Dave Martin <Dave.Martin@xxxxxxx> writes:
> Architecture features that are conditionally visible to the guest
> will require run-time checks in the ID register accessor functions.
> In particular, read_id_reg() will need to perform checks in order
> to generate the correct emulated value for certain ID register
> fields such as ID_AA64PFR0_EL1.SVE for example.
>
> This patch propagates vcpu into read_id_reg() so that future
> patches can add run-time checks on the guest configuration here.
>
> For now, there is no functional change.
>
> Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx>
Reviewed-by: Alex Bennée <alex.bennee@xxxxxxxxxx>
> ---
> arch/arm64/kvm/sys_regs.c | 23 +++++++++++++----------
> 1 file changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index 22fbbdb..0dfd064 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -1029,7 +1029,8 @@ static bool access_cntp_cval(struct kvm_vcpu *vcpu,
> }
>
> /* Read a sanitised cpufeature ID register by sys_reg_desc */
> -static u64 read_id_reg(struct sys_reg_desc const *r, bool raz)
> +static u64 read_id_reg(const struct kvm_vcpu *vcpu,
> + 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);
> @@ -1060,7 +1061,7 @@ static bool __access_id_reg(struct kvm_vcpu *vcpu,
> if (p->is_write)
> return write_to_read_only(vcpu, p, r);
>
> - p->regval = read_id_reg(r, raz);
> + p->regval = read_id_reg(vcpu, r, raz);
> return true;
> }
>
> @@ -1089,16 +1090,18 @@ static u64 sys_reg_to_index(const struct sys_reg_desc *reg);
> * 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,
> +static int __get_id_reg(const struct kvm_vcpu *vcpu,
> + 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);
> + const u64 val = read_id_reg(vcpu, rd, raz);
>
> return reg_to_user(uaddr, &val, id);
> }
>
> -static int __set_id_reg(const struct sys_reg_desc *rd, void __user *uaddr,
> +static int __set_id_reg(const struct kvm_vcpu *vcpu,
> + const struct sys_reg_desc *rd, void __user *uaddr,
> bool raz)
> {
> const u64 id = sys_reg_to_index(rd);
> @@ -1110,7 +1113,7 @@ static int __set_id_reg(const struct sys_reg_desc *rd, void __user *uaddr,
> return err;
>
> /* This is what we mean by invariant: you can't change it. */
> - if (val != read_id_reg(rd, raz))
> + if (val != read_id_reg(vcpu, rd, raz))
> return -EINVAL;
>
> return 0;
> @@ -1119,25 +1122,25 @@ static int __set_id_reg(const struct sys_reg_desc *rd, void __user *uaddr,
> 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);
> + return __get_id_reg(vcpu, 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);
> + return __set_id_reg(vcpu, 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);
> + return __get_id_reg(vcpu, 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);
> + return __set_id_reg(vcpu, rd, uaddr, true);
> }
>
> /* sys_reg_desc initialiser for known cpufeature ID registers */
--
Alex Bennée
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