From c512298eed0360923d0cbc4a1f30bc0509af0d50 Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Thu, 5 Nov 2020 10:10:22 +0100 Subject: [PATCH] KVM: arm64: Remove AA64ZFR0_EL1 accessors The AA64ZFR0_EL1 accessors are just the general accessors with its visibility function open-coded. It also skips the if-else chain in read_id_reg, but there's no reason not to go there. Indeed consolidating ID register accessors and removing lines of code make it worthwhile. Remove the AA64ZFR0_EL1 accessors, replacing them with the general accessors for sanitized ID registers. No functional change intended. Signed-off-by: Andrew Jones Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20201105091022.15373-5-drjones@redhat.com --- arch/arm64/kvm/sys_regs.c | 61 +++++++-------------------------------- 1 file changed, 11 insertions(+), 50 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 4ee098abd87c..436043cd327e 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1154,6 +1154,16 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu, static unsigned int id_visibility(const struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { + u32 id = sys_reg((u32)r->Op0, (u32)r->Op1, + (u32)r->CRn, (u32)r->CRm, (u32)r->Op2); + + switch (id) { + case SYS_ID_AA64ZFR0_EL1: + if (!vcpu_has_sve(vcpu)) + return REG_RAZ; + break; + } + return 0; } @@ -1201,55 +1211,6 @@ static unsigned int sve_visibility(const struct kvm_vcpu *vcpu, return REG_HIDDEN; } -/* Generate the emulated ID_AA64ZFR0_EL1 value exposed to the guest */ -static u64 guest_id_aa64zfr0_el1(const struct kvm_vcpu *vcpu) -{ - if (!vcpu_has_sve(vcpu)) - return 0; - - return read_sanitised_ftr_reg(SYS_ID_AA64ZFR0_EL1); -} - -static bool access_id_aa64zfr0_el1(struct kvm_vcpu *vcpu, - struct sys_reg_params *p, - const struct sys_reg_desc *rd) -{ - if (p->is_write) - return write_to_read_only(vcpu, p, rd); - - p->regval = guest_id_aa64zfr0_el1(vcpu); - return true; -} - -static int get_id_aa64zfr0_el1(struct kvm_vcpu *vcpu, - const struct sys_reg_desc *rd, - const struct kvm_one_reg *reg, void __user *uaddr) -{ - u64 val; - - val = guest_id_aa64zfr0_el1(vcpu); - return reg_to_user(uaddr, &val, reg->id); -} - -static int set_id_aa64zfr0_el1(struct kvm_vcpu *vcpu, - const struct sys_reg_desc *rd, - const struct kvm_one_reg *reg, void __user *uaddr) -{ - 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 != guest_id_aa64zfr0_el1(vcpu)) - return -EINVAL; - - return 0; -} - /* * cpufeature ID register user accessors * @@ -1506,7 +1467,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { ID_SANITISED(ID_AA64PFR1_EL1), ID_UNALLOCATED(4,2), ID_UNALLOCATED(4,3), - { SYS_DESC(SYS_ID_AA64ZFR0_EL1), access_id_aa64zfr0_el1, .get_user = get_id_aa64zfr0_el1, .set_user = set_id_aa64zfr0_el1, }, + ID_SANITISED(ID_AA64ZFR0_EL1), ID_UNALLOCATED(4,5), ID_UNALLOCATED(4,6), ID_UNALLOCATED(4,7), -- GitLab