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-rw-r--r--arch/arm64/include/asm/kvm_host.h2
-rw-r--r--arch/arm64/include/uapi/asm/kvm.h32
-rw-r--r--arch/arm64/kvm/arm.c10
-rw-r--r--arch/arm64/kvm/sys_regs.c194
4 files changed, 206 insertions, 32 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 6a0b6f3b6f41..846a7706e925 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -1108,6 +1108,8 @@ int kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
struct kvm_arm_copy_mte_tags *copy_tags);
int kvm_vm_ioctl_set_counter_offset(struct kvm *kvm,
struct kvm_arm_counter_offset *offset);
+int kvm_vm_ioctl_get_reg_writable_masks(struct kvm *kvm,
+ struct reg_mask_range *range);
/* Guest/host FPSIMD coordination helpers */
int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index f7ddd73a8c0f..89d2fc872d9f 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -505,6 +505,38 @@ struct kvm_smccc_filter {
#define KVM_HYPERCALL_EXIT_SMC (1U << 0)
#define KVM_HYPERCALL_EXIT_16BIT (1U << 1)
+/*
+ * Get feature ID registers userspace writable mask.
+ *
+ * From DDI0487J.a, D19.2.66 ("ID_AA64MMFR2_EL1, AArch64 Memory Model
+ * Feature Register 2"):
+ *
+ * "The Feature ID space is defined as the System register space in
+ * AArch64 with op0==3, op1=={0, 1, 3}, CRn==0, CRm=={0-7},
+ * op2=={0-7}."
+ *
+ * This covers all currently known R/O registers that indicate
+ * anything useful feature wise, including the ID registers.
+ *
+ * If we ever need to introduce a new range, it will be described as
+ * such in the range field.
+ */
+#define KVM_ARM_FEATURE_ID_RANGE_IDX(op0, op1, crn, crm, op2) \
+ ({ \
+ __u64 __op1 = (op1) & 3; \
+ __op1 -= (__op1 == 3); \
+ (__op1 << 6 | ((crm) & 7) << 3 | (op2)); \
+ })
+
+#define KVM_ARM_FEATURE_ID_RANGE 0
+#define KVM_ARM_FEATURE_ID_RANGE_SIZE (3 * 8 * 8)
+
+struct reg_mask_range {
+ __u64 addr; /* Pointer to mask array */
+ __u32 range; /* Requested range */
+ __u32 reserved[13];
+};
+
#endif
#endif /* __ARM_KVM_H__ */
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index e16c5ebd2991..c6cad400490f 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -318,6 +318,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_ARM_SUPPORTED_BLOCK_SIZES:
r = kvm_supported_block_sizes();
break;
+ case KVM_CAP_ARM_SUPPORTED_REG_MASK_RANGES:
+ r = BIT(0);
+ break;
default:
r = 0;
}
@@ -1713,6 +1716,13 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
return kvm_vm_set_attr(kvm, &attr);
}
+ case KVM_ARM_GET_REG_WRITABLE_MASKS: {
+ struct reg_mask_range range;
+
+ if (copy_from_user(&range, argp, sizeof(range)))
+ return -EFAULT;
+ return kvm_vm_ioctl_get_reg_writable_masks(kvm, &range);
+ }
default:
return -EINVAL;
}
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 1a165186701b..2c4923fce573 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -379,7 +379,7 @@ static bool trap_loregion(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
- u64 val = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
+ u64 val = IDREG(vcpu->kvm, SYS_ID_AA64MMFR1_EL1);
u32 sr = reg_to_encoding(r);
if (!(val & (0xfUL << ID_AA64MMFR1_EL1_LO_SHIFT))) {
