[PATCH v2 02/13] KVM: arm64: MDCR_EL2 is a 64-bit register

[Fuad Tabba]

Hi Will,

On Thu, Jul 1, 2021 at 1:53 PM Will Deacon <will at kernel.org> wrote:
>
> On Tue, Jun 15, 2021 at 02:39:39PM +0100, Fuad Tabba wrote:
> > Fix the places in KVM that treat MDCR_EL2 as a 32-bit register.
> > More recent features (e.g., FEAT_SPEv1p2) use bits above 31.
> >
> > No functional change intended.
> >
> > Signed-off-by: Fuad Tabba <tabba at google.com>
> > ---
> >  arch/arm64/include/asm/kvm_arm.h   | 20 ++++++++++----------
> >  arch/arm64/include/asm/kvm_asm.h   |  2 +-
> >  arch/arm64/include/asm/kvm_host.h  |  2 +-
> >  arch/arm64/kvm/debug.c             |  5 +++--
> >  arch/arm64/kvm/hyp/nvhe/debug-sr.c |  2 +-
> >  arch/arm64/kvm/hyp/vhe/debug-sr.c  |  2 +-
> >  6 files changed, 17 insertions(+), 16 deletions(-)
> >
> > diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
> > index 692c9049befa..25d8a61888e4 100644
> > --- a/arch/arm64/include/asm/kvm_arm.h
> > +++ b/arch/arm64/include/asm/kvm_arm.h
> > @@ -280,18 +280,18 @@
> >  /* Hyp Debug Configuration Register bits */
> >  #define MDCR_EL2_E2TB_MASK   (UL(0x3))
> >  #define MDCR_EL2_E2TB_SHIFT  (UL(24))
> > -#define MDCR_EL2_TTRF                (1 << 19)
> > -#define MDCR_EL2_TPMS                (1 << 14)
> > +#define MDCR_EL2_TTRF                (UL(1) << 19)
> > +#define MDCR_EL2_TPMS                (UL(1) << 14)
> >  #define MDCR_EL2_E2PB_MASK   (UL(0x3))
> >  #define MDCR_EL2_E2PB_SHIFT  (UL(12))
> > -#define MDCR_EL2_TDRA                (1 << 11)
> > -#define MDCR_EL2_TDOSA               (1 << 10)
> > -#define MDCR_EL2_TDA         (1 << 9)
> > -#define MDCR_EL2_TDE         (1 << 8)
> > -#define MDCR_EL2_HPME                (1 << 7)
> > -#define MDCR_EL2_TPM         (1 << 6)
> > -#define MDCR_EL2_TPMCR               (1 << 5)
> > -#define MDCR_EL2_HPMN_MASK   (0x1F)
> > +#define MDCR_EL2_TDRA                (UL(1) << 11)
> > +#define MDCR_EL2_TDOSA               (UL(1) << 10)
> > +#define MDCR_EL2_TDA         (UL(1) << 9)
> > +#define MDCR_EL2_TDE         (UL(1) << 8)
> > +#define MDCR_EL2_HPME                (UL(1) << 7)
> > +#define MDCR_EL2_TPM         (UL(1) << 6)
> > +#define MDCR_EL2_TPMCR               (UL(1) << 5)
> > +#define MDCR_EL2_HPMN_MASK   (UL(0x1F))
>
> Personally, I prefer to use the BIT() macro for these things, but what
> you've got here is consistent with the rest of the file and I think that's
> more important.
>
> >  /* For compatibility with fault code shared with 32-bit */
> >  #define FSC_FAULT    ESR_ELx_FSC_FAULT
> > diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
> > index 5e9b33cbac51..d88a5550552c 100644
> > --- a/arch/arm64/include/asm/kvm_asm.h
> > +++ b/arch/arm64/include/asm/kvm_asm.h
> > @@ -209,7 +209,7 @@ extern u64 __vgic_v3_read_vmcr(void);
> >  extern void __vgic_v3_write_vmcr(u32 vmcr);
> >  extern void __vgic_v3_init_lrs(void);
> >
> > -extern u32 __kvm_get_mdcr_el2(void);
> > +extern u64 __kvm_get_mdcr_el2(void);
> >
> >  #define __KVM_EXTABLE(from, to)                                              \
> >       "       .pushsection    __kvm_ex_table, \"a\"\n"                \
> > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> > index 5645af2a1431..45fdd0b7063f 100644
> > --- a/arch/arm64/include/asm/kvm_host.h
> > +++ b/arch/arm64/include/asm/kvm_host.h
> > @@ -286,7 +286,7 @@ struct kvm_vcpu_arch {
> >
> >       /* HYP configuration */
> >       u64 hcr_el2;
> > -     u32 mdcr_el2;
> > +     u64 mdcr_el2;
> >
> >       /* Exception Information */
> >       struct kvm_vcpu_fault_info fault;
> > diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
> > index d5e79d7ee6e9..f7385bfbc9e4 100644
> > --- a/arch/arm64/kvm/debug.c
> > +++ b/arch/arm64/kvm/debug.c
> > @@ -21,7 +21,7 @@
> >                               DBG_MDSCR_KDE | \
> >                               DBG_MDSCR_MDE)
> >
> > -static DEFINE_PER_CPU(u32, mdcr_el2);
> > +static DEFINE_PER_CPU(u64, mdcr_el2);
> >
> >  /**
> >   * save/restore_guest_debug_regs
> > @@ -154,7 +154,8 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu)
> >
> >  void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
> >  {
> > -     unsigned long mdscr, orig_mdcr_el2 = vcpu->arch.mdcr_el2;
> > +     unsigned long mdscr;
> > +     u64 orig_mdcr_el2 = vcpu->arch.mdcr_el2;
>
> This is arm64 code, so 'unsigned long' is fine here and you can leave the
> existing code as-is.

I'll keep the existing code as it is.

Thanks,
/fuad


> With that:
>
> Acked-by: Will Deacon <will at kernel.org>
>
> Will