On Tue, Feb 19, 2019 at 02:54:30PM +0530, Amit Daniel Kachhap wrote:
> According to userspace settings, ptrauth key registers are conditionally
> present in guest system register list based on user specified flag
> KVM_ARM_VCPU_PTRAUTH.
>
> Reset routines still sets these registers to default values but they are
> left like that as they are conditionally accessible (set/get).
>
> Signed-off-by: Amit Daniel Kachhap <amit.kach...@arm.com>
> Cc: Mark Rutland <mark.rutl...@arm.com>
> Cc: Marc Zyngier <marc.zyng...@arm.com>
> Cc: Christoffer Dall <christoffer.d...@arm.com>
> Cc: kvm...@lists.cs.columbia.edu
> ---
> This patch needs patch [1] by Dave Martin and adds feature to manage
> accessibility in a scalable way.
>
> [1]:
> https://lore.kernel.org/linux-arm-kernel/1547757219-19439-13-git-send-email-dave.mar...@arm.com/
>
FYI, check_present() has changed a bit in the SVE v5 series [2].
The precise interface is still under discussion, so please take a look
and feel free to comment.
You'll probably need to tweak some things so that the KVM_GET_REG_LIST
output is consistent with the set of regs that do/don't yield -ENOENT in
KVM_GET_ONE_REG/KVM_SET_ONE_REG.
See other patches in the series for examples of how I use the modified
interface.
[...]
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index f7bcc60..c2f4974 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -1005,8 +1005,13 @@ static bool trap_ptrauth(struct kvm_vcpu *vcpu,
> return false;
> }
>
> +static bool check_ptrauth(const struct kvm_vcpu *vcpu, const struct
> sys_reg_desc *rd)
> +{
> + return kvm_arm_vcpu_ptrauth_allowed(vcpu);
> +}
> +
> #define __PTRAUTH_KEY(k) \
> - { SYS_DESC(SYS_## k), trap_ptrauth, reset_unknown, k }
> + { SYS_DESC(SYS_## k), trap_ptrauth, reset_unknown, k , .check_present =
> check_ptrauth}
Cheers
---Dave
[2] [PATCH v5 12/26] KVM: arm64: Support runtime sysreg visibility filtering
https://lists.cs.columbia.edu/pipermail/kvmarm/2019-February/034671.html