@@ -1220,8 +1220,14 @@ static s64 kvm_arm64_ftr_safe_value(u32 id, const struct arm64_ftr_bits *ftrp,
/* Some features have different safe value type in KVM than host features */
switch (id) {
case SYS_ID_AA64DFR0_EL1:
- if (kvm_ftr.shift == ID_AA64DFR0_EL1_PMUVer_SHIFT)
+ switch (kvm_ftr.shift) {
+ case ID_AA64DFR0_EL1_PMUVer_SHIFT:
kvm_ftr.type = FTR_LOWER_SAFE;
+ break;
+ case ID_AA64DFR0_EL1_DebugVer_SHIFT:
+ kvm_ftr.type = FTR_LOWER_SAFE;
+ break;
+ }
break;
case SYS_ID_DFR0_EL1:
if (kvm_ftr.shift == ID_DFR0_EL1_PerfMon_SHIFT)
@@ -1377,6 +1383,13 @@ static inline bool is_id_reg(u32 id)
sys_reg_CRm(id) < 8);
}
+static inline bool is_aa32_id_reg(u32 id)
+{
+ return (sys_reg_Op0(id) == 3 && sys_reg_Op1(id) == 0 &&
+ sys_reg_CRn(id) == 0 && sys_reg_CRm(id) >= 1 &&
+ sys_reg_CRm(id) <= 3);
+}
+
static unsigned int id_visibility(const struct kvm_vcpu *vcpu,
const struct sys_reg_desc *r)
{
@@ -1473,14 +1486,21 @@ static u64 read_sanitised_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
return val;
}
+#define ID_REG_LIMIT_FIELD_ENUM(val, reg, field, limit) \
+({ \
+ u64 __f_val = FIELD_GET(reg##_##field##_MASK, val); \
+ (val) &= ~reg##_##field##_MASK; \
+ (val) |= FIELD_PREP(reg##_##field##_MASK, \
+ min(__f_val, (u64)reg##_##field##_##limit)); \
+ (val); \
+})
+
static u64 read_sanitised_id_aa64dfr0_el1(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd)
{
u64 val = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
- /* Limit debug to ARMv8.0 */
- val &= ~ID_AA64DFR0_EL1_DebugVer_MASK;
- val |= SYS_FIELD_PREP_ENUM(ID_AA64DFR0_EL1, DebugVer, IMP);
+ val = ID_REG_LIMIT_FIELD_ENUM(val, ID_AA64DFR0_EL1, DebugVer, V8P8);
/*
* Only initialize the PMU version if the vCPU was configured with one.
@@ -1500,6 +1520,7 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd,
u64 val)
{
+ u8 debugver = SYS_FIELD_GET(ID_AA64DFR0_EL1, DebugVer, val);
u8 pmuver = SYS_FIELD_GET(ID_AA64DFR0_EL1, PMUVer, val);
/*
@@ -1519,6 +1540,13 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu,
if (pmuver == ID_AA64DFR0_EL1_PMUVer_IMP_DEF)
val &= ~ID_AA64DFR0_EL1_PMUVer_MASK;
+ /*
+ * ID_AA64DFR0_EL1.DebugVer is one of those awkward fields with a
+ * nonzero minimum safe value.
+ */
+ if (debugver < ID_AA64DFR0_EL1_DebugVer_IMP)
+ return -EINVAL;
+
return set_id_reg(vcpu, rd, val);
}
@@ -1532,6 +1560,8 @@ static u64 read_sanitised_id_dfr0_el1(struct kvm_vcpu *vcpu,
if (kvm_vcpu_has_pmu(vcpu))
val |= SYS_FIELD_PREP(ID_DFR0_EL1, PerfMon, perfmon);
+ val = ID_REG_LIMIT_FIELD_ENUM(val, ID_DFR0_EL1, CopDbg, Debugv8p8);
+
return val;
}
@@ -1540,6 +1570,7 @@ static int set_id_dfr0_el1(struct kvm_vcpu *vcpu,
u64 val)
{
u8 perfmon = SYS_FIELD_GET(ID_DFR0_EL1, PerfMon, val);
+ u8 copdbg = SYS_FIELD_GET(ID_DFR0_EL1, CopDbg, val);
if (perfmon == ID_DFR0_EL1_PerfMon_IMPDEF) {
val &= ~ID_DFR0_EL1_PerfMon_MASK;
@@ -1555,6 +1586,9 @@ static int set_id_dfr0_el1(struct kvm_vcpu *vcpu,
if (perfmon != 0 && perfmon < ID_DFR0_EL1_PerfMon_PMUv3)
return -EINVAL;
+ if (copdbg < ID_DFR0_EL1_CopDbg_Armv8)
+ return -EINVAL;
+
return set_id_reg(vcpu, rd, val);
}
@@ -1821,11 +1855,14 @@ static unsigned int hidden_user_visibility(const struct kvm_vcpu *vcpu,
* from userspace.
