From 4e8ff73eb7ae3f7a7ec1d59f4d54935ae28f4795 Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Wed, 19 Jun 2024 17:40:27 +0000 Subject: KVM: arm64: Get sys_reg encoding from descriptor in idregs_debug_show() KVM is about to add support for more VM-scoped feature ID regs that live outside of the id_regs[] array, which means the index of the debugfs iterator may not actually be an index into the array. Prepare by getting the sys_reg encoding from the descriptor itself. Reviewed-by: Sebastian Ott Link: https://lore.kernel.org/r/20240619174036.483943-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton --- arch/arm64/kvm/sys_regs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 22b45a15d068..ad453c7ad6cc 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -3502,7 +3502,7 @@ static int idregs_debug_show(struct seq_file *s, void *v) return 0; seq_printf(s, "%20s:\t%016llx\n", - desc->name, IDREG(kvm, IDX_IDREG(kvm->arch.idreg_debugfs_iter))); + desc->name, IDREG(kvm, reg_to_encoding(desc))); return 0; } -- cgit From 410db103f6ebc68a505ef541291ec327e385205a Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Wed, 19 Jun 2024 17:40:28 +0000 Subject: KVM: arm64: Make idregs debugfs iterator search sysreg table directly CTR_EL0 complicates the existing scheme for iterating feature ID registers, as it is not in the contiguous range that we presently support. Just search the sysreg table for the Nth feature ID register in anticipation of this. Yes, the debugfs interface has quadratic time completixy now. Boo hoo. Reviewed-by: Sebastian Ott Link: https://lore.kernel.org/r/20240619174036.483943-3-oliver.upton@linux.dev Signed-off-by: Oliver Upton --- arch/arm64/kvm/sys_regs.c | 36 +++++++++++++++++++++++------------- 1 file changed, 23 insertions(+), 13 deletions(-) (limited to 'arch') diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index ad453c7ad6cc..1036f865c826 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2753,8 +2753,6 @@ static struct sys_reg_desc sys_insn_descs[] = { { SYS_DESC(SYS_DC_CIGDSW), access_dcgsw }, }; -static const struct sys_reg_desc *first_idreg; - static bool trap_dbgdidr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) @@ -3440,6 +3438,25 @@ static bool emulate_sys_reg(struct kvm_vcpu *vcpu, return false; } +static const struct sys_reg_desc *idregs_debug_find(struct kvm *kvm, u8 pos) +{ + unsigned long i, idreg_idx = 0; + + for (i = 0; i < ARRAY_SIZE(sys_reg_descs); i++) { + const struct sys_reg_desc *r = &sys_reg_descs[i]; + + if (!is_vm_ftr_id_reg(reg_to_encoding(r))) + continue; + + if (idreg_idx == pos) + return r; + + idreg_idx++; + } + + return NULL; +} + static void *idregs_debug_start(struct seq_file *s, loff_t *pos) { struct kvm *kvm = s->private; @@ -3451,7 +3468,7 @@ static void *idregs_debug_start(struct seq_file *s, loff_t *pos) if (test_bit(KVM_ARCH_FLAG_ID_REGS_INITIALIZED, &kvm->arch.flags) && *iter == (u8)~0) { *iter = *pos; - if (*iter >= KVM_ARM_ID_REG_NUM) + if (!idregs_debug_find(kvm, *iter)) iter = NULL; } else { iter = ERR_PTR(-EBUSY); @@ -3468,7 +3485,7 @@ static void *idregs_debug_next(struct seq_file *s, void *v, loff_t *pos) (*pos)++; - if ((kvm->arch.idreg_debugfs_iter + 1) < KVM_ARM_ID_REG_NUM) { + if (idregs_debug_find(kvm, kvm->arch.idreg_debugfs_iter + 1)) { kvm->arch.idreg_debugfs_iter++; return &kvm->arch.idreg_debugfs_iter; @@ -3493,10 +3510,10 @@ static void idregs_debug_stop(struct seq_file *s, void *v) static int idregs_debug_show(struct seq_file *s, void *v) { - struct kvm *kvm = s->private; const struct sys_reg_desc *desc; + struct kvm *kvm = s->private; - desc = first_idreg + kvm->arch.idreg_debugfs_iter; + desc = idregs_debug_find(kvm, kvm->arch.idreg_debugfs_iter); if (!desc->name) return 0; @@ -4115,7 +4132,6 @@ out: int __init kvm_sys_reg_table_init(void) { - struct sys_reg_params params; bool valid = true; unsigned int i; int ret = 0; @@ -4136,12 +4152,6 @@ int __init kvm_sys_reg_table_init(void) for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++) invariant_sys_regs[i].reset(NULL, &invariant_sys_regs[i]); - /* Find the first idreg (SYS_ID_PFR0_EL1) in sys_reg_descs. */ - params = encoding_to_params(SYS_ID_PFR0_EL1); - first_idreg = find_reg(¶ms, sys_reg_descs, ARRAY_SIZE(sys_reg_descs)); - if (!first_idreg) - return -EINVAL; - ret = populate_nv_trap_config(); for (i = 0; !ret && i < ARRAY_SIZE(sys_reg_descs); i++) -- cgit From 97ca3fcc15cc0b19ccacb56d25545f1df080fbc0 Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Wed, 19 Jun 2024 17:40:29 +0000 Subject: KVM: arm64: Use read-only helper for reading VM ID registers IDREG() expands to the storage of a particular ID reg, which can be useful for handling both reads and writes. However, outside of a select few situations, the ID registers should be considered read only. Replace current readers with a new macro that expands to the value of the field rather than the field itself. Reviewed-by: Sebastian Ott Link: https://lore.kernel.org/r/20240619174036.483943-4-oliver.upton@linux.dev Signed-off-by: Oliver Upton --- arch/arm64/include/asm/kvm_host.h | 16 +++++++++++++++- arch/arm64/kvm/pmu-emul.c | 2 +- arch/arm64/kvm/sys_regs.c | 6 +++--- 3 files changed, 19 insertions(+), 5 deletions(-) (limited to 'arch') diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 8170c04fde91..1201af636551 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1332,6 +1332,20 @@ static inline void kvm_hyp_reserve(void) { } void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu); bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu); +static inline u64 *__vm_id_reg(struct kvm_arch *ka, u32 reg) +{ + switch (reg) { + case sys_reg(3, 0, 0, 1, 0) ... sys_reg(3, 0, 0, 7, 7): + return &ka->id_regs[IDREG_IDX(reg)]; + default: + WARN_ON_ONCE(1); + return NULL; + } +} + +#define kvm_read_vm_id_reg(kvm, reg) \ + ({ u64 __val = *__vm_id_reg(&(kvm)->arch, reg); __val; }) + #define __expand_field_sign_unsigned(id, fld, val) \ ((u64)SYS_FIELD_VALUE(id, fld, val)) @@ -1348,7 +1362,7 @@ bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu); #define get_idreg_field_unsigned(kvm, id, fld) \ ({ \ - u64 __val = IDREG((kvm), SYS_##id); \ + u64 __val = kvm_read_vm_id_reg((kvm), SYS_##id); \ FIELD_GET(id##_##fld##_MASK, __val); \ }) diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index a35ce10e0a9f..7848daeafd03 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -54,7 +54,7 @@ static u32 __kvm_pmu_event_mask(unsigned int pmuver) static u32 kvm_pmu_event_mask(struct kvm *kvm) { - u64 dfr0 = IDREG(kvm, SYS_ID_AA64DFR0_EL1); + u64 dfr0 = kvm_read_vm_id_reg(kvm, SYS_ID_AA64DFR0_EL1); u8 pmuver = SYS_FIELD_GET(ID_AA64DFR0_EL1, PMUVer, dfr0); return __kvm_pmu_event_mask(pmuver); diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 1036f865c826..0692a109fd4d 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1565,7 +1565,7 @@ static u64 kvm_read_sanitised_id_reg(struct kvm_vcpu *vcpu, static u64 read_id_reg(const struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { - return IDREG(vcpu->kvm, reg_to_encoding(r)); + return kvm_read_vm_id_reg(vcpu->kvm, reg_to_encoding(r)); } static bool is_feature_id_reg(u32 encoding) @@ -2760,7 +2760,7 @@ static bool trap_dbgdidr(struct kvm_vcpu *vcpu, if (p->is_write) { return ignore_write(vcpu, p); } else { - u64 dfr = IDREG(vcpu->kvm, SYS_ID_AA64DFR0_EL1); + u64 dfr = kvm_read_vm_id_reg(vcpu->kvm, SYS_ID_AA64DFR0_EL1); u32 el3 = kvm_has_feat(vcpu->kvm, ID_AA64PFR0_EL1, EL3, IMP); p->regval = ((SYS_FIELD_GET(ID_AA64DFR0_EL1, WRPs, dfr) << 28) | @@ -3519,7 +3519,7 @@ static int idregs_debug_show(struct seq_file *s, void *v) return 0; seq_printf(s, "%20s:\t%016llx\n", - desc->name, IDREG(kvm, reg_to_encoding(desc))); + desc->name, kvm_read_vm_id_reg(kvm, reg_to_encoding(desc))); return 0; } -- cgit From d7508d27dd8878eb09e470855a546d96e0cfd4d3 Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Wed, 19 Jun 2024 17:40:30 +0000 Subject: KVM: arm64: Add helper for writing ID regs Replace the remaining usage of IDREG() with a new helper for setting the value of a feature ID register, with the benefit of cramming in some extra sanity checks. Reviewed-by: Sebastian Ott Link: https://lore.kernel.org/r/20240619174036.483943-5-oliver.upton@linux.dev Signed-off-by: Oliver Upton --- arch/arm64/include/asm/kvm_host.h | 3 ++- arch/arm64/kvm/nested.c | 4 ++-- arch/arm64/kvm/sys_regs.c | 17 ++++++++++++++--- 3 files changed, 18 insertions(+), 6 deletions(-) (limited to 'arch') diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 1201af636551..74e7c29364ee 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -327,7 +327,6 @@ struct kvm_arch { */ #define IDREG_IDX(id) (((sys_reg_CRm(id) - 1) << 3) | sys_reg_Op2(id)) #define IDX_IDREG(idx) sys_reg(3, 0, 0, ((idx) >> 3) + 1, (idx) & Op2_mask) -#define IDREG(kvm, id) ((kvm)->arch.id_regs[IDREG_IDX(id)]) #define KVM_ARM_ID_REG_NUM (IDREG_IDX(sys_reg(3, 0, 0, 7, 7)) + 1) u64 id_regs[KVM_ARM_ID_REG_NUM]; @@ -1346,6 +1345,8 @@ static inline u64 *__vm_id_reg(struct kvm_arch *ka, u32 reg) #define kvm_read_vm_id_reg(kvm, reg) \ ({ u64 __val = *__vm_id_reg(&(kvm)->arch, reg); __val; }) +void kvm_set_vm_id_reg(struct kvm *kvm, u32 reg, u64 val); + #define __expand_field_sign_unsigned(id, fld, val) \ ((u64)SYS_FIELD_VALUE(id, fld, val)) diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index 6813c7c7f00a..5db5bc9dd290 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -203,8 +203,8 @@ int kvm_init_nv_sysregs(struct kvm *kvm) } for (int i = 0; i < KVM_ARM_ID_REG_NUM; i++) - kvm->arch.id_regs[i] = limit_nv_id_reg(IDX_IDREG(i), - kvm->arch.id_regs[i]); + kvm_set_vm_id_reg(kvm, IDX_IDREG(i), limit_nv_id_reg(IDX_IDREG(i), + kvm->arch.id_regs[i])); /* VTTBR_EL2 */ res0 = res1 = 0; diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 0692a109fd4d..8e3358905371 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1851,7 +1851,7 @@ static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, ret = arm64_check_features(vcpu, rd, val); if (!ret) - IDREG(vcpu->kvm, id) = val; + kvm_set_vm_id_reg(vcpu->kvm, id, val); mutex_unlock(&vcpu->kvm->arch.config_lock); @@ -1867,6 +1867,18 @@ static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, return ret; } +void kvm_set_vm_id_reg(struct kvm *kvm, u32 reg, u64 val) +{ + u64 *p = __vm_id_reg(&kvm->arch, reg); + + lockdep_assert_held(&kvm->arch.config_lock); + + if (KVM_BUG_ON(kvm_vm_has_ran_once(kvm) || !p, kvm)) + return; + + *p = val; +} + static int get_raz_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, u64 *val) { @@ -3549,8 +3561,7 @@ static void reset_vm_ftr_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc if (test_bit(KVM_ARCH_FLAG_ID_REGS_INITIALIZED, &kvm->arch.flags)) return; - lockdep_assert_held(&kvm->arch.config_lock); - IDREG(kvm, id) = reg->reset(vcpu, reg); + kvm_set_vm_id_reg(kvm, id, reg->reset(vcpu, reg)); } static void reset_vcpu_ftr_id_reg(struct kvm_vcpu *vcpu, -- cgit From 44241f34fac96d23cb8eac944815a1fdbf4ce523 Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Wed, 19 Jun 2024 17:40:31 +0000 Subject: KVM: arm64: nv: Use accessors for modifying ID registers In the interest of abstracting away the underlying storage of feature ID registers, rework the nested code to go through the accessors instead of directly iterating the id_regs array. This means we now lose the property that ID registers unknown to the nested code get zeroed, but we really ought to be handling those explicitly going forward. Link: https://lore.kernel.org/r/20240619174036.483943-6-oliver.upton@linux.dev Signed-off-by: Oliver Upton --- arch/arm64/include/asm/kvm_host.h | 1 - arch/arm64/kvm/nested.c | 256 ++++++++++++++++++-------------------- 2 files changed, 122 insertions(+), 135 deletions(-) (limited to 'arch') diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 74e7c29364ee..294c78319f58 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -326,7 +326,6 @@ struct kvm_arch { * Atomic access to multiple idregs are guarded by kvm_arch.config_lock. */ #define IDREG_IDX(id) (((sys_reg_CRm(id) - 1) << 3) | sys_reg_Op2(id)) -#define IDX_IDREG(idx) sys_reg(3, 0, 0, ((idx) >> 3) + 1, (idx) & Op2_mask) #define KVM_ARM_ID_REG_NUM (IDREG_IDX(sys_reg(3, 0, 0, 7, 7)) + 1) u64 id_regs[KVM_ARM_ID_REG_NUM]; diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index 5db5bc9dd290..44085c13e673 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -23,141 +23,131 @@ * This list should get updated as new features get added to the NV * support, and new extension to the architecture. */ -static u64 limit_nv_id_reg(u32 id, u64 val) +static void limit_nv_id_regs(struct kvm *kvm) { - u64 tmp; - - switch (id) { - case SYS_ID_AA64ISAR0_EL1: - /* Support everything but TME, O.S. and Range TLBIs */ - val &= ~(NV_FTR(ISAR0, TLB) | - NV_FTR(ISAR0, TME)); - break; - - case SYS_ID_AA64ISAR1_EL1: - /* Support everything but Spec Invalidation */ - val &= ~(GENMASK_ULL(63, 56) | - NV_FTR(ISAR1, SPECRES)); - break; - - case SYS_ID_AA64PFR0_EL1: - /* No AMU, MPAM, S-EL2, RAS or SVE */ - val &= ~(GENMASK_ULL(55, 52) | - NV_FTR(PFR0, AMU) | - NV_FTR(PFR0, MPAM) | - NV_FTR(PFR0, SEL2) | - NV_FTR(PFR0, RAS) | - NV_FTR(PFR0, SVE) | - NV_FTR(PFR0, EL3) | - NV_FTR(PFR0, EL2) | - NV_FTR(PFR0, EL1)); - /* 64bit EL1/EL2/EL3 only */ - val |= FIELD_PREP(NV_FTR(PFR0, EL1), 0b0001); - val |= FIELD_PREP(NV_FTR(PFR0, EL2), 0b0001); - val |= FIELD_PREP(NV_FTR(PFR0, EL3), 0b0001); - break; - - case SYS_ID_AA64PFR1_EL1: - /* Only support SSBS */ - val &= NV_FTR(PFR1, SSBS); - break; - - case SYS_ID_AA64MMFR0_EL1: - /* Hide ECV, ExS, Secure Memory */ - val &= ~(NV_FTR(MMFR0, ECV) | - NV_FTR(MMFR0, EXS) | - NV_FTR(MMFR0, TGRAN4_2) | - NV_FTR(MMFR0, TGRAN16_2) | - NV_FTR(MMFR0, TGRAN64_2) | - NV_FTR(MMFR0, SNSMEM)); - - /* Disallow unsupported S2 page sizes */ - switch (PAGE_SIZE) { - case SZ_64K: - val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN16_2), 0b0001); - fallthrough; - case SZ_16K: - val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN4_2), 0b0001); - fallthrough; - case SZ_4K: - /* Support everything */ - break; - } - /* - * Since we can't support a guest S2 page size smaller than - * the host's own page size (due to KVM only populating its - * own S2 using the kernel's page size), advertise the - * limitation using FEAT_GTG. - */ - switch (PAGE_SIZE) { - case SZ_4K: - val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN4_2), 0b0010); - fallthrough; - case SZ_16K: - val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN16_2), 0b0010); - fallthrough; - case SZ_64K: - val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN64_2), 0b0010); - break; - } - /* Cap PARange to 48bits */ - tmp = FIELD_GET(NV_FTR(MMFR0, PARANGE), val); - if (tmp > 0b0101) { - val &= ~NV_FTR(MMFR0, PARANGE); - val |= FIELD_PREP(NV_FTR(MMFR0, PARANGE), 0b0101); - } + u64 val, tmp; + + /* Support everything but TME, O.S. and Range TLBIs */ + val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64ISAR0_EL1); + val &= ~(NV_FTR(ISAR0, TLB) | + NV_FTR(ISAR0, TME)); + kvm_set_vm_id_reg(kvm, SYS_ID_AA64ISAR0_EL1, val); + + /* Support everything but Spec Invalidation */ + val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64ISAR1_EL1); + val &= ~(GENMASK_ULL(63, 56) | + NV_FTR(ISAR1, SPECRES)); + kvm_set_vm_id_reg(kvm, SYS_ID_AA64ISAR1_EL1, val); + + /* No AMU, MPAM, S-EL2, RAS or SVE */ + kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1); + val &= ~(GENMASK_ULL(55, 52) | + NV_FTR(PFR0, AMU) | + NV_FTR(PFR0, MPAM) | + NV_FTR(PFR0, SEL2) | + NV_FTR(PFR0, RAS) | + NV_FTR(PFR0, SVE) | + NV_FTR(PFR0, EL3) | + NV_FTR(PFR0, EL2) | + NV_FTR(PFR0, EL1)); + /* 64bit EL1/EL2/EL3 only */ + val |= FIELD_PREP(NV_FTR(PFR0, EL1), 0b0001); + val |= FIELD_PREP(NV_FTR(PFR0, EL2), 0b0001); + val |= FIELD_PREP(NV_FTR(PFR0, EL3), 0b0001); + kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1, val); + + /* Only support SSBS */ + val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR1_EL1); + val &= NV_FTR(PFR1, SSBS); + kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR1_EL1, val); + + /* Hide ECV, ExS, Secure Memory */ + val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64MMFR0_EL1); + val &= ~(NV_FTR(MMFR0, ECV) | + NV_FTR(MMFR0, EXS) | + NV_FTR(MMFR0, TGRAN4_2) | + NV_FTR(MMFR0, TGRAN16_2) | + NV_FTR(MMFR0, TGRAN64_2) | + NV_FTR(MMFR0, SNSMEM)); + + /* Disallow unsupported S2 page sizes */ + switch (PAGE_SIZE) { + case SZ_64K: + val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN16_2), 0b0001); + fallthrough; + case SZ_16K: + val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN4_2), 0b0001); + fallthrough; + case SZ_4K: + /* Support everything */ break; - - case SYS_ID_AA64MMFR1_EL1: - val &= (NV_FTR(MMFR1, HCX) | - NV_FTR(MMFR1, PAN) | - NV_FTR(MMFR1, LO) | - NV_FTR(MMFR1, HPDS) | - NV_FTR(MMFR1, VH) | - NV_FTR(MMFR1, VMIDBits)); - break; - - case SYS_ID_AA64MMFR2_EL1: - val &= ~(NV_FTR(MMFR2, BBM) | - NV_FTR(MMFR2, TTL) | - GENMASK_ULL(47, 44) | - NV_FTR(MMFR2, ST) | - NV_FTR(MMFR2, CCIDX) | - NV_FTR(MMFR2, VARange)); - - /* Force TTL support */ - val |= FIELD_PREP(NV_FTR(MMFR2, TTL), 0b0001); - break; - - case SYS_ID_AA64MMFR4_EL1: - val = 0; - if (!cpus_have_final_cap(ARM64_HAS_HCR_NV1)) - val |= FIELD_PREP(NV_FTR(MMFR4, E2H0), - ID_AA64MMFR4_EL1_E2H0_NI_NV1); - break; - - case SYS_ID_AA64DFR0_EL1: - /* Only limited support for PMU, Debug, BPs and WPs */ - val &= (NV_FTR(DFR0, PMUVer) | - NV_FTR(DFR0, WRPs) | - NV_FTR(DFR0, BRPs) | - NV_FTR(DFR0, DebugVer)); - - /* Cap Debug to ARMv8.1 */ - tmp = FIELD_GET(NV_FTR(DFR0, DebugVer), val); - if (tmp > 0b0111) { - val &= ~NV_FTR(DFR0, DebugVer); - val |= FIELD_PREP(NV_FTR(DFR0, DebugVer), 0b0111); - } - break; - - default: - /* Unknown register, just wipe it clean */ - val = 0; + } + /* + * Since we can't support a guest S2 page size smaller than + * the host's own page size (due to KVM only populating its + * own S2 using the kernel's page size), advertise the + * limitation using FEAT_GTG. + */ + switch (PAGE_SIZE) { + case SZ_4K: + val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN4_2), 0b0010); + fallthrough; + case SZ_16K: + val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN16_2), 0b0010); + fallthrough; + case SZ_64K: + val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN64_2), 0b0010); break; } - - return val; + /* Cap PARange to 48bits */ + tmp = FIELD_GET(NV_FTR(MMFR0, PARANGE), val); + if (tmp > 0b0101) { + val &= ~NV_FTR(MMFR0, PARANGE); + val |= FIELD_PREP(NV_FTR(MMFR0, PARANGE), 0b0101); + } + kvm_set_vm_id_reg(kvm, SYS_ID_AA64MMFR0_EL1, val); + + val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64MMFR1_EL1); + val &= (NV_FTR(MMFR1, HCX) | + NV_FTR(MMFR1, PAN) | + NV_FTR(MMFR1, LO) | + NV_FTR(MMFR1, HPDS) | + NV_FTR(MMFR1, VH) | + NV_FTR(MMFR1, VMIDBits)); + kvm_set_vm_id_reg(kvm, SYS_ID_AA64MMFR1_EL1, val); + + val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64MMFR2_EL1); + val &= ~(NV_FTR(MMFR2, BBM) | + NV_FTR(MMFR2, TTL) | + GENMASK_ULL(47, 44) | + NV_FTR(MMFR2, ST) | + NV_FTR(MMFR2, CCIDX) | + NV_FTR(MMFR2, VARange)); + + /* Force TTL support */ + val |= FIELD_PREP(NV_FTR(MMFR2, TTL), 0b0001); + kvm_set_vm_id_reg(kvm, SYS_ID_AA64MMFR2_EL1, val); + + val = 0; + if (!cpus_have_final_cap(ARM64_HAS_HCR_NV1)) + val |= FIELD_PREP(NV_FTR(MMFR4, E2H0), + ID_AA64MMFR4_EL1_E2H0_NI_NV1); + kvm_set_vm_id_reg(kvm, SYS_ID_AA64MMFR4_EL1, val); + + /* Only limited support for PMU, Debug, BPs and WPs */ + val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64DFR0_EL1); + val &= (NV_FTR(DFR0, PMUVer) | + NV_FTR(DFR0, WRPs) | + NV_FTR(DFR0, BRPs) | + NV_FTR(DFR0, DebugVer)); + + /* Cap Debug to ARMv8.1 */ + tmp = FIELD_GET(NV_FTR(DFR0, DebugVer), val); + if (tmp > 0b0111) { + val &= ~NV_FTR(DFR0, DebugVer); + val |= FIELD_PREP(NV_FTR(DFR0, DebugVer), 0b0111); + } + kvm_set_vm_id_reg(kvm, SYS_ID_AA64DFR0_EL1, val); } u64 kvm_vcpu_sanitise_vncr_reg(const struct kvm_vcpu *vcpu, enum vcpu_sysreg sr) @@ -202,9 +192,7 @@ int kvm_init_nv_sysregs(struct kvm *kvm) goto out; } - for (int i = 0; i < KVM_ARM_ID_REG_NUM; i++) - kvm_set_vm_id_reg(kvm, IDX_IDREG(i), limit_nv_id_reg(IDX_IDREG(i), - kvm->arch.id_regs[i])); + limit_nv_id_regs(kvm); /* VTTBR_EL2 */ res0 = res1 = 0; -- cgit From f1ff3fc5209a1d63a4018bdb4231fbb073063c9a Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Wed, 19 Jun 2024 17:40:32 +0000 Subject: KVM: arm64: unify code to prepare traps There are 2 functions to calculate traps via HCR_EL2: * kvm_init_sysreg() called via KVM_RUN (before the 1st run or when the pid changes) * vcpu_reset_hcr() called via KVM_ARM_VCPU_INIT To unify these 2 and to support traps that are dependent on the ID register configuration, move the code from vcpu_reset_hcr() to sys_regs.c and call it via kvm_init_sysreg(). We still have to keep the non-FWB handling stuff in vcpu_reset_hcr(). Also the initialization with HCR_GUEST_FLAGS is kept there but guarded by !vcpu_has_run_once() to ensure that previous calculated values don't get overwritten. While at it rename kvm_init_sysreg() to kvm_calculate_traps() to better reflect what it's doing. Signed-off-by: Sebastian Ott Reviewed-by: Eric Auger Link: https://lore.kernel.org/r/20240619174036.483943-7-oliver.upton@linux.dev Signed-off-by: Oliver Upton --- arch/arm64/include/asm/kvm_emulate.h | 40 ++++++++---------------------------- arch/arm64/include/asm/kvm_host.h | 2 +- arch/arm64/kvm/arm.c | 2 +- arch/arm64/kvm/sys_regs.c | 34 ++++++++++++++++++++++++++++-- 4 files changed, 