get_id_isar5_el1 },
        { SYS_DESC(SYS_CLIDR_EL1), NULL, get_clidr_el1 },
        { SYS_DESC(SYS_AIDR_EL1), NULL, get_aidr_el1 },
        { SYS_DESC(SYS_CTR_EL0), NULL, get_ctr_el0 },
@@ -2066,12 +2257,31 @@ static bool copy_reg_to_user(const struct sys_reg_desc *reg, u64 __user **uind)
        return true;
 }
 
+static int walk_one_sys_reg(const struct sys_reg_desc *rd,
+                           u64 __user **uind,
+                           unsigned int *total)
+{
+       /*
+        * Ignore registers we trap but don't save,
+        * and for which no custom user accessor is provided.
+        */
+       if (!(rd->reg || rd->get_user))
+               return 0;
+
+       if (!copy_reg_to_user(rd, uind))
+               return -EFAULT;
+
+       (*total)++;
+       return 0;
+}
+
 /* Assumed ordered tables, see kvm_sys_reg_table_init. */
 static int walk_sys_regs(struct kvm_vcpu *vcpu, u64 __user *uind)
 {
        const struct sys_reg_desc *i1, *i2, *end1, *end2;
        unsigned int total = 0;
        size_t num;
+       int err;
 
        /* We check for duplicates here, to allow arch-specific overrides. */
        i1 = get_target_table(vcpu->arch.target, true, &num);
@@ -2085,21 +2295,13 @@ static int walk_sys_regs(struct kvm_vcpu *vcpu, u64 __user *uind)
        while (i1 || i2) {
                int cmp = cmp_sys_reg(i1, i2);
                /* target-specific overrides generic entry. */
-               if (cmp <= 0) {
-                       /* Ignore registers we trap but don't save. */
-                       if (i1->reg) {
-                               if (!copy_reg_to_user(i1, &uind))
-                                       return -EFAULT;
-                               total++;
-                       }
-               } else {
-                       /* Ignore registers we trap but don't save. */
-                       if (i2->reg) {
-                               if (!copy_reg_to_user(i2, &uind))
-                                       return -EFAULT;
-                               total++;
-                       }
-               }
+               if (cmp <= 0)
+                       err = walk_one_sys_reg(i1, &uind, &total);
+               else
+                       err = walk_one_sys_reg(i2, &uind, &total);
+
+               if (err)
+                       return err;
 
                if (cmp <= 0 && ++i1 == end1)
                        i1 = NULL;