*/
-/* sys_reg_desc initialiser for known cpufeature ID registers */
-#define ID_SANITISED(name) { \
+#define ID_DESC(name) \
SYS_DESC(SYS_##name), \
.access = access_id_reg, \
- .get_user = get_id_reg, \
+ .get_user = get_id_reg \
+
+/* sys_reg_desc initialiser for known cpufeature ID registers */
+#define ID_SANITISED(name) { \
+ ID_DESC(name), \
.set_user = set_id_reg, \
.visibility = id_visibility, \
.reset = kvm_read_sanitised_id_reg, \
@@ -1834,15 +1871,22 @@ static unsigned int hidden_user_visibility(const struct kvm_vcpu *vcpu,
/* sys_reg_desc initialiser for known cpufeature ID registers */
#define AA32_ID_SANITISED(name) { \
- SYS_DESC(SYS_##name), \
- .access = access_id_reg, \
- .get_user = get_id_reg, \
+ ID_DESC(name), \
.set_user = set_id_reg, \
.visibility = aa32_id_visibility, \
.reset = kvm_read_sanitised_id_reg, \
.val = 0, \
}
+/* sys_reg_desc initialiser for writable ID registers */
+#define ID_WRITABLE(name, mask) { \
+ ID_DESC(name), \
+ .set_user = set_id_reg, \
+ .visibility = id_visibility, \
+ .reset = kvm_read_sanitised_id_reg, \
+ .val = mask, \
+}
+
/*
* sys_reg_desc initialiser for architecturally unallocated cpufeature ID
* register with encoding Op0=3, Op1=0, CRn=0, CRm=crm, Op2=op2
@@ -1864,9 +1908,7 @@ static unsigned int hidden_user_visibility(const struct kvm_vcpu *vcpu,
* RAZ for the guest.
*/
#define ID_HIDDEN(name) { \
- SYS_DESC(SYS_##name), \
- .access = access_id_reg, \
- .get_user = get_id_reg, \
+ ID_DESC(name), \
.set_user = set_id_reg, \
.visibility = raz_visibility, \
.reset = kvm_read_sanitised_id_reg, \
@@ -1984,7 +2026,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
.set_user = set_id_dfr0_el1,
.visibility = aa32_id_visibility,
.reset = read_sanitised_id_dfr0_el1,
- .val = ID_DFR0_EL1_PerfMon_MASK, },
+ .val = ID_DFR0_EL1_PerfMon_MASK |
+ ID_DFR0_EL1_CopDbg_MASK, },
ID_HIDDEN(ID_AFR0_EL1),
AA32_ID_SANITISED(ID_MMFR0_EL1),
AA32_ID_SANITISED(ID_MMFR1_EL1),
@@ -2018,11 +2061,17 @@ static const struct sys_reg_desc sys_reg_descs[] = {
.get_user = get_id_reg,
.set_user = set_id_reg,
.reset = read_sanitised_id_aa64pfr0_el1,
- .val = ID_AA64PFR0_EL1_CSV2_MASK | ID_AA64PFR0_EL1_CSV3_MASK, },
+ .val = ~(ID_AA64PFR0_EL1_AMU |
+ ID_AA64PFR0_EL1_MPAM |
+ ID_AA64PFR0_EL1_SVE |
+ ID_AA64PFR0_EL1_RAS |
+ ID_AA64PFR0_EL1_GIC |
+ ID_AA64PFR0_EL1_AdvSIMD |
+ ID_AA64PFR0_EL1_FP), },
ID_SANITISED(ID_AA64PFR1_EL1),
ID_UNALLOCATED(4,2),
ID_UNALLOCATED(4,3),