43 insertions(+), 35 deletions(-) (limited to 'arch') diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index 501e3e019c93..84dc3fac9711 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -69,39 +69,17 @@ static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu) static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu) { - vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS; - if (has_vhe() || has_hvhe()) - vcpu->arch.hcr_el2 |= HCR_E2H; - if (cpus_have_final_cap(ARM64_HAS_RAS_EXTN)) { - /* route synchronous external abort exceptions to EL2 */ - vcpu->arch.hcr_el2 |= HCR_TEA; - /* trap error record accesses */ - vcpu->arch.hcr_el2 |= HCR_TERR; - } + if (!vcpu_has_run_once(vcpu)) + vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS; - if (cpus_have_final_cap(ARM64_HAS_STAGE2_FWB)) { - vcpu->arch.hcr_el2 |= HCR_FWB; - } else { - /* - * For non-FWB CPUs, we trap VM ops (HCR_EL2.TVM) until M+C - * get set in SCTLR_EL1 such that we can detect when the guest - * MMU gets turned on and do the necessary cache maintenance - * then. - */ + /* + * For non-FWB CPUs, we trap VM ops (HCR_EL2.TVM) until M+C + * get set in SCTLR_EL1 such that we can detect when the guest + * MMU gets turned on and do the necessary cache maintenance + * then. + */ + if (!cpus_have_final_cap(ARM64_HAS_STAGE2_FWB)) vcpu->arch.hcr_el2 |= HCR_TVM; - } - - if (cpus_have_final_cap(ARM64_HAS_EVT) && - !cpus_have_final_cap(ARM64_MISMATCHED_CACHE_TYPE)) - vcpu->arch.hcr_el2 |= HCR_TID4; - else - vcpu->arch.hcr_el2 |= HCR_TID2; - - if (vcpu_el1_is_32bit(vcpu)) - vcpu->arch.hcr_el2 &= ~HCR_RW; - - if (kvm_has_mte(vcpu->kvm)) - vcpu->arch.hcr_el2 |= HCR_ATA; } static inline unsigned long *vcpu_hcr(struct kvm_vcpu *vcpu) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 294c78319f58..26042875d6fc 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1120,7 +1120,7 @@ int __init populate_nv_trap_config(void); bool lock_all_vcpus(struct kvm *kvm); void unlock_all_vcpus(struct kvm *kvm); -void kvm_init_sysreg(struct kvm_vcpu *); +void kvm_calculate_traps(struct kvm_vcpu *vcpu); /* MMIO helpers */ void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data); diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 9996a989b52e..6b217afb4e8e 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -797,7 +797,7 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu) * This needs to happen after NV has imposed its own restrictions on * the feature set */ - kvm_init_sysreg(vcpu); + kvm_calculate_traps(vcpu); ret = kvm_timer_enable(vcpu); if (ret) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 8e3358905371..a467ff4290a7 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -4069,11 +4069,33 @@ int kvm_vm_ioctl_get_reg_writable_masks(struct kvm *kvm, struct reg_mask_range * return 0; } -void kvm_init_sysreg(struct kvm_vcpu *vcpu) +static void vcpu_set_hcr(struct kvm_vcpu *vcpu) { struct kvm *kvm = vcpu->kvm; - mutex_lock(&kvm->arch.config_lock); + if (has_vhe() || has_hvhe()) + vcpu->arch.hcr_el2 |= HCR_E2H; + if (cpus_have_final_cap(ARM64_HAS_RAS_EXTN)) { + /* route synchronous external abort exceptions to EL2 */ + vcpu->arch.hcr_el2 |= HCR_TEA; + /* trap error record accesses */ + vcpu->arch.hcr_el2 |= HCR_TERR; + } + + if (cpus_have_final_cap(ARM64_HAS_STAGE2_FWB)) + vcpu->arch.hcr_el2 |= HCR_FWB; + + if (cpus_have_final_cap(ARM64_HAS_EVT) && + !cpus_have_final_cap(ARM64_MISMATCHED_CACHE_TYPE)) + vcpu->arch.hcr_el2 |= HCR_TID4; + else + vcpu->arch.hcr_el2 |= HCR_TID2; + + if (vcpu_el1_is_32bit(vcpu)) + vcpu->arch.hcr_el2 &= ~HCR_RW; + + if (kvm_has_mte(vcpu->kvm)) + vcpu->arch.hcr_el2 |= HCR_ATA; /* * In the absence of FGT, we cannot independently trap TLBI @@ -4082,6 +4104,14 @@ void kvm_init_sysreg(struct kvm_vcpu *vcpu) */ if (!kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, OS)) vcpu->arch.hcr_el2 |= HCR_TTLBOS; +} + +void kvm_calculate_traps(struct kvm_vcpu *vcpu) +{ + struct kvm *kvm = vcpu->kvm; + + mutex_lock(&kvm->arch.config_lock); + vcpu_set_hcr(vcpu); if (cpus_have_final_cap(ARM64_HAS_HCX)) { vcpu->arch.hcrx_el2 = HCRX_GUEST_FLAGS; -- cgit From 2843cae26644fbc922e93c7c4c279f70fb3275f1 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Wed, 19 Jun 2024 17:40:33 +0000 Subject: KVM: arm64: Treat CTR_EL0 as a VM feature ID