| Message ID | 20240904082419.1982402-1-maz@kernel.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | KVM: arm64: Get rid of REG_HIDDEN_USER | expand |
On Wed, Sep 04, 2024 at 09:24:16AM +0100, Marc Zyngier wrote: > REG_HIDDEN_USER was introduced as a way to deal with the ARMv8.3 flavour of > FEAT_NV, where most EL12 sysreg accesses would trap and yet be mapped to a > EL1 register (KVM doing in SW what FEAT_NV2 does in HW). This handling > imposed that the EL12 register shouldn't be visible to userspace, hence the > special REG_HIDDEN_USER visibility. > > Since 4d4f52052ba8 ("KVM: arm64: nv: Drop EL12 register traps that are > redirected to VNCR") and the admission that KVM would never be supporting > the original FEAT_NV, REG_HIDDEN_USER only had a few users, all of which > could either be replaced by a more ad-hoc mechanism, or removed altogether. > > This series goes ahead and cleans it up for good, removing a tiny bit of > unnecessary complexity. Yeah, let's toss it. Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
On Wed, 04 Sep 2024 09:24:16 +0100, Marc Zyngier wrote: > REG_HIDDEN_USER was introduced as a way to deal with the ARMv8.3 flavour of > FEAT_NV, where most EL12 sysreg accesses would trap and yet be mapped to a > EL1 register (KVM doing in SW what FEAT_NV2 does in HW). This handling > imposed that the EL12 register shouldn't be visible to userspace, hence the > special REG_HIDDEN_USER visibility. > > Since 4d4f52052ba8 ("KVM: arm64: nv: Drop EL12 register traps that are > redirected to VNCR") and the admission that KVM would never be supporting > the original FEAT_NV, REG_HIDDEN_USER only had a few users, all of which > could either be replaced by a more ad-hoc mechanism, or removed altogether. > > [...] Applied to next, thanks! [1/3] KVM: arm64: Simplify handling of CNTKCTL_EL12 commit: 989fce63b2cb5061701c9fa04711d992dfaff5c6 [2/3] KVM: arm64: Simplify visibility handling of AArch32 SPSR_* commit: 84ed45456cee7e77effea8407f4f32b262f2e2ea [3/3] KVM: arm64: Get rid of REG_HIDDEN_USER visibility qualifier commit: 0746096faca01823021f662282e1f067a69b965b Cheers, M.
REG_HIDDEN_USER was introduced as a way to deal with the ARMv8.3 flavour of FEAT_NV, where most EL12 sysreg accesses would trap and yet be mapped to a EL1 register (KVM doing in SW what FEAT_NV2 does in HW). This handling imposed that the EL12 register shouldn't be visible to userspace, hence the special REG_HIDDEN_USER visibility. Since 4d4f52052ba8 ("KVM: arm64: nv: Drop EL12 register traps that are redirected to VNCR") and the admission that KVM would never be supporting the original FEAT_NV, REG_HIDDEN_USER only had a few users, all of which could either be replaced by a more ad-hoc mechanism, or removed altogether. This series goes ahead and cleans it up for good, removing a tiny bit of unnecessary complexity. Marc Zyngier (3): KVM: arm64: Simplify handling of CNTKCTL_EL12 KVM: arm64: Simplify visibility handling of AArch32 SPSR_* KVM: arm64: Get rid of REG_HIDDEN_USER visibility qualifier arch/arm64/kvm/sys_regs.c | 52 +++++++++++++++------------------------ arch/arm64/kvm/sys_regs.h | 14 ++--------- 2 files changed, 22 insertions(+), 44 deletions(-)