- ID_SANITISED(ID_AA64ZFR0_EL1),
+ ID_WRITABLE(ID_AA64ZFR0_EL1, ~ID_AA64ZFR0_EL1_RES0),
ID_HIDDEN(ID_AA64SMFR0_EL1),
ID_UNALLOCATED(4,6),
ID_UNALLOCATED(4,7),
@@ -2033,7 +2082,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
.get_user = get_id_reg,
.set_user = set_id_aa64dfr0_el1,
.reset = read_sanitised_id_aa64dfr0_el1,
- .val = ID_AA64DFR0_EL1_PMUVer_MASK, },
+ .val = ID_AA64DFR0_EL1_PMUVer_MASK |
+ ID_AA64DFR0_EL1_DebugVer_MASK, },
ID_SANITISED(ID_AA64DFR1_EL1),
ID_UNALLOCATED(5,2),
ID_UNALLOCATED(5,3),
@@ -2043,9 +2093,15 @@ static const struct sys_reg_desc sys_reg_descs[] = {
ID_UNALLOCATED(5,7),
/* CRm=6 */
- ID_SANITISED(ID_AA64ISAR0_EL1),
- ID_SANITISED(ID_AA64ISAR1_EL1),
- ID_SANITISED(ID_AA64ISAR2_EL1),
+ ID_WRITABLE(ID_AA64ISAR0_EL1, ~ID_AA64ISAR0_EL1_RES0),
+ ID_WRITABLE(ID_AA64ISAR1_EL1, ~(ID_AA64ISAR1_EL1_GPI |
+ ID_AA64ISAR1_EL1_GPA |
+ ID_AA64ISAR1_EL1_API |
+ ID_AA64ISAR1_EL1_APA)),
+ ID_WRITABLE(ID_AA64ISAR2_EL1, ~(ID_AA64ISAR2_EL1_RES0 |
+ ID_AA64ISAR2_EL1_MOPS |
+ ID_AA64ISAR2_EL1_APA3 |
+ ID_AA64ISAR2_EL1_GPA3)),
ID_UNALLOCATED(6,3),
ID_UNALLOCATED(6,4),
ID_UNALLOCATED(6,5),
@@ -2053,9 +2109,23 @@ static const struct sys_reg_desc sys_reg_descs[] = {
ID_UNALLOCATED(6,7),
/* CRm=7 */
- ID_SANITISED(ID_AA64MMFR0_EL1),
- ID_SANITISED(ID_AA64MMFR1_EL1),
- ID_SANITISED(ID_AA64MMFR2_EL1),
+ ID_WRITABLE(ID_AA64MMFR0_EL1, ~(ID_AA64MMFR0_EL1_RES0 |
+ ID_AA64MMFR0_EL1_TGRAN4_2 |
+ ID_AA64MMFR0_EL1_TGRAN64_2 |
+ ID_AA64MMFR0_EL1_TGRAN16_2)),
+ ID_WRITABLE(ID_AA64MMFR1_EL1, ~(ID_AA64MMFR1_EL1_RES0 |
+ ID_AA64MMFR1_EL1_HCX |
+ ID_AA64MMFR1_EL1_XNX |
+ ID_AA64MMFR1_EL1_TWED |
+ ID_AA64MMFR1_EL1_XNX |
+ ID_AA64MMFR1_EL1_VH |
+ ID_AA64MMFR1_EL1_VMIDBits)),
+ ID_WRITABLE(ID_AA64MMFR2_EL1, ~(ID_AA64MMFR2_EL1_RES0 |
+ ID_AA64MMFR2_EL1_EVT |
+ ID_AA64MMFR2_EL1_FWB |
+ ID_AA64MMFR2_EL1_IDS |
+ ID_AA64MMFR2_EL1_NV |
+ ID_AA64MMFR2_EL1_CCIDX)),
ID_SANITISED(ID_AA64MMFR3_EL1),
ID_UNALLOCATED(7,4),
ID_UNALLOCATED(7,5),
@@ -2452,14 +2522,15 @@ static bool trap_dbgdidr(struct kvm_vcpu *vcpu,
if (p->is_write) {
return ignore_write(vcpu, p);
} else {
- u64 dfr = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
- u64 pfr = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
- u32 el3 = !!cpuid_feature_extract_unsigned_field(pfr, ID_AA64PFR0_EL1_EL3_SHIFT);
-
- p->regval = ((((dfr >> ID_AA64DFR0_EL1_WRPs_SHIFT) & 0xf) << 28) |
- (((dfr >> ID_AA64DFR0_EL1_BRPs_SHIFT) & 0xf) << 24) |