register CTR_EL0 is currently handled as an invariant register, thus guests will be presented with the host value of that register. Add emulation for CTR_EL0 based on a per VM value. Userspace can switch off DIC and IDC bits and reduce DminLine and IminLine sizes. Naturally, ensure CTR_EL0 is trapped (HCR_EL2.TID2=1) any time that a VM's CTR_EL0 differs from hardware. Signed-off-by: Sebastian Ott Reviewed-by: Shaoqin Huang Link: https://lore.kernel.org/r/20240619174036.483943-8-oliver.upton@linux.dev Signed-off-by: Oliver Upton --- arch/arm64/include/asm/kvm_host.h | 4 ++++ arch/arm64/kvm/sys_regs.c | 20 ++++++++++---------- 2 files changed, 14 insertions(+), 10 deletions(-) (limited to 'arch') diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 26042875d6fc..f6de08e81d49 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -329,6 +329,8 @@ struct kvm_arch { #define KVM_ARM_ID_REG_NUM (IDREG_IDX(sys_reg(3, 0, 0, 7, 7)) + 1) u64 id_regs[KVM_ARM_ID_REG_NUM]; + u64 ctr_el0; + /* Masks for VNCR-baked sysregs */ struct kvm_sysreg_masks *sysreg_masks; @@ -1335,6 +1337,8 @@ static inline u64 *__vm_id_reg(struct kvm_arch *ka, u32 reg) switch (reg) { case sys_reg(3, 0, 0, 1, 0) ... sys_reg(3, 0, 0, 7, 7): return &ka->id_regs[IDREG_IDX(reg)]; + case SYS_CTR_EL0: + return &ka->ctr_el0; default: WARN_ON_ONCE(1); return NULL; diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index a467ff4290a7..a12f3bdfb43d 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1583,6 +1583,9 @@ static bool is_feature_id_reg(u32 encoding) */ static inline bool is_vm_ftr_id_reg(u32 id) { + if (id == SYS_CTR_EL0) + return true; + 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) < 8); @@ -1898,7 +1901,7 @@ static bool access_ctr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, if (p->is_write) return write_to_read_only(vcpu, p, r); - p->regval = read_sanitised_ftr_reg(SYS_CTR_EL0); + p->regval = kvm_read_vm_id_reg(vcpu->kvm, SYS_CTR_EL0); return true; } @@ -2487,7 +2490,10 @@ static const struct sys_reg_desc sys_reg_descs[] = { { SYS_DESC(SYS_CCSIDR2_EL1), undef_access }, { SYS_DESC(SYS_SMIDR_EL1), undef_access }, { SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 }, - { SYS_DESC(SYS_CTR_EL0), access_ctr }, + ID_WRITABLE(CTR_EL0, CTR_EL0_DIC_MASK | + CTR_EL0_IDC_MASK | + CTR_EL0_DminLine_MASK | + CTR_EL0_IminLine_MASK), { SYS_DESC(SYS_SVCR), undef_access }, { PMU_SYS_REG(PMCR_EL0), .access = access_pmcr, .reset = reset_pmcr, @@ -3725,18 +3731,11 @@ FUNCTION_INVARIANT(midr_el1) FUNCTION_INVARIANT(revidr_el1) FUNCTION_INVARIANT(aidr_el1) -static u64 get_ctr_el0(struct kvm_vcpu *v, const struct sys_reg_desc *r) -{ - ((struct sys_reg_desc *)r)->val = read_sanitised_ftr_reg(SYS_CTR_EL0); - return ((struct sys_reg_desc *)r)->val; -} - /* ->val is filled in by kvm_sys_reg_table_init() */ static struct sys_reg_desc invariant_sys_regs[] __ro_after_init = { { SYS_DESC(SYS_MIDR_EL1), NULL, get_midr_el1 }, { SYS_DESC(SYS_REVIDR_EL1), NULL, get_revidr_el1 }, { SYS_DESC(SYS_AIDR_EL1), NULL, get_aidr_el1 }, - { SYS_DESC(SYS_CTR_EL0), NULL, get_ctr_el0 }, }; static int get_invariant_sys_reg(u64 id, u64 __user *uaddr) @@ -4086,7 +4085,8 @@ static void vcpu_set_hcr(struct kvm_vcpu *vcpu) vcpu->arch.hcr_el2 |= HCR_FWB; if (cpus_have_final_cap(ARM64_HAS_EVT) && - !cpus_have_final_cap(ARM64_MISMATCHED_CACHE_TYPE)) + !cpus_have_final_cap(ARM64_MISMATCHED_CACHE_TYPE) && + kvm_read_vm_id_reg(kvm, SYS_CTR_EL0) == read_sanitised_ftr_reg(SYS_CTR_EL0)) vcpu->arch.hcr_el2 |= HCR_TID4; else vcpu->arch.hcr_el2 |= HCR_TID2; -- cgit From bb4fa769dcdd0b6e47ecbf0363489be510498b1d Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Wed, 19 Jun 2024 17:40:34 +0000 Subject: KVM: arm64: show writable masks for feature registers Instead of using ~0UL provide the actual writable mask for non-id feature registers in the output of the KVM_ARM_GET_REG_WRITABLE_MASKS ioctl. This changes the mask for the CTR_EL0 and CLIDR_EL1 registers. Signed-off-by: Sebastian Ott Reviewed-by: Eric Auger Link: https://lore.kernel.org/r/20240619174036.483943-9-oliver.upton@linux.dev Signed-off-by: Oliver Upton --- arch/arm64/kvm/sys_regs.c | 19 +++++-------------- 1 file changed, 5 insertions(+), 14 deletions(-) (limited to 'arch') diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index a12f3bdfb43d..d8d2a7880576 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2486,7 +2486,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { { SYS_DESC(SYS_CCSIDR_EL1), access_ccsidr }, { SYS_DESC(SYS_CLIDR_EL1), access_clidr, reset_clidr, CLIDR_EL1, - .set_user = set_clidr }, + .set_user = set_clidr, .val = ~CLIDR_EL1_RES0 }, { SYS_DESC(SYS_CCSIDR2_EL1), undef_access }, { SYS_DESC(SYS_SMIDR_EL1), undef_access }, { SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 }, @@ -4046,20 +4046,11 @@ int kvm_vm_ioctl_get_reg_writable_masks(struct kvm *kvm, struct reg_mask_range * 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_vm_ftr_id_reg(encoding)) { - if (!reg->val || - (is_aa32_id_reg(encoding) && !kvm_supports_32bit_el0())) - continue; - val = reg->val; - } else { - val = ~0UL; + if (!reg->val || + (is_aa32_id_reg(encoding) && !kvm_supports_32bit_el0())) { + continue; } + val = reg->val; if (put_user(val, (masks + KVM_ARM_FEATURE_ID_RANGE_INDEX(encoding)))) return -EFAULT; -- cgit From 76d36012276a328ac0a1e9c7415cafd092447ce7 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Wed, 19 Jun 2024 17:40:35 +0000 Subject: KVM: arm64: rename functions for invariant sys regs Invariant system id registers are populated with host values at initialization time using their .reset function cb. These are currently called get_* which is usually used by the functions implementing the .get_user callback. Change their function names to reset_* to reflect what they are used for. Signed-off-by: Sebastian Ott Reviewed-by: Eric Auger Link: https://lore.kernel.org/r/20240619174036.483943-10-oliver.upton@linux.dev Signed-off-by: Oliver Upton --- arch/arm64/kvm/sys_regs.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'arch') diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index d8d2a7880576..71a4ed58f94b 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -3720,8 +3720,8 @@ id_to_sys_reg_desc(struct kvm_vcpu *vcpu, u64 id, */ #define FUNCTION_INVARIANT(reg) \ - static u64 get_##reg(struct kvm_vcpu *v, \ - const struct sys_reg_desc *r) \ + static u64 reset_##reg(struct kvm_vcpu *v, \ + const struct sys_reg_desc *r) \ { \ ((struct sys_reg_desc *)r)->val = read_sysreg(reg); \ return ((struct sys_reg_desc *)r)->val; \ @@ -3733,9 +3733,9 @@ FUNCTION_INVARIANT(aidr_el1) /* ->val is filled in by kvm_sys_reg_table_init() */ static struct sys_reg_desc invariant_sys_regs[] __ro_after_init = { - { SYS_DESC(SYS_MIDR_EL1), NULL, get_midr_el1 }, - { SYS_DESC(SYS_REVIDR_EL1), NULL, get_revidr_el1 }, - { SYS_DESC(SYS_AIDR_EL1), NULL, get_aidr_el1 }, + { SYS_DESC(SYS_MIDR_EL1), NULL, reset_midr_el1 }, + { SYS_DESC(SYS_REVIDR_EL1), NULL, reset_revidr_el1 }, + { SYS_DESC(SYS_AIDR_EL1), NULL, reset_aidr_el1 }, }; static int get_invariant_sys_reg(u64 id, u64 __user *uaddr) -- cgit From 33d85a93c6c3c0c1fc2d168ee5a9ae604c439fa7 Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Fri, 21 Jun 2024 22:40:44 +0000 Subject: KVM: arm64: nv: Unfudge ID_AA64PFR0_EL1 masking Marc reports that L1 VMs aren't booting with the NV series applied to today's kvmarm/next. After bisecting the issue, it appears that 44241f34fac9 ("KVM: arm64: nv: Use accessors for modifying ID registers") is to blame. Poking around at the issue a bit further, it'd appear that the value for ID_AA64PFR0_EL1 is complete garbage, as 'val' still contains the value we set ID_AA64ISAR1_EL1 to. Fix the read-modify-write pattern to actually use ID_AA64PFR0_EL1 as the starting point. Excuse me as I return to my shame cube. Reported-by: Marc Zyngier Fixes: 44241f34fac9 ("KVM: arm64: nv: Use accessors for modifying ID registers") Acked-by: Marc Zyngier Tested-by: Marc Zyngier Link: https://lore.kernel.org/r/20240621224044.2465901-1-oliver.upton@linux.dev Signed-off-by: Oliver Upton --- arch/arm64/kvm/nested.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index 44085c13e673..794ed18c0537 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -40,7 +40,7 @@ static void limit_nv_id_regs(struct kvm *kvm) kvm_set_vm_id_reg(kvm, SYS_ID_AA64ISAR1_EL1, val); /* No AMU, MPAM, S-EL2, RAS or SVE */ - kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1); + val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1); val &= ~(GENMASK_ULL(55, 52) | NV_FTR(PFR0, AMU) | NV_FTR(PFR0, MPAM) | -- cgit