- (((dfr >> ID_AA64DFR0_EL1_CTX_CMPs_SHIFT) & 0xf) << 20)
- | (6 << 16) | (1 << 15) | (el3 << 14) | (el3 << 12));
+ u64 dfr = IDREG(vcpu->kvm, SYS_ID_AA64DFR0_EL1);
+ u64 pfr = IDREG(vcpu->kvm, SYS_ID_AA64PFR0_EL1);
+ u32 el3 = !!SYS_FIELD_GET(ID_AA64PFR0_EL1, EL3, pfr);
+
+ p->regval = ((SYS_FIELD_GET(ID_AA64DFR0_EL1, WRPs, dfr) << 28) |
+ (SYS_FIELD_GET(ID_AA64DFR0_EL1, BRPs, dfr) << 24) |
+ (SYS_FIELD_GET(ID_AA64DFR0_EL1, CTX_CMPs, dfr) << 20) |
+ (SYS_FIELD_GET(ID_AA64DFR0_EL1, DebugVer, dfr) << 16) |
+ (1 << 15) | (el3 << 14) | (el3 << 12));
return true;
}
}
@@ -3586,6 +3657,65 @@ int kvm_arm_copy_sys_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
return write_demux_regids(uindices);
}
+#define KVM_ARM_FEATURE_ID_RANGE_INDEX(r) \
+ KVM_ARM_FEATURE_ID_RANGE_IDX(sys_reg_Op0(r), \
+ sys_reg_Op1(r), \
+ sys_reg_CRn(r), \
+ sys_reg_CRm(r), \
+ sys_reg_Op2(r))
+
+static bool is_feature_id_reg(u32 encoding)
+{
+ return (sys_reg_Op0(encoding) == 3 &&
+ (sys_reg_Op1(encoding) < 2 || sys_reg_Op1(encoding) == 3) &&
+ sys_reg_CRn(encoding) == 0 &&
+ sys_reg_CRm(encoding) <= 7);
+}
+
+int kvm_vm_ioctl_get_reg_writable_masks(struct kvm *kvm, struct reg_mask_range *range)
+{
+ const void *zero_page = page_to_virt(ZERO_PAGE(0));
+ u64 __user *masks = (u64 __user *)range->addr;
+
+ /* Only feature id range is supported, reserved[13] must be zero. */
+ if (range->range ||
+ memcmp(range->reserved, zero_page, sizeof(range->reserved)))
+ return -EINVAL;
+
+ /* Wipe the whole thing first */
+ if (clear_user(masks, KVM_ARM_FEATURE_ID_RANGE_SIZE * sizeof(__u64)))
+ return -EFAULT;
+
+ for (int i = 0; i < ARRAY_SIZE(sys_reg_descs); i++) {
+ const struct sys_reg_desc *reg = &sys_reg_descs[i];
+ u32 encoding = reg_to_encoding(reg);
+ u64 val;
+
+ if (!is_feature_id_reg(encoding) || !reg->set_user)
+ continue;
+
+ /*
+ * For ID registers, we return the writable mask. Other feature
+ * registers return a full 64bit mask. That's not necessary
+ * compliant with a given revision of the architecture, but the
+ * RES0/RES1 definitions allow us to do that.
+ */
+ if (is_id_reg(encoding)) {
+ if (!reg->val ||
+ (is_aa32_id_reg(encoding) && !kvm_supports_32bit_el0()))
+ continue;
+ val = reg->val;
+ } else {
+ val = ~0UL;
+ }
+
+ if (put_user(val, (masks + KVM_ARM_FEATURE_ID_RANGE_INDEX(encoding))))
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
int __init kvm_sys_reg_table_init(void)
{
struct sys_reg_params params;